Factor out a libhw

9 files changed, 10 insertions, 1235 deletions

diff --git a/cmd/sbc_harness/CMakeLists.txt b/cmd/sbc_harness/CMakeLists.txt
index d6261cb..57ebe99 100644
--- a/cmd/sbc_harness/CMakeLists.txt
+++ b/cmd/sbc_harness/CMakeLists.txt
@@ -8,20 +8,17 @@ if (PICO_PLATFORM STREQUAL "rp2040")
 add_executable(sbc_harness
 	main.c
 	usb_keyboard.c
-	hw/rp2040_hwspi.c
-	hw/w5500.c
 )
 target_include_directories(sbc_harness PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/config)
 target_include_directories(sbc_harness PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(sbc_harness
 	pico_stdlib
 	hardware_flash
-	hardware_gpio
-	hardware_spi
 
 	libmisc
 	libusb
 	#libdhcp
+	libhw
 )
 
 pico_enable_stdio_usb(sbc_harness 0)
diff --git a/cmd/sbc_harness/hw/rp2040_hwspi.c b/cmd/sbc_harness/hw/rp2040_hwspi.c
deleted file mode 100644
index 6742c60..0000000
--- a/cmd/sbc_harness/hw/rp2040_hwspi.c
+++ /dev/null
@@ -1,123 +0,0 @@
-/* hw/rp2040_hwspi.c - `implements_spi` implementation for the RP2040's
- *                     ARM Primecell SSP (PL022) (implementation file)
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#include <assert.h>
-
-#include <hardware/spi.h>  /* pico-sdk:hardware_spi */
-#include <hardware/gpio.h> /* pico-sdk:hardware_gpio5 */
-
-#include <libmisc/vcall.h>
-
-#include "hw/rp2040_hwspi.h"
-
-static void rp2040_hwspi_readwritev(implements_spi *, const struct bidi_iovec *iov, int iovcnt);
-
-struct spi_vtable rp2040_hwspi_vtable = {
-	.readwritev = rp2040_hwspi_readwritev,
-};
-
-void _rp2040_hwspi_init(struct rp2040_hwspi *self,
-                        enum rp2040_hwspi_instance inst_num,
-                        enum spi_mode mode,
-                        uint baudrate_hz,
-                        uint pin_miso,
-                        uint pin_mosi,
-                        uint pin_clk,
-                        uint pin_cs) {
-	/* Be not weary: This is but 12 lines of actual code; and many
-	 * lines of comments and assert()s.  */
-	spi_inst_t *inst;
-
-	assert(self);
-	assert(baudrate_hz);
-	assert(pin_miso != pin_mosi);
-	assert(pin_miso != pin_clk);
-	assert(pin_miso != pin_cs);
-	assert(pin_mosi != pin_clk);
-	assert(pin_mosi != pin_cs);
-	assert(pin_clk != pin_cs);
-
-	/* I know we called this "hwspi", but we're actually going to
-	 * disconnect the CS pin from the PL022 SSP and manually drive
-	 * it from software.  This is because the PL022 has a maximum
-	 * of 16-bit frames, while we need to be able to do *at least*
-	 * 32-bit frames (and ideally, much larger).  By managing it
-	 * ourselves, we can just keep CS pulled low extra-long,
-	 * making the frame extra-long.  */
-
-	/* Regarding the constraints on pin assignments: see the
-	 * RP2040 datasheet, table 2, in §1.4.3 "GPIO Functions".  */
-	switch (inst_num) {
-	case RP2040_HWSPI_0:
-		inst = spi0;
-		assert(pin_miso ==  0 || pin_miso ==  4 || pin_miso == 16 || pin_miso == 20);
-		/*assert(pin_cs   ==  1 || pin_cs   ==  5 || pin_cs   == 17 || pin_cs   == 21);*/
-		assert(pin_clk  ==  2 || pin_clk  ==  6 || pin_clk  == 18 || pin_clk  == 22);
-		assert(pin_mosi ==  3 || pin_mosi ==  7 || pin_mosi == 19 || pin_mosi == 23);
-		break;
-	case RP2040_HWSPI_1:
-		inst = spi1;
-		assert(pin_miso ==  8 || pin_miso == 12 || pin_miso == 24 || pin_miso == 28);
-		/*assert(pin_cs   ==  9 || pin_cs   == 13 || pin_cs   == 25 || pin_cs   == 29);*/
-		assert(pin_clk  == 10 || pin_clk  == 14 || pin_clk  == 26);
-		assert(pin_mosi == 11 || pin_mosi == 15 || pin_mosi == 27);
-		break;
-	default:
-		assert(false);
-	}
-
-	spi_init(inst, baudrate_hz);
-	spi_set_format(inst, 8,
-	               (mode & 0b10) ? SPI_CPOL_1 : SPI_CPOL_0,
-	               (mode & 0b01) ? SPI_CPHA_1 : SPI_CPHA_0,
-	               SPI_MSB_FIRST);
-
-	/* Connect the pins to the PL022; set them each to "function
-	 * 1" (again, see the RP2040 datasheet, table 2, in §1.4.3
-	 * "GPIO Functions").
-	 *
-	 * ("GPIO_FUNC_SPI" is how the pico-sdk spells "function 1",
-	 * since on the RP2040 all of the "function 1" functions are
-	 * some part of SPI.)  */
-	gpio_set_function(pin_clk,  GPIO_FUNC_SPI);
-	gpio_set_function(pin_mosi, GPIO_FUNC_SPI);
-	gpio_set_function(pin_miso, GPIO_FUNC_SPI);
-
-	/* Initialize the CS pin for software control.  */
-	gpio_init(pin_cs);
-	gpio_set_dir(pin_cs, GPIO_OUT);
-	gpio_put(pin_cs, 1);
-
-	/* Return.  */
-	self->vtable = &rp2040_hwspi_vtable;
-	self->inst = inst;
-	self->pin_cs = pin_cs;
-}
-
-static void rp2040_hwspi_readwritev(implements_spi *_self, const struct bidi_iovec *iov, int iovcnt) {
-	struct rp2040_hwspi *self = VCALL_SELF(struct rp2040_hwspi, implements_spi, _self);
-	assert(self);
-	spi_inst_t *inst = self->inst;
-
-	assert(inst);
-	assert(iov);
-	assert(iovcnt);
-
-	gpio_put(self->pin_cs, 0);
-	/* TODO: Replace blocking reads+writes with DMA.  */
-	for (int i = 0; i < iovcnt; i++) {
-		if (iov[i].iov_write_src && iov[i].iov_read_dst)
-			spi_write_read_blocking(inst, iov[i].iov_write_src, iov[i].iov_read_dst, iov[i].iov_len);
-		else if (iov[i].iov_write_src)
-			spi_write_blocking(inst, iov[i].iov_write_src, iov[i].iov_len);
-		else if (iov[i].iov_read_dst)
-			spi_read_blocking(inst, 0, iov[i].iov_read_dst, iov[i].iov_len);
-		else
-			assert(false);
-	}
-	gpio_put(self->pin_cs, 1);
-}
diff --git a/cmd/sbc_harness/hw/rp2040_hwspi.h b/cmd/sbc_harness/hw/rp2040_hwspi.h
deleted file mode 100644
index 393eae6..0000000
--- a/cmd/sbc_harness/hw/rp2040_hwspi.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* hw/rp2040_hwspi.h - `implements_spi` implementation for the RP2040's
- *                     ARM Primecell SSP (PL022) (header file)
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#ifndef _HW_RP2040_HWSPI_H_
-#define _HW_RP2040_HWSPI_H_
-
-#include <pico/binary_info.h> /* for bi_* */
-
-#include "hw/spi.h"
-
-enum rp2040_hwspi_instance {
-	RP2040_HWSPI_0 = 0,
-	RP2040_HWSPI_1 = 1,
-};
-
-struct rp2040_hwspi {
-	implements_spi;
-
-	void /*spi_inst_t*/    *inst;
-	uint                    pin_cs;
-};
-
-/**
- * Initialize an instance of `struct rp2040_hwspi`.
