lib9p: Remove uses of printf

16 files changed, 2524 insertions, 3176 deletions

diff --git a/build-aux/measurestack/app_main.py b/build-aux/measurestack/app_main.py
index c5b5a79..69247ed 100644
--- a/build-aux/measurestack/app_main.py
+++ b/build-aux/measurestack/app_main.py
@@ -28,7 +28,7 @@ def main(
     # sbc-harness ####################################################
 
     libmisc_plugin = app_plugins.LibMiscPlugin(arg_c_fnames)
-    lib9p_plugin = app_plugins.Lib9PPlugin(arg_base_dir, arg_c_fnames, libmisc_plugin)
+    lib9p_plugin = app_plugins.Lib9PPlugin(arg_base_dir, arg_c_fnames)
 
     def sbc_is_thread(name: QName) -> int:
         if str(name).endswith("_cr") and name.base() != BaseName("lib9p_srv_read_cr"):
@@ -48,7 +48,7 @@ def main(
     plugins += [
         app_plugins.CmdPlugin(),
         libmisc_plugin,
-        app_plugins.PicoFmtPlugin(arg_pico_platform, lib9p_plugin.formatters),
+        app_plugins.PicoFmtPlugin(arg_pico_platform, []),
         app_plugins.LibHWPlugin(arg_pico_platform, libmisc_plugin),
         app_plugins.LibCRPlugin(),
         app_plugins.LibCRIPCPlugin(),
diff --git a/build-aux/measurestack/app_plugins.py b/build-aux/measurestack/app_plugins.py
index 8009c0c..26eb66d 100644
--- a/build-aux/measurestack/app_plugins.py
+++ b/build-aux/measurestack/app_plugins.py
@@ -260,20 +260,12 @@ class Lib9PPlugin:
     lib9p_msgs: set[str]
     _CONFIG_9P_MAX_CONNS: int | None
     _CONFIG_9P_MAX_REQS: int | None
-    formatters: typing.Collection[BaseName]
 
     def __init__(
         self,
         arg_base_dir: str,
         arg_c_fnames: typing.Collection[str],
-        libmisc_plugin: LibMiscPlugin,
     ) -> None:
-        self.formatters = {
-            x.base()
-            for x in libmisc_plugin.objcalls["format"]
-            if str(x.base()).startswith("lib9p_")
-        }
-
         # Find filenames #######################################################
 
         def _is_config_h(fname: str) -> bool:
@@ -347,7 +339,7 @@ class Lib9PPlugin:
     re_table_call = re.compile(
         r"\s*_lib9p_(?P<meth>validate|unmarshal|marshal)\(.*(?P<grp>[RT])msg.*\);\s*"
     )
-    re_print_call = re.compile(r".*lib9p_table_msg.*\.box_as_fmt_formatter\(.*")
+    re_print_call = re.compile(r".*lib9p_table_msg.*\.print\(.*")
 
     def indirect_callees(
         self, loc: str, line: str
@@ -366,9 +358,7 @@ class Lib9PPlugin:
                 ], True
             if self.re_print_call.fullmatch(line):
                 # Functions for disabled protocol extensions will be missing.
-                return [
-                    QName(f"lib9p_msg_{msg}_format") for msg in self.lib9p_msgs
-                ], True
+                return [QName(f"fmt_print_{msg}") for msg in self.lib9p_msgs], True
         if "lib9p/srv.c:" in loc:
             if "srv->msglog(" in line:
                 # Actual ROMs shouldn't set this, and so will be missing on rp2040 builds.
diff --git a/build-aux/measurestack/test_app_plugins.py b/build-aux/measurestack/test_app_plugins.py
index 808d55a..3e281b7 100644
--- a/build-aux/measurestack/test_app_plugins.py
+++ b/build-aux/measurestack/test_app_plugins.py
@@ -8,7 +8,7 @@
 import typing
 
 from . import analyze, app_plugins, testutil, util
-from .analyze import BaseName, QName
+from .analyze import QName
 
 
 def test_fct() -> None:
@@ -70,102 +70,3 @@ def test_fct() -> None:
 
     graph_plugin.assert_nstatic(result.groups["Main"].rows[QName("a")].nstatic, exp_a)
     graph_plugin.assert_nstatic(result.groups["Main"].rows[QName("b")].nstatic, exp_b)
-
-
-def test_assert_formatter() -> None:
-    #     _____________________________________________________
-    #    |                                                     |
-    #    |                                                     |
-    #    |        main                                         |
-    #    |          |                                          |
-    #    |     __wrap_vprintf                                  |
-    #    |          |                     _______________      |
-    #    |    fmt_vfctprintf             /               \     |
-    #    |            \         fmt_state_printf          |    |
-    #    |             \____   ____/                      |    |
-    #    |                  \ /                           |    |
-    #    |              _vfctprintf                       |    |
-    #    |              ____/ \____                       ^    |
-    #    |             /           ?<---snip              |    |
-    #    |     conv_builtin         \                     |    |
-    #    |          |            libfmt_conv_formatter    |    |
-    #    |          |                      |              |    |
-    #    |           \           lib9p_msg_Rread_format   |    |
-    #    |            \___________     __/   \___________/     |
-    #    |                        \   /                        |
-    #    |                 fmt_state_putchar                   |
-    #    |                          |                          |
-    #    |               stdio_buffered_printer                |
-    #    |                                                     |
-    #    |_____________________________________________________|
-    #
-    graph: typing.Sequence[tuple[str, typing.Collection[str]]] = [
-        ("main", {"vprintf"}),
-        ("__wrap_vprintf", {"fmt_vfctprintf"}),
-        ("fmt_vfctprintf", {"_vfctprintf"}),
-        ("fmt_state_printf", {"_vfctprintf"}),
-        ("_vfctprintf", {"conv_builtin", "libfmt_conv_formatter"}),
-        ("conv_builtin", {"fmt_state_putchar"}),
-        ("libfmt_conv_formatter", {"lib9p_msg_Rread_format"}),
-        ("lib9p_msg_Rread_format", {"fmt_state_putchar", "fmt_state_printf"}),
-        ("fmt_state_putchar", {"stdio_buffered_printer", "_out_buffer"}),
-        ("stdio_buffered_printer", {}),
-        ("_out_buffer", {}),  # wrong fct
-    ]
-
-    # 1  2  3  4  5  6  7  8  9 10 11 <= call_depth
-    # - main()                                                 ; +
-    #    - __wrap__vprintf()                                   ; +
-    #       - fmt_vfctprintf()                                 ; +
-    #          - _vfctprintf()                                 ; +
-    #             - conv_builtin()                             ;
-    #                - fmt_state_putchar()                     ;
-    #                   - stdio_buffered_printer()             ;
-    #             - libfmt_conv_formatter()                    ; +
-    #                - lib9p_msg_Rread_format()                ; +
-    #                   - fmt_state_putchar()                  ;
-    #                      - stdio_buffered_printer()          ;
-    #                   - fmt_state_printf()                   ; +
-    #                      - _vfctprintf()                     ; +
-    #                         - conv_builtin()                 ; +
-    #                            - fmt_state_putchar()         ; +
-    #                               - stdio_buffered_printer() ; +
-    #                         - libfmt_conv_formatter()        ; skip (formatter won't use %v)
-    max_call_depth = 11
-    exp = [
-        "main",
-        "__wrap_vprintf",
-        "fmt_vfctprintf",
-        "_vfctprintf",
-        "libfmt_conv_formatter",
-        "lib9p_msg_Rread_format",
-        "fmt_state_printf",
-        "_vfctprintf",
-        "conv_builtin",
-        "fmt_state_putchar",
-        "stdio_buffered_printer",
-    ]
-
-    graph_plugin = testutil.GraphProviderPlugin(max_call_depth, graph)
-
-    plugins: list[util.Plugin] = [
-        graph_plugin,
-        app_plugins.LibMiscPlugin(arg_c_fnames=[]),
-        app_plugins.PicoFmtPlugin("rp2040", [BaseName("lib9p_msg_Rread_format")]),
-    ]
-
-    def test_filter(name: QName) -> tuple[int, bool]:
-        if name.base() == BaseName("main"):
-            return 1, True
-        return 0, False
-
-    result = analyze.analyze(
-        ci_fnames=[],
-        app_func_filters={
-            "Main": test_filter,
-        },
-        app=util.PluginApplication(testutil.nop_location_xform, plugins),
-        cfg_max_call_depth=max_call_depth,
-    )
-
-    graph_plugin.assert_nstatic(result.groups["Main"].rows[QName("main")].nstatic, exp)
diff --git a/lib9p/CMakeLists.txt b/lib9p/CMakeLists.txt
index cff07ad..2a2f858 100644
--- a/lib9p/CMakeLists.txt
+++ b/lib9p/CMakeLists.txt
@@ -10,7 +10,6 @@ target_sources(lib9p_core INTERFACE
 	core_generated.c
 )
 target_link_libraries(lib9p_core INTERFACE
-	libfmt
 	libhw_generic
 	libmisc
 )
diff --git a/lib9p/core.c b/lib9p/core.c
index a44bab6..464b31d 100644
--- a/lib9p/core.c
+++ b/lib9p/core.c
@@ -7,7 +7,6 @@
 #include <stdarg.h>         /* for va_* */
 #include <string.h>         /* for strlen(), strnlen(), strncpy(), memcmp(), memset() */
 
-#include <libfmt/fmt.h>     /* for fmt_vsnprintf() */
 #include <libmisc/assert.h> /* for assert() */
 #include <libmisc/endian.h> /* for uint32le_decode() */
 #include <libmisc/log.h>    /* for const_byte_str() */
@@ -62,46 +61,6 @@ bool lib9p_ctx_has_error(struct lib9p_ctx *ctx) {
 	return ctx->err_msg[0];
 }
 
-int _lib9p_error(struct lib9p_ctx *ctx,
-#if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
-                lib9p_errno_t linux_errno,
-#endif
-                char const *msg) {
-	if (lib9p_ctx_has_error(ctx))
-		return -1;
-	strncpy(ctx->err_msg, msg, sizeof(ctx->err_msg));
-	ctx->err_msg[sizeof(ctx->err_msg)-1] = '\0';
-
-#if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
-	ctx->err_num = linux_errno;
-#endif
-
-	return -1;
-}
-
-int _lib9p_errorf(struct lib9p_ctx *ctx,
-#if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
-                 lib9p_errno_t linux_errno,
-#endif
-                 char const *fmt, ...) {
-	int n;
-	va_list args;
-
-	if (lib9p_ctx_has_error(ctx))
-		return -1;
-	va_start(args, fmt);
-	n = fmt_vsnprintf(ctx->err_msg, sizeof(ctx->err_msg), fmt, args);
-	va_end(args);
-	if ((size_t)(n+1) < sizeof(ctx->err_msg))
-		memset(&ctx->err_msg[n+1], 0, sizeof(ctx->err_msg)-(n+1));
-
-#if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
-	ctx->err_num = linux_errno;
-#endif
-
-	return -1;
-}
-
 /* bounds checks **************************************************************/
 
 static inline void assert_ver(enum lib9p_version ver) {
@@ -141,33 +100,32 @@ const char *lib9p_msgtype_str(enum lib9p_version ver, enum lib9p_msg_type typ) {
 	return _lib9p_table_msg[ver][typ].name ?: const_byte_str(typ);
 }
 
-lo_interface fmt_formatter lo_box_lib9p_msg_as_fmt_formatter(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body) {
-	assert(ctx);
-	assert_ver(ctx->version);
-	assert_typ(typ);
-	assert(_lib9p_table_msg[ctx->version][typ].box_as_fmt_formatter);
-	return _lib9p_table_msg[ctx->version][typ].box_as_fmt_formatter(body);
-}
-
 /* main message functions *****************************************************/
 
-#define _lib9p_validate(LOW_TYP_BIT, ERRMSG, TABLE) do {                                                             \
-	assert_ver(ctx->version);                                                                                    \
-	/* Inspect the first 5 bytes ourselves.  */                                                                  \
-	uint32_t net_size = uint32le_decode(net_bytes);                                                              \
-	if (net_size < 5)                                                                                            \
-		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "message is impossibly short");                       \
-	uint8_t typ = net_bytes[4];                                                                                  \
-	if (typ % 2 != LOW_TYP_BIT)                                                                                  \
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, ERRMSG ": message_type=%s",                       \
-		                    lib9p_msgtype_str(ctx->version, typ));                                           \
-	struct _lib9p_recv_tentry tentry = TABLE[ctx->version][typ/2];                                               \
-	if (!tentry.validate)                                                                                        \
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, "unknown message type: %s (protocol_version=%s)", \
-		                    lib9p_msgtype_str(ctx->version, typ), lib9p_version_str(ctx->version));          \
-	                                                                                                             \
-	/* Now use the message-type-specific tentry to process the whole thing.  */                                  \
-	return tentry.validate(ctx, net_size, net_bytes);                                                            \
+void fmt_print_lib9p_msg(lo_interface fmt_dest w, struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body) {
+       assert(ctx);
+       assert_ver(ctx->version);
+       assert_typ(typ);
+       assert(_lib9p_table_msg[ctx->version][typ].print);
+       _lib9p_table_msg[ctx->version][typ].print(w, ctx, body);
+}
+
+#define _lib9p_validate(LOW_TYP_BIT, ERRMSG, TABLE) do {                                                                           \
+	assert_ver(ctx->version);                                                                                                  \
+	/* Inspect the first 5 bytes ourselves.  */                                                                                \
+	uint32_t net_size = uint32le_decode(net_bytes);                                                                            \
+	if (net_size < 5)                                                                                                          \
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "message is impossibly short");                                     \
+	uint8_t typ = net_bytes[4];                                                                                                \
+	if (typ % 2 != LOW_TYP_BIT)                                                                                                \
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, ERRMSG ": message_type=", lib9p_msgtype_str(ctx->version, typ)); \
+	struct _lib9p_recv_tentry tentry = TABLE[ctx->version][typ/2];                                                             \
+	if (!tentry.validate)                                                                                                      \
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, "unknown message type: ", lib9p_msgtype_str(ctx->version, typ),  \
+		                   " (protocol_version=", lib9p_version_str(ctx->version), ")");                                   \
+                                                                                                                                   \
+	/* Now use the message-type-specific tentry to process the whole thing.  */                                                \
+	return tentry.validate(ctx, net_size, net_bytes);                                                                          \
 } while (0)
 
 ssize_t lib9p_Tmsg_validate(struct lib9p_ctx *ctx, uint8_t *net_bytes) {
diff --git a/lib9p/core_gen/c.py b/lib9p/core_gen/c.py
index 393766b..60ceb70 100644
--- a/lib9p/core_gen/c.py
+++ b/lib9p/core_gen/c.py
@@ -7,7 +7,7 @@ import sys
 
 import idl
 
-from . import c9util, c_format, c_marshal, c_unmarshal, c_validate, cutil
+from . import c9util, c_fmt_print, c_marshal, c_unmarshal, c_validate, cutil
 
 # This strives to be "general-purpose" in that it just acts on the
 # *.9p inputs; but (unfortunately?) there are a few special-cases in
@@ -35,15 +35,6 @@ def gen_c(versions: set[str], typs: list[idl.UserType]) -> str:
 #include "core_tables.h"
 #include "core_utf8.h"
 """
-    # libmisc/obj.h vtables ####################################################
-    ret += """
-/* libmisc/obj.h vtables ******************************************************/
-"""
-    for typ in typs:
-        ret += cutil.ifdef_push(1, c9util.ver_ifdef(typ.in_versions))
-        ret += f"LO_IMPLEMENTATION_C(fmt_formatter, {c9util.typename(typ)}, {c9util.basename(typ)}, static);\n"
-    ret += cutil.ifdef_pop(0)
-
     # utilities ################################################################
     ret += """
 /* utilities ******************************************************************/
@@ -111,8 +102,8 @@ def gen_c(versions: set[str], typs: list[idl.UserType]) -> str:
     # marshal_* ################################################################
     ret += c_marshal.gen_c_marshal(versions, typs)
 
-    # *_format #################################################################
-    ret += c_format.gen_c_format(versions, typs)
+    # fmt_print_* ##############################################################
+    ret += c_fmt_print.gen_c_fmt_print(versions, typs)
 
     # tables.h #################################################################
     ret += """
@@ -156,8 +147,8 @@ def gen_c(versions: set[str], typs: list[idl.UserType]) -> str:
     ret += "\n"
     ret += cutil.macro(
         f"#define _MSG(typ) [{c9util.Ident('TYP_')}##typ] = {{\n"
-        f"\t\t.name                 = #typ,\n"
-        f"\t\t.box_as_fmt_formatter = (_box_as_fmt_formatter_fn_t)lo_box_{c9util.ident('msg_')}##typ##_as_fmt_formatter,\n"
+        f"\t\t.name  = #typ,\n"
+        f"\t\t.print = (_print_fn_t)fmt_print_##typ,\n"
         f"\t}}\n"
     )
     ret += msg_table("_msg_tentry", "_table_msg", "_MSG", (0, 0x100, 1))
diff --git a/lib9p/core_gen/c_format.py b/lib9p/core_gen/c_fmt_print.py
index c633fbb..eaacddb 100644
--- a/lib9p/core_gen/c_format.py
+++ b/lib9p/core_gen/c_fmt_print.py
@@ -1,4 +1,4 @@
-# lib9p/core_gen/c_format.py - Generate C pretty-print functions
+# lib9p/core_gen/c_fmt_print.py - Generate C pretty-print functions
 #
 # Copyright (C) 2024-2025  Luke T. Shumaker <lukeshu@lukeshu.com>
 # SPDX-License-Identifier: AGPL-3.0-or-later
@@ -6,14 +6,14 @@
 
 import idl
 
-from . import c9util, cutil
+from . import c9util, cutil, idlutil
 
 # This strives to be "general-purpose" in that it just acts on the
 # *.9p inputs; but (unfortunately?) there are a few special-cases in
 # this script, marked with "SPECIAL".
 
 # pylint: disable=unused-variable
-__all__ = ["gen_c_format"]
+__all__ = ["gen_c_fmt_print"]
 
 
 def bf_numname(typ: idl.Bitfield, num: idl.BitNum, base: str) -> str:
@@ -21,46 +21,34 @@ def bf_numname(typ: idl.Bitfield, num: idl.BitNum, base: str) -> str:
     return c9util.Ident(c9util.add_prefix(prefix, base))
 
 
-def ext_printf(line: str) -> str:
-    assert line.startswith("\t")
-    assert line.endswith("\n")
-    # It sucks that %v trips -Wformat and -Wformat-extra-args
-    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47781
-    ret = "#pragma GCC diagnostic push\n"
-    ret += '#pragma GCC diagnostic ignored "-Wformat"\n'
-    ret += '#pragma GCC diagnostic ignored "-Wformat-extra-args"\n'
-    ret += line
-    ret += "#pragma GCC diagnostic pop\n"
-    return ret
-
-
-def gen_c_format(versions: set[str], typs: list[idl.UserType]) -> str:
+def gen_c_fmt_print(versions: set[str], typs: list[idl.UserType]) -> str:
     ret = """
-/* *_format *******************************************************************/
+/* fmt_print_* ****************************************************************/
 """
-    for typ in typs:
+    for typ in idlutil.topo_sorted(typs):
         ret += "\n"
         ret += cutil.ifdef_push(1, c9util.ver_ifdef(typ.in_versions))
-        ret += f"static void {c9util.basename(typ)}_format({c9util.typename(typ)} *self, struct fmt_state *state) {{\n"
+        storage = "" if typ.typname == "stat" else "static "  # SPECIAL (stat is public)
+        ret += f"[[maybe_unused]] {storage}void fmt_print_{typ.typname}(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, {c9util.typename(typ)} *self) {{\n"
         match typ:
             case idl.Number():
                 if typ.vals:
                     ret += "\tswitch (*self) {\n"
                     for name in typ.vals:
                         ret += f"\tcase {c9util.Ident(c9util.add_prefix(f'{typ.typname}_'.upper(), name))}:\n"
-                        ret += f'\t\tfmt_state_puts(state, "{name}");\n'
+                        ret += f'\t\tfmt_print_str(w, "{name}");\n'
                         ret += "\t\tbreak;\n"
                     ret += "\tdefault:\n"
-                    ret += f'\t\tfmt_state_printf(state, "%"PRIu{typ.static_size*8}, *self);\n'
+                    ret += "\t\tfmt_print_base10(w, *self);\n"
                     ret += "\t}\n"
                 else:
-                    ret += f'\t\tfmt_state_printf(state, "%"PRIu{typ.static_size*8}, *self);\n'
+                    ret += "\t\tfmt_print_base10(w, *self);\n"
             case idl.Bitfield():
                 val = "*self"
                 if typ.typname == "dm":  # SPECIAL (pretty file permissions)
                     val = f"(*self & ~(({c9util.typename(typ)})0777))"
                 ret += "\tbool empty = true;\n"
-                ret += "\tfmt_state_putchar(state, '(');\n"
+                ret += "\tfmt_print_byte(w, '(');\n"
                 nums: set[str] = set()
 
                 for bit in reversed(typ.bits):
@@ -72,8 +60,8 @@ def gen_c_format(versions: set[str], typs: list[idl.UserType]) -> str:
                                 bitname = bit.bitname
                             ret += f"\tif ({val} & (UINT{typ.static_size*8}_C(1)<<{bit.num})) {{\n"
                             ret += "\t\tif (!empty)\n"
-                            ret += "\t\t\tfmt_state_putchar(state, '|');\n"
-                            ret += f'\t\tfmt_state_puts(state, "{bitname}");\n'
+                            ret += "\t\t\tfmt_print_byte(w, '|');\n"
+                            ret += f'\t\tfmt_print_str(w, "{bitname}");\n'
                             ret += "\t\tempty = false;\n"
                             ret += "\t}\n"
                         case idl.BitNum():
@@ -86,34 +74,32 @@ def gen_c_format(versions: set[str], typs: list[idl.UserType]) -> str:
                                     f"{bit.cat.numname}_".upper(), name
                                 )
                                 ret += "\t\tif (!empty)\n"
-                                ret += "\t\t\tfmt_state_putchar(state, '|');\n"
-                                ret += f'\t\tfmt_state_puts(state, "{bitname}");\n'
+                                ret += "\t\t\tfmt_print_byte(w, '|');\n"
+                                ret += f'\t\tfmt_print_str(w, "{bitname}");\n'
                                 ret += "\t\tempty = false;\n"
                                 ret += "\t\tbreak;\n"
                             ret += "\tdefault:\n"
                             ret += "\t\tif (!empty)\n"
-                            ret += "\t\t\tfmt_state_putchar(state, '|');\n"
-                            ret += f'\t\tfmt_state_printf(state, "%"PRIu{typ.static_size*8}, {val} & {bf_numname(typ, bit.cat, 'MASK')});\n'
+                            ret += "\t\t\tfmt_print_byte(w, '|');\n"
+                            ret += f"\t\tfmt_print_base10(w, {val} & {bf_numname(typ, bit.cat, 'MASK')});\n"
                             ret += "\t\tempty = false;\n"
                             ret += "\t}\n"
                             nums.add(bit.cat.numname)
                 if typ.typname == "dm":  # SPECIAL (pretty file permissions)
                     ret += "\tif (!empty)\n"
-                    ret += "\t\tfmt_state_putchar(state, '|');\n"
-                    ret += f'\tfmt_state_printf(state, "%#04"PRIo{typ.static_size*8}, *self & 0777);\n'
+                    ret += "\t\tfmt_print_byte(w, '|');\n"
+                    ret += "\tfmt_print(w, (rjust, 4, '0', (base8, *self & 0777)));\n"
                 else:
                     ret += "\tif (empty)\n"
-                    ret += "\t\tfmt_state_putchar(state, '0');\n"
-                ret += "\tfmt_state_putchar(state, ')');\n"
+                    ret += "\t\tfmt_print_byte(w, '0');\n"
+                ret += "\tfmt_print_byte(w, ')');\n"
             case idl.Struct(typname="s"):  # SPECIAL (string)
-                ret += ext_printf(
-                    '\tfmt_state_printf(state, "%.*q", self->len, self->utf8);\n'
-                )
+                ret += "\tfmt_print_qmem(w, self->utf8, self->len);\n"
             case idl.Struct():  # and idl.Message():
                 if isinstance(typ, idl.Message):
-                    ret += f'\tfmt_state_puts(state, "{typ.typname} {{");\n'
+                    ret += f'\tfmt_print_str(w, "{typ.typname} {{");\n'
                 else:
-                    ret += "\tfmt_state_putchar(state, '{');\n"
+                    ret += "\tfmt_print_byte(w, '{');\n"
                 for member in typ.members:
                     if member.val:
                         continue
@@ -127,35 +113,33 @@ def gen_c_format(versions: set[str], typs: list[idl.UserType]) -> str:
                             cnt_typ = c9util.typename(member.cnt.typ)
                         if member.typ.static_size == 1:  # SPECIAL (data)
                             ret += f"\tif (is_valid_utf8_without_nul((uint8_t *)self->{member.membname}, (size_t){cnt_str})) {{\n"
-                            ret += ext_printf(
-                                f'\t\tfmt_state_printf(state, " {member.membname}=%.*q%s",\n'
-                                f"\t\t\t(int)({cnt_str} < 50 ? {cnt_str} : 50),\n"
-                                f"\t\t\t(char *)self->{member.membname},\n"
-                                f'\t\t\t{cnt_str} < 50 ? "" : "...");\n'
-                            )
+                            ret += f'\t\tfmt_print_str(w, " {member.membname}=");\n'
+                            ret += f"\t\tfmt_print_qmem(w, self->{member.membname}, {cnt_str} < 50 ? {cnt_str} : 50);\n"
+                            ret += f"\t\tif ({cnt_str} > 50)\n"
+                            ret += '\t\t\tfmt_print_str(w, "...");\n'
                             ret += "\t} else {\n"
-                            ret += f'\t\tfmt_state_puts(state, " {member.membname}=<bytedata>");\n'
+                            ret += f'\t\tfmt_print_str(w, " {member.membname}=<bytedata>");\n'
                             ret += "\t}\n"
                             continue
-                        ret += f'\tfmt_state_puts(state, " {member.membname}=[");\n'
+                        ret += f'\tfmt_print_str(w, " {member.membname}=[");\n'
                         ret += f"\tfor ({cnt_typ} i = 0; i < {cnt_str}; i++) {{\n"
                         ret += "\t\tif (i)\n"
-                        ret += "\t\t\tfmt_state_putchar(state, ',');\n"
-                        ret += "\t\tfmt_state_putchar(state, ' ');\n"
+                        ret += "\t\t\tfmt_print_byte(w, ',');\n"
+                        ret += "\t\tfmt_print_byte(w, ' ');\n"
                         if isinstance(member.typ, idl.Primitive):
-                            ret += f'\t\tfmt_state_printf(state, "%"PRIu{member.typ.static_size*8}, self->{member.membname}[i]);\n'
+                            ret += f"\t\tfmt_print_base10(w, self->{member.membname}[i]);\n"
                         else:
-                            ret += f"\t\t{c9util.basename(member.typ)}_format(&self->{member.membname}[i], state);\n"
+                            ret += f"\t\tfmt_print_{member.typ.typname}(w, ctx, &self->{member.membname}[i]);\n"
                         ret += "\t}\n"
-                        ret += '\tfmt_state_puts(state, " ]");\n'
+                        ret += '\tfmt_print_str(w, " ]");\n'
                     else:
-                        ret += f'\tfmt_state_puts(state, " {member.membname}=");\n'
+                        ret += f'\tfmt_print_str(w, " {member.membname}=");\n'
                         if isinstance(member.typ, idl.Primitive):
-                            ret += f'\tfmt_state_printf(state, "%"PRIu{member.typ.static_size*8}, self->{member.membname});\n'
+                            ret += f"\tfmt_print_base10(w, self->{member.membname});\n"
                         else:
-                            ret += f"\t{c9util.basename(member.typ)}_format(&self->{member.membname}, state);\n"
+                            ret += f"\tfmt_print_{member.typ.typname}(w, ctx, &self->{member.membname});\n"
                 ret += cutil.ifdef_pop(1)
-                ret += '\tfmt_state_puts(state, " }");\n'
+                ret += '\tfmt_print_str(w, " }");\n'
         ret += "}\n"
     ret += cutil.ifdef_pop(0)
 
