From c2f977be6492fd93b359c97dee9b2968fe56fef6 Mon Sep 17 00:00:00 2001 From: "Luke T. Shumaker" Date: Sat, 22 Feb 2025 00:30:47 -0700 Subject: cmd/sbc_harness: Add documentation for rom.bin and flash.bin --- .../static/Documentation/harness_flash_bin.txt | 24 +++++++++++++ .../static/Documentation/harness_rom_bin.txt | 41 ++++++++++++++++++++++ 2 files changed, 65 insertions(+) create mode 100644 cmd/sbc_harness/static/Documentation/harness_flash_bin.txt create mode 100644 cmd/sbc_harness/static/Documentation/harness_rom_bin.txt (limited to 'cmd/sbc_harness/static/Documentation') diff --git a/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt b/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt new file mode 100644 index 0000000..982d7e0 --- /dev/null +++ b/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt @@ -0,0 +1,24 @@ +NAME + /harness/flash.bin + +DESCRIPTION + Access to the flash storage chip (where the harness firmware + is stored). + + Any number of readers may read the flash contents. + +BUGS + - The size of the chip is configured at compile-time. If the + firmware is loaded onto hardware with a larger flash chip + than it was compiled for, then the upper part of the chip + will not be accessible with this file. If the firmware is + loaded onto hardware with a smaller flash chip than it was + compiled for, then accessing the missing upper part of the + chip will crash. + + - This file is not writable; it aught to be possible to update + the harness firmware by writing to this file. + +AUTHOR + Copyright (C) 2025 Luke T. Shumaker + SPDX-License-Identifier: AGPL-3.0-or-later diff --git a/cmd/sbc_harness/static/Documentation/harness_rom_bin.txt b/cmd/sbc_harness/static/Documentation/harness_rom_bin.txt new file mode 100644 index 0000000..63fd0a3 --- /dev/null +++ b/cmd/sbc_harness/static/Documentation/harness_rom_bin.txt @@ -0,0 +1,41 @@ +NAME + /harness/rom.bin + +DESCRIPTION + Read access to the RP2040 CPU's ROM. This contains code that + initializes the chip to load the main firmware from the + external flash chip, provides a failsafe USB-programmable + mode, and provides a few functions that the main firmware can + call to. + +BUGS + This ROM is programmed into the chip at the factory; revising + it means issuing a new revison of the RP2040 CPU. So while + the source code to the ROM is freely available to be used, + studied, and shared; one cannot install modified versions onto + the CPU. + +HISTORY + - RP2040 B0 : chips manufactured before September 2020 or so + - RP2040 B1 : chips manufactured after September 2020 or so + - Released to the public January 2021; chance whether you get + a B0 or a B1 chip. + - RP2040 B2 : released September 2021 + + Printed on the physical CPU is a label that indicates which + revision it is. For example: + + RP2-B2 21/24 + + indicates that it is the "B2" revision (and was manufactured + the 21st week (late May) of 2024). + +SEE ALSO + - /harness/cpuinfo.txt can report which CPU version you have. + + - The source code to each ROM revision is published at + https://github.com/raspberrypi/pico-bootrom-rp2040 + +AUTHOR + Copyright (C) 2025 Luke T. Shumaker + SPDX-License-Identifier: AGPL-3.0-or-later -- cgit v1.2.3-2-g168b