- *
- * @param self     : struct rp2040_hwspi        : the structure to initialize
- * @param name     : char *                     : a name for the SPI port; to include in the bininfo
- * @param inst_num : enum rp2040_hwspi_instance : the PL220 instance number; RP2040_HWSPI_{0,1}
- * @param mode     : enum spi_mode              : the SPI mode; SPI_MODE_{0..3}
- * @param pin_miso : uint                       : pin number; 0, 4, 16, or 20 for _HWSPI_0; 8, 12, 24, or 28 for _HWSPI_1
- * @param pin_mosi : uint                       : pin number; 3, 7, 19, or 23 for _HWSPI_0; 11, 15, or 27 for _HWSPI_1
- * @param pin_clk  : uint                       : pin number; 2, 6, 18, or 22 for _HWSPI_0; 10, 14, or 26 for _HWSPI_1
- * @param pin_cs   : uint                       : pin number; any unused GPIO pin
- *
- * There is no bit-order argument; the RP2040's hardware SPI always
- * uses MSB-first bit order.
- */
-#define rp2040_hwspi_init(self, name,                                    \
-                          inst_num, mode, baudrate_hz,                   \
-                          pin_miso, pin_mosi, pin_clk, pin_cs)           \
-	do {                                                             \
-		bi_decl(bi_4pins_with_names(pin_miso, name" SPI MISO",   \
-		                            pin_mosi, name" SPI MOSI",   \
-		                            pin_mosi, name" SPI CLK",    \
-		                            pin_mosi, name" SPI CS"));   \
-		_rp2040_hwspi_init(self,                                 \
-		                   inst_num, mode, baudrate_hz,          \
-		                   pin_miso, pin_mosi, pin_clk, pin_cs); \
-	} while(0)
-void _rp2040_hwspi_init(struct rp2040_hwspi *self,
-                        enum rp2040_hwspi_instance inst_num,
-                        enum spi_mode mode,
-                        uint baudrate_hz,
-                        uint pin_miso,
-                        uint pin_mosi,
-                        uint pin_clk,
-                        uint pin_cs);
-
-#endif /* _HW_RP2040_HWSPI_H_ */
diff --git a/cmd/sbc_harness/hw/spi.h b/cmd/sbc_harness/hw/spi.h
deleted file mode 100644
index da588de..0000000
--- a/cmd/sbc_harness/hw/spi.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/* hw/spi.h - Generic SPI definitions
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#ifndef _HW_SPI_H_
-#define _HW_SPI_H_
-
-#include <stddef.h> /* for size_t */
-
-enum spi_mode {
-	SPI_MODE_0 = 0, /* clk_polarity=0 (idle low), clk_phase=0 (sample on rise) */
-	SPI_MODE_1 = 1, /* clk_polarity=0 (idle low), clk_phase=1 (sample on fall) */
-	SPI_MODE_2 = 2, /* clk_polarity=1 (idle high), clk_phase=0 (sample on rise) */
-	SPI_MODE_3 = 3, /* clk_polarity=1 (idle high), clk_phase=1 (sample on fall) */
-};
-
-struct bidi_iovec {
-	void    *iov_read_dst;
-	void    *iov_write_src;
-	size_t   iov_len;
-};
-
-struct spi_vtable;
-
-typedef struct {
-	struct spi_vtable      *vtable;
-} implements_spi;
-
-/* This API assumes that an SPI frame is a multiple of 8-bits.
- *
- * It is my understanding that this is a common constraint of SPI
- * hardware, and that the RP2040 is somewhat unusual in that it allows
- * frames of any length 4-16 bits (we disconnect the CS pin from the
- * PL022 SSP and manually GPIO it from the CPU in order to achieve
- * longer frames).
- *
- * But, more relevantly: The W5500's protocol uses frames that are 4-N
- * octets; so we have no need for an API that allows a
- * non-multiple-of-8 number of bits.
- */
-struct spi_vtable {
-	void (*readwritev)(implements_spi *, const struct bidi_iovec *iov, int iovcnt);
-};
-
-#endif /* _HW_SPI_H_ */
diff --git a/cmd/sbc_harness/hw/w5500.c b/cmd/sbc_harness/hw/w5500.c
deleted file mode 100644
index 5e36bcf..0000000
--- a/cmd/sbc_harness/hw/w5500.c
+++ /dev/null
@@ -1,526 +0,0 @@
-/* hw/w5500.c - libmisc/net.h implementation for the WIZnet W5500 chip
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- *
- * -----------------------------------------------------------------------------
- * https://github.com/Wiznet/ioLibrary_Driver/blob/b981401e7f3d07015619adf44c13998e13e777f9/Ethernet/wizchip_conf.c
- * https://github.com/Wiznet/ioLibrary_Driver/blob/b981401e7f3d07015619adf44c13998e13e777f9/Ethernet/W5500/w5500.h
- * https://github.com/Wiznet/ioLibrary_Driver/blob/b981401e7f3d07015619adf44c13998e13e777f9/Ethernet/W5500/w5500.c
- * https://github.com/Wiznet/ioLibrary_Driver/blob/b981401e7f3d07015619adf44c13998e13e777f9/Ethernet/socket.c
- *
- * Copyright (c)  2013, WIZnet Co., LTD.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *     * Neither the name of the <ORGANIZATION> nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
- * THE POSSIBILITY OF SUCH DAMAGE.
- *
- * SPDX-Licence-Identifier: BSD-3-Clause
- *
- * -----------------------------------------------------------------------------
- * https://github.com/Wiznet/ioLibrary_Driver/blob/b981401e7f3d07015619adf44c13998e13e777f9/license.txt
- *
- * Copyright (c) 2014 WIZnet Co.,Ltd.
- * Copyright (c) WIZnet ioLibrary Project.