diff --git a/lib9p/core_gen/c_marshal.py b/lib9p/core_gen/c_marshal.py
index 322e1ef..bddf55f 100644
--- a/lib9p/core_gen/c_marshal.py
+++ b/lib9p/core_gen/c_marshal.py
@@ -381,10 +381,9 @@ def gen_c_marshal(versions: set[str], typs: list[idl.UserType]) -> str:
         else:
             ret += "\tif (needed_size > ctx->max_msg_size) {\n"
         if isinstance(typ, idl.Message):  # SPECIAL (disable for stat)
-            ret += f'\t\tlib9p_errorf(ctx, {c9util.IDENT("ERRNO_L_ERANGE")}, "%s message too large to marshal into %s limit (%"PRIu{szbits}" > %"PRIu32")",\n'
-            ret += f'\t\t\t"{typ.typname}",\n'
-            ret += f'\t\t\tctx->version ? "negotiated" : "{'client' if typ.msgid % 2 == 0 else 'server'}",\n'
-            ret += "\t\t\tneeded_size, ctx->max_msg_size);\n"
+            ret += f'\t\tlib9p_error(ctx, {c9util.IDENT("ERRNO_L_ERANGE")}, "{typ.typname} message too large to marshal into ",\n'
+            ret += f'\t\t\tctx->version ? "negotiated" : "{'client' if typ.msgid % 2 == 0 else 'server'}", " limit",\n'
+            ret += '\t\t\t" (", needed_size, " > ", ctx->max_msg_size, ")");\n'
         ret += "\t\treturn true;\n"
         ret += "\t}\n"
 
diff --git a/lib9p/core_gen/c_validate.py b/lib9p/core_gen/c_validate.py
index 3073ed0..9c55d8d 100644
--- a/lib9p/core_gen/c_validate.py
+++ b/lib9p/core_gen/c_validate.py
@@ -59,7 +59,7 @@ def gen_c_validate(versions: set[str], typs: list[idl.UserType]) -> str:
         "\t\t * that.  */\n"
         f'\t\treturn lib9p_error(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "message is too short for content");\n'
         "\tif (net_offset > net_size)\n"
-        f'\t\treturn lib9p_errorf(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "message is too short for content (%"PRIu32" > %"PRIu32") @ %d", net_offset, net_size, __LINE__);\n'
+        f'\t\treturn lib9p_error(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "message is too short for content (", net_offset, " > ", net_size, ")");\n'
     )
     ret += cutil.macro(
         "#define VALIDATE_NET_UTF8(n)\n"
@@ -190,11 +190,10 @@ def gen_c_validate(versions: set[str], typs: list[idl.UserType]) -> str:
                 for tok in child.val.tokens
             ):
                 nbits = 32
-            act = f"(uint{nbits}_t)GET_U{nbits}LE({lookup_sym(f'&{child.membname}')})"
-            exp = f"(uint{nbits}_t)({c9util.idl_expr(child.val, lookup_sym)})"
+            act = f"GET_U{nbits}LE({lookup_sym(f'&{child.membname}')})"
+            exp = f"{c9util.idl_expr(child.val, lookup_sym)}"
             ret += f"{'\t'*indent_lvl()}if ({act} != {exp})\n"
-            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_errorf(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "{path} value is wrong: actual: %"PRIu{nbits}" != correct:%"PRIu{nbits},\n'
-            ret += f"{'\t'*(indent_lvl()+2)}{act}, {exp});\n"
+            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_error(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "{path} value is wrong: actual:", (base10, {act}), " != correct:", (base10, {exp}));\n'
         if child.max:
             incr_flush()
             assert child.typ.static_size
@@ -205,19 +204,18 @@ def gen_c_validate(versions: set[str], typs: list[idl.UserType]) -> str:
                 for tok in child.max.tokens
             ):
                 nbits = 32
-            act = f"(uint{nbits}_t)GET_U{nbits}LE({lookup_sym(f'&{child.membname}')})"
-            exp = f"(uint{nbits}_t)({c9util.idl_expr(child.max, lookup_sym)})"
+            act = f"GET_U{nbits}LE({lookup_sym(f'&{child.membname}')})"
+            exp = f"{c9util.idl_expr(child.max, lookup_sym)}"
             ret += f"{'\t'*indent_lvl()}if ({act} > {exp})\n"
-            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_errorf(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "{path} value is too large: %"PRIu{nbits}" > %"PRIu{nbits},\n'
-            ret += f"{'\t'*(indent_lvl()+2)}{act}, {exp});\n"
+            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_error(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "{path} value is too large: ", (base10, {act}), " > ", (base10, {exp}));\n'
         if isinstance(child.typ, idl.Bitfield):
             incr_flush()
             nbytes = child.typ.static_size
             nbits = nbytes * 8
             act = f"GET_U{nbits}LE({lookup_sym(f'&{child.membname}')})"
             ret += f"{'\t'*indent_lvl()}if ({act} & ~{child.typ.typname}_masks[ctx->version])\n"
-            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_errorf(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "unknown bits in {child.typ.typname} bitfield: %#0{nbytes*2}"PRIx{nbits},\n'
-            ret += f"{'\t'*(indent_lvl()+2)}{act} & ~{child.typ.typname}_masks[ctx->version]);\n"
+            ret += f'{"\t"*(indent_lvl()+1)}return lib9p_error(ctx, {c9util.IDENT("ERRNO_L_EBADMSG")}, "unknown bits in {child.typ.typname} bitfield: ",\n'
+            ret += f"{'\t'*(indent_lvl()+2)}(base16_u{nbits}_, {act} & ~{child.typ.typname}_masks[ctx->version]));\n"
 
     def handle(
         path: idlutil.Path,
diff --git a/lib9p/core_gen/h.py b/lib9p/core_gen/h.py
index 3c857c1..acf8415 100644
--- a/lib9p/core_gen/h.py
+++ b/lib9p/core_gen/h.py
@@ -163,12 +163,7 @@ def gen_h(versions: set[str], typs: list[idl.UserType]) -> str:
 \t#error Do not include <lib9p/_core_generated.h> directly; include <lib9p/core.h> instead
 #endif
 
-#include <stdint.h> /* for uint{{n}}_t types */
-
-#include <libfmt/fmt.h> /* for fmt_formatter */
-#include <libhw/generic/io.h> /* for struct iovec */
 """
-
     id2typ: dict[int, idl.Message] = {}
     for msg in [msg for msg in typs if isinstance(msg, idl.Message)]:
         id2typ[msg.msgid] = msg
@@ -214,7 +209,6 @@ enum {c9util.ident('version')} {{
     ret += cutil.ifdef_pop(0)
     ret += f"\t{c9util.ver_enum('NUM')},\n"
     ret += "};\n"
-    ret += f"LO_IMPLEMENTATION_H(fmt_formatter, enum {c9util.ident('version')}, {c9util.ident('version')});\n"
 
     ret += """
 /* enum msg_type **************************************************************/
@@ -230,7 +224,6 @@ enum {c9util.ident('version')} {{
         ret += f"\t{c9util.Ident(f'TYP_{msg.typname:<{namewidth}}')} = {msg.msgid},\n"
     ret += cutil.ifdef_pop(0)
     ret += "};\n"
-    ret += f"LO_IMPLEMENTATION_H(fmt_formatter, enum {c9util.ident('msg_type')}, {c9util.ident('msg_type')});\n"
 
     ret += """
 /* payload types **************************************************************/
@@ -371,7 +364,6 @@ enum {c9util.ident('version')} {{
 
 def gen_number(typ: idl.Number) -> str:
     ret = f"typedef {c9util.typename(typ.prim)} {c9util.typename(typ)};\n"
-    ret += f"LO_IMPLEMENTATION_H(fmt_formatter, {c9util.typename(typ)}, {c9util.basename(typ)});\n"
 
     def lookup_sym(sym: str) -> str:
         assert False
@@ -390,7 +382,6 @@ def gen_number(typ: idl.Number) -> str:
 
 def gen_bitfield(typ: idl.Bitfield) -> str:
     ret = f"typedef {c9util.typename(typ.prim)} {c9util.typename(typ)};\n"
-    ret += f"LO_IMPLEMENTATION_H(fmt_formatter, {c9util.typename(typ)}, {c9util.basename(typ)});\n"
 
     def lookup_sym(sym: str) -> str:
         assert False
@@ -538,5 +529,4 @@ def gen_struct(typ: idl.Struct) -> str:  # and idl.Message
             ret += f"\t{c9util.typename(member.typ, member):<{typewidth}}  {'*' if member.cnt else ' '}{member.membname};\n"
         ret += cutil.ifdef_pop(1)
     ret += "};\n"
-    ret += f"LO_IMPLEMENTATION_H(fmt_formatter, {c9util.typename(typ)}, {c9util.basename(typ)});\n"
     return ret
diff --git a/lib9p/core_generated.c b/lib9p/core_generated.c
index 2532d12..81ace7d 100644
--- a/lib9p/core_generated.c
+++ b/lib9p/core_generated.c
@@ -12,132 +12,6 @@
 #include "core_tables.h"
 #include "core_utf8.h"
 
-/* libmisc/obj.h vtables ******************************************************/
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_tag_t, lib9p_tag, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_fid_t, lib9p_fid, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_s, lib9p_s, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_dm_t, lib9p_dm, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_qt_t, lib9p_qt, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_qid, lib9p_qid, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_stat, lib9p_stat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_o_t, lib9p_o, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tversion, lib9p_msg_Tversion, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rversion, lib9p_msg_Rversion, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tauth, lib9p_msg_Tauth, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rauth, lib9p_msg_Rauth, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tattach, lib9p_msg_Tattach, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rattach, lib9p_msg_Rattach, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rerror, lib9p_msg_Rerror, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tflush, lib9p_msg_Tflush, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rflush, lib9p_msg_Rflush, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Twalk, lib9p_msg_Twalk, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rwalk, lib9p_msg_Rwalk, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Topen, lib9p_msg_Topen, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Ropen, lib9p_msg_Ropen, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tcreate, lib9p_msg_Tcreate, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rcreate, lib9p_msg_Rcreate, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tread, lib9p_msg_Tread, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rread, lib9p_msg_Rread, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Twrite, lib9p_msg_Twrite, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rwrite, lib9p_msg_Rwrite, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tclunk, lib9p_msg_Tclunk, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rclunk, lib9p_msg_Rclunk, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tremove, lib9p_msg_Tremove, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rremove, lib9p_msg_Rremove, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tstat, lib9p_msg_Tstat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rstat, lib9p_msg_Rstat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Twstat, lib9p_msg_Twstat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rwstat, lib9p_msg_Rwstat, static);
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000_p9p
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Topenfd, lib9p_msg_Topenfd, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Ropenfd, lib9p_msg_Ropenfd, static);
-#endif /* CONFIG_9P_ENABLE_9P2000_p9p */
-#if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_nuid_t, lib9p_nuid, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_errno_t, lib9p_errno, static);
-#endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000_L
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_super_magic_t, lib9p_super_magic, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_lo_t, lib9p_lo, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_dt_t, lib9p_dt, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_mode_t, lib9p_mode, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_b4_t, lib9p_b4, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_getattr_t, lib9p_getattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_setattr_t, lib9p_setattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_lock_type_t, lib9p_lock_type, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_lock_flags_t, lib9p_lock_flags, static);
-LO_IMPLEMENTATION_C(fmt_formatter, lib9p_lock_status_t, lib9p_lock_status, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rlerror, lib9p_msg_Rlerror, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tstatfs, lib9p_msg_Tstatfs, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rstatfs, lib9p_msg_Rstatfs, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tlopen, lib9p_msg_Tlopen, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rlopen, lib9p_msg_Rlopen, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tlcreate, lib9p_msg_Tlcreate, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rlcreate, lib9p_msg_Rlcreate, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tsymlink, lib9p_msg_Tsymlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rsymlink, lib9p_msg_Rsymlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tmknod, lib9p_msg_Tmknod, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rmknod, lib9p_msg_Rmknod, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Trename, lib9p_msg_Trename, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rrename, lib9p_msg_Rrename, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Treadlink, lib9p_msg_Treadlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rreadlink, lib9p_msg_Rreadlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tgetattr, lib9p_msg_Tgetattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rgetattr, lib9p_msg_Rgetattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tsetattr, lib9p_msg_Tsetattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rsetattr, lib9p_msg_Rsetattr, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Txattrwalk, lib9p_msg_Txattrwalk, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rxattrwalk, lib9p_msg_Rxattrwalk, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Txattrcreate, lib9p_msg_Txattrcreate, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rxattrcreate, lib9p_msg_Rxattrcreate, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Treaddir, lib9p_msg_Treaddir, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rreaddir, lib9p_msg_Rreaddir, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tfsync, lib9p_msg_Tfsync, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rfsync, lib9p_msg_Rfsync, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tlock, lib9p_msg_Tlock, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rlock, lib9p_msg_Rlock, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tgetlock, lib9p_msg_Tgetlock, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rgetlock, lib9p_msg_Rgetlock, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tlink, lib9p_msg_Tlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rlink, lib9p_msg_Rlink, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tmkdir, lib9p_msg_Tmkdir, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rmkdir, lib9p_msg_Rmkdir, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Trenameat, lib9p_msg_Trenameat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rrenameat, lib9p_msg_Rrenameat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tunlinkat, lib9p_msg_Tunlinkat, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Runlinkat, lib9p_msg_Runlinkat, static);
-#endif /* CONFIG_9P_ENABLE_9P2000_L */
-#if CONFIG_9P_ENABLE_9P2000_e
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tsession, lib9p_msg_Tsession, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rsession, lib9p_msg_Rsession, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tsread, lib9p_msg_Tsread, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rsread, lib9p_msg_Rsread, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Tswrite, lib9p_msg_Tswrite, static);
-LO_IMPLEMENTATION_C(fmt_formatter, struct lib9p_msg_Rswrite, lib9p_msg_Rswrite, static);
-#endif /* CONFIG_9P_ENABLE_9P2000_e */
-
 /* utilities ******************************************************************/
 #if CONFIG_9P_ENABLE_9P2000
 	#define _is_ver_9P2000(v) (v == LIB9P_VER_9P2000)
@@ -355,7 +229,7 @@ static const lib9p_lock_flags_t lock_flags_masks[LIB9P_VER_NUM] = {
 		 * that.  */                                                                        \
 		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "message is too short for content"); \
 	if (net_offset > net_size)                                                                  \
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "message is too short for content (%"PRIu32" > %"PRIu32") @ %d", net_offset, net_size, __LINE__);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "message is too short for content (", net_offset, " > ", net_size, ")");
 #define VALIDATE_NET_UTF8(n)                                                                              \
 	{                                                                                                 \
 		size_t len = n;                                                                           \
@@ -387,8 +261,8 @@ static ssize_t validate_stat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *
 	uint32_t offsetof_qid_type = net_offset + 8;
 	VALIDATE_NET_BYTES(21);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_mode = net_offset + 0;
 	VALIDATE_NET_BYTES(22);
 	VALIDATE_NET_UTF8(LAST_U16LE());
@@ -406,12 +280,11 @@ static ssize_t validate_stat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof__stat_size) != (uint32_t)(offsetof_end - offsetof_fstype))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "stat->_stat_size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof__stat_size), (uint32_t)(offsetof_end - offsetof_fstype));
+	if (GET_U32LE(offsetof__stat_size) != offsetof_end - offsetof_fstype)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "stat->_stat_size value is wrong: actual:", (base10, GET_U32LE(offsetof__stat_size)), " != correct:", (base10, offsetof_end - offsetof_fstype));
 	if (GET_U32LE(offsetof_mode) & ~dm_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~dm_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~dm_masks[ctx->version]));
 	if (ret_net_size)
 		*ret_net_size = net_offset;
 	return (ssize_t)host_size;
@@ -427,12 +300,10 @@ static ssize_t validate_Tversion(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_BYTES(13);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tversion->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(100))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tversion->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(100));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tversion->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 100)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tversion->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 100));
 	return (ssize_t)host_size;
 }
 
@@ -444,12 +315,10 @@ static ssize_t validate_Rversion(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_BYTES(13);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rversion->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(101))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rversion->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(101));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rversion->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 101)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rversion->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 101));
 	return (ssize_t)host_size;
 }
 
@@ -470,12 +339,10 @@ static ssize_t validate_Tauth(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tauth->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(102))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tauth->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(102));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tauth->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 102)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tauth->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 102));
 	return (ssize_t)host_size;
 }
 
@@ -487,15 +354,13 @@ static ssize_t validate_Rauth(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_aqid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_aqid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_aqid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_aqid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rauth->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(103))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rauth->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(103));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rauth->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 103)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rauth->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 103));
 	return (ssize_t)host_size;
 }
 
@@ -514,12 +379,10 @@ static ssize_t validate_Tattach(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tattach->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(104))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tattach->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(104));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tattach->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 104)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tattach->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 104));
 	return (ssize_t)host_size;
 }
 
@@ -531,15 +394,13 @@ static ssize_t validate_Rattach(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rattach->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(105))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rattach->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(105));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rattach->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 105)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rattach->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 105));
 	return (ssize_t)host_size;
 }
 
@@ -558,12 +419,10 @@ static ssize_t validate_Rerror(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rerror->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(107))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rerror->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(107));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rerror->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 107)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rerror->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 107));
 	return (ssize_t)host_size;
 }
 
@@ -576,12 +435,10 @@ static ssize_t validate_Tflush(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 9;
 	VALIDATE_NET_BYTES(9);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tflush->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(108))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tflush->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(108));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tflush->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 108)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tflush->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 108));
 	return (ssize_t)host_size;
 }
 
@@ -592,12 +449,10 @@ static ssize_t validate_Rflush(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rflush->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(109))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rflush->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(109));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rflush->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 109)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rflush->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 109));
 	return (ssize_t)host_size;
 }
 
@@ -614,15 +469,12 @@ static ssize_t validate_Twalk(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 		VALIDATE_NET_UTF8(LAST_U16LE());
 	}
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(110))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(110));
-	if ((uint16_t)GET_U16LE(offsetof_nwname) > (uint16_t)(16))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->nwname value is too large: %"PRIu16" > %"PRIu16,
-			(uint16_t)GET_U16LE(offsetof_nwname), (uint16_t)(16));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 110)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 110));
+	if (GET_U16LE(offsetof_nwname) > 16)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twalk->nwname value is too large: ", (base10, GET_U16LE(offsetof_nwname)), " > ", (base10, 16));
 	return (ssize_t)host_size;
 }
 
@@ -638,19 +490,16 @@ static ssize_t validate_Rwalk(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 		uint32_t offsetof_wqid_type = net_offset + 0;
 		VALIDATE_NET_BYTES(13);
 		if (GET_U8LE(offsetof_wqid_type) & ~qt_masks[ctx->version])
-			return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-				GET_U8LE(offsetof_wqid_type) & ~qt_masks[ctx->version]);
+			return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+				(base16_u8_, GET_U8LE(offsetof_wqid_type) & ~qt_masks[ctx->version]));
 	}
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(111))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(111));
-	if ((uint16_t)GET_U16LE(offsetof_nwqid) > (uint16_t)(16))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->nwqid value is too large: %"PRIu16" > %"PRIu16,
-			(uint16_t)GET_U16LE(offsetof_nwqid), (uint16_t)(16));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 111)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 111));
+	if (GET_U16LE(offsetof_nwqid) > 16)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwalk->nwqid value is too large: ", (base10, GET_U16LE(offsetof_nwqid)), " > ", (base10, 16));
 	return (ssize_t)host_size;
 }
 
@@ -664,15 +513,13 @@ static ssize_t validate_Topen(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_mode = net_offset + 11;
 	uint32_t offsetof_end = net_offset + 12;
 	VALIDATE_NET_BYTES(12);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Topen->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(112))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Topen->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(112));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Topen->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 112)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Topen->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 112));
 	if (GET_U8LE(offsetof_mode) & ~o_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -684,16 +531,14 @@ static ssize_t validate_Ropen(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropen->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(113))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropen->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(113));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropen->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 113)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropen->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 113));
 	return (ssize_t)host_size;
 }
 
@@ -708,18 +553,16 @@ static ssize_t validate_Tcreate(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_mode = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 5;
 	VALIDATE_NET_BYTES(5);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(114))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(114));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 114)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 114));
 	if (GET_U32LE(offsetof_perm) & ~dm_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_perm) & ~dm_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_perm) & ~dm_masks[ctx->version]));
 	if (GET_U8LE(offsetof_mode) & ~o_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -731,16 +574,14 @@ static ssize_t validate_Rcreate(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(115))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(115));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 115)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 115));
 	return (ssize_t)host_size;
 }
 
@@ -755,18 +596,14 @@ static ssize_t validate_Tread(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_count = net_offset + 19;
 	uint32_t offsetof_end = net_offset + 23;
 	VALIDATE_NET_BYTES(23);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(116))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(116));
-	if ((uint64_t)GET_U64LE(offsetof_offset) > (uint64_t)(INT64_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->offset value is too large: %"PRIu64" > %"PRIu64,
-			(uint64_t)GET_U64LE(offsetof_offset), (uint64_t)(INT64_MAX));
-	if ((uint32_t)GET_U32LE(offsetof_count) > (uint32_t)(INT32_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->count value is too large: %"PRIu32" > %"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_count), (uint32_t)(INT32_MAX));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 116)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 116));
+	if (GET_U64LE(offsetof_offset) > INT64_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->offset value is too large: ", (base10, GET_U64LE(offsetof_offset)), " > ", (base10, INT64_MAX));
+	if (GET_U32LE(offsetof_count) > INT32_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tread->count value is too large: ", (base10, GET_U32LE(offsetof_count)), " > ", (base10, INT32_MAX));
 	return (ssize_t)host_size;
 }
 
@@ -779,15 +616,12 @@ static ssize_t validate_Rread(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	VALIDATE_NET_BYTES(11);
 	VALIDATE_NET_BYTES(LAST_U32LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(117))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(117));
-	if ((uint32_t)GET_U32LE(offsetof_count) > (uint32_t)(INT32_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->count value is too large: %"PRIu32" > %"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_count), (uint32_t)(INT32_MAX));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 117)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 117));
+	if (GET_U32LE(offsetof_count) > INT32_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rread->count value is too large: ", (base10, GET_U32LE(offsetof_count)), " > ", (base10, INT32_MAX));
 	return (ssize_t)host_size;
 }
 
@@ -801,18 +635,14 @@ static ssize_t validate_Twrite(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	VALIDATE_NET_BYTES(23);
 	VALIDATE_NET_BYTES(LAST_U32LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(118))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(118));
-	if ((uint64_t)GET_U64LE(offsetof_offset) > (uint64_t)(INT64_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->offset value is too large: %"PRIu64" > %"PRIu64,
-			(uint64_t)GET_U64LE(offsetof_offset), (uint64_t)(INT64_MAX));
-	if ((uint32_t)GET_U32LE(offsetof_count) > (uint32_t)(INT32_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->count value is too large: %"PRIu32" > %"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_count), (uint32_t)(INT32_MAX));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 118)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 118));
+	if (GET_U64LE(offsetof_offset) > INT64_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->offset value is too large: ", (base10, GET_U64LE(offsetof_offset)), " > ", (base10, INT64_MAX));
+	if (GET_U32LE(offsetof_count) > INT32_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twrite->count value is too large: ", (base10, GET_U32LE(offsetof_count)), " > ", (base10, INT32_MAX));
 	return (ssize_t)host_size;
 }
 
@@ -824,15 +654,12 @@ static ssize_t validate_Rwrite(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_count = net_offset + 7;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(119))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(119));
-	if ((uint32_t)GET_U32LE(offsetof_count) > (uint32_t)(INT32_MAX))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->count value is too large: %"PRIu32" > %"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_count), (uint32_t)(INT32_MAX));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 119)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 119));
+	if (GET_U32LE(offsetof_count) > INT32_MAX)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwrite->count value is too large: ", (base10, GET_U32LE(offsetof_count)), " > ", (base10, INT32_MAX));
 	return (ssize_t)host_size;
 }
 
@@ -843,12 +670,10 @@ static ssize_t validate_Tclunk(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tclunk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(120))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tclunk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(120));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tclunk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 120)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tclunk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 120));
 	return (ssize_t)host_size;
 }
 
@@ -859,12 +684,10 @@ static ssize_t validate_Rclunk(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rclunk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(121))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rclunk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(121));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rclunk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 121)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rclunk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 121));
 	return (ssize_t)host_size;
 }
 
@@ -875,12 +698,10 @@ static ssize_t validate_Tremove(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tremove->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(122))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tremove->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(122));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tremove->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 122)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tremove->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 122));
 	return (ssize_t)host_size;
 }
 
@@ -891,12 +712,10 @@ static ssize_t validate_Rremove(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rremove->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(123))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rremove->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(123));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rremove->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 123)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rremove->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 123));
 	return (ssize_t)host_size;
 }
 
@@ -909,12 +728,10 @@ static ssize_t validate_Tstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(124))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(124));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 124)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 124));
 	return (ssize_t)host_size;
 }
 
@@ -930,8 +747,8 @@ static ssize_t validate_Rstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_stat_qid_type = net_offset + 17;
 	VALIDATE_NET_BYTES(30);
 	if (GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_stat_mode = net_offset + 0;
 	VALIDATE_NET_BYTES(22);
 	VALIDATE_NET_UTF8(LAST_U16LE());
@@ -949,22 +766,18 @@ static ssize_t validate_Rstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_stat_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_stat__stat_size) != (uint32_t)(offsetof_stat_end - offsetof_stat_fstype))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->stat._stat_size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_stat__stat_size), (uint32_t)(offsetof_stat_end - offsetof_stat_fstype));
+	if (GET_U32LE(offsetof_stat__stat_size) != offsetof_stat_end - offsetof_stat_fstype)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->stat._stat_size value is wrong: actual:", (base10, GET_U32LE(offsetof_stat__stat_size)), " != correct:", (base10, offsetof_stat_end - offsetof_stat_fstype));
 	if (GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(125))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(125));
-	if ((uint32_t)GET_U32LE(offsetof_nstat) != (uint32_t)(offsetof_end - offsetof_stat))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->nstat value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_nstat), (uint32_t)(offsetof_end - offsetof_stat));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 125)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 125));
+	if (GET_U32LE(offsetof_nstat) != offsetof_end - offsetof_stat)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstat->nstat value is wrong: actual:", (base10, GET_U32LE(offsetof_nstat)), " != correct:", (base10, offsetof_end - offsetof_stat));
 	return (ssize_t)host_size;
 }
 
@@ -980,8 +793,8 @@ static ssize_t validate_Twstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_stat_qid_type = net_offset + 21;
 	VALIDATE_NET_BYTES(34);
 	if (GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_stat_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_stat_mode = net_offset + 0;
 	VALIDATE_NET_BYTES(22);
 	VALIDATE_NET_UTF8(LAST_U16LE());
@@ -999,22 +812,18 @@ static ssize_t validate_Twstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	uint32_t offsetof_stat_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_stat__stat_size) != (uint32_t)(offsetof_stat_end - offsetof_stat_fstype))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->stat._stat_size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_stat__stat_size), (uint32_t)(offsetof_stat_end - offsetof_stat_fstype));
+	if (GET_U32LE(offsetof_stat__stat_size) != offsetof_stat_end - offsetof_stat_fstype)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->stat._stat_size value is wrong: actual:", (base10, GET_U32LE(offsetof_stat__stat_size)), " != correct:", (base10, offsetof_stat_end - offsetof_stat_fstype));
 	if (GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in dm bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_stat_mode) & ~dm_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(126))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(126));
-	if ((uint32_t)GET_U32LE(offsetof_nstat) != (uint32_t)(offsetof_end - offsetof_stat))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->nstat value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_nstat), (uint32_t)(offsetof_end - offsetof_stat));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 126)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 126));
+	if (GET_U32LE(offsetof_nstat) != offsetof_end - offsetof_stat)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Twstat->nstat value is wrong: actual:", (base10, GET_U32LE(offsetof_nstat)), " != correct:", (base10, offsetof_end - offsetof_stat));
 	return (ssize_t)host_size;
 }
 
@@ -1025,12 +834,10 @@ static ssize_t validate_Rwstat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwstat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(127))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwstat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(127));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwstat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 127)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rwstat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 127));
 	return (ssize_t)host_size;
 }
 
@@ -1044,15 +851,13 @@ static ssize_t validate_Topenfd(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_mode = net_offset + 11;
 	uint32_t offsetof_end = net_offset + 12;
 	VALIDATE_NET_BYTES(12);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Topenfd->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(98))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Topenfd->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(98));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Topenfd->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 98)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Topenfd->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 98));
 	if (GET_U8LE(offsetof_mode) & ~o_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in o bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_mode) & ~o_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1064,16 +869,14 @@ static ssize_t validate_Ropenfd(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 8;
 	VALIDATE_NET_BYTES(8);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropenfd->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(99))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropenfd->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(99));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropenfd->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 99)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Ropenfd->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 99));
 	return (ssize_t)host_size;
 }
 
