886d29bcd8
The function to read board IDs from tristate GPIOs currently supports two output modes: a normal base-3 integer, or a custom format where every two bits represent one tristate pin. Each board decides which representation to use on its own, which is inconsistent and provides another possible gotcha to trip over when reading unfamiliar code. The two-bits-per-pin format creates the additional problem that a complete list of IDs (such as some boards use to build board-ID tables) necessarily has "holes" in them (since 0b11 does not correspond to a possible pin state), which makes them extremely tricky to write, read and expand. It's also very unintuitive in my opinion, although it was intended to make it easier to read individual pin states from a hex representation. This patch switches all boards over to base-3 and removes the other format to improve consistency. The tristate reading function will just print the pin states as they are read to make it easier to debug them, and we add a new BASE3() macro that can generate ternary numbers from pin states. Also change the order of all static initializers of board ID pin lists to write the most significant bit first, hoping that this can help clear up confusion about the endianness of the pins. CQ-DEPEND=CL:219902 BUG=None TEST=Booted on a Nyan_Blaze (with board ID 1, unfortunately the only one I have). Compiled on Daisy, Peach_Pit, Nyan, Nyan_Big, Nyan_Blaze, Rush, Rush_Ryu, Storm, Veryon_Pinky and Falco for good measure. Change-Id: I3ce5a0829f260db7d7df77e6788c2c6d13901b8f Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 2fa9545ac431c9af111ee4444d593ee4cf49554d Original-Change-Id: I6133cdaf01ed6590ae07e88d9e85a33dc013211a Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/219901 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9401 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
------------------------------------------------------------------------------- coreboot README ------------------------------------------------------------------------------- coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload. With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required. coreboot was formerly known as LinuxBIOS. Payloads -------- After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot. See http://www.coreboot.org/Payloads for a list of supported payloads. Supported Hardware ------------------ coreboot supports a wide range of chipsets, devices, and mainboards. For details please consult: * http://www.coreboot.org/Supported_Motherboards * http://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * gcc / g++ * make Optional: * doxygen (for generating/viewing documentation) * iasl (for targets with ACPI support) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig') * flex and bison (for regenerating parsers) Building coreboot ----------------- Please consult http://www.coreboot.org/Build_HOWTO for details. Testing coreboot Without Modifying Your Hardware ------------------------------------------------ If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU. Please see http://www.coreboot.org/QEMU for details. Website and Mailing List ------------------------ Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website: http://www.coreboot.org You can contact us directly on the coreboot mailing list: http://www.coreboot.org/Mailinglist Copyright and License --------------------- The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details. coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details. This makes the resulting coreboot images licensed under the GPL, version 2.