- * All rights reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- *
- * SPDX-Licence-Identifier: MIT
- */
-
-#include <pico/time.h>     /* for sleep_ms() */
-#include <hardware/gpio.h> /* pico-sdk:hardware_gpio */
-
-#include <libcr/coroutine.h> /* for cr_yield() */
-#include <libmisc/vcall.h>   /* for VCALL_SELF() */
-
-#include "hw/w5500_ll.h"
-#include "hw/w5500.h"
-
-/* Config *********************************************************************/
-
-#include "config.h"
-
-/* These are the default values of the Linux kernel's
- * net.ipv4.ip_local_port_range, so I figure they're probably good
- * values to use.  */
-#ifndef CONFIG_W5500_LOCAL_PORT_MIN
-	#define CONFIG_W5500_LOCAL_PORT_MIN 32768
-#endif
-
-#ifndef CONFIG_W5500_LOCAL_PORT_MAX
-	#define CONFIG_W5500_LOCAL_PORT_MAX 60999
-#endif
-
-#ifndef CONFIG_W5500_NUM
-	#error config.h must define CONFIG_W5500_NUM
-#endif
-
-/* C language *****************************************************************/
-
-#define UNUSED(name)
-#define ARRAY_LEN(ary) (sizeof(ary)/sizeof((ary)[0]))
-
-/* mid-level utilities ********************************************************/
-
-#if 0
-static uint16_t w5500_get_local_port(struct w5500 *self) {
-	uint16_t ret = self->next_local_port++;
-	if (self->next_local_port > CONFIG_W5500_LOCAL_PORT_MAX)
-		self->next_local_port = CONFIG_W5500_LOCAL_PORT_MIN;
-	return ret;
-}
-#endif
-
-static COROUTINE w5500_irq_cr(void *_chip) {
-	struct w5500 *chip = _chip;
-	cr_begin();
-
-	for (;;) {
-		cr_sema_wait(&chip->intr);
-		if (w5500ll_read_common_reg(chip->spidev, chip_interrupt))
-			w5500ll_write_common_reg(chip->spidev, chip_interrupt, 0xFF);
-
-		uint8_t sockmask = w5500ll_read_common_reg(chip->spidev, sock_interrupt);
-		for (uint8_t socknum = 0; socknum < 8; socknum++) {
-			if (!(sockmask & (1<<socknum)))
-				continue;
-			struct _w5500_tcp_listener *listener = &chip->listeners[socknum];
-
-			uint8_t sockintr = w5500ll_read_sock_reg(chip->spidev, socknum, interrupt);
-
-			/* SOCKINTR_SEND_OK is useless.  */
-			uint8_t listen_bits = sockintr & (SOCKINTR_TIMEOUT|SOCKINTR_CONN),
-				read_bits   = sockintr & (SOCKINTR_TIMEOUT|SOCKINTR_RECV|SOCKINTR_FIN);
-
-			if (listen_bits)
-				cr_sema_signal(&listener->listen_sema);
-			if (read_bits)
-				cr_sema_signal(&listener->read_sema);
-
-			w5500ll_write_sock_reg(chip->spidev, socknum, interrupt, sockintr);
-		}
-	}
-
-	cr_end();
-}
-
-/* init() *********************************************************************/
-
-static implements_net_stream_conn *w5500_tcp_accept(implements_net_stream_listener *listener);
-static ssize_t w5500_tcp_read(implements_net_stream_conn *conn, void *buf, size_t count);
-static ssize_t w5500_tcp_write(implements_net_stream_conn *conn, void *buf, size_t count);
-static int w5500_tcp_close(implements_net_stream_conn *conn, bool rd, bool wr);
-
-static struct net_stream_listener_vtable w5500_tcp_listener_vtable = {
-	.accept = w5500_tcp_accept,
-};
-
-static struct net_stream_conn_vtable w5500_tcp_conn_vtable = {
-	.read  = w5500_tcp_read,
-	.write = w5500_tcp_write,
-	.close = w5500_tcp_close,
-};
-
-static struct w5500 *w5500_chips[CONFIG_W5500_NUM] = {0};
-
-static void w5500_intrhandler(uint gpio, uint32_t UNUSED(event_mask)) {
-	for (size_t i = 0; i < ARRAY_LEN(w5500_chips); i++)
-		if (w5500_chips[i] && w5500_chips[i]->pin_intr == gpio)
-			cr_sema_signal_from_intrhandler(&w5500_chips[i]->intr);
-}
-
-void _w5500_init(struct w5500 *chip,
-                 implements_spi *spi, uint pin_intr, uint pin_reset,
-                 struct net_eth_addr addr) {
-	assert(chip);
-	assert(spi);
-
-	/* Initialize the data structures.  */
-	*chip = (struct w5500){
-		/* const-after-init */
-		.spidev          = spi,
-		.pin_intr        = pin_intr,
-		.pin_reset       = pin_reset,
-		.hwaddr          = addr,
-		/* mutable */
-		.next_local_port = CONFIG_W5500_LOCAL_PORT_MIN,
-	};
-	for (uint8_t i = 0; i < 8; i++) {
-		chip->listeners[i] = (struct _w5500_tcp_listener){
-			/* const-after-init */
-			.vtable = &w5500_tcp_listener_vtable,
-			.socknum = i,
-			.active_conn = {
-				/* const-after-init */
-				.vtable = &w5500_tcp_conn_vtable,
-				/* mutable */
-				.read_open = false,
-				.write_open = false,
-			},
-			/* mutable */
-			.port = 0,
-		};
-	}
-
-	/* Initialize the hardware.  */
-	gpio_set_irq_enabled_with_callback(pin_intr, GPIO_IRQ_EDGE_FALL, true, w5500_intrhandler);
-	gpio_set_dir(chip->pin_reset, GPIO_OUT);
-	w5500_hard_reset(chip);
-
-	/* Finally, wire in the interrupt handler.  */
-	cr_disable_interrupts();
-	for (size_t i = 0; i < ARRAY_LEN(w5500_chips); i++) {
-		if (w5500_chips[i] == NULL) {
-			w5500_chips[i] = chip;
-			break;
-		}
-	}
-	cr_enable_interrupts();
-	coroutine_add(w5500_irq_cr, chip);
-}
-
-/* chip methods ***************************************************************/
-
-static inline void w5500_post_reset(struct w5500 *chip) {
-	/* The W5500 does not have a built-in MAC address, we must
-	 * provide one.  */
-	w5500ll_write_common_reg(chip->spidev, eth_addr, chip->hwaddr);
-
-	/* The RP2040 needs a 1/sys_clk hysteresis between interrupts
-	 * for us to notice them.  At the maximum-rated clock-rate of
-	 * 133MHz, that means 7.5ns (but the sbc-harness overclocks
-	 * the RP2040, so we could get away with even shorter).
-	 *
-	 * If intlevel is non-zero, then the hysteresis is
-	 * (intlevel+1)*4/(150MHz), or (intlevel+1)*26.7ns; so even
-	 * the shortest-possible hysteresis much larger than necessary
-	 * for us.  */
-	w5500ll_write_common_reg(chip->spidev, intlevel, uint16be_marshal(1));
-
-	/* This implementation does not care about any of the
-	 * chip-level interrupts.  */
-	w5500ll_write_common_reg(chip->spidev, chip_interrupt_mask, 0);
-
-	/* This implementation cares about interrupts for each
-	 * socket.  */
-	w5500ll_write_common_reg(chip->spidev, sock_interrupt_mask, 0xFF);
-
-	/* Configure retry/timeout.