@@ -1086,12 +889,10 @@ static ssize_t validate_Rlerror(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlerror->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(7))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlerror->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(7));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlerror->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 7)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlerror->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 7));
 	return (ssize_t)host_size;
 }
 
@@ -1102,12 +903,10 @@ static ssize_t validate_Tstatfs(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstatfs->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(8))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstatfs->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(8));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstatfs->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 8)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tstatfs->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 8));
 	return (ssize_t)host_size;
 }
 
@@ -1118,12 +917,10 @@ static ssize_t validate_Rstatfs(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 67;
 	VALIDATE_NET_BYTES(67);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstatfs->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(9))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstatfs->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(9));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstatfs->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 9)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rstatfs->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 9));
 	return (ssize_t)host_size;
 }
 
@@ -1135,15 +932,13 @@ static ssize_t validate_Tlopen(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_flags = net_offset + 11;
 	uint32_t offsetof_end = net_offset + 15;
 	VALIDATE_NET_BYTES(15);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlopen->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(12))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlopen->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(12));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlopen->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 12)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlopen->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 12));
 	if (GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lo bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lo bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1155,16 +950,14 @@ static ssize_t validate_Rlopen(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlopen->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(13))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlopen->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(13));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlopen->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 13)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlopen->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 13));
 	return (ssize_t)host_size;
 }
 
@@ -1179,18 +972,16 @@ static ssize_t validate_Tlcreate(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_mode = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 12;
 	VALIDATE_NET_BYTES(12);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(14))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(14));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 14)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 14));
 	if (GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lo bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lo bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_flags) & ~lo_masks[ctx->version]));
 	if (GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1202,16 +993,14 @@ static ssize_t validate_Rlcreate(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(15))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(15));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 15)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 15));
 	return (ssize_t)host_size;
 }
 
@@ -1226,12 +1015,10 @@ static ssize_t validate_Tsymlink(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsymlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(16))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsymlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(16));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsymlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 16)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsymlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 16));
 	return (ssize_t)host_size;
 }
 
@@ -1243,15 +1030,13 @@ static ssize_t validate_Rsymlink(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsymlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(17))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsymlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(17));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsymlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 17)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsymlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 17));
 	return (ssize_t)host_size;
 }
 
@@ -1265,15 +1050,13 @@ static ssize_t validate_Tmknod(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_mode = net_offset + 0;
 	uint32_t offsetof_end = net_offset + 16;
 	VALIDATE_NET_BYTES(16);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmknod->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(18))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmknod->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(18));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmknod->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 18)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmknod->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 18));
 	if (GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1285,15 +1068,13 @@ static ssize_t validate_Rmknod(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmknod->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(19))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmknod->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(19));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmknod->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 19)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmknod->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 19));
 	return (ssize_t)host_size;
 }
 
@@ -1305,12 +1086,10 @@ static ssize_t validate_Trename(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	VALIDATE_NET_BYTES(17);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Trename->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(20))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Trename->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(20));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Trename->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 20)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Trename->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 20));
 	return (ssize_t)host_size;
 }
 
@@ -1321,12 +1100,10 @@ static ssize_t validate_Rrename(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrename->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(21))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrename->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(21));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrename->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 21)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrename->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 21));
 	return (ssize_t)host_size;
 }
 
@@ -1337,12 +1114,10 @@ static ssize_t validate_Treadlink(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Treadlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(22))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Treadlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(22));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Treadlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 22)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Treadlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 22));
 	return (ssize_t)host_size;
 }
 
@@ -1354,12 +1129,10 @@ static ssize_t validate_Rreadlink(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	VALIDATE_NET_BYTES(9);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreadlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(23))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreadlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(23));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreadlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 23)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreadlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 23));
 	return (ssize_t)host_size;
 }
 
@@ -1371,15 +1144,13 @@ static ssize_t validate_Tgetattr(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_request_mask = net_offset + 11;
 	uint32_t offsetof_end = net_offset + 19;
 	VALIDATE_NET_BYTES(19);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetattr->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(24))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetattr->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(24));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetattr->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 24)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetattr->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 24));
 	if (GET_U64LE(offsetof_request_mask) & ~getattr_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in getattr bitfield: %#016"PRIx64,
-			GET_U64LE(offsetof_request_mask) & ~getattr_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in getattr bitfield: ",
+			(base16_u64_, GET_U64LE(offsetof_request_mask) & ~getattr_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1392,23 +1163,21 @@ static ssize_t validate_Rgetattr(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_qid_type = net_offset + 15;
 	VALIDATE_NET_BYTES(28);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_mode = net_offset + 0;
 	uint32_t offsetof_end = net_offset + 132;
 	VALIDATE_NET_BYTES(132);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetattr->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(25))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetattr->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(25));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetattr->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 25)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetattr->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 25));
 	if (GET_U64LE(offsetof_valid) & ~getattr_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in getattr bitfield: %#016"PRIx64,
-			GET_U64LE(offsetof_valid) & ~getattr_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in getattr bitfield: ",
+			(base16_u64_, GET_U64LE(offsetof_valid) & ~getattr_masks[ctx->version]));
 	if (GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1421,18 +1190,16 @@ static ssize_t validate_Tsetattr(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_mode = net_offset + 15;
 	uint32_t offsetof_end = net_offset + 67;
 	VALIDATE_NET_BYTES(67);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsetattr->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(26))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsetattr->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(26));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsetattr->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 26)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsetattr->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 26));
 	if (GET_U32LE(offsetof_valid) & ~setattr_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in setattr bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_valid) & ~setattr_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in setattr bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_valid) & ~setattr_masks[ctx->version]));
 	if (GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1443,12 +1210,10 @@ static ssize_t validate_Rsetattr(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsetattr->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(27))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsetattr->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(27));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsetattr->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 27)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsetattr->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 27));
 	return (ssize_t)host_size;
 }
 
@@ -1460,12 +1225,10 @@ static ssize_t validate_Txattrwalk(struct lib9p_ctx *ctx, uint32_t net_size, uin
 	VALIDATE_NET_BYTES(17);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrwalk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(30))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrwalk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(30));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrwalk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 30)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrwalk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 30));
 	return (ssize_t)host_size;
 }
 
@@ -1476,12 +1239,10 @@ static ssize_t validate_Rxattrwalk(struct lib9p_ctx *ctx, uint32_t net_size, uin
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 15;
 	VALIDATE_NET_BYTES(15);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrwalk->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(31))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrwalk->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(31));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrwalk->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 31)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrwalk->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 31));
 	return (ssize_t)host_size;
 }
 
@@ -1494,12 +1255,10 @@ static ssize_t validate_Txattrcreate(struct lib9p_ctx *ctx, uint32_t net_size, u
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 12;
 	VALIDATE_NET_BYTES(12);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(32))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(32));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 32)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Txattrcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 32));
 	return (ssize_t)host_size;
 }
 
@@ -1510,12 +1269,10 @@ static ssize_t validate_Rxattrcreate(struct lib9p_ctx *ctx, uint32_t net_size, u
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrcreate->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(33))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrcreate->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(33));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrcreate->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 33)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rxattrcreate->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 33));
 	return (ssize_t)host_size;
 }
 
@@ -1526,12 +1283,10 @@ static ssize_t validate_Treaddir(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 23;
 	VALIDATE_NET_BYTES(23);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Treaddir->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(40))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Treaddir->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(40));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Treaddir->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 40)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Treaddir->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 40));
 	return (ssize_t)host_size;
 }
 
@@ -1543,12 +1298,10 @@ static ssize_t validate_Rreaddir(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_BYTES(11);
 	VALIDATE_NET_BYTES(LAST_U32LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreaddir->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(41))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreaddir->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(41));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreaddir->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 41)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rreaddir->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 41));
 	return (ssize_t)host_size;
 }
 
@@ -1559,12 +1312,10 @@ static ssize_t validate_Tfsync(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 15;
 	VALIDATE_NET_BYTES(15);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tfsync->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(50))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tfsync->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(50));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tfsync->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 50)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tfsync->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 50));
 	return (ssize_t)host_size;
 }
 
@@ -1575,12 +1326,10 @@ static ssize_t validate_Rfsync(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rfsync->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(51))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rfsync->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(51));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rfsync->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 51)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rfsync->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 51));
 	return (ssize_t)host_size;
 }
 
@@ -1593,15 +1342,13 @@ static ssize_t validate_Tlock(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	VALIDATE_NET_BYTES(38);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlock->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(52))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlock->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(52));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlock->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 52)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlock->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 52));
 	if (GET_U32LE(offsetof_flags) & ~lock_flags_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lock_flags bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_flags) & ~lock_flags_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in lock_flags bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_flags) & ~lock_flags_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1612,12 +1359,10 @@ static ssize_t validate_Rlock(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 8;
 	VALIDATE_NET_BYTES(8);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlock->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(53))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlock->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(53));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlock->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 53)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlock->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 53));
 	return (ssize_t)host_size;
 }
 
@@ -1629,12 +1374,10 @@ static ssize_t validate_Tgetlock(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_BYTES(34);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetlock->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(54))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetlock->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(54));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetlock->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 54)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tgetlock->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 54));
 	return (ssize_t)host_size;
 }
 
@@ -1646,12 +1389,10 @@ static ssize_t validate_Rgetlock(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	VALIDATE_NET_BYTES(30);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetlock->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(55))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetlock->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(55));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetlock->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 55)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rgetlock->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 55));
 	return (ssize_t)host_size;
 }
 
@@ -1663,12 +1404,10 @@ static ssize_t validate_Tlink(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	VALIDATE_NET_BYTES(17);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(70))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(70));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 70)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 70));
 	return (ssize_t)host_size;
 }
 
@@ -1679,12 +1418,10 @@ static ssize_t validate_Rlink(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlink->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(71))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlink->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(71));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlink->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 71)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rlink->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 71));
 	return (ssize_t)host_size;
 }
 
@@ -1698,15 +1435,13 @@ static ssize_t validate_Tmkdir(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_mode = net_offset + 0;
 	uint32_t offsetof_end = net_offset + 8;
 	VALIDATE_NET_BYTES(8);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmkdir->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(72))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmkdir->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(72));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmkdir->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 72)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tmkdir->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 72));
 	if (GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: %#08"PRIx32,
-			GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in mode bitfield: ",
+			(base16_u32_, GET_U32LE(offsetof_mode) & ~mode_masks[ctx->version]));
 	return (ssize_t)host_size;
 }
 
@@ -1718,15 +1453,13 @@ static ssize_t validate_Rmkdir(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	uint32_t offsetof_qid_type = net_offset + 7;
 	VALIDATE_NET_BYTES(20);
 	if (GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version])
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: %#02"PRIx8,
-			GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]);
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "unknown bits in qt bitfield: ",
+			(base16_u8_, GET_U8LE(offsetof_qid_type) & ~qt_masks[ctx->version]));
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmkdir->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(73))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmkdir->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(73));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmkdir->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 73)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rmkdir->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 73));
 	return (ssize_t)host_size;
 }
 
@@ -1740,12 +1473,10 @@ static ssize_t validate_Trenameat(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	VALIDATE_NET_BYTES(6);
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Trenameat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(74))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Trenameat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(74));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Trenameat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 74)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Trenameat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 74));
 	return (ssize_t)host_size;
 }
 
@@ -1756,12 +1487,10 @@ static ssize_t validate_Rrenameat(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrenameat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(75))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrenameat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(75));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrenameat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 75)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rrenameat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 75));
 	return (ssize_t)host_size;
 }
 
@@ -1774,12 +1503,10 @@ static ssize_t validate_Tunlinkat(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	VALIDATE_NET_UTF8(LAST_U16LE());
 	uint32_t offsetof_end = net_offset + 4;
 	VALIDATE_NET_BYTES(4);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tunlinkat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(76))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tunlinkat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(76));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tunlinkat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 76)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tunlinkat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 76));
 	return (ssize_t)host_size;
 }
 
@@ -1790,12 +1517,10 @@ static ssize_t validate_Runlinkat(struct lib9p_ctx *ctx, uint32_t net_size, uint
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Runlinkat->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(77))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Runlinkat->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(77));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Runlinkat->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 77)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Runlinkat->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 77));
 	return (ssize_t)host_size;
 }
 
@@ -1808,12 +1533,10 @@ static ssize_t validate_Tsession(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 15;
 	VALIDATE_NET_BYTES(15);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsession->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(150))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsession->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(150));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsession->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 150)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsession->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 150));
 	return (ssize_t)host_size;
 }
 
@@ -1824,12 +1547,10 @@ static ssize_t validate_Rsession(struct lib9p_ctx *ctx, uint32_t net_size, uint8
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 7;
 	VALIDATE_NET_BYTES(7);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsession->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(151))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsession->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(151));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsession->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 151)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsession->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 151));
 	return (ssize_t)host_size;
 }
 
@@ -1845,12 +1566,10 @@ static ssize_t validate_Tsread(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 		VALIDATE_NET_UTF8(LAST_U16LE());
 	}
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsread->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(152))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsread->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(152));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsread->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 152)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tsread->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 152));
 	return (ssize_t)host_size;
 }
 
@@ -1862,12 +1581,10 @@ static ssize_t validate_Rsread(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t
 	VALIDATE_NET_BYTES(11);
 	VALIDATE_NET_BYTES(LAST_U32LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsread->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(153))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsread->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(153));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsread->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 153)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rsread->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 153));
 	return (ssize_t)host_size;
 }
 
@@ -1885,12 +1602,10 @@ static ssize_t validate_Tswrite(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	VALIDATE_NET_BYTES(4);
 	VALIDATE_NET_BYTES(LAST_U32LE());
 	uint32_t offsetof_end = net_offset + 0;
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tswrite->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(154))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Tswrite->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(154));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tswrite->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 154)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Tswrite->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 154));
 	return (ssize_t)host_size;
 }
 
@@ -1901,12 +1616,10 @@ static ssize_t validate_Rswrite(struct lib9p_ctx *ctx, uint32_t net_size, uint8_
 	uint32_t offsetof_typ = net_offset + 4;
 	uint32_t offsetof_end = net_offset + 11;
 	VALIDATE_NET_BYTES(11);
-	if ((uint32_t)GET_U32LE(offsetof_size) != (uint32_t)(offsetof_end - offsetof_size))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rswrite->size value is wrong: actual: %"PRIu32" != correct:%"PRIu32,
-			(uint32_t)GET_U32LE(offsetof_size), (uint32_t)(offsetof_end - offsetof_size));
-	if ((uint8_t)GET_U8LE(offsetof_typ) != (uint8_t)(155))
-		return lib9p_errorf(ctx, LIB9P_ERRNO_L_EBADMSG, "Rswrite->typ value is wrong: actual: %"PRIu8" != correct:%"PRIu8,
-			(uint8_t)GET_U8LE(offsetof_typ), (uint8_t)(155));
+	if (GET_U32LE(offsetof_size) != offsetof_end - offsetof_size)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rswrite->size value is wrong: actual:", (base10, GET_U32LE(offsetof_size)), " != correct:", (base10, offsetof_end - offsetof_size));
+	if (GET_U8LE(offsetof_typ) != 155)
+		return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "Rswrite->typ value is wrong: actual:", (base10, GET_U8LE(offsetof_typ)), " != correct:", (base10, 155));
 	return (ssize_t)host_size;
 }
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
@@ -3057,10 +2770,9 @@ static bool marshal_stat(struct lib9p_ctx *ctx, struct lib9p_stat *val, struct _
 static bool marshal_Tversion(struct lib9p_ctx *ctx, struct lib9p_msg_Tversion *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 13 + val->version.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tversion",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tversion message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3077,10 +2789,9 @@ static bool marshal_Tversion(struct lib9p_ctx *ctx, struct lib9p_msg_Tversion *v
 static bool marshal_Rversion(struct lib9p_ctx *ctx, struct lib9p_msg_Rversion *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 13 + val->version.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rversion",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rversion message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3104,10 +2815,9 @@ static bool marshal_Tauth(struct lib9p_ctx *ctx, struct lib9p_msg_Tauth *val, st
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tauth",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tauth message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3131,10 +2841,9 @@ static bool marshal_Tauth(struct lib9p_ctx *ctx, struct lib9p_msg_Tauth *val, st
 static bool marshal_Rauth(struct lib9p_ctx *ctx, struct lib9p_msg_Rauth *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 20;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rauth",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rauth message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3156,10 +2865,9 @@ static bool marshal_Tattach(struct lib9p_ctx *ctx, struct lib9p_msg_Tattach *val
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tattach",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tattach message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3184,10 +2892,9 @@ static bool marshal_Tattach(struct lib9p_ctx *ctx, struct lib9p_msg_Tattach *val
 static bool marshal_Rattach(struct lib9p_ctx *ctx, struct lib9p_msg_Rattach *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 20;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rattach",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rattach message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3211,10 +2918,9 @@ static bool marshal_Rerror(struct lib9p_ctx *ctx, struct lib9p_msg_Rerror *val,
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rerror",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rerror message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3237,10 +2943,9 @@ static bool marshal_Rerror(struct lib9p_ctx *ctx, struct lib9p_msg_Rerror *val,
 static bool marshal_Tflush(struct lib9p_ctx *ctx, struct lib9p_msg_Tflush *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 9;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tflush",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tflush message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3255,10 +2960,9 @@ static bool marshal_Tflush(struct lib9p_ctx *ctx, struct lib9p_msg_Tflush *val,
 static bool marshal_Rflush(struct lib9p_ctx *ctx, struct lib9p_msg_Rflush *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rflush",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rflush message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3275,10 +2979,9 @@ static bool marshal_Twalk(struct lib9p_ctx *ctx, struct lib9p_msg_Twalk *val, st
 		needed_size += 2 + val->wname[i].len;
 	}
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Twalk",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Twalk message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3299,10 +3002,9 @@ static bool marshal_Twalk(struct lib9p_ctx *ctx, struct lib9p_msg_Twalk *val, st
 static bool marshal_Rwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Rwalk *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 9 + (val->nwqid)*13;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rwalk",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rwalk message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3324,10 +3026,9 @@ static bool marshal_Rwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Rwalk *val, st
 static bool marshal_Topen(struct lib9p_ctx *ctx, struct lib9p_msg_Topen *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 12;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Topen",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Topen message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3343,10 +3044,9 @@ static bool marshal_Topen(struct lib9p_ctx *ctx, struct lib9p_msg_Topen *val, st
 static bool marshal_Ropen(struct lib9p_ctx *ctx, struct lib9p_msg_Ropen *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 24;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Ropen",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Ropen message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3364,10 +3064,9 @@ static bool marshal_Ropen(struct lib9p_ctx *ctx, struct lib9p_msg_Ropen *val, st
 static bool marshal_Tcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Tcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 18 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tcreate",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3386,10 +3085,9 @@ static bool marshal_Tcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Tcreate *val
 static bool marshal_Rcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 24;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rcreate",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3409,10 +3107,9 @@ static bool marshal_Rcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rcreate *val
 static bool marshal_Tread(struct lib9p_ctx *ctx, struct lib9p_msg_Tread *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 23;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tread",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tread message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3429,10 +3126,9 @@ static bool marshal_Tread(struct lib9p_ctx *ctx, struct lib9p_msg_Tread *val, st
 static bool marshal_Rread(struct lib9p_ctx *ctx, struct lib9p_msg_Rread *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11 + val->count;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rread",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rread message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3448,10 +3144,9 @@ static bool marshal_Rread(struct lib9p_ctx *ctx, struct lib9p_msg_Rread *val, st
 static bool marshal_Twrite(struct lib9p_ctx *ctx, struct lib9p_msg_Twrite *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 23 + val->count;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Twrite",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Twrite message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3469,10 +3164,9 @@ static bool marshal_Twrite(struct lib9p_ctx *ctx, struct lib9p_msg_Twrite *val,
 static bool marshal_Rwrite(struct lib9p_ctx *ctx, struct lib9p_msg_Rwrite *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rwrite",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rwrite message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3487,10 +3181,9 @@ static bool marshal_Rwrite(struct lib9p_ctx *ctx, struct lib9p_msg_Rwrite *val,
 static bool marshal_Tclunk(struct lib9p_ctx *ctx, struct lib9p_msg_Tclunk *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tclunk",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tclunk message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3505,10 +3198,9 @@ static bool marshal_Tclunk(struct lib9p_ctx *ctx, struct lib9p_msg_Tclunk *val,
 static bool marshal_Rclunk(struct lib9p_ctx *ctx, struct lib9p_msg_Rclunk *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rclunk",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rclunk message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3522,10 +3214,9 @@ static bool marshal_Rclunk(struct lib9p_ctx *ctx, struct lib9p_msg_Rclunk *val,
 static bool marshal_Tremove(struct lib9p_ctx *ctx, struct lib9p_msg_Tremove *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tremove",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tremove message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3540,10 +3231,9 @@ static bool marshal_Tremove(struct lib9p_ctx *ctx, struct lib9p_msg_Tremove *val
 static bool marshal_Rremove(struct lib9p_ctx *ctx, struct lib9p_msg_Rremove *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rremove",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rremove message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3559,10 +3249,9 @@ static bool marshal_Rremove(struct lib9p_ctx *ctx, struct lib9p_msg_Rremove *val
 static bool marshal_Tstat(struct lib9p_ctx *ctx, struct lib9p_msg_Tstat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tstat",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tstat message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3582,10 +3271,9 @@ static bool marshal_Rstat(struct lib9p_ctx *ctx, struct lib9p_msg_Rstat *val, st
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rstat",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rstat message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3640,10 +3328,9 @@ static bool marshal_Twstat(struct lib9p_ctx *ctx, struct lib9p_msg_Twstat *val,
 	}
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Twstat",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Twstat message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3694,10 +3381,9 @@ static bool marshal_Twstat(struct lib9p_ctx *ctx, struct lib9p_msg_Twstat *val,
 static bool marshal_Rwstat(struct lib9p_ctx *ctx, struct lib9p_msg_Rwstat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rwstat",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rwstat message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3713,10 +3399,9 @@ static bool marshal_Rwstat(struct lib9p_ctx *ctx, struct lib9p_msg_Rwstat *val,
 static bool marshal_Topenfd(struct lib9p_ctx *ctx, struct lib9p_msg_Topenfd *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 12;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Topenfd",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Topenfd message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3732,10 +3417,9 @@ static bool marshal_Topenfd(struct lib9p_ctx *ctx, struct lib9p_msg_Topenfd *val
 static bool marshal_Ropenfd(struct lib9p_ctx *ctx, struct lib9p_msg_Ropenfd *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 28;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Ropenfd",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Ropenfd message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3756,10 +3440,9 @@ static bool marshal_Ropenfd(struct lib9p_ctx *ctx, struct lib9p_msg_Ropenfd *val
 static bool marshal_Rlerror(struct lib9p_ctx *ctx, struct lib9p_msg_Rlerror *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rlerror",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rlerror message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3774,10 +3457,9 @@ static bool marshal_Rlerror(struct lib9p_ctx *ctx, struct lib9p_msg_Rlerror *val
 static bool marshal_Tstatfs(struct lib9p_ctx *ctx, struct lib9p_msg_Tstatfs *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tstatfs",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tstatfs message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3792,10 +3474,9 @@ static bool marshal_Tstatfs(struct lib9p_ctx *ctx, struct lib9p_msg_Tstatfs *val
 static bool marshal_Rstatfs(struct lib9p_ctx *ctx, struct lib9p_msg_Rstatfs *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 67;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rstatfs",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rstatfs message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3818,10 +3499,9 @@ static bool marshal_Rstatfs(struct lib9p_ctx *ctx, struct lib9p_msg_Rstatfs *val
 static bool marshal_Tlopen(struct lib9p_ctx *ctx, struct lib9p_msg_Tlopen *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 15;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tlopen",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tlopen message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3837,10 +3517,9 @@ static bool marshal_Tlopen(struct lib9p_ctx *ctx, struct lib9p_msg_Tlopen *val,
 static bool marshal_Rlopen(struct lib9p_ctx *ctx, struct lib9p_msg_Rlopen *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 24;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rlopen",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rlopen message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3858,10 +3537,9 @@ static bool marshal_Rlopen(struct lib9p_ctx *ctx, struct lib9p_msg_Rlopen *val,
 static bool marshal_Tlcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Tlcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 25 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tlcreate",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tlcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3881,10 +3559,9 @@ static bool marshal_Tlcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Tlcreate *v
 static bool marshal_Rlcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rlcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 24;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rlcreate",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rlcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3902,10 +3579,9 @@ static bool marshal_Rlcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rlcreate *v
 static bool marshal_Tsymlink(struct lib9p_ctx *ctx, struct lib9p_msg_Tsymlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 19 + val->name.len + val->symtgt.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tsymlink",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tsymlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3925,10 +3601,9 @@ static bool marshal_Tsymlink(struct lib9p_ctx *ctx, struct lib9p_msg_Tsymlink *v
 static bool marshal_Rsymlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rsymlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 20;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rsymlink",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rsymlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3945,10 +3620,9 @@ static bool marshal_Rsymlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rsymlink *v
 static bool marshal_Tmknod(struct lib9p_ctx *ctx, struct lib9p_msg_Tmknod *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 29 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tmknod",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tmknod message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3969,10 +3643,9 @@ static bool marshal_Tmknod(struct lib9p_ctx *ctx, struct lib9p_msg_Tmknod *val,
 static bool marshal_Rmknod(struct lib9p_ctx *ctx, struct lib9p_msg_Rmknod *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 20;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rmknod",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rmknod message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -3989,10 +3662,9 @@ static bool marshal_Rmknod(struct lib9p_ctx *ctx, struct lib9p_msg_Rmknod *val,
 static bool marshal_Trename(struct lib9p_ctx *ctx, struct lib9p_msg_Trename *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 17 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Trename",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Trename message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4010,10 +3682,9 @@ static bool marshal_Trename(struct lib9p_ctx *ctx, struct lib9p_msg_Trename *val
 static bool marshal_Rrename(struct lib9p_ctx *ctx, struct lib9p_msg_Rrename *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rrename",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rrename message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4027,10 +3698,9 @@ static bool marshal_Rrename(struct lib9p_ctx *ctx, struct lib9p_msg_Rrename *val
 static bool marshal_Treadlink(struct lib9p_ctx *ctx, struct lib9p_msg_Treadlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Treadlink",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Treadlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4045,10 +3715,9 @@ static bool marshal_Treadlink(struct lib9p_ctx *ctx, struct lib9p_msg_Treadlink
 static bool marshal_Rreadlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rreadlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 9 + val->target.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rreadlink",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rreadlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4064,10 +3733,9 @@ static bool marshal_Rreadlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rreadlink
 static bool marshal_Tgetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Tgetattr *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 19;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tgetattr",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tgetattr message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4083,10 +3751,9 @@ static bool marshal_Tgetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Tgetattr *v
 static bool marshal_Rgetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Rgetattr *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 160;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rgetattr",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rgetattr message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4122,10 +3789,9 @@ static bool marshal_Rgetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Rgetattr *v
 static bool marshal_Tsetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Tsetattr *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 67;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tsetattr",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tsetattr message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4149,10 +3815,9 @@ static bool marshal_Tsetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Tsetattr *v
 static bool marshal_Rsetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Rsetattr *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rsetattr",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rsetattr message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4166,10 +3831,9 @@ static bool marshal_Rsetattr(struct lib9p_ctx *ctx, struct lib9p_msg_Rsetattr *v
 static bool marshal_Txattrwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Txattrwalk *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 17 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Txattrwalk",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Txattrwalk message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4187,10 +3851,9 @@ static bool marshal_Txattrwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Txattrwal
 static bool marshal_Rxattrwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrwalk *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 15;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rxattrwalk",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rxattrwalk message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4205,10 +3868,9 @@ static bool marshal_Rxattrwalk(struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrwal
 static bool marshal_Txattrcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Txattrcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 25 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Txattrcreate",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Txattrcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4227,10 +3889,9 @@ static bool marshal_Txattrcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Txattrc
 static bool marshal_Rxattrcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrcreate *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rxattrcreate",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rxattrcreate message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4244,10 +3905,9 @@ static bool marshal_Rxattrcreate(struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrc
 static bool marshal_Treaddir(struct lib9p_ctx *ctx, struct lib9p_msg_Treaddir *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 23;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Treaddir",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Treaddir message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4264,10 +3924,9 @@ static bool marshal_Treaddir(struct lib9p_ctx *ctx, struct lib9p_msg_Treaddir *v
 static bool marshal_Rreaddir(struct lib9p_ctx *ctx, struct lib9p_msg_Rreaddir *val, struct _marshal_ret *ret) {
 	uint64_t needed_size = 11 + val->count;
 	if (needed_size > (uint64_t)(ctx->max_msg_size)) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu64" > %"PRIu32")",
-			"Rreaddir",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rreaddir message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = (uint32_t)needed_size;
@@ -4283,10 +3942,9 @@ static bool marshal_Rreaddir(struct lib9p_ctx *ctx, struct lib9p_msg_Rreaddir *v
 static bool marshal_Tfsync(struct lib9p_ctx *ctx, struct lib9p_msg_Tfsync *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 15;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tfsync",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tfsync message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4302,10 +3960,9 @@ static bool marshal_Tfsync(struct lib9p_ctx *ctx, struct lib9p_msg_Tfsync *val,
 static bool marshal_Rfsync(struct lib9p_ctx *ctx, struct lib9p_msg_Rfsync *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rfsync",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rfsync message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4319,10 +3976,9 @@ static bool marshal_Rfsync(struct lib9p_ctx *ctx, struct lib9p_msg_Rfsync *val,
 static bool marshal_Tlock(struct lib9p_ctx *ctx, struct lib9p_msg_Tlock *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 38 + val->client_id.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tlock",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tlock message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4344,10 +4000,9 @@ static bool marshal_Tlock(struct lib9p_ctx *ctx, struct lib9p_msg_Tlock *val, st
 static bool marshal_Rlock(struct lib9p_ctx *ctx, struct lib9p_msg_Rlock *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 8;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rlock",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rlock message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4362,10 +4017,9 @@ static bool marshal_Rlock(struct lib9p_ctx *ctx, struct lib9p_msg_Rlock *val, st
 static bool marshal_Tgetlock(struct lib9p_ctx *ctx, struct lib9p_msg_Tgetlock *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 34 + val->client_id.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tgetlock",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tgetlock message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4386,10 +4040,9 @@ static bool marshal_Tgetlock(struct lib9p_ctx *ctx, struct lib9p_msg_Tgetlock *v
 static bool marshal_Rgetlock(struct lib9p_ctx *ctx, struct lib9p_msg_Rgetlock *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 30 + val->client_id.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rgetlock",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rgetlock message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4409,10 +4062,9 @@ static bool marshal_Rgetlock(struct lib9p_ctx *ctx, struct lib9p_msg_Rgetlock *v
 static bool marshal_Tlink(struct lib9p_ctx *ctx, struct lib9p_msg_Tlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 17 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tlink",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4430,10 +4082,9 @@ static bool marshal_Tlink(struct lib9p_ctx *ctx, struct lib9p_msg_Tlink *val, st
 static bool marshal_Rlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rlink *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rlink",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rlink message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4447,10 +4098,9 @@ static bool marshal_Rlink(struct lib9p_ctx *ctx, struct lib9p_msg_Rlink *val, st
 static bool marshal_Tmkdir(struct lib9p_ctx *ctx, struct lib9p_msg_Tmkdir *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 21 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tmkdir",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tmkdir message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4469,10 +4119,9 @@ static bool marshal_Tmkdir(struct lib9p_ctx *ctx, struct lib9p_msg_Tmkdir *val,
 static bool marshal_Rmkdir(struct lib9p_ctx *ctx, struct lib9p_msg_Rmkdir *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 20;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rmkdir",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rmkdir message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4489,10 +4138,9 @@ static bool marshal_Rmkdir(struct lib9p_ctx *ctx, struct lib9p_msg_Rmkdir *val,
 static bool marshal_Trenameat(struct lib9p_ctx *ctx, struct lib9p_msg_Trenameat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 19 + val->oldname.len + val->newname.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Trenameat",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Trenameat message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4512,10 +4160,9 @@ static bool marshal_Trenameat(struct lib9p_ctx *ctx, struct lib9p_msg_Trenameat
 static bool marshal_Rrenameat(struct lib9p_ctx *ctx, struct lib9p_msg_Rrenameat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rrenameat",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rrenameat message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4529,10 +4176,9 @@ static bool marshal_Rrenameat(struct lib9p_ctx *ctx, struct lib9p_msg_Rrenameat
 static bool marshal_Tunlinkat(struct lib9p_ctx *ctx, struct lib9p_msg_Tunlinkat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 17 + val->name.len;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tunlinkat",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tunlinkat message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4550,10 +4196,9 @@ static bool marshal_Tunlinkat(struct lib9p_ctx *ctx, struct lib9p_msg_Tunlinkat
 static bool marshal_Runlinkat(struct lib9p_ctx *ctx, struct lib9p_msg_Runlinkat *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Runlinkat",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Runlinkat message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4569,10 +4214,9 @@ static bool marshal_Runlinkat(struct lib9p_ctx *ctx, struct lib9p_msg_Runlinkat
 static bool marshal_Tsession(struct lib9p_ctx *ctx, struct lib9p_msg_Tsession *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 15;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Tsession",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tsession message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4587,10 +4231,9 @@ static bool marshal_Tsession(struct lib9p_ctx *ctx, struct lib9p_msg_Tsession *v
 static bool marshal_Rsession(struct lib9p_ctx *ctx, struct lib9p_msg_Rsession *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 7;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rsession",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rsession message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4607,10 +4250,9 @@ static bool marshal_Tsread(struct lib9p_ctx *ctx, struct lib9p_msg_Tsread *val,
 		needed_size += 2 + val->wname[i].len;
 	}
 	if (needed_size > (uint64_t)(ctx->max_msg_size)) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu64" > %"PRIu32")",
-			"Tsread",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tsread message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = (uint32_t)needed_size;
@@ -4630,10 +4272,9 @@ static bool marshal_Tsread(struct lib9p_ctx *ctx, struct lib9p_msg_Tsread *val,
 static bool marshal_Rsread(struct lib9p_ctx *ctx, struct lib9p_msg_Rsread *val, struct _marshal_ret *ret) {
 	uint64_t needed_size = 11 + val->count;
 	if (needed_size > (uint64_t)(ctx->max_msg_size)) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu64" > %"PRIu32")",
-			"Rsread",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rsread message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = (uint32_t)needed_size;
@@ -4652,10 +4293,9 @@ static bool marshal_Tswrite(struct lib9p_ctx *ctx, struct lib9p_msg_Tswrite *val
 		needed_size += 2 + val->wname[i].len;
 	}
 	if (needed_size > (uint64_t)(ctx->max_msg_size)) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu64" > %"PRIu32")",
-			"Tswrite",
-			ctx->version ? "negotiated" : "client",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Tswrite message too large to marshal into ",
+			ctx->version ? "negotiated" : "client", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = (uint32_t)needed_size;
@@ -4677,10 +4317,9 @@ static bool marshal_Tswrite(struct lib9p_ctx *ctx, struct lib9p_msg_Tswrite *val
 static bool marshal_Rswrite(struct lib9p_ctx *ctx, struct lib9p_msg_Rswrite *val, struct _marshal_ret *ret) {
 	uint32_t needed_size = 11;
 	if (needed_size > ctx->max_msg_size) {
-		lib9p_errorf(ctx, LIB9P_ERRNO_L_ERANGE, "%s message too large to marshal into %s limit (%"PRIu32" > %"PRIu32")",
-			"Rswrite",
-			ctx->version ? "negotiated" : "server",
-			needed_size, ctx->max_msg_size);
+		lib9p_error(ctx, LIB9P_ERRNO_L_ERANGE, "Rswrite message too large to marshal into ",
+			ctx->version ? "negotiated" : "server", " limit",
+			" (", needed_size, " > ", ctx->max_msg_size, ")");
 		return true;
 	}
 	uint32_t offsetof_end = needed_size;
@@ -4693,3158 +4332,3152 @@ static bool marshal_Rswrite(struct lib9p_ctx *ctx, struct lib9p_msg_Rswrite *val
 }
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
 