-	 *
-	 *     timeout_arp = 0.1ms * retry_time * (retry_count+1)
-	 *
-	 *                                        retry_count
-	 *     timeout_tcp = 0.1ms * retry_time * Σ 2^min(n, floor(1+log_2(65535/retry_time)))
-	 *                                        n=0
-	 *
-	 * For retry_time=2000, retry_count=3, this means
-	 *
-	 *     timeout_arp = 0.8s
-	 *     timeout_tcp = 3.0s
-	 */
-	w5500ll_write_common_reg(chip->spidev, retry_time, uint16be_marshal(2000));
-	w5500ll_write_common_reg(chip->spidev, retry_count, 3);
-}
-
-void w5500_hard_reset(struct w5500 *chip) {
-	/* TODO: Replace blocking sleep_ms() with something libcr-friendly.  */
-	gpio_put(chip->pin_reset, 0);
-	sleep_ms(1); /* minimum of 500us */
-	gpio_put(chip->pin_reset, 1);
-	sleep_ms(2); /* minimum of 1ms */
-
-	w5500_post_reset(chip);
-}
-
-void w5500_soft_reset(struct w5500 *chip) {
-	w5500ll_write_common_reg(chip->spidev, mode, CHIPMODE_RST);
-	while (w5500ll_read_common_reg(chip->spidev, mode) & CHIPMODE_RST)
-		cr_yield();
-
-	w5500_post_reset(chip);
-}
-
-void w5500_netcfg(struct w5500 *chip, struct w5500_netcfg cfg) {
-	w5500ll_write_common_reg(chip->spidev, ip_gateway_addr, cfg.gateway_addr);
-	w5500ll_write_common_reg(chip->spidev, ip_subnet_mask, cfg.subnet_mask);
-	w5500ll_write_common_reg(chip->spidev, ip_addr, cfg.addr);
-}
-
-implements_net_stream_listener *w5500_tcp_listen(struct w5500 *chip, uint8_t socknum,
-                                                 uint16_t port) {
-	assert(chip);
-	assert(socknum < 8);
-	assert(port);
-
-	assert(chip->listeners[socknum].port == 0);
-	chip->listeners[socknum].port = port;
-
-	return &chip->listeners[socknum];
-}
-
-/*
-implements_net_packet_conn *w5500_udp_conn(struct w5500 *chip, uint8_t socknum,
-                                           uint16_t port) {
-	assert(chip);
-	assert(socknum < 8);
-	assert(port);
-
-	assert(chip->listeners[socknum].port == 0);
-	chip->listeners[socknum].port = port;
-
-	return &chip->listeners[socknum];
-}
-*/
-
-/* tcp_listener methods *******************************************************/
-
-static struct w5500 *w5500_tcp_listener_chip(struct _w5500_tcp_listener *listener) {
-	assert(listener);
-	assert(listener->socknum < 8);
-
-	struct _w5500_tcp_listener *sock0 = &listener[-listener->socknum];
-	assert(sock0);
-	struct w5500 *chip =
-		((void *)sock0) - offsetof(struct w5500, listeners);
-	assert(chip);
-	return chip;
-}
-
-static inline void w5500_tcp_listener_cmd(struct _w5500_tcp_listener *listener, uint8_t cmd) {
-	assert(listener);
-	struct w5500 *chip = w5500_tcp_listener_chip(listener);
-	uint8_t socknum = listener->socknum;
-
-	cr_mutex_lock(&listener->cmd_mu);
-	w5500ll_write_sock_reg(chip->spidev, socknum, command, cmd);
-	while (w5500ll_read_sock_reg(chip->spidev, socknum, command) != 0x00)
-		cr_yield();
-	cr_mutex_unlock(&listener->cmd_mu);
-}
-
-static inline void w5500_tcp_listener_cmd_close(struct _w5500_tcp_listener *listener) {
-	assert(listener);
-	struct w5500 *chip = w5500_tcp_listener_chip(listener);
-	uint8_t socknum = listener->socknum;
-
-	w5500_tcp_listener_cmd(listener, CMD_CLOSE);
-	w5500ll_write_sock_reg(chip->spidev, socknum, interrupt, 0xFF);
-	while (w5500ll_read_sock_reg(chip->spidev, socknum, state) != STATE_CLOSED)
-		cr_yield();
-
-	listener->active_conn.read_open = listener->active_conn.write_open = false;
-}
-
-#define ASSERT_LISTENER()                                          \
-	struct _w5500_tcp_listener *self =                         \
-		VCALL_SELF(struct _w5500_tcp_listener,             \
-		           implements_net_stream_listener, _self); \
-	struct w5500 *chip = w5500_tcp_listener_chip(self);        \
-	uint8_t socknum = self->socknum;
-
-static implements_net_stream_conn *w5500_tcp_accept(implements_net_stream_listener *_self) {
-	ASSERT_LISTENER();
-
- restart:
-	/* Mimics socket.c:socket().  */
-	w5500_tcp_listener_cmd_close(self);
-	w5500ll_write_sock_reg(chip->spidev, socknum, mode, SOCKMODE_TCP);
-	w5500ll_write_sock_reg(chip->spidev, socknum, local_port, uint16be_marshal(self->port));
-	w5500_tcp_listener_cmd(self, CMD_OPEN);
-	while (w5500ll_read_sock_reg(chip->spidev, socknum, state) != STATE_TCP_INIT)
-		cr_yield();
-
-	/* Mimics socket.c:listen().  */
-	w5500_tcp_listener_cmd(self, CMD_LISTEN);
-	for (;;) {
-		uint8_t state = w5500ll_read_sock_reg(chip->spidev, socknum, state);
-		switch (state) {
-		case STATE_TCP_LISTEN:
-		case STATE_TCP_SYNRECV:
-			cr_sema_wait(&self->listen_sema);
-			break;
-		case STATE_TCP_ESTABLISHED:
-			self->active_conn.read_open = true;
-			/* fall-through */
-		case STATE_TCP_CLOSE_WAIT:
-			self->active_conn.write_open = true;
-			return &self->active_conn;
-		default:
-			goto restart;
-		}
-	}
-}
-
-/* tcp_conn methods ***********************************************************/
-
-static struct _w5500_tcp_listener *w5500_tcp_conn_listener(struct _w5500_tcp_conn *conn) {
-	assert(conn);
-
-	struct _w5500_tcp_listener *list =
-		((void *)conn) - offsetof(struct _w5500_tcp_listener, active_conn);
-	return list;
-}
-
-#define ASSERT_CONN()                                                       \
-	struct _w5500_tcp_conn *self =                                          \
-		VCALL_SELF(struct _w5500_tcp_conn, implements_net_stream_conn, _self); \
-	struct _w5500_tcp_listener *listener = w5500_tcp_conn_listener(self);   \
-	struct w5500 *chip = w5500_tcp_listener_chip(listener);             \
-	uint8_t socknum = listener->socknum;
-
-static ssize_t w5500_tcp_write(implements_net_stream_conn *_self, void *buf, size_t count) {
-	ASSERT_CONN();
-	assert(buf);
-	assert(count);
-
-	/* What we really want is to pause until we receive an ACK for
-	 * some data we just queued, so that we can line up some new
-	 * data to keep the buffer full.  But that's not what
-	 * SEND_FINIAIUI, the SEND_FINISHED interrupt doesn't fire
-	 * until we receive the *last* ACK for the data, when the
-	 * buffer is entirely empty.
-	 *
-	 * Which means we basically have to busy-poll for space in the
-	 * buffer becoming available.
-	 *
-	 * We'll add more data to the buffer whenever there is
-	 * `min_free_space` in the buffer (or the rest of the data
-	 * fits in the buffer).