-/* *_format *******************************************************************/
+/* fmt_print_* ****************************************************************/
 
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-static void lib9p_tag_format(lib9p_tag_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_tag(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_tag_t *self) {
 	switch (*self) {
 	case LIB9P_TAG_NOTAG:
-		fmt_state_puts(state, "NOTAG");
+		fmt_print_str(w, "NOTAG");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu16, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_fid_format(lib9p_fid_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_fid(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_fid_t *self) {
 	switch (*self) {
 	case LIB9P_FID_NOFID:
-		fmt_state_puts(state, "NOFID");
+		fmt_print_str(w, "NOFID");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu32, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_s_format(struct lib9p_s *self, struct fmt_state *state) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-	fmt_state_printf(state, "%.*q", self->len, self->utf8);
-#pragma GCC diagnostic pop
-}
-
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-static void lib9p_dm_format(lib9p_dm_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_dm(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_dm_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DIR");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DIR");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "APPEND");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "APPEND");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "EXCL");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "EXCL");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "_PLAN9_MOUNT");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "_PLAN9_MOUNT");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "AUTH");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "AUTH");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "TMP");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "TMP");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DEVICE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DEVICE");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PIPE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PIPE");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SOCKET");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SOCKET");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SETUID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SETUID");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SETGID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SETGID");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<17");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<17");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<16");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<16");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<15)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<15");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<15");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<14)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<14");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<14");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<13)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<13");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<13");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<12)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<12");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<12");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<11");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<11");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<10");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<10");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<9");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<9");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OWNER_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OWNER_R");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OWNER_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OWNER_W");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OWNER_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OWNER_X");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GROUP_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GROUP_R");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GROUP_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GROUP_W");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GROUP_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GROUP_X");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OTHER_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OTHER_R");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OTHER_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OTHER_W");
 		empty = false;
 	}
 	if ((*self & ~((lib9p_dm_t)0777)) & (UINT32_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "OTHER_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "OTHER_X");
 		empty = false;
 	}
 	if (!empty)
-		fmt_state_putchar(state, '|');
-	fmt_state_printf(state, "%#04"PRIo32, *self & 0777);
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '|');
+	fmt_print(w, (rjust, 4, '0', (base8, *self & 0777)));
+	fmt_print_byte(w, ')');
 }
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-static void lib9p_qt_format(lib9p_qt_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_qt(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_qt_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT8_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DIR");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DIR");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "APPEND");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "APPEND");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "EXCL");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "EXCL");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "_PLAN9_MOUNT");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "_PLAN9_MOUNT");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "AUTH");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "AUTH");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "TMP");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "TMP");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SYMLINK");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SYMLINK");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<0");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<0");
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
-}
-
-static void lib9p_qid_format(struct lib9p_qid *self, struct fmt_state *state) {
-	fmt_state_putchar(state, '{');
-	fmt_state_puts(state, " type=");
-	lib9p_qt_format(&self->type, state);
-	fmt_state_puts(state, " vers=");
-	fmt_state_printf(state, "%"PRIu32, self->vers);
-	fmt_state_puts(state, " path=");
-	fmt_state_printf(state, "%"PRIu64, self->path);
-	fmt_state_puts(state, " }");
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_stat_format(struct lib9p_stat *self, struct fmt_state *state) {
-	fmt_state_putchar(state, '{');
-	fmt_state_puts(state, " fstype=");
-	fmt_state_printf(state, "%"PRIu16, self->fstype);
-	fmt_state_puts(state, " fsdev=");
-	fmt_state_printf(state, "%"PRIu32, self->fsdev);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_dm_format(&self->mode, state);
-	fmt_state_puts(state, " atime=");
-	fmt_state_printf(state, "%"PRIu32, self->atime);
-	fmt_state_puts(state, " mtime=");
-	fmt_state_printf(state, "%"PRIu32, self->mtime);
-	fmt_state_puts(state, " length=");
-	fmt_state_printf(state, "%"PRIu64, self->length);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " owner_uname=");
-	lib9p_s_format(&self->owner_uname, state);
-	fmt_state_puts(state, " owner_gname=");
-	lib9p_s_format(&self->owner_gname, state);
-	fmt_state_puts(state, " last_modifier_uname=");
-	lib9p_s_format(&self->last_modifier_uname, state);
-#if CONFIG_9P_ENABLE_9P2000_u
-	fmt_state_puts(state, " extension=");
-	lib9p_s_format(&self->extension, state);
-	fmt_state_puts(state, " owner_unum=");
-	lib9p_nuid_format(&self->owner_unum, state);
-	fmt_state_puts(state, " owner_gnum=");
-	lib9p_nuid_format(&self->owner_gnum, state);
-	fmt_state_puts(state, " last_modifier_unum=");
-	lib9p_nuid_format(&self->last_modifier_unum, state);
-#endif /* CONFIG_9P_ENABLE_9P2000_u */
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_o_format(lib9p_o_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_o(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_o_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT8_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<7");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<7");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "RCLOSE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "RCLOSE");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "CEXEC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "CEXEC");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "TRUNC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "TRUNC");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<3");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<3");
 		empty = false;
 	}
 	if (*self & (UINT8_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<2");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<2");
 		empty = false;
 	}
 	switch (*self & LIB9P_O_MODE_MASK) {
 	case LIB9P_O_MODE_READ:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_READ");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_READ");
 		empty = false;
 		break;
 	case LIB9P_O_MODE_WRITE:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_WRITE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_WRITE");
 		empty = false;
 		break;
 	case LIB9P_O_MODE_RDWR:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_RDWR");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_RDWR");
 		empty = false;
 		break;
 	case LIB9P_O_MODE_EXEC:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_EXEC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_EXEC");
 		empty = false;
 		break;
 	default:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_printf(state, "%"PRIu8, *self & LIB9P_O_MODE_MASK);
+			fmt_print_byte(w, '|');
+		fmt_print_base10(w, *self & LIB9P_O_MODE_MASK);
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-static void lib9p_msg_Tversion_format(struct lib9p_msg_Tversion *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tversion {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " max_msg_size=");
-	fmt_state_printf(state, "%"PRIu32, self->max_msg_size);
-	fmt_state_puts(state, " version=");
-	lib9p_s_format(&self->version, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rversion_format(struct lib9p_msg_Rversion *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rversion {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " max_msg_size=");
-	fmt_state_printf(state, "%"PRIu32, self->max_msg_size);
-	fmt_state_puts(state, " version=");
-	lib9p_s_format(&self->version, state);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_msg_Tauth_format(struct lib9p_msg_Tauth *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tauth {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " afid=");
-	lib9p_fid_format(&self->afid, state);
-	fmt_state_puts(state, " uname=");
-	lib9p_s_format(&self->uname, state);
-	fmt_state_puts(state, " aname=");
-	lib9p_s_format(&self->aname, state);
 #if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
-	fmt_state_puts(state, " unum=");
-	lib9p_nuid_format(&self->unum, state);
-#endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rauth_format(struct lib9p_msg_Rauth *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rauth {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " aqid=");
-	lib9p_qid_format(&self->aqid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tattach_format(struct lib9p_msg_Tattach *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tattach {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " afid=");
-	lib9p_fid_format(&self->afid, state);
-	fmt_state_puts(state, " uname=");
-	lib9p_s_format(&self->uname, state);
-	fmt_state_puts(state, " aname=");
-	lib9p_s_format(&self->aname, state);
-#if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
-	fmt_state_puts(state, " unum=");
-	lib9p_nuid_format(&self->unum, state);
-#endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rattach_format(struct lib9p_msg_Rattach *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rattach {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
-static void lib9p_msg_Rerror_format(struct lib9p_msg_Rerror *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rerror {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " errstr=");
-	lib9p_s_format(&self->errstr, state);
-#if CONFIG_9P_ENABLE_9P2000_u
-	fmt_state_puts(state, " errnum=");
-	lib9p_errno_format(&self->errnum, state);
-#endif /* CONFIG_9P_ENABLE_9P2000_u */
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_msg_Tflush_format(struct lib9p_msg_Tflush *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tflush {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " oldtag=");
-	fmt_state_printf(state, "%"PRIu16, self->oldtag);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rflush_format(struct lib9p_msg_Rflush *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rflush {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Twalk_format(struct lib9p_msg_Twalk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Twalk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " newfid=");
-	lib9p_fid_format(&self->newfid, state);
-	fmt_state_puts(state, " nwname=");
-	fmt_state_printf(state, "%"PRIu16, self->nwname);
-	fmt_state_puts(state, " wname=[");
-	for (uint16_t i = 0; i < self->nwname; i++) {
-		if (i)
-			fmt_state_putchar(state, ',');
-		fmt_state_putchar(state, ' ');
-		lib9p_s_format(&self->wname[i], state);
-	}
-	fmt_state_puts(state, " ]");
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rwalk_format(struct lib9p_msg_Rwalk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rwalk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " nwqid=");
-	fmt_state_printf(state, "%"PRIu16, self->nwqid);
-	fmt_state_puts(state, " wqid=[");
-	for (uint16_t i = 0; i < self->nwqid; i++) {
-		if (i)
-			fmt_state_putchar(state, ',');
-		fmt_state_putchar(state, ' ');
-		lib9p_qid_format(&self->wqid[i], state);
-	}
-	fmt_state_puts(state, " ]");
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_msg_Topen_format(struct lib9p_msg_Topen *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Topen {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_o_format(&self->mode, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Ropen_format(struct lib9p_msg_Ropen *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Ropen {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " iounit=");
-	fmt_state_printf(state, "%"PRIu32, self->iounit);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tcreate_format(struct lib9p_msg_Tcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " perm=");
-	lib9p_dm_format(&self->perm, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_o_format(&self->mode, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rcreate_format(struct lib9p_msg_Rcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " iounit=");
-	fmt_state_printf(state, "%"PRIu32, self->iounit);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_msg_Tread_format(struct lib9p_msg_Tread *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tread {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " offset=");
-	fmt_state_printf(state, "%"PRIu64, self->offset);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rread_format(struct lib9p_msg_Rread *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rread {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-		fmt_state_printf(state, " data=%.*q%s",
-			(int)(self->count < 50 ? self->count : 50),
-			(char *)self->data,
-			self->count < 50 ? "" : "...");
-#pragma GCC diagnostic pop
-	} else {
-		fmt_state_puts(state, " data=<bytedata>");
-	}
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Twrite_format(struct lib9p_msg_Twrite *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Twrite {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " offset=");
-	fmt_state_printf(state, "%"PRIu64, self->offset);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-		fmt_state_printf(state, " data=%.*q%s",
-			(int)(self->count < 50 ? self->count : 50),
-			(char *)self->data,
-			self->count < 50 ? "" : "...");
-#pragma GCC diagnostic pop
-	} else {
-		fmt_state_puts(state, " data=<bytedata>");
-	}
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rwrite_format(struct lib9p_msg_Rwrite *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rwrite {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tclunk_format(struct lib9p_msg_Tclunk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tclunk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rclunk_format(struct lib9p_msg_Rclunk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rclunk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tremove_format(struct lib9p_msg_Tremove *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tremove {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rremove_format(struct lib9p_msg_Rremove *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rremove {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_msg_Tstat_format(struct lib9p_msg_Tstat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tstat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rstat_format(struct lib9p_msg_Rstat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rstat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " stat=");
-	lib9p_stat_format(&self->stat, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Twstat_format(struct lib9p_msg_Twstat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Twstat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " stat=");
-	lib9p_stat_format(&self->stat, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rwstat_format(struct lib9p_msg_Rwstat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rwstat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
-#if CONFIG_9P_ENABLE_9P2000_p9p
-static void lib9p_msg_Topenfd_format(struct lib9p_msg_Topenfd *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Topenfd {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_o_format(&self->mode, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Ropenfd_format(struct lib9p_msg_Ropenfd *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Ropenfd {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " iounit=");
-	fmt_state_printf(state, "%"PRIu32, self->iounit);
-	fmt_state_puts(state, " unixfd=");
-	fmt_state_printf(state, "%"PRIu32, self->unixfd);
-	fmt_state_puts(state, " }");
-}
-
-#endif /* CONFIG_9P_ENABLE_9P2000_p9p */
-#if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
-static void lib9p_nuid_format(lib9p_nuid_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_nuid(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_nuid_t *self) {
 	switch (*self) {
 	case LIB9P_NUID_NONUID:
-		fmt_state_puts(state, "NONUID");
+		fmt_print_str(w, "NONUID");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu32, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_errno_format(lib9p_errno_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_errno(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_errno_t *self) {
 	switch (*self) {
 	case LIB9P_ERRNO_NOERROR:
-		fmt_state_puts(state, "NOERROR");
+		fmt_print_str(w, "NOERROR");
 		break;
 	case LIB9P_ERRNO_L_EPERM:
-		fmt_state_puts(state, "L_EPERM");
+		fmt_print_str(w, "L_EPERM");
 		break;
 	case LIB9P_ERRNO_L_ENOENT:
-		fmt_state_puts(state, "L_ENOENT");
+		fmt_print_str(w, "L_ENOENT");
 		break;
 	case LIB9P_ERRNO_L_ESRCH:
-		fmt_state_puts(state, "L_ESRCH");
+		fmt_print_str(w, "L_ESRCH");
 		break;
 	case LIB9P_ERRNO_L_EINTR:
-		fmt_state_puts(state, "L_EINTR");
+		fmt_print_str(w, "L_EINTR");
 		break;
 	case LIB9P_ERRNO_L_EIO:
-		fmt_state_puts(state, "L_EIO");
+		fmt_print_str(w, "L_EIO");
 		break;
 	case LIB9P_ERRNO_L_ENXIO:
-		fmt_state_puts(state, "L_ENXIO");
+		fmt_print_str(w, "L_ENXIO");
 		break;
 	case LIB9P_ERRNO_L_E2BIG:
-		fmt_state_puts(state, "L_E2BIG");
+		fmt_print_str(w, "L_E2BIG");
 		break;
 	case LIB9P_ERRNO_L_ENOEXEC:
-		fmt_state_puts(state, "L_ENOEXEC");
+		fmt_print_str(w, "L_ENOEXEC");
 		break;
 	case LIB9P_ERRNO_L_EBADF:
-		fmt_state_puts(state, "L_EBADF");
+		fmt_print_str(w, "L_EBADF");
 		break;
 	case LIB9P_ERRNO_L_ECHILD:
-		fmt_state_puts(state, "L_ECHILD");
+		fmt_print_str(w, "L_ECHILD");
 		break;
 	case LIB9P_ERRNO_L_EAGAIN:
-		fmt_state_puts(state, "L_EAGAIN");
+		fmt_print_str(w, "L_EAGAIN");
 		break;
 	case LIB9P_ERRNO_L_ENOMEM:
-		fmt_state_puts(state, "L_ENOMEM");
+		fmt_print_str(w, "L_ENOMEM");
 		break;
 	case LIB9P_ERRNO_L_EACCES:
-		fmt_state_puts(state, "L_EACCES");
+		fmt_print_str(w, "L_EACCES");
 		break;
 	case LIB9P_ERRNO_L_EFAULT:
-		fmt_state_puts(state, "L_EFAULT");
+		fmt_print_str(w, "L_EFAULT");
 		break;
 	case LIB9P_ERRNO_L_ENOTBLK:
-		fmt_state_puts(state, "L_ENOTBLK");
+		fmt_print_str(w, "L_ENOTBLK");
 		break;
 	case LIB9P_ERRNO_L_EBUSY:
-		fmt_state_puts(state, "L_EBUSY");
+		fmt_print_str(w, "L_EBUSY");
 		break;
 	case LIB9P_ERRNO_L_EEXIST:
-		fmt_state_puts(state, "L_EEXIST");
+		fmt_print_str(w, "L_EEXIST");
 		break;
 	case LIB9P_ERRNO_L_EXDEV:
-		fmt_state_puts(state, "L_EXDEV");
+		fmt_print_str(w, "L_EXDEV");
 		break;
 	case LIB9P_ERRNO_L_ENODEV:
-		fmt_state_puts(state, "L_ENODEV");
+		fmt_print_str(w, "L_ENODEV");
 		break;
 	case LIB9P_ERRNO_L_ENOTDIR:
-		fmt_state_puts(state, "L_ENOTDIR");
+		fmt_print_str(w, "L_ENOTDIR");
 		break;
 	case LIB9P_ERRNO_L_EISDIR:
-		fmt_state_puts(state, "L_EISDIR");
+		fmt_print_str(w, "L_EISDIR");
 		break;
 	case LIB9P_ERRNO_L_EINVAL:
-		fmt_state_puts(state, "L_EINVAL");
+		fmt_print_str(w, "L_EINVAL");
 		break;
 	case LIB9P_ERRNO_L_ENFILE:
-		fmt_state_puts(state, "L_ENFILE");
+		fmt_print_str(w, "L_ENFILE");
 		break;
 	case LIB9P_ERRNO_L_EMFILE:
-		fmt_state_puts(state, "L_EMFILE");
+		fmt_print_str(w, "L_EMFILE");
 		break;
 	case LIB9P_ERRNO_L_ENOTTY:
-		fmt_state_puts(state, "L_ENOTTY");
+		fmt_print_str(w, "L_ENOTTY");
 		break;
 	case LIB9P_ERRNO_L_ETXTBSY:
-		fmt_state_puts(state, "L_ETXTBSY");
+		fmt_print_str(w, "L_ETXTBSY");
 		break;
 	case LIB9P_ERRNO_L_EFBIG:
-		fmt_state_puts(state, "L_EFBIG");
+		fmt_print_str(w, "L_EFBIG");
 		break;
 	case LIB9P_ERRNO_L_ENOSPC:
-		fmt_state_puts(state, "L_ENOSPC");
+		fmt_print_str(w, "L_ENOSPC");
 		break;
 	case LIB9P_ERRNO_L_ESPIPE:
-		fmt_state_puts(state, "L_ESPIPE");
+		fmt_print_str(w, "L_ESPIPE");
 		break;
 	case LIB9P_ERRNO_L_EROFS:
-		fmt_state_puts(state, "L_EROFS");
+		fmt_print_str(w, "L_EROFS");
 		break;
 	case LIB9P_ERRNO_L_EMLINK:
-		fmt_state_puts(state, "L_EMLINK");
+		fmt_print_str(w, "L_EMLINK");
 		break;
 	case LIB9P_ERRNO_L_EPIPE:
-		fmt_state_puts(state, "L_EPIPE");
+		fmt_print_str(w, "L_EPIPE");
 		break;
 	case LIB9P_ERRNO_L_EDOM:
-		fmt_state_puts(state, "L_EDOM");
+		fmt_print_str(w, "L_EDOM");
 		break;
 	case LIB9P_ERRNO_L_ERANGE:
-		fmt_state_puts(state, "L_ERANGE");
+		fmt_print_str(w, "L_ERANGE");
 		break;
 	case LIB9P_ERRNO_L_EDEADLK:
-		fmt_state_puts(state, "L_EDEADLK");
+		fmt_print_str(w, "L_EDEADLK");
 		break;
 	case LIB9P_ERRNO_L_ENAMETOOLONG:
-		fmt_state_puts(state, "L_ENAMETOOLONG");
+		fmt_print_str(w, "L_ENAMETOOLONG");
 		break;
 	case LIB9P_ERRNO_L_ENOLCK:
-		fmt_state_puts(state, "L_ENOLCK");
+		fmt_print_str(w, "L_ENOLCK");
 		break;
 	case LIB9P_ERRNO_L_ENOSYS:
-		fmt_state_puts(state, "L_ENOSYS");
+		fmt_print_str(w, "L_ENOSYS");
 		break;
 	case LIB9P_ERRNO_L_ENOTEMPTY:
-		fmt_state_puts(state, "L_ENOTEMPTY");
+		fmt_print_str(w, "L_ENOTEMPTY");
 		break;
 	case LIB9P_ERRNO_L_ELOOP:
-		fmt_state_puts(state, "L_ELOOP");
+		fmt_print_str(w, "L_ELOOP");
 		break;
 	case LIB9P_ERRNO_L_ENOMSG:
-		fmt_state_puts(state, "L_ENOMSG");
+		fmt_print_str(w, "L_ENOMSG");
 		break;
 	case LIB9P_ERRNO_L_EIDRM:
-		fmt_state_puts(state, "L_EIDRM");
+		fmt_print_str(w, "L_EIDRM");
 		break;
 	case LIB9P_ERRNO_L_ECHRNG:
-		fmt_state_puts(state, "L_ECHRNG");
+		fmt_print_str(w, "L_ECHRNG");
 		break;
 	case LIB9P_ERRNO_L_EL2NSYNC:
-		fmt_state_puts(state, "L_EL2NSYNC");
+		fmt_print_str(w, "L_EL2NSYNC");
 		break;
 	case LIB9P_ERRNO_L_EL3HLT:
-		fmt_state_puts(state, "L_EL3HLT");
+		fmt_print_str(w, "L_EL3HLT");
 		break;
 	case LIB9P_ERRNO_L_EL3RST:
-		fmt_state_puts(state, "L_EL3RST");
+		fmt_print_str(w, "L_EL3RST");
 		break;
 	case LIB9P_ERRNO_L_ELNRNG:
-		fmt_state_puts(state, "L_ELNRNG");
+		fmt_print_str(w, "L_ELNRNG");
 		break;
 	case LIB9P_ERRNO_L_EUNATCH:
-		fmt_state_puts(state, "L_EUNATCH");
+		fmt_print_str(w, "L_EUNATCH");
 		break;
 	case LIB9P_ERRNO_L_ENOCSI:
-		fmt_state_puts(state, "L_ENOCSI");
+		fmt_print_str(w, "L_ENOCSI");
 		break;
 	case LIB9P_ERRNO_L_EL2HLT:
-		fmt_state_puts(state, "L_EL2HLT");
+		fmt_print_str(w, "L_EL2HLT");
 		break;
 	case LIB9P_ERRNO_L_EBADE:
-		fmt_state_puts(state, "L_EBADE");
+		fmt_print_str(w, "L_EBADE");
 		break;
 	case LIB9P_ERRNO_L_EBADR:
-		fmt_state_puts(state, "L_EBADR");
+		fmt_print_str(w, "L_EBADR");
 		break;
 	case LIB9P_ERRNO_L_EXFULL:
-		fmt_state_puts(state, "L_EXFULL");
+		fmt_print_str(w, "L_EXFULL");
 		break;
 	case LIB9P_ERRNO_L_ENOANO:
-		fmt_state_puts(state, "L_ENOANO");
+		fmt_print_str(w, "L_ENOANO");
 		break;
 	case LIB9P_ERRNO_L_EBADRQC:
-		fmt_state_puts(state, "L_EBADRQC");
+		fmt_print_str(w, "L_EBADRQC");
 		break;
 	case LIB9P_ERRNO_L_EBADSLT:
-		fmt_state_puts(state, "L_EBADSLT");
+		fmt_print_str(w, "L_EBADSLT");
 		break;
 	case LIB9P_ERRNO_L_EBFONT:
-		fmt_state_puts(state, "L_EBFONT");
+		fmt_print_str(w, "L_EBFONT");
 		break;
 	case LIB9P_ERRNO_L_ENOSTR:
-		fmt_state_puts(state, "L_ENOSTR");
+		fmt_print_str(w, "L_ENOSTR");
 		break;
 	case LIB9P_ERRNO_L_ENODATA:
-		fmt_state_puts(state, "L_ENODATA");
+		fmt_print_str(w, "L_ENODATA");
 		break;
 	case LIB9P_ERRNO_L_ETIME:
-		fmt_state_puts(state, "L_ETIME");
+		fmt_print_str(w, "L_ETIME");
 		break;
 	case LIB9P_ERRNO_L_ENOSR:
-		fmt_state_puts(state, "L_ENOSR");
+		fmt_print_str(w, "L_ENOSR");
 		break;
 	case LIB9P_ERRNO_L_ENONET:
-		fmt_state_puts(state, "L_ENONET");
+		fmt_print_str(w, "L_ENONET");
 		break;
 	case LIB9P_ERRNO_L_ENOPKG:
-		fmt_state_puts(state, "L_ENOPKG");
+		fmt_print_str(w, "L_ENOPKG");
 		break;
 	case LIB9P_ERRNO_L_EREMOTE:
-		fmt_state_puts(state, "L_EREMOTE");
+		fmt_print_str(w, "L_EREMOTE");
 		break;
 	case LIB9P_ERRNO_L_ENOLINK:
-		fmt_state_puts(state, "L_ENOLINK");
+		fmt_print_str(w, "L_ENOLINK");
 		break;
 	case LIB9P_ERRNO_L_EADV:
-		fmt_state_puts(state, "L_EADV");
+		fmt_print_str(w, "L_EADV");
 		break;
 	case LIB9P_ERRNO_L_ESRMNT:
-		fmt_state_puts(state, "L_ESRMNT");
+		fmt_print_str(w, "L_ESRMNT");
 		break;
 	case LIB9P_ERRNO_L_ECOMM:
-		fmt_state_puts(state, "L_ECOMM");
+		fmt_print_str(w, "L_ECOMM");
 		break;
 	case LIB9P_ERRNO_L_EPROTO:
-		fmt_state_puts(state, "L_EPROTO");
+		fmt_print_str(w, "L_EPROTO");
 		break;
 	case LIB9P_ERRNO_L_EMULTIHOP:
-		fmt_state_puts(state, "L_EMULTIHOP");
+		fmt_print_str(w, "L_EMULTIHOP");
 		break;
 	case LIB9P_ERRNO_L_EDOTDOT:
-		fmt_state_puts(state, "L_EDOTDOT");
+		fmt_print_str(w, "L_EDOTDOT");
 		break;
 	case LIB9P_ERRNO_L_EBADMSG:
-		fmt_state_puts(state, "L_EBADMSG");
+		fmt_print_str(w, "L_EBADMSG");
 		break;
 	case LIB9P_ERRNO_L_EOVERFLOW:
-		fmt_state_puts(state, "L_EOVERFLOW");
+		fmt_print_str(w, "L_EOVERFLOW");
 		break;
 	case LIB9P_ERRNO_L_ENOTUNIQ:
-		fmt_state_puts(state, "L_ENOTUNIQ");
+		fmt_print_str(w, "L_ENOTUNIQ");
 		break;
 	case LIB9P_ERRNO_L_EBADFD:
-		fmt_state_puts(state, "L_EBADFD");
+		fmt_print_str(w, "L_EBADFD");
 		break;
 	case LIB9P_ERRNO_L_EREMCHG:
-		fmt_state_puts(state, "L_EREMCHG");
+		fmt_print_str(w, "L_EREMCHG");
 		break;
 	case LIB9P_ERRNO_L_ELIBACC:
-		fmt_state_puts(state, "L_ELIBACC");
+		fmt_print_str(w, "L_ELIBACC");
 		break;
 	case LIB9P_ERRNO_L_ELIBBAD:
-		fmt_state_puts(state, "L_ELIBBAD");
+		fmt_print_str(w, "L_ELIBBAD");
 		break;
 	case LIB9P_ERRNO_L_ELIBSCN:
-		fmt_state_puts(state, "L_ELIBSCN");
+		fmt_print_str(w, "L_ELIBSCN");
 		break;
 	case LIB9P_ERRNO_L_ELIBMAX:
-		fmt_state_puts(state, "L_ELIBMAX");
+		fmt_print_str(w, "L_ELIBMAX");
 		break;
 	case LIB9P_ERRNO_L_ELIBEXEC:
-		fmt_state_puts(state, "L_ELIBEXEC");
+		fmt_print_str(w, "L_ELIBEXEC");
 		break;
 	case LIB9P_ERRNO_L_EILSEQ:
-		fmt_state_puts(state, "L_EILSEQ");
+		fmt_print_str(w, "L_EILSEQ");
 		break;
 	case LIB9P_ERRNO_L_ERESTART:
-		fmt_state_puts(state, "L_ERESTART");
+		fmt_print_str(w, "L_ERESTART");
 		break;
 	case LIB9P_ERRNO_L_ESTRPIPE:
-		fmt_state_puts(state, "L_ESTRPIPE");
+		fmt_print_str(w, "L_ESTRPIPE");
 		break;
 	case LIB9P_ERRNO_L_EUSERS:
-		fmt_state_puts(state, "L_EUSERS");
+		fmt_print_str(w, "L_EUSERS");
 		break;
 	case LIB9P_ERRNO_L_ENOTSOCK:
-		fmt_state_puts(state, "L_ENOTSOCK");
+		fmt_print_str(w, "L_ENOTSOCK");
 		break;
 	case LIB9P_ERRNO_L_EDESTADDRREQ:
-		fmt_state_puts(state, "L_EDESTADDRREQ");
+		fmt_print_str(w, "L_EDESTADDRREQ");
 		break;
 	case LIB9P_ERRNO_L_EMSGSIZE:
-		fmt_state_puts(state, "L_EMSGSIZE");
+		fmt_print_str(w, "L_EMSGSIZE");
 		break;
 	case LIB9P_ERRNO_L_EPROTOTYPE:
-		fmt_state_puts(state, "L_EPROTOTYPE");
+		fmt_print_str(w, "L_EPROTOTYPE");
 		break;
 	case LIB9P_ERRNO_L_ENOPROTOOPT:
-		fmt_state_puts(state, "L_ENOPROTOOPT");
+		fmt_print_str(w, "L_ENOPROTOOPT");
 		break;
 	case LIB9P_ERRNO_L_EPROTONOSUPPORT:
-		fmt_state_puts(state, "L_EPROTONOSUPPORT");
+		fmt_print_str(w, "L_EPROTONOSUPPORT");
 		break;
 	case LIB9P_ERRNO_L_ESOCKTNOSUPPORT:
-		fmt_state_puts(state, "L_ESOCKTNOSUPPORT");
+		fmt_print_str(w, "L_ESOCKTNOSUPPORT");
 		break;
 	case LIB9P_ERRNO_L_EOPNOTSUPP:
-		fmt_state_puts(state, "L_EOPNOTSUPP");
+		fmt_print_str(w, "L_EOPNOTSUPP");
 		break;
 	case LIB9P_ERRNO_L_EPFNOSUPPORT:
-		fmt_state_puts(state, "L_EPFNOSUPPORT");
+		fmt_print_str(w, "L_EPFNOSUPPORT");
 		break;
 	case LIB9P_ERRNO_L_EAFNOSUPPORT:
-		fmt_state_puts(state, "L_EAFNOSUPPORT");
+		fmt_print_str(w, "L_EAFNOSUPPORT");
 		break;
 	case LIB9P_ERRNO_L_EADDRINUSE:
-		fmt_state_puts(state, "L_EADDRINUSE");
+		fmt_print_str(w, "L_EADDRINUSE");
 		break;
 	case LIB9P_ERRNO_L_EADDRNOTAVAIL:
-		fmt_state_puts(state, "L_EADDRNOTAVAIL");
+		fmt_print_str(w, "L_EADDRNOTAVAIL");
 		break;
 	case LIB9P_ERRNO_L_ENETDOWN:
-		fmt_state_puts(state, "L_ENETDOWN");
+		fmt_print_str(w, "L_ENETDOWN");
 		break;
 	case LIB9P_ERRNO_L_ENETUNREACH:
-		fmt_state_puts(state, "L_ENETUNREACH");
+		fmt_print_str(w, "L_ENETUNREACH");
 		break;
 	case LIB9P_ERRNO_L_ENETRESET:
-		fmt_state_puts(state, "L_ENETRESET");
+		fmt_print_str(w, "L_ENETRESET");
 		break;
 	case LIB9P_ERRNO_L_ECONNABORTED:
-		fmt_state_puts(state, "L_ECONNABORTED");
+		fmt_print_str(w, "L_ECONNABORTED");
 		break;
 	case LIB9P_ERRNO_L_ECONNRESET:
-		fmt_state_puts(state, "L_ECONNRESET");
+		fmt_print_str(w, "L_ECONNRESET");
 		break;
 	case LIB9P_ERRNO_L_ENOBUFS:
-		fmt_state_puts(state, "L_ENOBUFS");
+		fmt_print_str(w, "L_ENOBUFS");
 		break;
 	case LIB9P_ERRNO_L_EISCONN:
-		fmt_state_puts(state, "L_EISCONN");
+		fmt_print_str(w, "L_EISCONN");
 		break;
 	case LIB9P_ERRNO_L_ENOTCONN:
-		fmt_state_puts(state, "L_ENOTCONN");
+		fmt_print_str(w, "L_ENOTCONN");
 		break;
 	case LIB9P_ERRNO_L_ESHUTDOWN:
-		fmt_state_puts(state, "L_ESHUTDOWN");
+		fmt_print_str(w, "L_ESHUTDOWN");
 		break;
 	case LIB9P_ERRNO_L_ETOOMANYREFS:
-		fmt_state_puts(state, "L_ETOOMANYREFS");
+		fmt_print_str(w, "L_ETOOMANYREFS");
 		break;
 	case LIB9P_ERRNO_L_ETIMEDOUT:
-		fmt_state_puts(state, "L_ETIMEDOUT");
+		fmt_print_str(w, "L_ETIMEDOUT");
 		break;
 	case LIB9P_ERRNO_L_ECONNREFUSED:
-		fmt_state_puts(state, "L_ECONNREFUSED");
+		fmt_print_str(w, "L_ECONNREFUSED");
 		break;
 	case LIB9P_ERRNO_L_EHOSTDOWN:
-		fmt_state_puts(state, "L_EHOSTDOWN");
+		fmt_print_str(w, "L_EHOSTDOWN");
 		break;
 	case LIB9P_ERRNO_L_EHOSTUNREACH:
-		fmt_state_puts(state, "L_EHOSTUNREACH");
+		fmt_print_str(w, "L_EHOSTUNREACH");
 		break;
 	case LIB9P_ERRNO_L_EALREADY:
-		fmt_state_puts(state, "L_EALREADY");
+		fmt_print_str(w, "L_EALREADY");
 		break;
 	case LIB9P_ERRNO_L_EINPROGRESS:
-		fmt_state_puts(state, "L_EINPROGRESS");
+		fmt_print_str(w, "L_EINPROGRESS");
 		break;
 	case LIB9P_ERRNO_L_ESTALE:
-		fmt_state_puts(state, "L_ESTALE");
+		fmt_print_str(w, "L_ESTALE");
 		break;
 	case LIB9P_ERRNO_L_EUCLEAN:
-		fmt_state_puts(state, "L_EUCLEAN");
+		fmt_print_str(w, "L_EUCLEAN");
 		break;
 	case LIB9P_ERRNO_L_ENOTNAM:
-		fmt_state_puts(state, "L_ENOTNAM");
+		fmt_print_str(w, "L_ENOTNAM");
 		break;
 	case LIB9P_ERRNO_L_ENAVAIL:
-		fmt_state_puts(state, "L_ENAVAIL");
+		fmt_print_str(w, "L_ENAVAIL");
 		break;
 	case LIB9P_ERRNO_L_EISNAM:
-		fmt_state_puts(state, "L_EISNAM");
+		fmt_print_str(w, "L_EISNAM");
 		break;
 	case LIB9P_ERRNO_L_EREMOTEIO:
-		fmt_state_puts(state, "L_EREMOTEIO");
+		fmt_print_str(w, "L_EREMOTEIO");
 		break;
 	case LIB9P_ERRNO_L_EDQUOT:
-		fmt_state_puts(state, "L_EDQUOT");
+		fmt_print_str(w, "L_EDQUOT");
 		break;
 	case LIB9P_ERRNO_L_ENOMEDIUM:
-		fmt_state_puts(state, "L_ENOMEDIUM");
+		fmt_print_str(w, "L_ENOMEDIUM");
 		break;
 	case LIB9P_ERRNO_L_EMEDIUMTYPE:
-		fmt_state_puts(state, "L_EMEDIUMTYPE");
+		fmt_print_str(w, "L_EMEDIUMTYPE");
 		break;
 	case LIB9P_ERRNO_L_ECANCELED:
-		fmt_state_puts(state, "L_ECANCELED");
+		fmt_print_str(w, "L_ECANCELED");
 		break;
 	case LIB9P_ERRNO_L_ENOKEY:
-		fmt_state_puts(state, "L_ENOKEY");
+		fmt_print_str(w, "L_ENOKEY");
 		break;
 	case LIB9P_ERRNO_L_EKEYEXPIRED:
-		fmt_state_puts(state, "L_EKEYEXPIRED");
+		fmt_print_str(w, "L_EKEYEXPIRED");
 		break;
 	case LIB9P_ERRNO_L_EKEYREVOKED:
-		fmt_state_puts(state, "L_EKEYREVOKED");
+		fmt_print_str(w, "L_EKEYREVOKED");
 		break;
 	case LIB9P_ERRNO_L_EKEYREJECTED:
-		fmt_state_puts(state, "L_EKEYREJECTED");
+		fmt_print_str(w, "L_EKEYREJECTED");
 		break;
 	case LIB9P_ERRNO_L_EOWNERDEAD:
-		fmt_state_puts(state, "L_EOWNERDEAD");
+		fmt_print_str(w, "L_EOWNERDEAD");
 		break;
 	case LIB9P_ERRNO_L_ENOTRECOVERABLE:
-		fmt_state_puts(state, "L_ENOTRECOVERABLE");
+		fmt_print_str(w, "L_ENOTRECOVERABLE");
 		break;
 	case LIB9P_ERRNO_L_ERFKILL:
-		fmt_state_puts(state, "L_ERFKILL");
+		fmt_print_str(w, "L_ERFKILL");
 		break;
 	case LIB9P_ERRNO_L_EHWPOISON:
-		fmt_state_puts(state, "L_EHWPOISON");
+		fmt_print_str(w, "L_EHWPOISON");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu32, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000_L
-static void lib9p_super_magic_format(lib9p_super_magic_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_super_magic(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_super_magic_t *self) {
 	switch (*self) {
 	case LIB9P_SUPER_MAGIC_V9FS_MAGIC:
-		fmt_state_puts(state, "V9FS_MAGIC");
+		fmt_print_str(w, "V9FS_MAGIC");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu32, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_lo_format(lib9p_lo_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_lo(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_lo_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT32_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<31");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<31");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<30");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<30");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<29");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<29");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<28");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<28");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<27");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<27");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<26");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<26");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<23");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<23");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<21");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<21");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SYNC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SYNC");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "CLOEXEC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "CLOEXEC");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "NOATIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "NOATIME");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "NOFOLLOW");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "NOFOLLOW");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DIRECTORY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DIRECTORY");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<15)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "LARGEFILE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "LARGEFILE");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<14)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DIRECT");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DIRECT");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<13)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "BSD_FASYNC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "BSD_FASYNC");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<12)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DSYNC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DSYNC");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "NONBLOCK");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "NONBLOCK");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "APPEND");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "APPEND");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "TRUNC");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "TRUNC");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "NOCTTY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "NOCTTY");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "EXCL");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "EXCL");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "CREATE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "CREATE");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<5");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<5");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<4");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<4");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<3");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<3");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<2");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<2");
 		empty = false;
 	}
 	switch (*self & LIB9P_LO_MODE_MASK) {
 	case LIB9P_LO_MODE_RDONLY:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_RDONLY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_RDONLY");
 		empty = false;
 		break;
 	case LIB9P_LO_MODE_WRONLY:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_WRONLY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_WRONLY");
 		empty = false;
 		break;
 	case LIB9P_LO_MODE_RDWR:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_RDWR");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_RDWR");
 		empty = false;
 		break;
 	case LIB9P_LO_MODE_NOACCESS:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE_NOACCESS");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE_NOACCESS");
 		empty = false;
 		break;
 	default:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_printf(state, "%"PRIu32, *self & LIB9P_LO_MODE_MASK);
+			fmt_print_byte(w, '|');
+		fmt_print_base10(w, *self & LIB9P_LO_MODE_MASK);
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
-static void lib9p_dt_format(lib9p_dt_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_dt(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_dt_t *self) {
 	switch (*self) {
 	case LIB9P_DT_UNKNOWN:
-		fmt_state_puts(state, "UNKNOWN");
+		fmt_print_str(w, "UNKNOWN");
 		break;
 	case LIB9P_DT_PIPE:
-		fmt_state_puts(state, "PIPE");
+		fmt_print_str(w, "PIPE");
 		break;
 	case LIB9P_DT_CHAR_DEV:
-		fmt_state_puts(state, "CHAR_DEV");
+		fmt_print_str(w, "CHAR_DEV");
 		break;
 	case LIB9P_DT_DIRECTORY:
-		fmt_state_puts(state, "DIRECTORY");
+		fmt_print_str(w, "DIRECTORY");
 		break;
 	case LIB9P_DT_BLOCK_DEV:
-		fmt_state_puts(state, "BLOCK_DEV");
+		fmt_print_str(w, "BLOCK_DEV");
 		break;
 	case LIB9P_DT_REGULAR:
-		fmt_state_puts(state, "REGULAR");
+		fmt_print_str(w, "REGULAR");
 		break;
 	case LIB9P_DT_SYMLINK:
-		fmt_state_puts(state, "SYMLINK");
+		fmt_print_str(w, "SYMLINK");
 		break;
 	case LIB9P_DT_SOCKET:
-		fmt_state_puts(state, "SOCKET");
+		fmt_print_str(w, "SOCKET");
 		break;
 	case _LIB9P_DT_WHITEOUT:
-		fmt_state_puts(state, "_WHITEOUT");
+		fmt_print_str(w, "_WHITEOUT");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu8, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_mode_format(lib9p_mode_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_mode(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_mode_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT32_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<31");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<31");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<30");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<30");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<29");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<29");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<28");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<28");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<27");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<27");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<26");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<26");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<23");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<23");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<21");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<21");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<20");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<20");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<19");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<19");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<18");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<18");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<17");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<17");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<16");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<16");
 		empty = false;
 	}
 	switch (*self & LIB9P_MODE_FMT_MASK) {
 	case LIB9P_MODE_FMT_PIPE:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_PIPE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_PIPE");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_CHAR_DEV:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_CHAR_DEV");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_CHAR_DEV");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_DIRECTORY:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_DIRECTORY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_DIRECTORY");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_BLOCK_DEV:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_BLOCK_DEV");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_BLOCK_DEV");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_REGULAR:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_REGULAR");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_REGULAR");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_SYMLINK:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_SYMLINK");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_SYMLINK");
 		empty = false;
 		break;
 	case LIB9P_MODE_FMT_SOCKET:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "FMT_SOCKET");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "FMT_SOCKET");
 		empty = false;
 		break;
 	default:
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_printf(state, "%"PRIu32, *self & LIB9P_MODE_FMT_MASK);
+			fmt_print_byte(w, '|');
+		fmt_print_base10(w, *self & LIB9P_MODE_FMT_MASK);
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_SETGROUP");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_SETGROUP");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_SETUSER");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_SETUSER");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_STICKY");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_STICKY");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OWNER_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OWNER_R");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OWNER_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OWNER_W");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OWNER_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OWNER_X");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_GROUP_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_GROUP_R");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_GROUP_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_GROUP_W");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_GROUP_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_GROUP_X");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OTHER_R");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OTHER_R");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OTHER_W");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OTHER_W");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "PERM_OTHER_X");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "PERM_OTHER_X");
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
-static void lib9p_b4_format(lib9p_b4_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_b4(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_b4_t *self) {
 	switch (*self) {
 	case LIB9P_B4_FALSE:
-		fmt_state_puts(state, "FALSE");
+		fmt_print_str(w, "FALSE");
 		break;
 	case LIB9P_B4_TRUE:
-		fmt_state_puts(state, "TRUE");
+		fmt_print_str(w, "TRUE");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu32, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_getattr_format(lib9p_getattr_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_getattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_getattr_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT64_C(1)<<63)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<63");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<63");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<62)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<62");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<62");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<61)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<61");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<61");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<60)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<60");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<60");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<59)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<59");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<59");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<58)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<58");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<58");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<57)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<57");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<57");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<56)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<56");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<56");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<55)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<55");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<55");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<54)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<54");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<54");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<53)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<53");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<53");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<52)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<52");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<52");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<51)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<51");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<51");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<50)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<50");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<50");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<49)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<49");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<49");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<48)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<48");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<48");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<47)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<47");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<47");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<46)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<46");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<46");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<45)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<45");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<45");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<44)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<44");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<44");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<43)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<43");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<43");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<42)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<42");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<42");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<41)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<41");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<41");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<40)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<40");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<40");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<39)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<39");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<39");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<38)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<38");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<38");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<37)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<37");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<37");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<36)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<36");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<36");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<35)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<35");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<35");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<34)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<34");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<34");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<33)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<33");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<33");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<32)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<32");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<32");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<31");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<31");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<30");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<30");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<29");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<29");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<28");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<28");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<27");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<27");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<26");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<26");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<23");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<23");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<21");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<21");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<20");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<20");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<19");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<19");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<18");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<18");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<17");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<17");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<16");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<16");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<15)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<15");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<15");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<14)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<14");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<14");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<13)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "DATA_VERSION");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "DATA_VERSION");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<12)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GEN");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GEN");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "BTIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "BTIME");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "BLOCKS");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "BLOCKS");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SIZE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SIZE");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "INO");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "INO");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "CTIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "CTIME");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MTIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MTIME");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "ATIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "ATIME");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "RDEV");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "RDEV");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GID");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "UID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "UID");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "NLINK");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "NLINK");
 		empty = false;
 	}
 	if (*self & (UINT64_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE");
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
-static void lib9p_setattr_format(lib9p_setattr_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_setattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_setattr_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT32_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<31");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<31");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<30");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<30");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<29");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<29");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<28");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<28");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<27");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<27");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<26");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<26");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<23");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<23");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<21");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<21");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<20");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<20");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<19");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<19");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<18");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<18");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<17");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<17");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<16");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<16");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<15)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<15");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<15");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<14)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<14");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<14");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<13)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<13");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<13");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<12)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<12");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<12");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<11");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<11");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<10");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<10");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<9");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<9");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MTIME_SET");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MTIME_SET");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "ATIME_SET");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "ATIME_SET");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "CTIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "CTIME");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MTIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MTIME");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "ATIME");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "ATIME");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "SIZE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "SIZE");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "GID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "GID");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "UID");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "UID");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "MODE");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "MODE");
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
-static void lib9p_lock_type_format(lib9p_lock_type_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_lock_type(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_lock_type_t *self) {
 	switch (*self) {
 	case LIB9P_LOCK_TYPE_RDLCK:
-		fmt_state_puts(state, "RDLCK");
+		fmt_print_str(w, "RDLCK");
 		break;
 	case LIB9P_LOCK_TYPE_WRLCK:
-		fmt_state_puts(state, "WRLCK");
+		fmt_print_str(w, "WRLCK");
 		break;
 	case LIB9P_LOCK_TYPE_UNLCK:
-		fmt_state_puts(state, "UNLCK");
+		fmt_print_str(w, "UNLCK");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu8, *self);
+		fmt_print_base10(w, *self);
 	}
 }
 
-static void lib9p_lock_flags_format(lib9p_lock_flags_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_lock_flags(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_lock_flags_t *self) {
 	bool empty = true;
-	fmt_state_putchar(state, '(');
+	fmt_print_byte(w, '(');
 	if (*self & (UINT32_C(1)<<31)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<31");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<31");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<30)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<30");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<30");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<29)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<29");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<29");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<28)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<28");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<28");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<27)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<27");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<27");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<26)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<26");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<26");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<25)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<25");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<25");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<24)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<24");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<24");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<23)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<23");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<23");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<22)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<22");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<22");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<21)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<21");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<21");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<20)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<20");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<20");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<19)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<19");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<19");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<18)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<18");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<18");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<17)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<17");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<17");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<16)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<16");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<16");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<15)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<15");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<15");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<14)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<14");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<14");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<13)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<13");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<13");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<12)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<12");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<12");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<11)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<11");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<11");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<10)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<10");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<10");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<9)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<9");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<9");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<8)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<8");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<8");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<7)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<7");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<7");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<6)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<6");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<6");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<5)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<5");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<5");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<4)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<4");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<4");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<3)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<3");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<3");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<2)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "1<<2");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "1<<2");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<1)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "RECLAIM");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "RECLAIM");
 		empty = false;
 	}
 	if (*self & (UINT32_C(1)<<0)) {
 		if (!empty)
-			fmt_state_putchar(state, '|');
-		fmt_state_puts(state, "BLOCK");
+			fmt_print_byte(w, '|');
+		fmt_print_str(w, "BLOCK");
 		empty = false;
 	}
 	if (empty)
-		fmt_state_putchar(state, '0');
-	fmt_state_putchar(state, ')');
+		fmt_print_byte(w, '0');
+	fmt_print_byte(w, ')');
 }
 