-	 *
-	 * This `min_free_space` can probably stand to be tuned; must
-	 * be >0, <=bufsize.  `1500-58` is the 100BaseT MTU minus the
-	 * Ethernet+IP+TCP overhead.  */
-	uint16_t bufsize = ((uint16_t)w5500ll_read_sock_reg(chip->spidev, socknum, tx_buf_size))*1024;
-	uint16_t min_free_space = MIN(1500-58, bufsize/4);
-
-	size_t done = 0;
-	while (done < count) {
-		if (!self->write_open)
-			return -1;
-		uint8_t state = w5500ll_read_sock_reg(chip->spidev, socknum, state);
-		if (state != STATE_TCP_ESTABLISHED && state != STATE_TCP_CLOSE_WAIT)
-			return -1;
-
-		uint16_t freesize = uint16be_unmarshal(w5500ll_read_sock_reg(chip->spidev, socknum, tx_free_size));
-		if (freesize < count-done && freesize < min_free_space) {
-			/* Wait for more buffer space.  */
-			cr_yield();
-			continue;
-		}
-
-		/* Queue data to be sent.  */
-		uint16_t ptr = uint16be_unmarshal(w5500ll_read_sock_reg(chip->spidev, socknum, tx_write_pointer));
-		w5500ll_write(chip->spidev, ptr, CTL_BLOCK_SOCK(socknum, TX), &((char *)buf)[done], freesize);
-		w5500ll_write_sock_reg(chip->spidev, socknum, tx_write_pointer, uint16be_marshal(ptr+freesize));
-
-		/* Submit the queue.  */
-		w5500_tcp_listener_cmd(listener, CMD_SEND);
-		done += freesize;
-	}
-	return done;
-}
-
-static ssize_t w5500_tcp_read(implements_net_stream_conn *_self, void *buf, size_t count) {
-	ASSERT_CONN();
-	assert(buf);
-	assert(count);
-
-	size_t done = 0;
-	while (!done) {
-		if (!self->read_open)
-			return -1;
-		uint8_t state = w5500ll_read_sock_reg(chip->spidev, socknum, state);
-		switch (state) {
-		case STATE_TCP_CLOSE_WAIT:
-			return 0; /* EOF */
-		case STATE_TCP_ESTABLISHED: case STATE_TCP_FIN_WAIT:
-			break; /* OK */
-		default:
-			return -1;
-		}
-
-		uint16_t avail = uint16be_unmarshal(w5500ll_read_sock_reg(chip->spidev, socknum, rx_size));
-		if (!avail) {
-			cr_sema_wait(&listener->read_sema);
-			continue;
-		}
-		if ((size_t)avail > count)
-			avail = count;
-		uint16_t ptr = uint16be_unmarshal(w5500ll_read_sock_reg(chip->spidev, socknum, rx_read_pointer));
-		w5500ll_read(chip->spidev, ptr, CTL_BLOCK_SOCK(socknum, RX), &((char *)buf)[done], avail);
-		w5500ll_write_sock_reg(chip->spidev, socknum, rx_read_pointer, uint16be_marshal(ptr+avail));
-
-		w5500_tcp_listener_cmd(listener, CMD_RECV);
-		done += avail;
-	}
-	return done;
-}
-
-static int w5500_tcp_close(implements_net_stream_conn *_self, bool rd, bool wr) {
-	ASSERT_CONN();
-
-	if (rd)
-		self->read_open = false;
-
-	if (wr && self->write_open) {
-		w5500_tcp_listener_cmd(listener, CMD_DISCON);
-		while (self->write_open) {
-			uint8_t state = w5500ll_read_sock_reg(chip->spidev, socknum, state);
-			switch (state) {
-			case STATE_TCP_FIN_WAIT:
-				self->write_open = false;
-				/* Can still read */
-				if (!self->read_open)
-					w5500_tcp_listener_cmd_close(listener);
-				break;
-			case STATE_CLOSED:
-				self->write_open = false;
-				break;
-			}
-		}
-	}
-
-	return 0;
-}
-
-/* udp_conn methods ***********************************************************/
diff --git a/cmd/sbc_harness/hw/w5500.h b/cmd/sbc_harness/hw/w5500.h
deleted file mode 100644
index 2ff04df..0000000
--- a/cmd/sbc_harness/hw/w5500.h
+++ /dev/null
@@ -1,102 +0,0 @@
-/* hw/w5500.h - libmisc/net.h implementation for the WIZnet W5500 chip
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#ifndef _HW_W5500_H_
-#define _HW_W5500_H_
-
-#include <libcr_ipc/sema.h>
-#include <libcr_ipc/mutex.h>
-#include <libmisc/net.h>
-
-#include "hw/spi.h"
-
-struct _w5500_tcp_conn {
-	/* const-after-init */
-	implements_net_stream_conn;
-	/* mutable */
-	bool                             read_open;
-	bool                             write_open;
-};
-
-struct _w5500_tcp_listener {
-	/* const-after-init */
-	implements_net_stream_listener;
-	uint8_t                          socknum;
-	struct _w5500_tcp_conn           active_conn;
-
-	/* mutable */
-	uint16_t                         port;
-	cr_mutex_t                       cmd_mu;
-	cr_sema_t                        listen_sema, read_sema;
-};
-
-struct w5500 {
-	/* const-after-init */
-	implements_spi                  *spidev;
-	uint                             pin_intr;
-	uint                             pin_reset;
-	struct net_eth_addr              hwaddr;
-
-	/* mutable */
-	uint16_t                         next_local_port;
-	struct _w5500_tcp_listener       listeners[8];
-	cr_sema_t                        intr;
-};
-
-/**
- * Initialize a WIZnet W5500 Ethernet-and-TCP/IP-offload chip.
- *
- * The W5500 has 3 lines of communication with the MCU:
- *
- *  - An SPI-based RPC protocol:
- *    + mode: mode 0 or mode 3
- *    + bit-order: MSB-first
- *    + clock frequency: 33.3MHz - 80MHz
- *  - An interrupt pin that it pulls low when an event happens (to let
- *    the MCU know that it should do an SPI RPC "get" to see what
- *    happened.)
- *  - A reset pin that the MCU can pull low to reset the W5500.
- */
-#define w5500_init(self, name, spi, pin_intr, pin_reset, eth_addr) do { \
-		bi_decl(bi_2pins_with_names(pin_intr, name" interrupt", \
-		                            pin_reset, name" reset"));  \
-		_w5500_init(self, spi, pin_intr, pin_reset, eth_addr);  \
-	} while (0)
-void _w5500_init(struct w5500 *self,
-                 implements_spi *spi, uint pin_intr, uint pin_reset,
-                 struct net_eth_addr addr);
-
-/**
- * TODO.
- */
-void w5500_hard_reset(struct w5500 *self);
-
-/**
- * TODO.
- */
-void w5500_soft_reset(struct w5500 *self);
-
-struct w5500_netcfg {
-	struct net_ip4_addr gateway_addr;
-	struct net_ip4_addr subnet_mask;
-	struct net_ip4_addr addr;
-};
-
-/**
- * TODO.
- */
-void w5500_netcfg(struct w5500 *self, struct w5500_netcfg cfg);
-
-implements_net_stream_listener *w5500_tcp_listen(struct w5500 *self, uint8_t socknum,
-                                                 uint16_t port);
-
-/**
- * TODO.
- */
-implements_net_packet_conn *w5500_udp_conn(struct w5500 *self, uint8_t socknum,
-                                           uint16_t port);
-
-#endif /* _HW_W5500_H_ */
diff --git a/cmd/sbc_harness/hw/w5500_ll.h b/cmd/sbc_harness/hw/w5500_ll.h
deleted file mode 100644
index 4cc3b11..0000000
--- a/cmd/sbc_harness/hw/w5500_ll.h
+++ /dev/null
@@ -1,362 +0,0 @@
-/* hw/w5500_ll.h - Low-level header library for the WIZnet W5500 chip
- *
- * Based entirely on the W5500 datasheet, v1.1.0.
- * https://docs.wiznet.io/img/products/w5500/W5500_ds_v110e.pdf
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#ifndef _HW_W5500_LL_H_
-#define _HW_W5500_LL_H_
-
-#include <assert.h> /* for assert(), static_assert() */
-#include <stdint.h> /* for uint{n}_t */
-#include <string.h> /* for memcmp() */
-
-#include <libmisc/net.h>    /* for struct net_eth_addr, struct net_ip4_addr */
-#include <libmisc/vcall.h>  /* for VCALL() */
-#include <libmisc/endian.h> /* for uint16be_t */
-#include "hw/spi.h"         /* for implements_spi */
-
-
-/* Low-level protocol built on SPI frames.  ***********************************/
-
-/* A u8 control byte has 3 parts: block-ID, R/W, and operating-mode.  */
-
-/* Part 1: Block ID.  */
-#define CTL_MASK_BLOCK        0b11111000
-#define _CTL_BLOCK_RES           0b00000
-#define _CTL_BLOCK_REG           0b01000
-#define _CTL_BLOCK_TX            0b10000
-#define _CTL_BLOCK_RX            0b11000
-#define CTL_BLOCK_SOCK(n,part)  (((n)<<5)|(_CTL_BLOCK_##part))
-#define CTL_BLOCK_COMMON_REG CTL_BLOCK_SOCK(0,RES)
-
-/* Part 2: R/W.  */
-#define CTL_MASK_RW 0b100
-#define CTL_R       0b000
-#define CTL_W       0b100
-
-/* Part 3: Operating mode.  */
-#define CTL_MASK_OM 0b11
-#define CTL_OM_VDM  0b00
-#define CTL_OM_FDM1 0b01
-#define CTL_OM_FDM2 0b10
-#define CTL_OM_FDM4 0b11
-
-/* Even though SPI is a full-duplex protocol, the W5500's spiframe on top of it is only half-duplex.