-static void lib9p_lock_status_format(lib9p_lock_status_t *self, struct fmt_state *state) {
+[[maybe_unused]] static void fmt_print_lock_status(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, lib9p_lock_status_t *self) {
 	switch (*self) {
 	case LIB9P_LOCK_STATUS_SUCCESS:
-		fmt_state_puts(state, "SUCCESS");
+		fmt_print_str(w, "SUCCESS");
 		break;
 	case LIB9P_LOCK_STATUS_BLOCKED:
-		fmt_state_puts(state, "BLOCKED");
+		fmt_print_str(w, "BLOCKED");
 		break;
 	case LIB9P_LOCK_STATUS_ERROR:
-		fmt_state_puts(state, "ERROR");
+		fmt_print_str(w, "ERROR");
 		break;
 	case LIB9P_LOCK_STATUS_GRACE:
-		fmt_state_puts(state, "GRACE");
+		fmt_print_str(w, "GRACE");
 		break;
 	default:
-		fmt_state_printf(state, "%"PRIu8, *self);
-	}
-}
-
-static void lib9p_msg_Rlerror_format(struct lib9p_msg_Rlerror *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rlerror {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " errnum=");
-	lib9p_errno_format(&self->errnum, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tstatfs_format(struct lib9p_msg_Tstatfs *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tstatfs {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rstatfs_format(struct lib9p_msg_Rstatfs *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rstatfs {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " type=");
-	lib9p_super_magic_format(&self->type, state);
-	fmt_state_puts(state, " bsize=");
-	fmt_state_printf(state, "%"PRIu32, self->bsize);
-	fmt_state_puts(state, " blocks=");
-	fmt_state_printf(state, "%"PRIu64, self->blocks);
-	fmt_state_puts(state, " bfree=");
-	fmt_state_printf(state, "%"PRIu64, self->bfree);
-	fmt_state_puts(state, " bavail=");
-	fmt_state_printf(state, "%"PRIu64, self->bavail);
-	fmt_state_puts(state, " files=");
-	fmt_state_printf(state, "%"PRIu64, self->files);
-	fmt_state_puts(state, " ffree=");
-	fmt_state_printf(state, "%"PRIu64, self->ffree);
-	fmt_state_puts(state, " fsid=");
-	fmt_state_printf(state, "%"PRIu64, self->fsid);
-	fmt_state_puts(state, " namelen=");
-	fmt_state_printf(state, "%"PRIu32, self->namelen);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tlopen_format(struct lib9p_msg_Tlopen *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tlopen {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " flags=");
-	lib9p_lo_format(&self->flags, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rlopen_format(struct lib9p_msg_Rlopen *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rlopen {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " iounit=");
-	fmt_state_printf(state, "%"PRIu32, self->iounit);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tlcreate_format(struct lib9p_msg_Tlcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tlcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " flags=");
-	lib9p_lo_format(&self->flags, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_mode_format(&self->mode, state);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rlcreate_format(struct lib9p_msg_Rlcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rlcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " iounit=");
-	fmt_state_printf(state, "%"PRIu32, self->iounit);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tsymlink_format(struct lib9p_msg_Tsymlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tsymlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " symtgt=");
-	lib9p_s_format(&self->symtgt, state);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rsymlink_format(struct lib9p_msg_Rsymlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rsymlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tmknod_format(struct lib9p_msg_Tmknod *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tmknod {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " dfid=");
-	lib9p_fid_format(&self->dfid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_mode_format(&self->mode, state);
-	fmt_state_puts(state, " major=");
-	fmt_state_printf(state, "%"PRIu32, self->major);
-	fmt_state_puts(state, " minor=");
-	fmt_state_printf(state, "%"PRIu32, self->minor);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rmknod_format(struct lib9p_msg_Rmknod *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rmknod {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Trename_format(struct lib9p_msg_Trename *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Trename {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " dfid=");
-	lib9p_fid_format(&self->dfid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rrename_format(struct lib9p_msg_Rrename *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rrename {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Treadlink_format(struct lib9p_msg_Treadlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Treadlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rreadlink_format(struct lib9p_msg_Rreadlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rreadlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " target=");
-	lib9p_s_format(&self->target, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tgetattr_format(struct lib9p_msg_Tgetattr *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tgetattr {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " request_mask=");
-	lib9p_getattr_format(&self->request_mask, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rgetattr_format(struct lib9p_msg_Rgetattr *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rgetattr {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " valid=");
-	lib9p_getattr_format(&self->valid, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_mode_format(&self->mode, state);
-	fmt_state_puts(state, " uid=");
-	lib9p_nuid_format(&self->uid, state);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " nlink=");
-	fmt_state_printf(state, "%"PRIu64, self->nlink);
-	fmt_state_puts(state, " rdev=");
-	fmt_state_printf(state, "%"PRIu64, self->rdev);
-	fmt_state_puts(state, " filesize=");
-	fmt_state_printf(state, "%"PRIu64, self->filesize);
-	fmt_state_puts(state, " blksize=");
-	fmt_state_printf(state, "%"PRIu64, self->blksize);
-	fmt_state_puts(state, " blocks=");
-	fmt_state_printf(state, "%"PRIu64, self->blocks);
-	fmt_state_puts(state, " atime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->atime_sec);
-	fmt_state_puts(state, " atime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->atime_nsec);
-	fmt_state_puts(state, " mtime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->mtime_sec);
-	fmt_state_puts(state, " mtime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->mtime_nsec);
-	fmt_state_puts(state, " ctime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->ctime_sec);
-	fmt_state_puts(state, " ctime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->ctime_nsec);
-	fmt_state_puts(state, " btime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->btime_sec);
-	fmt_state_puts(state, " btime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->btime_nsec);
-	fmt_state_puts(state, " gen=");
-	fmt_state_printf(state, "%"PRIu64, self->gen);
-	fmt_state_puts(state, " data_version=");
-	fmt_state_printf(state, "%"PRIu64, self->data_version);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tsetattr_format(struct lib9p_msg_Tsetattr *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tsetattr {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " valid=");
-	lib9p_setattr_format(&self->valid, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_mode_format(&self->mode, state);
-	fmt_state_puts(state, " uid=");
-	lib9p_nuid_format(&self->uid, state);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " filesize=");
-	fmt_state_printf(state, "%"PRIu64, self->filesize);
-	fmt_state_puts(state, " atime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->atime_sec);
-	fmt_state_puts(state, " atime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->atime_nsec);
-	fmt_state_puts(state, " mtime_sec=");
-	fmt_state_printf(state, "%"PRIu64, self->mtime_sec);
-	fmt_state_puts(state, " mtime_nsec=");
-	fmt_state_printf(state, "%"PRIu64, self->mtime_nsec);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rsetattr_format(struct lib9p_msg_Rsetattr *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rsetattr {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Txattrwalk_format(struct lib9p_msg_Txattrwalk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Txattrwalk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " newfid=");
-	lib9p_fid_format(&self->newfid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rxattrwalk_format(struct lib9p_msg_Rxattrwalk *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rxattrwalk {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " attr_size=");
-	fmt_state_printf(state, "%"PRIu64, self->attr_size);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Txattrcreate_format(struct lib9p_msg_Txattrcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Txattrcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " attr_size=");
-	fmt_state_printf(state, "%"PRIu64, self->attr_size);
-	fmt_state_puts(state, " flags=");
-	fmt_state_printf(state, "%"PRIu32, self->flags);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rxattrcreate_format(struct lib9p_msg_Rxattrcreate *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rxattrcreate {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Treaddir_format(struct lib9p_msg_Treaddir *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Treaddir {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " offset=");
-	fmt_state_printf(state, "%"PRIu64, self->offset);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rreaddir_format(struct lib9p_msg_Rreaddir *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rreaddir {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
+		fmt_print_base10(w, *self);
+	}
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000_L */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
+[[maybe_unused]] static void fmt_print_s(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_s *self) {
+	fmt_print_qmem(w, self->utf8, self->len);
+}
+
+[[maybe_unused]] static void fmt_print_qid(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_qid *self) {
+	fmt_print_byte(w, '{');
+	fmt_print_str(w, " type=");
+	fmt_print_qt(w, ctx, &self->type);
+	fmt_print_str(w, " vers=");
+	fmt_print_base10(w, self->vers);
+	fmt_print_str(w, " path=");
+	fmt_print_base10(w, self->path);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Tflush(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tflush *self) {
+	fmt_print_str(w, "Tflush {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " oldtag=");
+	fmt_print_base10(w, self->oldtag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rflush(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rflush *self) {
+	fmt_print_str(w, "Rflush {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Topen(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Topen *self) {
+	fmt_print_str(w, "Topen {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " mode=");
+	fmt_print_o(w, ctx, &self->mode);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Tread(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tread *self) {
+	fmt_print_str(w, "Tread {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " offset=");
+	fmt_print_base10(w, self->offset);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rread(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rread *self) {
+	fmt_print_str(w, "Rread {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
+		fmt_print_str(w, " data=");
+		fmt_print_qmem(w, self->data, self->count < 50 ? self->count : 50);
+		if (self->count > 50)
+			fmt_print_str(w, "...");
+	} else {
+		fmt_print_str(w, " data=<bytedata>");
+	}
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Twrite(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Twrite *self) {
+	fmt_print_str(w, "Twrite {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " offset=");
+	fmt_print_base10(w, self->offset);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
+		fmt_print_str(w, " data=");
+		fmt_print_qmem(w, self->data, self->count < 50 ? self->count : 50);
+		if (self->count > 50)
+			fmt_print_str(w, "...");
+	} else {
+		fmt_print_str(w, " data=<bytedata>");
+	}
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rwrite(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rwrite *self) {
+	fmt_print_str(w, "Rwrite {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tclunk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tclunk *self) {
+	fmt_print_str(w, "Tclunk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rclunk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rclunk *self) {
+	fmt_print_str(w, "Rclunk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tremove(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tremove *self) {
+	fmt_print_str(w, "Tremove {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rremove(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rremove *self) {
+	fmt_print_str(w, "Rremove {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Tstat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tstat *self) {
+	fmt_print_str(w, "Tstat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rwstat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rwstat *self) {
+	fmt_print_str(w, "Rwstat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_p9p
+[[maybe_unused]] static void fmt_print_Topenfd(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Topenfd *self) {
+	fmt_print_str(w, "Topenfd {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " mode=");
+	fmt_print_o(w, ctx, &self->mode);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000_p9p */
+#if CONFIG_9P_ENABLE_9P2000_L
+[[maybe_unused]] static void fmt_print_Rlerror(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rlerror *self) {
+	fmt_print_str(w, "Rlerror {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " errnum=");
+	fmt_print_errno(w, ctx, &self->errnum);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tstatfs(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tstatfs *self) {
+	fmt_print_str(w, "Tstatfs {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rstatfs(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rstatfs *self) {
+	fmt_print_str(w, "Rstatfs {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " type=");
+	fmt_print_super_magic(w, ctx, &self->type);
+	fmt_print_str(w, " bsize=");
+	fmt_print_base10(w, self->bsize);
+	fmt_print_str(w, " blocks=");
+	fmt_print_base10(w, self->blocks);
+	fmt_print_str(w, " bfree=");
+	fmt_print_base10(w, self->bfree);
+	fmt_print_str(w, " bavail=");
+	fmt_print_base10(w, self->bavail);
+	fmt_print_str(w, " files=");
+	fmt_print_base10(w, self->files);
+	fmt_print_str(w, " ffree=");
+	fmt_print_base10(w, self->ffree);
+	fmt_print_str(w, " fsid=");
+	fmt_print_base10(w, self->fsid);
+	fmt_print_str(w, " namelen=");
+	fmt_print_base10(w, self->namelen);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tlopen(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tlopen *self) {
+	fmt_print_str(w, "Tlopen {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " flags=");
+	fmt_print_lo(w, ctx, &self->flags);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rrename(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rrename *self) {
+	fmt_print_str(w, "Rrename {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Treadlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Treadlink *self) {
+	fmt_print_str(w, "Treadlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tgetattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tgetattr *self) {
+	fmt_print_str(w, "Tgetattr {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " request_mask=");
+	fmt_print_getattr(w, ctx, &self->request_mask);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tsetattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tsetattr *self) {
+	fmt_print_str(w, "Tsetattr {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " valid=");
+	fmt_print_setattr(w, ctx, &self->valid);
+	fmt_print_str(w, " mode=");
+	fmt_print_mode(w, ctx, &self->mode);
+	fmt_print_str(w, " uid=");
+	fmt_print_nuid(w, ctx, &self->uid);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " filesize=");
+	fmt_print_base10(w, self->filesize);
+	fmt_print_str(w, " atime_sec=");
+	fmt_print_base10(w, self->atime_sec);
+	fmt_print_str(w, " atime_nsec=");
+	fmt_print_base10(w, self->atime_nsec);
+	fmt_print_str(w, " mtime_sec=");
+	fmt_print_base10(w, self->mtime_sec);
+	fmt_print_str(w, " mtime_nsec=");
+	fmt_print_base10(w, self->mtime_nsec);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rsetattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rsetattr *self) {
+	fmt_print_str(w, "Rsetattr {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rxattrwalk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrwalk *self) {
+	fmt_print_str(w, "Rxattrwalk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " attr_size=");
+	fmt_print_base10(w, self->attr_size);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rxattrcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rxattrcreate *self) {
+	fmt_print_str(w, "Rxattrcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Treaddir(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Treaddir *self) {
+	fmt_print_str(w, "Treaddir {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " offset=");
+	fmt_print_base10(w, self->offset);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rreaddir(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rreaddir *self) {
+	fmt_print_str(w, "Rreaddir {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
 	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-		fmt_state_printf(state, " data=%.*q%s",
-			(int)(self->count < 50 ? self->count : 50),
-			(char *)self->data,
-			self->count < 50 ? "" : "...");
-#pragma GCC diagnostic pop
+		fmt_print_str(w, " data=");
+		fmt_print_qmem(w, self->data, self->count < 50 ? self->count : 50);
+		if (self->count > 50)
+			fmt_print_str(w, "...");
 	} else {
-		fmt_state_puts(state, " data=<bytedata>");
-	}
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tfsync_format(struct lib9p_msg_Tfsync *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tfsync {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " datasync=");
-	lib9p_b4_format(&self->datasync, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rfsync_format(struct lib9p_msg_Rfsync *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rfsync {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tlock_format(struct lib9p_msg_Tlock *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tlock {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " type=");
-	lib9p_lock_type_format(&self->type, state);
-	fmt_state_puts(state, " flags=");
-	lib9p_lock_flags_format(&self->flags, state);
-	fmt_state_puts(state, " start=");
-	fmt_state_printf(state, "%"PRIu64, self->start);
-	fmt_state_puts(state, " length=");
-	fmt_state_printf(state, "%"PRIu64, self->length);
-	fmt_state_puts(state, " proc_id=");
-	fmt_state_printf(state, "%"PRIu32, self->proc_id);
-	fmt_state_puts(state, " client_id=");
-	lib9p_s_format(&self->client_id, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rlock_format(struct lib9p_msg_Rlock *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rlock {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " status=");
-	lib9p_lock_status_format(&self->status, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tgetlock_format(struct lib9p_msg_Tgetlock *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tgetlock {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " type=");
-	lib9p_lock_type_format(&self->type, state);
-	fmt_state_puts(state, " start=");
-	fmt_state_printf(state, "%"PRIu64, self->start);
-	fmt_state_puts(state, " length=");
-	fmt_state_printf(state, "%"PRIu64, self->length);
-	fmt_state_puts(state, " proc_id=");
-	fmt_state_printf(state, "%"PRIu32, self->proc_id);
-	fmt_state_puts(state, " client_id=");
-	lib9p_s_format(&self->client_id, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rgetlock_format(struct lib9p_msg_Rgetlock *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rgetlock {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " type=");
-	lib9p_lock_type_format(&self->type, state);
-	fmt_state_puts(state, " start=");
-	fmt_state_printf(state, "%"PRIu64, self->start);
-	fmt_state_puts(state, " length=");
-	fmt_state_printf(state, "%"PRIu64, self->length);
-	fmt_state_puts(state, " proc_id=");
-	fmt_state_printf(state, "%"PRIu32, self->proc_id);
-	fmt_state_puts(state, " client_id=");
-	lib9p_s_format(&self->client_id, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tlink_format(struct lib9p_msg_Tlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " dfid=");
-	lib9p_fid_format(&self->dfid, state);
-	fmt_state_puts(state, " fid=");
-	lib9p_fid_format(&self->fid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rlink_format(struct lib9p_msg_Rlink *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rlink {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tmkdir_format(struct lib9p_msg_Tmkdir *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tmkdir {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " dfid=");
-	lib9p_fid_format(&self->dfid, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " mode=");
-	lib9p_mode_format(&self->mode, state);
-	fmt_state_puts(state, " gid=");
-	lib9p_nuid_format(&self->gid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rmkdir_format(struct lib9p_msg_Rmkdir *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rmkdir {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " qid=");
-	lib9p_qid_format(&self->qid, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Trenameat_format(struct lib9p_msg_Trenameat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Trenameat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " olddirfid=");
-	lib9p_fid_format(&self->olddirfid, state);
-	fmt_state_puts(state, " oldname=");
-	lib9p_s_format(&self->oldname, state);
-	fmt_state_puts(state, " newdirfid=");
-	lib9p_fid_format(&self->newdirfid, state);
-	fmt_state_puts(state, " newname=");
-	lib9p_s_format(&self->newname, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rrenameat_format(struct lib9p_msg_Rrenameat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rrenameat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tunlinkat_format(struct lib9p_msg_Tunlinkat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tunlinkat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " dirfd=");
-	lib9p_fid_format(&self->dirfd, state);
-	fmt_state_puts(state, " name=");
-	lib9p_s_format(&self->name, state);
-	fmt_state_puts(state, " flags=");
-	fmt_state_printf(state, "%"PRIu32, self->flags);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Runlinkat_format(struct lib9p_msg_Runlinkat *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Runlinkat {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
+		fmt_print_str(w, " data=<bytedata>");
+	}
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tfsync(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tfsync *self) {
+	fmt_print_str(w, "Tfsync {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " datasync=");
+	fmt_print_b4(w, ctx, &self->datasync);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rfsync(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rfsync *self) {
+	fmt_print_str(w, "Rfsync {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rlock(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rlock *self) {
+	fmt_print_str(w, "Rlock {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " status=");
+	fmt_print_lock_status(w, ctx, &self->status);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rlink *self) {
+	fmt_print_str(w, "Rlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rrenameat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rrenameat *self) {
+	fmt_print_str(w, "Rrenameat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Runlinkat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Runlinkat *self) {
+	fmt_print_str(w, "Runlinkat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
 }
 
 #endif /* CONFIG_9P_ENABLE_9P2000_L */
 #if CONFIG_9P_ENABLE_9P2000_e
-static void lib9p_msg_Tsession_format(struct lib9p_msg_Tsession *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tsession {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " key=");
-	fmt_state_printf(state, "%"PRIu64, self->key);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Rsession_format(struct lib9p_msg_Rsession *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rsession {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " }");
-}
-
-static void lib9p_msg_Tsread_format(struct lib9p_msg_Tsread *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tsread {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	fmt_state_printf(state, "%"PRIu32, self->fid);
-	fmt_state_puts(state, " nwname=");
-	fmt_state_printf(state, "%"PRIu16, self->nwname);
-	fmt_state_puts(state, " wname=[");
+[[maybe_unused]] static void fmt_print_Tsession(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tsession *self) {
+	fmt_print_str(w, "Tsession {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " key=");
+	fmt_print_base10(w, self->key);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rsession(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rsession *self) {
+	fmt_print_str(w, "Rsession {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rsread(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rsread *self) {
+	fmt_print_str(w, "Rsread {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
+		fmt_print_str(w, " data=");
+		fmt_print_qmem(w, self->data, self->count < 50 ? self->count : 50);
+		if (self->count > 50)
+			fmt_print_str(w, "...");
+	} else {
+		fmt_print_str(w, " data=<bytedata>");
+	}
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rswrite(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rswrite *self) {
+	fmt_print_str(w, "Rswrite {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] void fmt_print_stat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_stat *self) {
+	fmt_print_byte(w, '{');
+	fmt_print_str(w, " fstype=");
+	fmt_print_base10(w, self->fstype);
+	fmt_print_str(w, " fsdev=");
+	fmt_print_base10(w, self->fsdev);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " mode=");
+	fmt_print_dm(w, ctx, &self->mode);
+	fmt_print_str(w, " atime=");
+	fmt_print_base10(w, self->atime);
+	fmt_print_str(w, " mtime=");
+	fmt_print_base10(w, self->mtime);
+	fmt_print_str(w, " length=");
+	fmt_print_base10(w, self->length);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " owner_uname=");
+	fmt_print_s(w, ctx, &self->owner_uname);
+	fmt_print_str(w, " owner_gname=");
+	fmt_print_s(w, ctx, &self->owner_gname);
+	fmt_print_str(w, " last_modifier_uname=");
+	fmt_print_s(w, ctx, &self->last_modifier_uname);
+#if CONFIG_9P_ENABLE_9P2000_u
+	fmt_print_str(w, " extension=");
+	fmt_print_s(w, ctx, &self->extension);
+	fmt_print_str(w, " owner_unum=");
+	fmt_print_nuid(w, ctx, &self->owner_unum);
+	fmt_print_str(w, " owner_gnum=");
+	fmt_print_nuid(w, ctx, &self->owner_gnum);
+	fmt_print_str(w, " last_modifier_unum=");
+	fmt_print_nuid(w, ctx, &self->last_modifier_unum);
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
+[[maybe_unused]] static void fmt_print_Tversion(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tversion *self) {
+	fmt_print_str(w, "Tversion {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " max_msg_size=");
+	fmt_print_base10(w, self->max_msg_size);
+	fmt_print_str(w, " version=");
+	fmt_print_s(w, ctx, &self->version);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rversion(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rversion *self) {
+	fmt_print_str(w, "Rversion {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " max_msg_size=");
+	fmt_print_base10(w, self->max_msg_size);
+	fmt_print_str(w, " version=");
+	fmt_print_s(w, ctx, &self->version);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Tauth(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tauth *self) {
+	fmt_print_str(w, "Tauth {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " afid=");
+	fmt_print_fid(w, ctx, &self->afid);
+	fmt_print_str(w, " uname=");
+	fmt_print_s(w, ctx, &self->uname);
+	fmt_print_str(w, " aname=");
+	fmt_print_s(w, ctx, &self->aname);
+#if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
+	fmt_print_str(w, " unum=");
+	fmt_print_nuid(w, ctx, &self->unum);
+#endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rauth(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rauth *self) {
+	fmt_print_str(w, "Rauth {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " aqid=");
+	fmt_print_qid(w, ctx, &self->aqid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tattach(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tattach *self) {
+	fmt_print_str(w, "Tattach {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " afid=");
+	fmt_print_fid(w, ctx, &self->afid);
+	fmt_print_str(w, " uname=");
+	fmt_print_s(w, ctx, &self->uname);
+	fmt_print_str(w, " aname=");
+	fmt_print_s(w, ctx, &self->aname);
+#if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
+	fmt_print_str(w, " unum=");
+	fmt_print_nuid(w, ctx, &self->unum);
+#endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rattach(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rattach *self) {
+	fmt_print_str(w, "Rattach {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
+[[maybe_unused]] static void fmt_print_Rerror(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rerror *self) {
+	fmt_print_str(w, "Rerror {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " errstr=");
+	fmt_print_s(w, ctx, &self->errstr);
+#if CONFIG_9P_ENABLE_9P2000_u
+	fmt_print_str(w, " errnum=");
+	fmt_print_errno(w, ctx, &self->errnum);
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Twalk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Twalk *self) {
+	fmt_print_str(w, "Twalk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " newfid=");
+	fmt_print_fid(w, ctx, &self->newfid);
+	fmt_print_str(w, " nwname=");
+	fmt_print_base10(w, self->nwname);
+	fmt_print_str(w, " wname=[");
 	for (uint16_t i = 0; i < self->nwname; i++) {
 		if (i)
-			fmt_state_putchar(state, ',');
-		fmt_state_putchar(state, ' ');
-		lib9p_s_format(&self->wname[i], state);
+			fmt_print_byte(w, ',');
+		fmt_print_byte(w, ' ');
+		fmt_print_s(w, ctx, &self->wname[i]);
 	}
-	fmt_state_puts(state, " ]");
-	fmt_state_puts(state, " }");
+	fmt_print_str(w, " ]");
+	fmt_print_str(w, " }");
 }
 
-static void lib9p_msg_Rsread_format(struct lib9p_msg_Rsread *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rsread {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-		fmt_state_printf(state, " data=%.*q%s",
-			(int)(self->count < 50 ? self->count : 50),
-			(char *)self->data,
-			self->count < 50 ? "" : "...");
-#pragma GCC diagnostic pop
-	} else {
-		fmt_state_puts(state, " data=<bytedata>");
+[[maybe_unused]] static void fmt_print_Rwalk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rwalk *self) {
+	fmt_print_str(w, "Rwalk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " nwqid=");
+	fmt_print_base10(w, self->nwqid);
+	fmt_print_str(w, " wqid=[");
+	for (uint16_t i = 0; i < self->nwqid; i++) {
+		if (i)
+			fmt_print_byte(w, ',');
+		fmt_print_byte(w, ' ');
+		fmt_print_qid(w, ctx, &self->wqid[i]);
 	}
-	fmt_state_puts(state, " }");
+	fmt_print_str(w, " ]");
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Ropen(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Ropen *self) {
+	fmt_print_str(w, "Ropen {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " iounit=");
+	fmt_print_base10(w, self->iounit);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tcreate *self) {
+	fmt_print_str(w, "Tcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " perm=");
+	fmt_print_dm(w, ctx, &self->perm);
+	fmt_print_str(w, " mode=");
+	fmt_print_o(w, ctx, &self->mode);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rcreate *self) {
+	fmt_print_str(w, "Rcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " iounit=");
+	fmt_print_base10(w, self->iounit);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_p9p
+[[maybe_unused]] static void fmt_print_Ropenfd(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Ropenfd *self) {
+	fmt_print_str(w, "Ropenfd {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " iounit=");
+	fmt_print_base10(w, self->iounit);
+	fmt_print_str(w, " unixfd=");
+	fmt_print_base10(w, self->unixfd);
+	fmt_print_str(w, " }");
 }
 