- * Lame.  */
-
-static inline void
-w5500ll_write(implements_spi *spidev, uint16_t addr, uint8_t block, void *data, size_t data_len) {
-	assert(spidev);
-	assert((block & ~CTL_MASK_BLOCK) == 0);
-	assert(data);
-	assert(data_len);
-
-	uint8_t header[3] = {
-		(uint8_t)((addr >> 8) & 0xFF),
-		(uint8_t)(addr & 0xFF),
-		(block & CTL_MASK_BLOCK) | CTL_W | CTL_OM_VDM,
-	};
-	struct bidi_iovec iov[] = {
-		{.iov_read_dst = NULL, .iov_write_src = header, .iov_len = sizeof(header)},
-		{.iov_read_dst = NULL, .iov_write_src = data,   .iov_len = data_len},
-	};
-	VCALL(spidev, readwritev, iov, 2);
-}
-
-static inline void
-w5500ll_read(implements_spi *spidev, uint16_t addr, uint8_t block, void *data, size_t data_len) {
-	assert(spidev);
-	assert((block & ~CTL_MASK_BLOCK) == 0);
-	assert(data);
-	assert(data_len);
-
-	uint8_t header[3] = {
-		(uint8_t)((addr >> 8) & 0xFF),
-		(uint8_t)(addr & 0xFF),
-		(block & CTL_MASK_BLOCK) | CTL_R | CTL_OM_VDM,
-	};
-	struct bidi_iovec iov[] = {
-		{.iov_read_dst = NULL, .iov_write_src = header, .iov_len = sizeof(header)},
-		{.iov_read_dst = data, .iov_write_src = NULL,   .iov_len = data_len},
-	};
-	VCALL(spidev, readwritev, iov, 2);
-}
-
-/* Common chip-wide registers.  ***********************************************/
-
-struct w5500ll_block_common_reg {
-	uint8_t                 mode;                  /* MR; bitfield, see CHIPMODE_{x} below */
-	struct net_ip4_addr     ip_gateway_addr;       /* GAR0 ... GAR3 */
-	struct net_ip4_addr     ip_subnet_mask;        /* SUBR0 ... SUBR3 */
-	struct net_eth_addr     eth_addr;              /* SHAR0 ... SHAR5 */
-	struct net_ip4_addr     ip_addr;               /* SIPR0 ... SIPR3 */
-
-	uint16be_t              intlevel;              /* INTLEVEL0, INTLEVEL1; if non-zero,
-	                                                * hysteresis between pin_intr being pulled
-	                                                * low (hysteresis=(intlevel+1)*4/(150MHz)) */
-	uint8_t                 chip_interrupt;        /* IR; bitfield, see CHIPINTR_{x} below */
-	uint8_t                 chip_interrupt_mask;   /* IMR; bitfield, see CHIPINTR_{x} below, 0=disable, 1=enable */
-	uint8_t                 sock_interrupt;        /* SIR; bitfield of which sockets have their .interrupt set  */
-	uint8_t                 sock_interrupt_mask;   /* SIMR; bitfield of sockets, 0=disable, 1=enable */
-	uint16be_t              retry_time;            /* RTR0, RTR0; configures re-transmission period, in units of 100µs */
-	uint8_t                 retry_count;           /* RCR; configures max re-transmission count */
-
-	uint8_t                 ppp_lcp_request_timer; /* PTIMER */
-	uint8_t                 ppp_lcp_magic_bumber;  /* PMAGIC */
-	struct net_eth_addr     ppp_dst_eth_addr;      /* PHAR0 ... PHAR5 */
-	uint16be_t              ppp_sess_id;           /* PSID0 ... PSID1 */
-	uint16be_t              ppp_max_seg_size;      /* PMRU0 ... PMRU1 */
-
-	struct net_ip4_addr     unreachable_ip_addr;   /* UIPR0 ... UIPR3 */
-	uint16be_t              unreachable_port;      /* UPORTR0, UPORTR1 */
-
-	uint8_t                 phy_cfg;               /* PHYCFGR */
-
-	uint8_t                 _reserved[10];
-
-	uint8_t                 chip_version;          /* VERSIONR */
-};
-static_assert(sizeof(struct w5500ll_block_common_reg) == 0x3A);
-
-/* bitfield */
-#define CHIPMODE_RST        ((uint8_t)(1<<7)) /* software reset */
-#define _CHIPMODE_UNUSED6   ((uint8_t)(1<<6))
-#define CHIPMODE_WOL        ((uint8_t)(1<<5)) /* wake-on-lan */
-#define CHIPMODE_BLOCK_PING ((uint8_t)(1<<4))
-#define CHIPMODE_PPP        ((uint8_t)(1<<3))
-#define _CHIPMODE_UNUSED2   ((uint8_t)(1<<2))
-#define CHIPMODE_FORCE_ARP  ((uint8_t)(1<<1))
-#define _CHIPMODE_UNUSED0   ((uint8_t)(1<<0))
-
-#define CHIPINTR_CONFLICT  ((uint8_t)(1<<7)) /* ARP says remote IP is self */
-#define CHIPINTR_UNREACH   ((uint8_t)(1<<6))
-#define CHIPINTR_PPP_CLOSE ((uint8_t)(1<<6))
-#define CHIPINTR_WOL       ((uint8_t)(1<<4)) /* wake-on-LAN */
-#define _CHIPINTR_UNUSED3  ((uint8_t)(1<<3))
-#define _CHIPINTR_UNUSED2  ((uint8_t)(1<<2))
-#define _CHIPINTR_UNUSED1  ((uint8_t)(1<<1))
-#define _CHIPINTR_UNUSED0  ((uint8_t)(1<<0))
-
-#define w5500ll_write_common_reg(spidev, field, val)       \
-	w5500ll_write_reg(spidev,                          \
-	                  CTL_BLOCK_COMMON_REG,            \
-	                  struct w5500ll_block_common_reg, \
-	                  field, val)
-
-
-#define w5500ll_read_common_reg(spidev, field)            \
-	w5500ll_read_reg(spidev,                          \
-	                 CTL_BLOCK_COMMON_REG,            \
-	                 struct w5500ll_block_common_reg, \
-	                 field)
-
-/* Per-socket registers.  *****************************************************/
-
-struct w5500ll_block_sock_reg {
-	uint8_t                 mode;             /* Sn_MR; see SOCKMODE_{x} below */
-	uint8_t                 command;          /* Sn_CR; see CMD_{x} below */
-	uint8_t                 interrupt;        /* Sn_IR; bitfield, see SOCKINTR_{x} below */
-	uint8_t                 state;            /* Sn_SR; see STATE_{x} below */
-	uint16be_t              local_port;       /* Sn_PORT0, Sn_PORT1 */
-	struct net_eth_addr     remote_eth_addr;  /* Sn_DHAR0 ... SnDHAR5 */
-	struct net_ip4_addr     remote_ip_addr;   /* Sn_DIPR0 ... Sn_DIP3 */
-	uint16be_t              remote_port;      /* Sn_DPORT0 ... Sn_DPORT1 */
-
-	uint16be_t              max_seg_size;     /* Sn_MSSR0, Sn_MSSR1 */
-	uint8_t                 _reserved0[1];
-	uint8_t                 ip_tos;           /* Sn_TOS */
-	uint8_t                 ip_ttl;           /* Sn_TTL */
-	uint8_t                 _reserved1[7];
-
-	uint8_t                 rx_buf_size;      /* Sn_RXBUF_SIZE; in KiB, power of 2, <= 16 */
-	uint8_t                 tx_buf_size;      /* Sn_TXBUF_SIZE; in KiB, power of 2, <= 16 */
-	uint16be_t              tx_free_size;     /* Sn_TX_FSR0, Sn_TX_FSR1 */
-	uint16be_t              tx_read_pointer;  /* Sn_TX_RD0, Sn_TX_RD1 */
-	uint16be_t              tx_write_pointer; /* Sn_TX_WR0, Sn_TX_WR1 */
-	uint16be_t              rx_size;          /* Sn_RX_RSR0, Sn_RX_RSR1 */
-	uint16be_t              rx_read_pointer;  /* Sn_RX_RD0, Sn_RX_RD1 */
-	uint16be_t              rx_write_pointer; /* Sn_RX_WR0, Sn_RX_WR1 */
-
-	uint8_t                 interrupt_mask;   /* Sn_IMR */
-	uint16be_t              fragment_offset;  /* Sn_FRAG0, Sn_FRAG1 */
-	uint8_t                 keepalive_timer;  /* Sn_KPALVTR */
-};