-static void lib9p_msg_Tswrite_format(struct lib9p_msg_Tswrite *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Tswrite {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " fid=");
-	fmt_state_printf(state, "%"PRIu32, self->fid);
-	fmt_state_puts(state, " nwname=");
-	fmt_state_printf(state, "%"PRIu16, self->nwname);
-	fmt_state_puts(state, " wname=[");
+#endif /* CONFIG_9P_ENABLE_9P2000_p9p */
+#if CONFIG_9P_ENABLE_9P2000_L
+[[maybe_unused]] static void fmt_print_Rlopen(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rlopen *self) {
+	fmt_print_str(w, "Rlopen {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " iounit=");
+	fmt_print_base10(w, self->iounit);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tlcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tlcreate *self) {
+	fmt_print_str(w, "Tlcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " flags=");
+	fmt_print_lo(w, ctx, &self->flags);
+	fmt_print_str(w, " mode=");
+	fmt_print_mode(w, ctx, &self->mode);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rlcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rlcreate *self) {
+	fmt_print_str(w, "Rlcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " iounit=");
+	fmt_print_base10(w, self->iounit);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tsymlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tsymlink *self) {
+	fmt_print_str(w, "Tsymlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " symtgt=");
+	fmt_print_s(w, ctx, &self->symtgt);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rsymlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rsymlink *self) {
+	fmt_print_str(w, "Rsymlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tmknod(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tmknod *self) {
+	fmt_print_str(w, "Tmknod {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " dfid=");
+	fmt_print_fid(w, ctx, &self->dfid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " mode=");
+	fmt_print_mode(w, ctx, &self->mode);
+	fmt_print_str(w, " major=");
+	fmt_print_base10(w, self->major);
+	fmt_print_str(w, " minor=");
+	fmt_print_base10(w, self->minor);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rmknod(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rmknod *self) {
+	fmt_print_str(w, "Rmknod {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Trename(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Trename *self) {
+	fmt_print_str(w, "Trename {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " dfid=");
+	fmt_print_fid(w, ctx, &self->dfid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rreadlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rreadlink *self) {
+	fmt_print_str(w, "Rreadlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " target=");
+	fmt_print_s(w, ctx, &self->target);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rgetattr(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rgetattr *self) {
+	fmt_print_str(w, "Rgetattr {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " valid=");
+	fmt_print_getattr(w, ctx, &self->valid);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " mode=");
+	fmt_print_mode(w, ctx, &self->mode);
+	fmt_print_str(w, " uid=");
+	fmt_print_nuid(w, ctx, &self->uid);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " nlink=");
+	fmt_print_base10(w, self->nlink);
+	fmt_print_str(w, " rdev=");
+	fmt_print_base10(w, self->rdev);
+	fmt_print_str(w, " filesize=");
+	fmt_print_base10(w, self->filesize);
+	fmt_print_str(w, " blksize=");
+	fmt_print_base10(w, self->blksize);
+	fmt_print_str(w, " blocks=");
+	fmt_print_base10(w, self->blocks);
+	fmt_print_str(w, " atime_sec=");
+	fmt_print_base10(w, self->atime_sec);
+	fmt_print_str(w, " atime_nsec=");
+	fmt_print_base10(w, self->atime_nsec);
+	fmt_print_str(w, " mtime_sec=");
+	fmt_print_base10(w, self->mtime_sec);
+	fmt_print_str(w, " mtime_nsec=");
+	fmt_print_base10(w, self->mtime_nsec);
+	fmt_print_str(w, " ctime_sec=");
+	fmt_print_base10(w, self->ctime_sec);
+	fmt_print_str(w, " ctime_nsec=");
+	fmt_print_base10(w, self->ctime_nsec);
+	fmt_print_str(w, " btime_sec=");
+	fmt_print_base10(w, self->btime_sec);
+	fmt_print_str(w, " btime_nsec=");
+	fmt_print_base10(w, self->btime_nsec);
+	fmt_print_str(w, " gen=");
+	fmt_print_base10(w, self->gen);
+	fmt_print_str(w, " data_version=");
+	fmt_print_base10(w, self->data_version);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Txattrwalk(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Txattrwalk *self) {
+	fmt_print_str(w, "Txattrwalk {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " newfid=");
+	fmt_print_fid(w, ctx, &self->newfid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Txattrcreate(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Txattrcreate *self) {
+	fmt_print_str(w, "Txattrcreate {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " attr_size=");
+	fmt_print_base10(w, self->attr_size);
+	fmt_print_str(w, " flags=");
+	fmt_print_base10(w, self->flags);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tlock(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tlock *self) {
+	fmt_print_str(w, "Tlock {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " type=");
+	fmt_print_lock_type(w, ctx, &self->type);
+	fmt_print_str(w, " flags=");
+	fmt_print_lock_flags(w, ctx, &self->flags);
+	fmt_print_str(w, " start=");
+	fmt_print_base10(w, self->start);
+	fmt_print_str(w, " length=");
+	fmt_print_base10(w, self->length);
+	fmt_print_str(w, " proc_id=");
+	fmt_print_base10(w, self->proc_id);
+	fmt_print_str(w, " client_id=");
+	fmt_print_s(w, ctx, &self->client_id);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tgetlock(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tgetlock *self) {
+	fmt_print_str(w, "Tgetlock {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " type=");
+	fmt_print_lock_type(w, ctx, &self->type);
+	fmt_print_str(w, " start=");
+	fmt_print_base10(w, self->start);
+	fmt_print_str(w, " length=");
+	fmt_print_base10(w, self->length);
+	fmt_print_str(w, " proc_id=");
+	fmt_print_base10(w, self->proc_id);
+	fmt_print_str(w, " client_id=");
+	fmt_print_s(w, ctx, &self->client_id);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rgetlock(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rgetlock *self) {
+	fmt_print_str(w, "Rgetlock {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " type=");
+	fmt_print_lock_type(w, ctx, &self->type);
+	fmt_print_str(w, " start=");
+	fmt_print_base10(w, self->start);
+	fmt_print_str(w, " length=");
+	fmt_print_base10(w, self->length);
+	fmt_print_str(w, " proc_id=");
+	fmt_print_base10(w, self->proc_id);
+	fmt_print_str(w, " client_id=");
+	fmt_print_s(w, ctx, &self->client_id);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tlink(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tlink *self) {
+	fmt_print_str(w, "Tlink {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " dfid=");
+	fmt_print_fid(w, ctx, &self->dfid);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tmkdir(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tmkdir *self) {
+	fmt_print_str(w, "Tmkdir {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " dfid=");
+	fmt_print_fid(w, ctx, &self->dfid);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " mode=");
+	fmt_print_mode(w, ctx, &self->mode);
+	fmt_print_str(w, " gid=");
+	fmt_print_nuid(w, ctx, &self->gid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Rmkdir(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rmkdir *self) {
+	fmt_print_str(w, "Rmkdir {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " qid=");
+	fmt_print_qid(w, ctx, &self->qid);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Trenameat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Trenameat *self) {
+	fmt_print_str(w, "Trenameat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " olddirfid=");
+	fmt_print_fid(w, ctx, &self->olddirfid);
+	fmt_print_str(w, " oldname=");
+	fmt_print_s(w, ctx, &self->oldname);
+	fmt_print_str(w, " newdirfid=");
+	fmt_print_fid(w, ctx, &self->newdirfid);
+	fmt_print_str(w, " newname=");
+	fmt_print_s(w, ctx, &self->newname);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tunlinkat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tunlinkat *self) {
+	fmt_print_str(w, "Tunlinkat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " dirfd=");
+	fmt_print_fid(w, ctx, &self->dirfd);
+	fmt_print_str(w, " name=");
+	fmt_print_s(w, ctx, &self->name);
+	fmt_print_str(w, " flags=");
+	fmt_print_base10(w, self->flags);
+	fmt_print_str(w, " }");
+}
+
+#endif /* CONFIG_9P_ENABLE_9P2000_L */
+#if CONFIG_9P_ENABLE_9P2000_e
+[[maybe_unused]] static void fmt_print_Tsread(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tsread *self) {
+	fmt_print_str(w, "Tsread {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_base10(w, self->fid);
+	fmt_print_str(w, " nwname=");
+	fmt_print_base10(w, self->nwname);
+	fmt_print_str(w, " wname=[");
+	for (uint16_t i = 0; i < self->nwname; i++) {
+		if (i)
+			fmt_print_byte(w, ',');
+		fmt_print_byte(w, ' ');
+		fmt_print_s(w, ctx, &self->wname[i]);
+	}
+	fmt_print_str(w, " ]");
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Tswrite(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Tswrite *self) {
+	fmt_print_str(w, "Tswrite {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_base10(w, self->fid);
+	fmt_print_str(w, " nwname=");
+	fmt_print_base10(w, self->nwname);
+	fmt_print_str(w, " wname=[");
 	for (uint16_t i = 0; i < self->nwname; i++) {
 		if (i)
-			fmt_state_putchar(state, ',');
-		fmt_state_putchar(state, ' ');
-		lib9p_s_format(&self->wname[i], state);
+			fmt_print_byte(w, ',');
+		fmt_print_byte(w, ' ');
+		fmt_print_s(w, ctx, &self->wname[i]);
 	}
-	fmt_state_puts(state, " ]");
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
+	fmt_print_str(w, " ]");
+	fmt_print_str(w, " count=");
+	fmt_print_base10(w, self->count);
 	if (is_valid_utf8_without_nul((uint8_t *)self->data, (size_t)self->count)) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-		fmt_state_printf(state, " data=%.*q%s",
-			(int)(self->count < 50 ? self->count : 50),
-			(char *)self->data,
-			self->count < 50 ? "" : "...");
-#pragma GCC diagnostic pop
+		fmt_print_str(w, " data=");
+		fmt_print_qmem(w, self->data, self->count < 50 ? self->count : 50);
+		if (self->count > 50)
+			fmt_print_str(w, "...");
 	} else {
-		fmt_state_puts(state, " data=<bytedata>");
+		fmt_print_str(w, " data=<bytedata>");
 	}
-	fmt_state_puts(state, " }");
+	fmt_print_str(w, " }");
 }
 
-static void lib9p_msg_Rswrite_format(struct lib9p_msg_Rswrite *self, struct fmt_state *state) {
-	fmt_state_puts(state, "Rswrite {");
-	fmt_state_puts(state, " tag=");
-	lib9p_tag_format(&self->tag, state);
-	fmt_state_puts(state, " count=");
-	fmt_state_printf(state, "%"PRIu32, self->count);
-	fmt_state_puts(state, " }");
-}
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
+[[maybe_unused]] static void fmt_print_Rstat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Rstat *self) {
+	fmt_print_str(w, "Rstat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " stat=");
+	fmt_print_stat(w, ctx, &self->stat);
+	fmt_print_str(w, " }");
+}
+
+[[maybe_unused]] static void fmt_print_Twstat(lo_interface fmt_dest w, [[maybe_unused]] struct lib9p_ctx *ctx, struct lib9p_msg_Twstat *self) {
+	fmt_print_str(w, "Twstat {");
+	fmt_print_str(w, " tag=");
+	fmt_print_tag(w, ctx, &self->tag);
+	fmt_print_str(w, " fid=");
+	fmt_print_fid(w, ctx, &self->fid);
+	fmt_print_str(w, " stat=");
+	fmt_print_stat(w, ctx, &self->stat);
+	fmt_print_str(w, " }");
+}
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 
 /* tables.h *******************************************************************/
 
@@ -7869,9 +7502,9 @@ const struct _lib9p_ver_tentry _lib9p_table_ver[LIB9P_VER_NUM] = {
 #endif /* CONFIG_9P_ENABLE_uninitialized */
 };
 
-#define _MSG(typ) [LIB9P_TYP_##typ] = {                                                                        \
-		.name                 = #typ,                                                                  \
-		.box_as_fmt_formatter = (_box_as_fmt_formatter_fn_t)lo_box_lib9p_msg_##typ##_as_fmt_formatter, \
+#define _MSG(typ) [LIB9P_TYP_##typ] = {                \
+		.name  = #typ,                         \
+		.print = (_print_fn_t)fmt_print_##typ, \
 	}
 const struct _lib9p_msg_tentry _lib9p_table_msg[LIB9P_VER_NUM][0x100] = {
 #if CONFIG_9P_ENABLE_9P2000
diff --git a/lib9p/core_include/lib9p/_core_generated.h b/lib9p/core_include/lib9p/_core_generated.h
index 9e6366f..5b9a67d 100644
--- a/lib9p/core_include/lib9p/_core_generated.h
+++ b/lib9p/core_include/lib9p/_core_generated.h
@@ -4,10 +4,6 @@
 	#error Do not include <lib9p/_core_generated.h> directly; include <lib9p/core.h> instead
 #endif
 
-#include <stdint.h> /* for uint{n}_t types */
-
-#include <libfmt/fmt.h> /* for fmt_formatter */
-#include <libhw/generic/io.h> /* for struct iovec */
 
 /* config *********************************************************************/
 
@@ -67,7 +63,6 @@ enum lib9p_version {
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 	LIB9P_VER_NUM,
 };
-LO_IMPLEMENTATION_H(fmt_formatter, enum lib9p_version, lib9p_version);
 
 /* enum msg_type **************************************************************/
 
@@ -167,26 +162,22 @@ enum lib9p_msg_type { /* uint8_t */
 	LIB9P_TYP_Rswrite      = 155,
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
 };
-LO_IMPLEMENTATION_H(fmt_formatter, enum lib9p_msg_type, lib9p_msg_type);
 
 /* payload types **************************************************************/
 
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
 /* size = 2 ; max_iov = 1 ; max_copy = 2 */
 typedef uint16_t lib9p_tag_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_tag_t, lib9p_tag);
 #define LIB9P_TAG_NOTAG ((lib9p_tag_t)(UINT16_MAX))
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_fid_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_fid_t, lib9p_fid);
 #define LIB9P_FID_NOFID ((lib9p_fid_t)(UINT32_MAX))
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_dm_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_dm_t, lib9p_dm);
 /* bits */
 #define   LIB9P_DM_DIR           ((lib9p_dm_t)(UINT32_C(1)<<31))
 #define   LIB9P_DM_APPEND        ((lib9p_dm_t)(UINT32_C(1)<<30))
@@ -231,7 +222,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_dm_t, lib9p_dm);
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
 /* size = 1 ; max_iov = 1 ; max_copy = 1 */
 typedef uint8_t lib9p_qt_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_qt_t, lib9p_qt);
 /* bits */
 #define   LIB9P_QT_DIR           ((lib9p_qt_t)(UINT8_C(1)<<7))
 #define   LIB9P_QT_APPEND        ((lib9p_qt_t)(UINT8_C(1)<<6))
@@ -250,7 +240,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_qt_t, lib9p_qt);
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
 /* size = 1 ; max_iov = 1 ; max_copy = 1 */
 typedef uint8_t lib9p_o_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_o_t, lib9p_o);
 /* bits */
 #define   _LIB9P_O_UNUSED_7        ((lib9p_o_t)(UINT8_C(1)<<7))
 #define   LIB9P_O_RCLOSE           ((lib9p_o_t)(UINT8_C(1)<<6))
@@ -273,12 +262,10 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_o_t, lib9p_o);
 #if CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_nuid_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_nuid_t, lib9p_nuid);
 #define LIB9P_NUID_NONUID ((lib9p_nuid_t)(UINT32_MAX))
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_errno_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_errno_t, lib9p_errno);
 #define LIB9P_ERRNO_NOERROR           ((lib9p_errno_t)(0))
 #define LIB9P_ERRNO_L_EPERM           ((lib9p_errno_t)(1))
 #define LIB9P_ERRNO_L_ENOENT          ((lib9p_errno_t)(2))
@@ -416,12 +403,10 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_errno_t, lib9p_errno);
 #if CONFIG_9P_ENABLE_9P2000_L
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_super_magic_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_super_magic_t, lib9p_super_magic);
 #define LIB9P_SUPER_MAGIC_V9FS_MAGIC ((lib9p_super_magic_t)(16914839))
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_lo_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lo_t, lib9p_lo);
 /* bits */
 #define   _LIB9P_LO_UNUSED_31  ((lib9p_lo_t)(UINT32_C(1)<<31))
 #define   _LIB9P_LO_UNUSED_30  ((lib9p_lo_t)(UINT32_C(1)<<30))
@@ -466,7 +451,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lo_t, lib9p_lo);
 
 /* size = 1 ; max_iov = 1 ; max_copy = 1 */
 typedef uint8_t lib9p_dt_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_dt_t, lib9p_dt);
 #define LIB9P_DT_UNKNOWN   ((lib9p_dt_t)(0))
 #define LIB9P_DT_PIPE      ((lib9p_dt_t)(1))
 #define LIB9P_DT_CHAR_DEV  ((lib9p_dt_t)(2))
@@ -479,7 +463,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_dt_t, lib9p_dt);
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_mode_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_mode_t, lib9p_mode);
 /* bits */
 #define   _LIB9P_MODE_UNUSED_31     ((lib9p_mode_t)(UINT32_C(1)<<31))
 #define   _LIB9P_MODE_UNUSED_30     ((lib9p_mode_t)(UINT32_C(1)<<30))
@@ -527,13 +510,11 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_mode_t, lib9p_mode);
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_b4_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_b4_t, lib9p_b4);
 #define LIB9P_B4_FALSE ((lib9p_b4_t)(0))
 #define LIB9P_B4_TRUE  ((lib9p_b4_t)(1))
 
 /* size = 8 ; max_iov = 1 ; max_copy = 8 */
 typedef uint64_t lib9p_getattr_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_getattr_t, lib9p_getattr);
 /* bits */
 #define   _LIB9P_GETATTR_UNUSED_63    ((lib9p_getattr_t)(UINT64_C(1)<<63))
 #define   _LIB9P_GETATTR_UNUSED_62    ((lib9p_getattr_t)(UINT64_C(1)<<62))
@@ -605,7 +586,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_getattr_t, lib9p_getattr);
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_setattr_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_setattr_t, lib9p_setattr);
 /* bits */
 #define   _LIB9P_SETATTR_UNUSED_31  ((lib9p_setattr_t)(UINT32_C(1)<<31))
 #define   _LIB9P_SETATTR_UNUSED_30  ((lib9p_setattr_t)(UINT32_C(1)<<30))
@@ -642,14 +622,12 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_setattr_t, lib9p_setattr);
 
 /* size = 1 ; max_iov = 1 ; max_copy = 1 */
 typedef uint8_t lib9p_lock_type_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lock_type_t, lib9p_lock_type);
 #define LIB9P_LOCK_TYPE_RDLCK ((lib9p_lock_type_t)(0))
 #define LIB9P_LOCK_TYPE_WRLCK ((lib9p_lock_type_t)(1))
 #define LIB9P_LOCK_TYPE_UNLCK ((lib9p_lock_type_t)(2))
 
 /* size = 4 ; max_iov = 1 ; max_copy = 4 */
 typedef uint32_t lib9p_lock_flags_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lock_flags_t, lib9p_lock_flags);
 /* bits */
 #define   _LIB9P_LOCK_FLAGS_UNUSED_31  ((lib9p_lock_flags_t)(UINT32_C(1)<<31))
 #define   _LIB9P_LOCK_FLAGS_UNUSED_30  ((lib9p_lock_flags_t)(UINT32_C(1)<<30))
@@ -686,7 +664,6 @@ LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lock_flags_t, lib9p_lock_flags);
 
 /* size = 1 ; max_iov = 1 ; max_copy = 1 */
 typedef uint8_t lib9p_lock_status_t;
-LO_IMPLEMENTATION_H(fmt_formatter, lib9p_lock_status_t, lib9p_lock_status);
 #define LIB9P_LOCK_STATUS_SUCCESS ((lib9p_lock_status_t)(0))
 #define LIB9P_LOCK_STATUS_BLOCKED ((lib9p_lock_status_t)(1))
 #define LIB9P_LOCK_STATUS_ERROR   ((lib9p_lock_status_t)(2))
@@ -699,7 +676,6 @@ struct lib9p_s {
 	uint16_t                  len;
 	[[gnu::nonstring]] char  *utf8;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_s, lib9p_s);
 
 /* size = 13 ; max_iov = 1 ; max_copy = 13 */
 struct lib9p_qid {
@@ -707,7 +683,6 @@ struct lib9p_qid {
 	uint32_t     vers;
 	uint64_t     path;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_qid, lib9p_qid);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -716,13 +691,11 @@ struct lib9p_msg_Tflush {
 	lib9p_tag_t   tag;
 	uint16_t      oldtag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tflush, lib9p_msg_Tflush);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rflush {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rflush, lib9p_msg_Rflush);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -732,7 +705,6 @@ struct lib9p_msg_Topen {
 	lib9p_fid_t   fid;
 	lib9p_o_t     mode;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Topen, lib9p_msg_Topen);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -743,7 +715,6 @@ struct lib9p_msg_Tread {
 	uint64_t      offset;
 	uint32_t      count;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tread, lib9p_msg_Tread);
 
 /* min_size = 11 ; exp_size = 8,203 ; max_size = 2,147,483,658 ; max_iov = 2 ; max_copy = 11 */
 struct lib9p_msg_Rread {
@@ -751,7 +722,6 @@ struct lib9p_msg_Rread {
 	uint32_t                  count;
 	[[gnu::nonstring]] char  *data;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rread, lib9p_msg_Rread);
 
 /* min_size = 23 ; exp_size = 8,215 ; max_size = 2,147,483,670 ; max_iov = 2 ; max_copy = 23 */
 struct lib9p_msg_Twrite {
@@ -761,40 +731,34 @@ struct lib9p_msg_Twrite {
 	uint32_t                  count;
 	[[gnu::nonstring]] char  *data;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Twrite, lib9p_msg_Twrite);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Rwrite {
 	lib9p_tag_t   tag;
 	uint32_t      count;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rwrite, lib9p_msg_Rwrite);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Tclunk {
 	lib9p_tag_t   tag;
 	lib9p_fid_t   fid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tclunk, lib9p_msg_Tclunk);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rclunk {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rclunk, lib9p_msg_Rclunk);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Tremove {
 	lib9p_tag_t   tag;
 	lib9p_fid_t   fid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tremove, lib9p_msg_Tremove);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rremove {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rremove, lib9p_msg_Rremove);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -803,13 +767,11 @@ struct lib9p_msg_Tstat {
 	lib9p_tag_t   tag;
 	lib9p_fid_t   fid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tstat, lib9p_msg_Tstat);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rwstat {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rwstat, lib9p_msg_Rwstat);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000_p9p
@@ -819,7 +781,6 @@ struct lib9p_msg_Topenfd {
 	lib9p_fid_t   fid;
 	lib9p_o_t     mode;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Topenfd, lib9p_msg_Topenfd);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_p9p */
 #if CONFIG_9P_ENABLE_9P2000_L
@@ -828,14 +789,12 @@ struct lib9p_msg_Rlerror {
 	lib9p_tag_t     tag;
 	lib9p_errno_t   errnum;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rlerror, lib9p_msg_Rlerror);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Tstatfs {
 	lib9p_tag_t   tag;
 	lib9p_fid_t   fid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tstatfs, lib9p_msg_Tstatfs);
 
 /* size = 67 ; max_iov = 1 ; max_copy = 67 */
 struct lib9p_msg_Rstatfs {
@@ -850,7 +809,6 @@ struct lib9p_msg_Rstatfs {
 	uint64_t              fsid;
 	uint32_t              namelen;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rstatfs, lib9p_msg_Rstatfs);
 
 /* size = 15 ; max_iov = 1 ; max_copy = 15 */
 struct lib9p_msg_Tlopen {
@@ -858,20 +816,17 @@ struct lib9p_msg_Tlopen {
 	lib9p_fid_t   fid;
 	lib9p_lo_t    flags;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tlopen, lib9p_msg_Tlopen);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rrename {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rrename, lib9p_msg_Rrename);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Treadlink {
 	lib9p_tag_t   tag;
 	lib9p_fid_t   fid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Treadlink, lib9p_msg_Treadlink);
 
 /* size = 19 ; max_iov = 1 ; max_copy = 19 */
 struct lib9p_msg_Tgetattr {
@@ -879,7 +834,6 @@ struct lib9p_msg_Tgetattr {
 	lib9p_fid_t       fid;
 	lib9p_getattr_t   request_mask;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tgetattr, lib9p_msg_Tgetattr);
 
 /* size = 67 ; max_iov = 1 ; max_copy = 67 */
 struct lib9p_msg_Tsetattr {
@@ -895,26 +849,22 @@ struct lib9p_msg_Tsetattr {
 	uint64_t          mtime_sec;
 	uint64_t          mtime_nsec;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tsetattr, lib9p_msg_Tsetattr);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rsetattr {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rsetattr, lib9p_msg_Rsetattr);
 
 /* size = 15 ; max_iov = 1 ; max_copy = 15 */
 struct lib9p_msg_Rxattrwalk {
 	lib9p_tag_t   tag;
 	uint64_t      attr_size;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rxattrwalk, lib9p_msg_Rxattrwalk);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rxattrcreate {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rxattrcreate, lib9p_msg_Rxattrcreate);
 
 /* size = 23 ; max_iov = 1 ; max_copy = 23 */
 struct lib9p_msg_Treaddir {
@@ -923,7 +873,6 @@ struct lib9p_msg_Treaddir {
 	uint64_t      offset;
 	uint32_t      count;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Treaddir, lib9p_msg_Treaddir);
 
 /* min_size = 11 ; exp_size = 8,203 ; max_size = 4,294,967,306 (warning: >UINT32_MAX) ; max_iov = 2 ; max_copy = 11 */
 struct lib9p_msg_Rreaddir {
@@ -931,7 +880,6 @@ struct lib9p_msg_Rreaddir {
 	uint32_t                  count;
 	[[gnu::nonstring]] char  *data;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rreaddir, lib9p_msg_Rreaddir);
 
 /* size = 15 ; max_iov = 1 ; max_copy = 15 */
 struct lib9p_msg_Tfsync {
@@ -939,38 +887,32 @@ struct lib9p_msg_Tfsync {
 	lib9p_fid_t   fid;
 	lib9p_b4_t    datasync;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tfsync, lib9p_msg_Tfsync);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rfsync {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rfsync, lib9p_msg_Rfsync);
 
 /* size = 8 ; max_iov = 1 ; max_copy = 8 */
 struct lib9p_msg_Rlock {
 	lib9p_tag_t           tag;
 	lib9p_lock_status_t   status;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rlock, lib9p_msg_Rlock);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rlink {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rlink, lib9p_msg_Rlink);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rrenameat {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rrenameat, lib9p_msg_Rrenameat);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Runlinkat {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Runlinkat, lib9p_msg_Runlinkat);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_L */
 #if CONFIG_9P_ENABLE_9P2000_e
@@ -979,13 +921,11 @@ struct lib9p_msg_Tsession {
 	lib9p_tag_t   tag;
 	uint64_t      key;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tsession, lib9p_msg_Tsession);
 
 /* size = 7 ; max_iov = 1 ; max_copy = 7 */
 struct lib9p_msg_Rsession {
 	lib9p_tag_t   tag;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rsession, lib9p_msg_Rsession);
 
 /* min_size = 11 ; exp_size = 8,203 ; max_size = 4,294,967,306 (warning: >UINT32_MAX) ; max_iov = 2 ; max_copy = 11 */
 struct lib9p_msg_Rsread {
@@ -993,14 +933,12 @@ struct lib9p_msg_Rsread {
 	uint32_t                  count;
 	[[gnu::nonstring]] char  *data;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rsread, lib9p_msg_Rsread);
 
 /* size = 11 ; max_iov = 1 ; max_copy = 11 */
 struct lib9p_msg_Rswrite {
 	lib9p_tag_t   tag;
 	uint32_t      count;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rswrite, lib9p_msg_Rswrite);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -1027,7 +965,6 @@ struct lib9p_stat {
 	lib9p_nuid_t       last_modifier_unum;
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_stat, lib9p_stat);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
@@ -1037,7 +974,6 @@ struct lib9p_msg_Tversion {
 	uint32_t         max_msg_size;
 	struct lib9p_s   version;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tversion, lib9p_msg_Tversion);
 
 /* min_size = 13 ; exp_size = 40 ; max_size = 65,548 ; max_iov = 2 ; max_copy = 13 */
 struct lib9p_msg_Rversion {
@@ -1045,7 +981,6 @@ struct lib9p_msg_Rversion {
 	uint32_t         max_msg_size;
 	struct lib9p_s   version;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rversion, lib9p_msg_Rversion);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -1063,14 +998,12 @@ struct lib9p_msg_Tauth {
 	lib9p_nuid_t     unum;
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tauth, lib9p_msg_Tauth);
 
 /* size = 20 ; max_iov = 1 ; max_copy = 20 */
 struct lib9p_msg_Rauth {
 	lib9p_tag_t        tag;
 	struct lib9p_qid   aqid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rauth, lib9p_msg_Rauth);
 
 /* LIB9P_VER_9P2000    : min_size = 19 ; exp_size = 73 ; max_size = 131,089 ; max_iov = 4 ; max_copy = 19 */
 /* LIB9P_VER_9P2000_L  : min_size = 23 ; exp_size = 77 ; max_size = 131,093 ; max_iov = 5 ; max_copy = 23 */
@@ -1087,14 +1020,12 @@ struct lib9p_msg_Tattach {
 	lib9p_nuid_t     unum;
 #endif /* CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_u */
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tattach, lib9p_msg_Tattach);
 
 /* size = 20 ; max_iov = 1 ; max_copy = 20 */
 struct lib9p_msg_Rattach {
 	lib9p_tag_t        tag;
 	struct lib9p_qid   qid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rattach, lib9p_msg_Rattach);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized
@@ -1110,7 +1041,6 @@ struct lib9p_msg_Rerror {
 	lib9p_errno_t    errnum;
 #endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rerror, lib9p_msg_Rerror);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_uninitialized */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -1122,7 +1052,6 @@ struct lib9p_msg_Twalk {
 	uint16_t         nwname;
 	struct lib9p_s  *wname;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Twalk, lib9p_msg_Twalk);
 
 /* min_size = 9 ; exp_size = 217 ; max_size = 217 ; max_iov = 1 ; max_copy = 217 */
 struct lib9p_msg_Rwalk {
@@ -1130,7 +1059,6 @@ struct lib9p_msg_Rwalk {
 	uint16_t           nwqid;
 	struct lib9p_qid  *wqid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rwalk, lib9p_msg_Rwalk);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_L || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -1140,7 +1068,6 @@ struct lib9p_msg_Ropen {
 	struct lib9p_qid   qid;
 	uint32_t           iounit;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Ropen, lib9p_msg_Ropen);
 
 /* min_size = 18 ; exp_size = 45 ; max_size = 65,553 ; max_iov = 3 ; max_copy = 18 */
 struct lib9p_msg_Tcreate {
@@ -1150,7 +1077,6 @@ struct lib9p_msg_Tcreate {
 	lib9p_dm_t       perm;
 	lib9p_o_t        mode;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tcreate, lib9p_msg_Tcreate);
 
 /* size = 24 ; max_iov = 1 ; max_copy = 24 */
 struct lib9p_msg_Rcreate {
@@ -1158,7 +1084,6 @@ struct lib9p_msg_Rcreate {
 	struct lib9p_qid   qid;
 	uint32_t           iounit;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rcreate, lib9p_msg_Rcreate);
 
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 #if CONFIG_9P_ENABLE_9P2000_p9p
@@ -1169,7 +1094,6 @@ struct lib9p_msg_Ropenfd {
 	uint32_t           iounit;
 	uint32_t           unixfd;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Ropenfd, lib9p_msg_Ropenfd);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_p9p */
 #if CONFIG_9P_ENABLE_9P2000_L
@@ -1179,7 +1103,6 @@ struct lib9p_msg_Rlopen {
 	struct lib9p_qid   qid;
 	uint32_t           iounit;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rlopen, lib9p_msg_Rlopen);
 
 /* min_size = 25 ; exp_size = 52 ; max_size = 65,560 ; max_iov = 3 ; max_copy = 25 */
 struct lib9p_msg_Tlcreate {
@@ -1190,7 +1113,6 @@ struct lib9p_msg_Tlcreate {
 	lib9p_mode_t     mode;
 	lib9p_nuid_t     gid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tlcreate, lib9p_msg_Tlcreate);
 