-static_assert(sizeof(struct w5500ll_block_sock_reg) == 0x30);
-
-/* low 4 bits are the main enum, high 4 bits are flags */
-#define SOCKMODE_CLOSED ((uint8_t)0b0000)
-#define SOCKMODE_TCP    ((uint8_t)0b0001)
-#define SOCKMODE_UDP    ((uint8_t)0b0010)
-#define SOCKMODE_MACRAW ((uint8_t)0b0100)
-
-#define SOCKMODE_FLAG_TCP_NODELAY_ACK         ((uint8_t)(1<<5))
-
-#define SOCKMODE_FLAG_UDP_ENABLE_MULTICAST    ((uint8_t)(1<<7))
-#define SOCKMODE_FLAG_UDP_BLOCK_BROADCAST     ((uint8_t)(1<<6))
-#define SOCKMODE_FLAG_UDP_MULTICAST_DOWNGRADE ((uint8_t)(1<<5))
-#define SOCKMODE_FLAG_UDP_BLOCK_UNICAST       ((uint8_t)(1<<4))
-
-#define SOCKMODE_FLAG_MACRAW_MAC_FILTERING    ((uint8_t)(1<<7))
-#define SOCKMODE_FLAG_MACRAW_BLOCK_BROADCAST  ((uint8_t)(1<<6))
-#define SOCKMODE_FLAG_MACRAW_BLOCK_MULTICAST  ((uint8_t)(1<<5))
-#define SOCKMODE_FLAG_MACRAW_BLOCK_V6         ((uint8_t)(1<<4))
-
-#define CMD_OPEN      ((uint8_t)0x01)
-#define CMD_LISTEN    ((uint8_t)0x02) /* TCP-only */
-#define CMD_CONNECT   ((uint8_t)0x04) /* TCP-only: dial */
-#define CMD_DISCON    ((uint8_t)0x08) /* TCP-only: send FIN */
-#define CMD_CLOSE     ((uint8_t)0x10)
-#define CMD_SEND      ((uint8_t)0x20)
-#define CMD_SEND_MAC  ((uint8_t)0x21) /* UDP-only: send to remote_eth_addr without doing ARP on remote_ip_addr */
-#define CMD_SEND_KEEP ((uint8_t)0x22) /* TCP-only: send a keepalive without any data */
-#define CMD_RECV      ((uint8_t)0x40)
-
-#define _SOCKINTR_SEND_UNUSED7 ((uint8_t)1<<7)
-#define _SOCKINTR_SEND_UNUSED6 ((uint8_t)1<<6)
-#define _SOCKINTR_SEND_UNUSED5 ((uint8_t)1<<5)
-#define SOCKINTR_SEND_OK       ((uint8_t)1<<4)
-#define SOCKINTR_TIMEOUT       ((uint8_t)1<<3)
-#define SOCKINTR_RECV          ((uint8_t)1<<2)
-#define SOCKINTR_FIN           ((uint8_t)1<<1)
-#define SOCKINTR_CONN          ((uint8_t)1<<1) /* first for SYN, then when SOCKMODE_ESTABLISHED */
-
-#define STATE_CLOSED          ((uint8_t)0x00)
-
-/**
- * The TCP state diagram is as follows.
- *  - Reading the W5500's "state" register does not distinguish between FIN_WAIT_1 and FIN_WAIT_2;
- *    it just has a single FIN_WAIT.
- *  - At any point the state can jump to "CLOSED" either by CMD_CLOSE or by a timeout.
- *  - Writing data is valid in ESTABLISHED and CLOSE_WAIT.
- *  - Reading data is valid in ESTABLISHED and FIN_WAIT.
- *
- *     TCP state diagram, showing the flow of   │ CLOSED │      ━━ role separator     ┌───────┐
- *     SYN, FIN, and their assocaited ACKs.     └────────┘      ══ state transition   │ state │
- *                                                   V          ┈┈ packet flow        └───────┘
- *                                              (CMD_OPEN)                                ║
- *                                                   V                              (action/event)
- *                                              ┌────────┐
- *     ┏━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━│  INIT  │━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┓
- *     ┃ server         ┃                       └────────┘                        ┃         client ┃
- *     ┣━━━━━━━━━━━━━━━━┛                         V ┃┃ V                          ┗━━━━━━━━━━━━━━━━┫
- *     ┃                              ╔═══════════╝ ┃┃ ╚═══════════╗                               ┃
- *     ┃                        (CMD_LISTEN)        ┃┃       (CMD_CONNECT)                         ┃
- *     ┃                              V            ┌┃┃┈┈┈┈┈┈┈┈<(send SYN)                          ┃
- *     ┃                         ┌────────┐        ┊┃┃             V                               ┃
- *     ┃                         │ LISTEN │        ┊┃┃        ┌─────────┐                          ┃
- *     ┃                         └────────┘        ┊┃┃        │ SYNSENT │                          ┃
- *     ┃                              V            ┊┃┃        └─────────┘                          ┃
- *     ┃                          (recv SYN)<┈┈┈┈┈┈┘┃┃             V                               ┃
- *     ┃                        (send SYN+ACK)>┈┈┈┈┐┃┃             ║                               ┃
- *     ┃                              V            └┃┃┈┈┈┈┈┈>(recv SYN+ACK)                        ┃
- *     ┃                        ┌─────────┐        ┌┃┃┈┈┈┈┈┈┈┈<(send ack)                          ┃
- *     ┃                        │ SYNRECV │        ┊┃┃             ║                               ┃
- *     ┃                        └─────────┘        ┊┃┃             ║                               ┃
- *     ┃                          V     V          ┊┃┃             ║                               ┃
- *     ┃                          ║  (recv ACK)<┈┈┈┘┃┃             ║                               ┃
- *     ┃                          ║     ╚═════════╗ ┃┃ ╔═══════════╝                               ┃
- *     ┃                          ╚═══╗           V ┃┃ V                                           ┃
- *     ┃                              ║       ┌─────────────┐                                      ┃
- *     ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━║━━━━━━━│ ESTABLISHED │━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
- *     ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━║━━━━━━━└─────────────┘━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
- *     ┃                              ║           V ┃┃ V                                           ┃
- *     ┃                              ╠═══════════╝ ┃┃ ╚═══════════╗                               ┃
- *     ┃                         (CMD_DISCON)       ┃┃             ║                               ┃
- *     ┃   Both sides sent   ┌┈┈┈<(send FIN)>┈┈┈┈┈┈┐┃┃             ║                               ┃
- *     ┃  FIN at the "same"  ┊        V            └┃┃┈┈┈┈┈┈┈┈>(recv FIN)                          ┃
- *     ┃   time; both are    ┊  ┌────────────┐     ┌┃┃┈┈┈┈┈┈┈┈<(send ACK)                          ┃
- *     ┃   active closers    ┊  │ FIN_WAIT_1 │     ┊┃┃             V                               ┃
- *     ┃         / \         ┊  └────────────┘     ┊┃┃      ┌────────────┐                         ┃
- *     ┃ ,------'   '------, ┊     V     V         ┊┃┃      │ CLOSE_WAIT │                         ┃
- *     ┃          ╔════════════════╝     ║         ┊┃┃      └────────────┘                         ┃
- *     ┃      (recv FIN)<┈┈┈┈┤        ╔══╝         ┊┃┃             V                               ┃
- *     ┃  ┌┈┈<(send ACK)>┈┈┐ ┊        ║            ┊┃┃             ║                               ┃
- *     ┃  ┊       ║        └┈┈┈┈┈>(recv ACK)<┈┈┈┈┈┈┘┃┃             ║                               ┃
- *     ┃  ┊       V          ┊        V             ┃┃             ║                               ┃
- *     ┃  ┊  ┌─────────┐     ┊  ┌────────────┐      ┃┃             ║                               ┃
- *     ┃  ┊  │ CLOSING │     ┊  │ FIN_WAIT_2 │      ┃┃             ║                               ┃
- *     ┃  ┊  └─────────┘     ┊  └────────────┘      ┃┃        (CMD_DISCON)                         ┃
- *     ┃  ┊       V          ┊        V            ┌┃┃┈┈┈┈┈┈┈┈<(send FIN)                          ┃
- *     ┃  ┊       ║          └┈┈┈>(recv FIN)<┈┈┈┈┈┈┘┃┃             ║                               ┃
- *     ┃  ┊       ║        ┌┈┈┈┈┈<(send ACK)>┈┈┈┈┈┈┐┃┃             V                               ┃
- *     ┃  └┈┈>(recv ACK)<┈┈┘          ╚═╗          ┊┃┃        ┌──────────┐                         ┃
- *     ┃          ╚════════════════╗    ║          ┊┃┃        │ LAST_ACK │                         ┃
- *     ┃                           V    V          ┊┃┃        └──────────┘                         ┃
- *     ┃                        ┌───────────┐      ┊┃┃             V                               ┃
- *     ┃                        │ TIME_WAIT │      ┊┃┃             ║                               ┃
- *     ┃                        └───────────┘      └┃┃┈┈┈┈┈┈┈┈>(recv ACK)                          ┃
- *     ┃                              V             ┃┃             ║                               ┃
- *     ┣━━━━━━━━━━━━━━━━┓     (2*MSL has elapsed)   ┃┃             ║              ┏━━━━━━━━━━━━━━━━┫
- *     ┃ active closer  ┃             ╚═══════════╗ ┃┃ ╔═══════════╝              ┃ passive closer ┃
- *     ┗━━━━━━━━━━━━━━━━┻━━━━━━━━━━━━━━━━━━━━━━━━━V━┛┗━V━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━━━━━━┛
- *                                              ┌────────┐
- *                                              │ CLOSED │
- */
-#define STATE_TCP_INIT        ((uint8_t)0x13)
-#define STATE_TCP_LISTEN      ((uint8_t)0x14) /* server */
-#define STATE_TCP_SYNSENT     ((uint8_t)0x15) /* client; during dial */
-#define STATE_TCP_SYNRECV     ((uint8_t)0x16) /* server; during accept */
-#define STATE_TCP_ESTABLISHED ((uint8_t)0x17)
-#define STATE_TCP_FIN_WAIT    ((uint8_t)0x18) /* during active close */
-#define STATE_TCP_CLOSING     ((uint8_t)0x1a) /* during active close */
-#define STATE_TCP_TIME_WAIT   ((uint8_t)0x1b) /* during active close */
-#define STATE_TCP_CLOSE_WAIT  ((uint8_t)0x1c) /* during passive close */
-#define STATE_TCP_LAST_ACK    ((uint8_t)0x1d) /* during passive close */
-
-#define STATE_UDP             ((uint8_t)0x22)
-
-#define STATE_MACRAW          ((uint8_t)0x42)
-
-#define w5500ll_write_sock_reg(spidev, socknum, field, val) \
-	w5500ll_write_reg(spidev,                           \
-	                  CTL_BLOCK_SOCK(socknum, REG),     \
-	                  struct w5500ll_block_sock_reg,    \
-	                  field, val)
-
-#define w5500ll_read_sock_reg(spidev, socknum, field)   \
-	w5500ll_read_reg(spidev,                        \
-	                 CTL_BLOCK_SOCK(socknum, REG),  \
-	                 struct w5500ll_block_sock_reg, \
-	                 field)
-
-/******************************************************************************/
-
-#define w5500ll_write_reg(spidev, blockid, blocktyp, field, val) do { \
-		typeof((blocktyp){}.field) lval = val;                \
-		w5500ll_write(spidev,                                 \
-		                     offsetof(blocktyp, field),       \
-		                     blockid,                         \
-		                     &lval,                           \
-		                     sizeof(lval));                   \
-	} while (0)
-
-/* The datasheet tells us that multi-byte reads are non-atomic and
- * that "it is recommended that you read all 16-bits twice or more
- * until getting the same value".  */
-#define w5500ll_read_reg(spidev, blockid, blocktyp, field) ({              \
-		typeof((blocktyp){}.field) val;                            \
-		w5500ll_read(spidev,                                       \
-		             offsetof(blocktyp, field),                    \
-		             blockid,                                      \
-		             &val,                                         \
-		             sizeof(val));                                 \
-		if (sizeof(val) > 1)                                       \
-			for (;;) {                                         \
-				typeof(val) val2;                          \
-				w5500ll_read(spidev,                       \
-				             offsetof(blocktyp, field),    \
-				             blockid,                      \
-				             &val2,                        \
-				             sizeof(val));                 \
-				if (memcmp(&val2, &val, sizeof(val)) == 0) \
-					break;                             \
-				val = val2;                                \
-			}                                                  \
-		val;                                                       \
-	})
-
-#endif /* _HW_W5500_LL_H_ */
diff --git a/cmd/sbc_harness/main.c b/cmd/sbc_harness/main.c
index 8ecc56c..b0c9659 100644
--- a/cmd/sbc_harness/main.c
+++ b/cmd/sbc_harness/main.c
@@ -4,17 +4,18 @@
  * SPDX-Licence-Identifier: AGPL-3.0-or-later
  */
 
-#include <string.h> /* for strlen() */
-#include <stdio.h> /* for printf() */
-#include "pico/stdlib.h"
-#include "hardware/flash.h"
+#include <string.h>         /* libc: for strlen() */
+#include <stdio.h>          /* libc: for printf() */
+
+#include <pico/stdlib.h>    /* pico-sdk:pico_stdlib: for stdio_uart_init() */
+#include <hardware/flash.h> /* pico-sdk:hardware_flash: for flash_get_unique_id() */
 
 #include <libcr/coroutine.h>
-#include <libusb/usb_common.h>
+#include <libhw/rp2040_hwspi.h>
+#include <libhw/w5500.h>
 #include <libmisc/hash.h>
+#include <libusb/usb_common.h>
 
-#include "hw/rp2040_hwspi.h"
-#include "hw/w5500.h"
 #include "usb_keyboard.h"
 
 COROUTINE hello_world_cr(void *_chan) {
diff --git a/cmd/sbc_harness/usb_keyboard.c b/cmd/sbc_harness/usb_keyboard.c
index b98345c..fcd0fe1 100644
--- a/cmd/sbc_harness/usb_keyboard.c
+++ b/cmd/sbc_harness/usb_keyboard.c
@@ -4,7 +4,7 @@
  * SPDX-Licence-Identifier: AGPL-3.0-or-later
  */
 
-#include "tusb.h"
+#include <tusb.h>
 
 #include <libusb/tusb_helpers.h> /* for TUD_ENDPOINT_IN */
 #include <libusb/usb_common.h>