 /* size = 24 ; max_iov = 1 ; max_copy = 24 */
 struct lib9p_msg_Rlcreate {
@@ -1198,7 +1120,6 @@ struct lib9p_msg_Rlcreate {
 	struct lib9p_qid   qid;
 	uint32_t           iounit;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rlcreate, lib9p_msg_Rlcreate);
 
 /* min_size = 19 ; exp_size = 73 ; max_size = 131,089 ; max_iov = 5 ; max_copy = 19 */
 struct lib9p_msg_Tsymlink {
@@ -1208,14 +1129,12 @@ struct lib9p_msg_Tsymlink {
 	struct lib9p_s   symtgt;
 	lib9p_nuid_t     gid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tsymlink, lib9p_msg_Tsymlink);
 
 /* size = 20 ; max_iov = 1 ; max_copy = 20 */
 struct lib9p_msg_Rsymlink {
 	lib9p_tag_t        tag;
 	struct lib9p_qid   qid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rsymlink, lib9p_msg_Rsymlink);
 
 /* min_size = 29 ; exp_size = 56 ; max_size = 65,564 ; max_iov = 3 ; max_copy = 29 */
 struct lib9p_msg_Tmknod {
@@ -1227,14 +1146,12 @@ struct lib9p_msg_Tmknod {
 	uint32_t         minor;
 	lib9p_nuid_t     gid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tmknod, lib9p_msg_Tmknod);
 
 /* size = 20 ; max_iov = 1 ; max_copy = 20 */
 struct lib9p_msg_Rmknod {
 	lib9p_tag_t        tag;
 	struct lib9p_qid   qid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rmknod, lib9p_msg_Rmknod);
 
 /* min_size = 17 ; exp_size = 44 ; max_size = 65,552 ; max_iov = 2 ; max_copy = 17 */
 struct lib9p_msg_Trename {
@@ -1243,14 +1160,12 @@ struct lib9p_msg_Trename {
 	lib9p_fid_t      dfid;
 	struct lib9p_s   name;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Trename, lib9p_msg_Trename);
 
 /* min_size = 9 ; exp_size = 36 ; max_size = 65,544 ; max_iov = 2 ; max_copy = 9 */
 struct lib9p_msg_Rreadlink {
 	lib9p_tag_t      tag;
 	struct lib9p_s   target;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rreadlink, lib9p_msg_Rreadlink);
 
 /* size = 160 ; max_iov = 1 ; max_copy = 160 */
 struct lib9p_msg_Rgetattr {
@@ -1276,7 +1191,6 @@ struct lib9p_msg_Rgetattr {
 	uint64_t           gen;
 	uint64_t           data_version;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rgetattr, lib9p_msg_Rgetattr);
 
 /* min_size = 17 ; exp_size = 44 ; max_size = 65,552 ; max_iov = 2 ; max_copy = 17 */
 struct lib9p_msg_Txattrwalk {
@@ -1285,7 +1199,6 @@ struct lib9p_msg_Txattrwalk {
 	lib9p_fid_t      newfid;
 	struct lib9p_s   name;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Txattrwalk, lib9p_msg_Txattrwalk);
 
 /* min_size = 25 ; exp_size = 52 ; max_size = 65,560 ; max_iov = 3 ; max_copy = 25 */
 struct lib9p_msg_Txattrcreate {
@@ -1295,7 +1208,6 @@ struct lib9p_msg_Txattrcreate {
 	uint64_t         attr_size;
 	uint32_t         flags;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Txattrcreate, lib9p_msg_Txattrcreate);
 
 /* min_size = 38 ; exp_size = 65 ; max_size = 65,573 ; max_iov = 2 ; max_copy = 38 */
 struct lib9p_msg_Tlock {
@@ -1308,7 +1220,6 @@ struct lib9p_msg_Tlock {
 	uint32_t             proc_id;
 	struct lib9p_s       client_id;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tlock, lib9p_msg_Tlock);
 
 /* min_size = 34 ; exp_size = 61 ; max_size = 65,569 ; max_iov = 2 ; max_copy = 34 */
 struct lib9p_msg_Tgetlock {
@@ -1320,7 +1231,6 @@ struct lib9p_msg_Tgetlock {
 	uint32_t            proc_id;
 	struct lib9p_s      client_id;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tgetlock, lib9p_msg_Tgetlock);
 
 /* min_size = 30 ; exp_size = 57 ; max_size = 65,565 ; max_iov = 2 ; max_copy = 30 */
 struct lib9p_msg_Rgetlock {
@@ -1331,7 +1241,6 @@ struct lib9p_msg_Rgetlock {
 	uint32_t            proc_id;
 	struct lib9p_s      client_id;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rgetlock, lib9p_msg_Rgetlock);
 
 /* min_size = 17 ; exp_size = 44 ; max_size = 65,552 ; max_iov = 2 ; max_copy = 17 */
 struct lib9p_msg_Tlink {
@@ -1340,7 +1249,6 @@ struct lib9p_msg_Tlink {
 	lib9p_fid_t      fid;
 	struct lib9p_s   name;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tlink, lib9p_msg_Tlink);
 
 /* min_size = 21 ; exp_size = 48 ; max_size = 65,556 ; max_iov = 3 ; max_copy = 21 */
 struct lib9p_msg_Tmkdir {
@@ -1350,14 +1258,12 @@ struct lib9p_msg_Tmkdir {
 	lib9p_mode_t     mode;
 	lib9p_nuid_t     gid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tmkdir, lib9p_msg_Tmkdir);
 
 /* size = 20 ; max_iov = 1 ; max_copy = 20 */
 struct lib9p_msg_Rmkdir {
 	lib9p_tag_t        tag;
 	struct lib9p_qid   qid;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rmkdir, lib9p_msg_Rmkdir);
 
 /* min_size = 19 ; exp_size = 73 ; max_size = 131,089 ; max_iov = 4 ; max_copy = 19 */
 struct lib9p_msg_Trenameat {
@@ -1367,7 +1273,6 @@ struct lib9p_msg_Trenameat {
 	lib9p_fid_t      newdirfid;
 	struct lib9p_s   newname;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Trenameat, lib9p_msg_Trenameat);
 
 /* min_size = 17 ; exp_size = 44 ; max_size = 65,552 ; max_iov = 3 ; max_copy = 17 */
 struct lib9p_msg_Tunlinkat {
@@ -1376,7 +1281,6 @@ struct lib9p_msg_Tunlinkat {
 	struct lib9p_s   name;
 	uint32_t         flags;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tunlinkat, lib9p_msg_Tunlinkat);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_L */
 #if CONFIG_9P_ENABLE_9P2000_e
@@ -1387,7 +1291,6 @@ struct lib9p_msg_Tsread {
 	uint16_t         nwname;
 	struct lib9p_s  *wname;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tsread, lib9p_msg_Tsread);
 
 /* min_size = 17 ; exp_size = 8,673 ; max_size = 8,589,934,607 (warning: >UINT32_MAX) ; max_iov = 2 + (CONFIG_9P_MAX_9P2000_e_WELEM * 2) ; max_copy = 17 + (CONFIG_9P_MAX_9P2000_e_WELEM * 2) */
 struct lib9p_msg_Tswrite {
@@ -1398,7 +1301,6 @@ struct lib9p_msg_Tswrite {
 	uint32_t                  count;
 	[[gnu::nonstring]] char  *data;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Tswrite, lib9p_msg_Tswrite);
 
 #endif /* CONFIG_9P_ENABLE_9P2000_e */
 #if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u
@@ -1410,7 +1312,6 @@ struct lib9p_msg_Rstat {
 	lib9p_tag_t         tag;
 	struct lib9p_stat   stat;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Rstat, lib9p_msg_Rstat);
 
 /* LIB9P_VER_9P2000    : min_size = 62 ; exp_size = 170 ; max_size = 262,202 ; max_iov = 8 ; max_copy = 62 */
 /* LIB9P_VER_9P2000_e  : min_size = 62 ; exp_size = 170 ; max_size = 262,202 ; max_iov = 8 ; max_copy = 62 */
@@ -1421,7 +1322,6 @@ struct lib9p_msg_Twstat {
 	lib9p_fid_t         fid;
 	struct lib9p_stat   stat;
 };
-LO_IMPLEMENTATION_H(fmt_formatter, struct lib9p_msg_Twstat, lib9p_msg_Twstat);
 #endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_p9p || CONFIG_9P_ENABLE_9P2000_u */
 
 /* containers *****************************************************************/
diff --git a/lib9p/core_include/lib9p/core.h b/lib9p/core_include/lib9p/core.h
index aa470de..4941220 100644
--- a/lib9p/core_include/lib9p/core.h
+++ b/lib9p/core_include/lib9p/core.h
@@ -7,9 +7,13 @@
 #ifndef _LIB9P_CORE_H_
 #define _LIB9P_CORE_H_
 
+#include <stdint.h>    /* for uint{n}_t */
+#include <string.h>    /* for memset() */
 #include <sys/types.h> /* for ssize_t */
 
+#include <libhw/generic/io.h> /* for struct iovec */
 #include <libmisc/assert.h>
+#include <libmisc/fmt.h>
 
 #define CONFIG_9P_ENABLE_uninitialized 1
 #include <lib9p/_core_generated.h>
@@ -55,31 +59,34 @@ void lib9p_ctx_clear_error(struct lib9p_ctx *ctx);
 
 bool lib9p_ctx_has_error(struct lib9p_ctx *ctx);
 
-/* NB: This __VA_ARGS__ definition of lib9p_errorf() is handy because it
- * will produce an error if .../__VA_ARGS__ is empty; which means that
- * it should be lib9p_error() instead!  */
 #if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
-	int _lib9p_error(struct lib9p_ctx *ctx, lib9p_errno_t linux_errno, char const *msg);
-	int _lib9p_errorf(struct lib9p_ctx *ctx, lib9p_errno_t linux_errno, char const *fmt, ...) [[gnu::format(printf, 3, 4)]];
-	/** Write an static error into ctx, return -1.  */
-	#define lib9p_error(ctx, errnum, errmsg) _lib9p_error(ctx, errnum, errmsg)
-	/** Write a printf-style error into ctx, return -1.  */
-	#define lib9p_errorf(ctx, errnum, fmt, ...) _lib9p_errorf(ctx, errnum, fmt, __VA_ARGS__)
+	#define _lib9p_set_err_num(ctx, linux_errno) do { (ctx)->err_num = linux_errno; } while (0)
 #else
-	int _lib9p_error(struct lib9p_ctx *ctx, char const *msg);
-	int _lib9p_errorf(struct lib9p_ctx *ctx, char const *fmt, ...) [[gnu::format(printf, 2, 3)]];
-	/** Write an static error into ctx, return -1.  */
-	#define lib9p_error(ctx, errnum, errmsg) _lib9p_error(ctx, errmsg)
-	/** Write a printf-style error into ctx, return -1.  */
-	#define lib9p_errorf(ctx, errnum, fmt, ...) _lib9p_errorf(ctx, fmt, __VA_ARGS__)
+	#define _lib9p_set_err_num(ctx, linux_errno) do { } while (0)
 #endif
 
+/** Write a <libmisc/fmt.h>-style error into ctx, return -1.  */
+#define lib9p_error(ctx, linux_errno, ...) ({                              \
+	if (!lib9p_ctx_has_error(ctx)) {                                   \
+		_lib9p_set_err_num(ctx, linux_errno);                      \
+		struct fmt_buf _w = {                                      \
+			.dat = (ctx)->err_msg,                             \
+			.cap = sizeof((ctx)->err_msg),                     \
+		};                                                         \
+		lo_interface fmt_dest w = lo_box_fmt_buf_as_fmt_dest(&_w); \
+		fmt_print(w, __VA_ARGS__);                                 \
+		if (_w.len < _w.cap)                                       \
+			memset(_w.dat + _w.len, 0, _w.cap - _w.len);       \
+	}                                                                  \
+	-1;                                                                \
+})
+
 /* misc utilities *************************************************************/
 
 uint32_t lib9p_version_min_Rerror_size(enum lib9p_version);
 uint32_t lib9p_version_min_Rread_size(enum lib9p_version);
 
-lo_interface fmt_formatter lo_box_lib9p_msg_as_fmt_formatter(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body);
+void fmt_print_lib9p_msg(lo_interface fmt_dest w, struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body);
 
 /* main T-message functions ***************************************************/
 
@@ -159,6 +166,9 @@ bool lib9p_Rmsg_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *bo
 /* `struct lib9p_stat` helpers ************************************************/
 
 #if _LIB9P_ENABLE_stat
+
+void fmt_print_lib9p_stat(lo_interface fmt_dest w, struct lib9p_ctx *ctx, struct lib9p_stat *stat);
+
 /**
  * Validate a message's `stat` structure.
  *
diff --git a/lib9p/core_tables.h b/lib9p/core_tables.h
index da2027a..e3dc8f4 100644
--- a/lib9p/core_tables.h
+++ b/lib9p/core_tables.h
@@ -21,10 +21,10 @@ extern const struct _lib9p_ver_tentry _lib9p_table_ver[LIB9P_VER_NUM];
 
 /* message ********************************************************************/
 
-typedef lo_interface fmt_formatter (*_box_as_fmt_formatter_fn_t)(void *host_val);
+typedef void (*_print_fn_t)(lo_interface fmt_dest, struct lib9p_ctx *, void *);
 struct _lib9p_msg_tentry {
-	const char                      *name;
-	_box_as_fmt_formatter_fn_t       box_as_fmt_formatter;
+	const char              *name;
+	_print_fn_t              print;
 };
 
 typedef ssize_t (*_validate_fn_t)(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *net_bytes);
diff --git a/lib9p/srv.c b/lib9p/srv.c
index dad1814..18165e0 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -54,12 +54,11 @@ void lib9p_srv_acknowledge_flush(struct lib9p_srv_ctx *ctx) {
 	ctx->flush_acknowledged = true;
 }
 
-#define req_debugf(fmt, ...)                                                   \
-	log_debugf("cid=%zu: %s(tag=%"PRIu16"): " fmt,                         \
-	           cr_getcid(),                                                \
-	           lib9p_msgtype_str(ctx->basectx.version, ctx->net_bytes[4]), \
-	           ctx->tag                                                    \
-	           __VA_OPT__(,) __VA_ARGS__)
+#define req_debug(...)                                                                                \
+	log_debugln(                                                                                  \
+		"cid=", cr_getcid(), ": ",                                                            \
+		lib9p_msgtype_str(ctx->basectx.version, ctx->net_bytes[4]), "(tag=", ctx->tag, "): ", \
+		__VA_ARGS__)
 
 /* structs ********************************************************************/
 
@@ -356,13 +355,7 @@ static void srv_msglog(struct srv_req *req, enum lib9p_msg_type typ, void *hostm
 		srv->msglog(req, typ, hostmsg);
 		return;
 	}
-	/* It sucks that %v trips -Wformat and -Wformat-extra-args
-	 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47781 */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-	log_infof("%c %v", typ % 2 ? '<' : '>', lo_box_lib9p_msg_as_fmt_formatter(&req->basectx, typ, hostmsg));
-#pragma GCC diagnostic pop
+	log_infoln(typ % 2 ? "< " : "> ", (lib9p_msg, &req->basectx, typ, hostmsg));
 }
 
 static ssize_t srv_write_Rmsg(struct srv_req *req, struct lib9p_Rmsg_send_buf *resp) {
@@ -373,7 +366,7 @@ static ssize_t srv_write_Rmsg(struct srv_req *req, struct lib9p_Rmsg_send_buf *r
 	return r;
 }
 
-#define srv_nonrespond_errorf log_errorf
+#define srv_nonrespond_error log_errorln
 
 static void srv_respond_error(struct srv_req *req) {
 #if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
@@ -409,7 +402,7 @@ static void srv_respond_error(struct srv_req *req) {
 	srv_msglog(req, LIB9P_TYP_Rerror, &host);
 	r = srv_write_Rmsg(req, &net);
 	if (r < 0)
-		srv_nonrespond_errorf("write: %s", net_strerror(-r));
+		srv_nonrespond_error("write: ", net_strerror(-r));
 }
 
 /* read coroutine *************************************************************/
@@ -421,11 +414,11 @@ static inline bool srv_read_exactly(lo_interface net_stream_conn fd, uint8_t *bu
 	while (*done < goal) {
 		ssize_t r = io_read(fd, &buf[*done], goal - *done);
 		if (r < 0) {
-			srv_nonrespond_errorf("read: %s", net_strerror(-r));
+			srv_nonrespond_error("read: ", net_strerror(-r));
 			return true;
 		} else if (r == 0) {
 			if (*done != 0)
-				srv_nonrespond_errorf("read: unexpected EOF");
+				srv_nonrespond_error("read: unexpected EOF");
 			return true;
 		}
 		*done += r;
@@ -443,7 +436,7 @@ void lib9p_srv_accept_and_read_loop(struct lib9p_srv *srv, lo_interface net_stre
 	for (;;) {
 		lo_interface net_stream_conn conn = LO_CALL(listener, accept);
 		if (LO_IS_NULL(conn)) {
-			srv_nonrespond_errorf("accept: error");
+			srv_nonrespond_error("accept: error");
 			srv->readers--;
 			if (srv->readers == 0)
 				while (srv->writers > 0)
@@ -478,7 +471,7 @@ void lib9p_srv_read(struct lib9p_srv *srv, lo_interface net_stream_conn _conn) {
 			break;
 		size_t goal = uint32le_decode(buf);
 		if (goal < 7) {
-			srv_nonrespond_errorf("T-message is impossibly small");
+			srv_nonrespond_error("T-message is impossibly small");
 			break;
 		}
 		if (srv_read_exactly(conn.fd, buf, 7, &done))
@@ -494,11 +487,9 @@ void lib9p_srv_read(struct lib9p_srv *srv, lo_interface net_stream_conn _conn) {
 			.net_bytes   = buf,
 		};
 		if (goal > sess.max_msg_size) {
-			lib9p_errorf(&req.basectx,
-			             LIB9P_ERRNO_L_EMSGSIZE, "T-message larger than %s limit (%zu > %"PRIu32")",
-			             sess.initialized ? "negotiated" : "server",
-			             goal,
-			             sess.max_msg_size);
+			lib9p_error(&req.basectx, LIB9P_ERRNO_L_EMSGSIZE,
+			            "T-message larger than ", sess.initialized ? "negotiated" : "server", " limit",
+			            " (", goal, " > ", sess.max_msg_size, ")");
 			srv_respond_error(&req);
 			continue;
 		}
@@ -541,7 +532,7 @@ void lib9p_srv_read(struct lib9p_srv *srv, lo_interface net_stream_conn _conn) {
 	MAP_FOREACH(&sess.fids, fid, fidinfo) {
 		srv_fid_del(&pseudoreq, fid, fidinfo, false);
 		if (lib9p_ctx_has_error(&pseudoreq.basectx)) {
-			srv_nonrespond_errorf("clunk: %.*s", CONFIG_9P_MAX_ERR_SIZE, pseudoreq.basectx.err_msg);
+			srv_nonrespond_error("clunk: ", (strn, pseudoreq.basectx.err_msg, CONFIG_9P_MAX_ERR_SIZE));
 			lib9p_ctx_clear_error(&pseudoreq.basectx);
 		}
 	}
@@ -746,9 +737,9 @@ static void handle_Tversion(struct srv_req *ctx,
 	uint32_t min_msg_size = _LIB9P_MAX(lib9p_version_min_Rerror_size(ctx->basectx.version),
 	                                   lib9p_version_min_Rread_size(ctx->basectx.version)+1);
 	if (req->max_msg_size < min_msg_size) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EDOM, "requested max_msg_size is less than minimum for %s (%"PRIu32" < %"PRIu32")",
-		             lib9p_version_str(version), req->max_msg_size, min_msg_size);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EDOM, "requested max_msg_size is less than minimum for ", lib9p_version_str(version),
+		            " (", req->max_msg_size, " < ", min_msg_size,")");
 		goto tversion_return;
 	}
 
@@ -780,7 +771,7 @@ static void handle_Tversion(struct srv_req *ctx,
 	MAP_FOREACH(&ctx->parent_sess->fids, fid, fidinfo) {
 		srv_fid_del(ctx, fid, fidinfo, false);
 		if (lib9p_ctx_has_error(&ctx->basectx)) {
-			srv_nonrespond_errorf("clunk: %.*s", CONFIG_9P_MAX_ERR_SIZE, ctx->basectx.err_msg);
+			srv_nonrespond_error("clunk: ", (strn, ctx->basectx.err_msg, CONFIG_9P_MAX_ERR_SIZE));
 			lib9p_ctx_clear_error(&ctx->basectx);
 		}
 	}
@@ -839,21 +830,22 @@ static void handle_Tattach(struct srv_req *ctx,
 			lib9p_error(&ctx->basectx,
 			            LIB9P_ERRNO_L_EACCES, "FID provided as auth-file is not an auth-file");
 		else if (!lib9p_str_eq(afid->user->name, req->uname))
-			lib9p_errorf(&ctx->basectx,
-			             LIB9P_ERRNO_L_EACCES, "FID provided as auth-file is for user=\"%.*s\" and cannot be used for user=\"%.*s\"",
-			             afid->user->name.len, afid->user->name.utf8,
-			             req->uname.len, req->uname.utf8);
+			lib9p_error(&ctx->basectx,
+			            LIB9P_ERRNO_L_EACCES,
+			            "FID provided as auth-file is for user=", (qmem, afid->user->name.utf8, afid->user->name.len),
+			            " and cannot be used for user=", (qmem, req->uname.utf8, req->uname.len));
 #if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L
 		else if (afid->user->num != req->unum)
-			lib9p_errorf(&ctx->basectx,
-			             LIB9P_ERRNO_L_EACCES, "FID provided as auth-file is for user=%"PRIu32" and cannot be used for user=%"PRIu32,
-			             afid->user->num, req->unum);
+			lib9p_error(&ctx->basectx,
+			            LIB9P_ERRNO_L_EACCES,
+			            "FID provided as auth-file is for user=", afid->user->num,
+			            " and cannot be used for user=", req->unum);
 #endif
 		else if (!lib9p_str_eq(afid->auth.aname, req->aname))
-			lib9p_errorf(&ctx->basectx,
-			             LIB9P_ERRNO_L_EACCES, "FID provided as auth-file is for tree=\"%.*s\" and cannot be used for tree=\"%.*s\"",
-			             afid->auth.aname.len, afid->auth.aname.utf8,
-			             req->aname.len, req->aname.utf8);
+			lib9p_error(&ctx->basectx,
+			            LIB9P_ERRNO_L_EACCES,
+			            "FID provided as auth-file is for tree=", (qmem, afid->auth.aname.utf8, afid->auth.aname.len),
+			            " and cannot be used for tree=", (qmem, req->aname.utf8, req->aname.len));
 		else if (!afid->auth.completed)
 			lib9p_error(&ctx->basectx,
 			            LIB9P_ERRNO_L_EACCES, "FID provided as auth-file has not completed authentication");
@@ -905,11 +897,11 @@ static void handle_Tflush(struct srv_req *ctx,
 		switch (cr_select_l(CR_SELECT_RECV(&oldreq->flush_ch, &res),
 		                    CR_SELECT_SEND(&ctx->flush_ch, &res))) {
 		case 0: /* original request returned */
-			req_debugf("original request (tag=%"PRIu16") returned", req->oldtag);
+			req_debug("original request (tag=", req->oldtag, ") returned");
 			ctx->flush_acknowledged = (res == _LIB9P_SRV_FLUSH_SILENT);
 			break;
 		case 1: /* flush itself got flushed */
-			req_debugf("flush itself flushed");
+			req_debug("flush itself flushed");
 			ctx->flush_acknowledged = true;
 			break;
 		}
@@ -929,8 +921,8 @@ static void handle_Twalk(struct srv_req *ctx,
 
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		             LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto twalk_return;
 	}
 	if (fidinfo->flags & FIDFLAG_OPEN) {
@@ -1007,8 +999,8 @@ static void handle_Topen(struct srv_req *ctx,
 	/* Check that the FID is valid for this.  */
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto topen_return;
 	}
 	if (fidinfo->flags & FIDFLAG_OPEN) {
@@ -1177,8 +1169,8 @@ static void handle_Tread(struct srv_req *ctx,
 	/* Check that the FID is valid for this.  */
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto tread_return;
 	}
 	if (!(fidinfo->flags & FIDFLAG_OPEN_R)) {
@@ -1198,9 +1190,8 @@ static void handle_Tread(struct srv_req *ctx,
 			fidinfo->dir.off = 0;
 			fidinfo->dir.buffered_dirent = (struct lib9p_srv_dirent){};
 		} else if (req->offset != fidinfo->dir.off) {
-			lib9p_errorf(&ctx->basectx,
-			             LIB9P_ERRNO_L_EINVAL, "invalid offset (must be 0 or %"PRIu64"): %"PRIu64,
-			             fidinfo->dir.off, req->offset);
+			lib9p_error(&ctx->basectx,
+			            LIB9P_ERRNO_L_EINVAL, "invalid offset (must be 0 or ", fidinfo->dir.off, "): ", req->offset);
 			goto tread_return;
 		}
 		/* Read.  */
@@ -1299,8 +1290,8 @@ static void handle_Twrite(struct srv_req *ctx,
 	/* Check that the FID is valid for this.  */
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto twrite_return;
 	}
 	if (!(fidinfo->flags & FIDFLAG_OPEN_W)) {
@@ -1326,8 +1317,8 @@ static void handle_Tclunk(struct srv_req *ctx,
 
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto tclunk_return;
 	}
 
@@ -1343,8 +1334,8 @@ static void handle_Tremove(struct srv_req *ctx,
 
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto tremove_return;
 	}
 
@@ -1379,8 +1370,8 @@ static void handle_Tstat(struct srv_req *ctx,
 
 	struct srv_fidinfo *fidinfo = map_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
-		lib9p_errorf(&ctx->basectx,
-		             LIB9P_ERRNO_L_EBADF, "bad file number %"PRIu32, req->fid);
+		lib9p_error(&ctx->basectx,
+		            LIB9P_ERRNO_L_EBADF, "bad file number ", req->fid);
 		goto tstat_return;
 	}
 	struct srv_pathinfo *pathinfo = map_load(&ctx->parent_sess->paths, fidinfo->path);
diff --git a/lib9p/tests/test_server/main.c b/lib9p/tests/test_server/main.c
index 9724e25..4caff16 100644
--- a/lib9p/tests/test_server/main.c
+++ b/lib9p/tests/test_server/main.c
@@ -128,22 +128,26 @@ static COROUTINE init_cr(void *) {
 	cr_exit();
 }
 
-static void log_fct(char character, void *_stream) {
-	FILE *stream = _stream;
-	putc(character, stream);
-	putchar(character);
+struct tstlog_stdout {};
+LO_IMPLEMENTATION_H(fmt_dest, struct tstlog_stdout, tstlog_stdout);
+LO_IMPLEMENTATION_C(fmt_dest, struct tstlog_stdout, tstlog_stdout, static);
+
+static size_t tstlog_bytes = 0;
+
+static void tstlog_stdout_putb(struct tstlog_stdout *, uint8_t b) {
+	putc(b, globals.logstream);
+	putchar(b);
+	tstlog_bytes++;
 }
 
-static void log_msg(struct lib9p_srv_ctx *ctx, enum lib9p_msg_type typ, void *hostmsg) {
-	/* It sucks that %v trips -Wformat and -Wformat-extra-args
-	 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47781 */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat"
-#pragma GCC diagnostic ignored "-Wformat-extra-args"
-	fmt_fctprintf(log_fct, globals.logstream,
-	              "%c %v\n", typ % 2 ? '<' : '>',
-	              lo_box_lib9p_msg_as_fmt_formatter(&ctx->basectx, typ, hostmsg));
-#pragma GCC diagnostic pop
+static size_t tstlog_stdout_tell(struct tstlog_stdout *) {
+	return tstlog_bytes;
+}
+
+static lo_interface fmt_dest tstlog_dest = { .vtable = &_lo_tstlog_stdout_fmt_dest_vtable };
+
+static void tstlog_msg(struct lib9p_srv_ctx *ctx, enum lib9p_msg_type typ, void *hostmsg) {
+	fmt_print(tstlog_dest, typ % 2 ? "< " : "> ", (lib9p_msg, &ctx->basectx, typ, hostmsg), "\n");
 	fflush(globals.logstream);
 }
 
@@ -155,7 +159,7 @@ int main(int argc, char *argv[]) {
 	globals.logstream = fopen(argv[2], "w");
 	if (!globals.logstream)
 		error(2, errno, "fopen");
-	globals.srv.msglog = log_msg;
+	globals.srv.msglog = tstlog_msg;
 
 	struct hostclock clock_monotonic = {
 		.clock_id = CLOCK_MONOTONIC,