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review.coreboot.org / coreboot / e07532fb160e54b9ded934c3964a2cf80f5ae780
commite07532fb160e54b9ded934c3964a2cf80f5ae780[log] [tgz]
authorFurquan Shaikh <furquan@google.com>Sat Apr 10 14:26:15 2021 -0700
committerMichael Niewöhner <foss@mniewoehner.de>Fri Apr 16 17:42:36 2021 +0000
treec87c11fc480e4ae478c98cb896fd5060758508e5
parent66ab5eb521fc7dd5995b7fae1a0beaf9dbef01d2 [diff]
drivers/intel/fsp2_0: Add support to identify GPIO config changes

Traditionally, for each Intel platform using FSP, FSP-S has at some
point configured GPIOs differently than the mainboard configuration in
coreboot. This has resulted in various side-effects in coreboot,
payload and OS because of misconfigured GPIOs. On more recent Intel
platforms, a UPD `GpioOverride` is added that coreboot can use to
ensure that FSP does not touch any GPIO configuration.

This change adds a debug option `CHECK_GPIO_CONFIG_CHANGES` to fsp2_0
driver in coreboot that makes a platform callback `gpio_snapshot` to
snapshot GPIO configuration before making a call to FSP SiliconInit
and Notify phases. This snapshot is then compared against the GPIO
configuration using platform callback `gpio_verify_snapshot` after
returning from FSP. The callbacks are not added to romstage (FSP-M)
because mainboard configures all pads in ramstage.

This debug hook allows developers to dump information about any pads
that have a different configuration after call to FSP in ramstage. It
is useful to identify missed UPD configurations or bugs in FSP that
might not honor the UPDs set by coreboot.

This debug hook expects the platform to implement the callbacks
`gpio_snapshot` and `gpio_verify_snapshot`. These can be implemented
as part of the common GPIO driver for platforms using
FSP2.0+. Platforms that implement this support must select the config
`HAVE_GPIO_SNAPSHOT_VERIFY_SUPPORT` to make the debug config
`CHECK_GPIO_CONFIG_CHANGES` visible to user.

Proposal for the GPIO snapshot/verify support was discussed in the RFC
CB:50829.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I5326fc98b6eba0f8ba946842253b288c0d42c523
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50989
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
3 files changed
tree: c87c11fc480e4ae478c98cb896fd5060758508e5
  1. 3rdparty/
  2. configs/
  3. Documentation/
  4. LICENSES/
  5. payloads/
  6. src/
  7. tests/
  8. util/
  9. .checkpatch.conf
  10. .clang-format
  11. .editorconfig
  12. .gitignore
  13. .gitmodules
  14. .gitreview
  15. AUTHORS
  16. COPYING
  17. gnat.adc
  18. MAINTAINERS
  19. Makefile
  20. Makefile.inc
  21. README.md
  22. toolchain.inc
README.md

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 https://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:

Build Requirements

  • make
  • gcc / g++ Because Linux distribution compilers tend to use lots of patches. coreboot does lots of "unusual" things in its build system, some of which break due to those patches, sometimes by gcc aborting, sometimes - and that's worse - by generating broken object code. Two options: use our toolchain (eg. make crosstools-i386) or enable the ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this case).
  • iasl (for targets with ACPI support)
  • pkg-config
  • libssl-dev (openssl)

Optional:

  • doxygen (for generating/viewing documentation)
  • gdb (for better debugging facilities on some targets)
  • ncurses (for make menuconfig and make nconfig)
  • flex and bison (for regenerating parsers)

Building coreboot

Please consult https://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 https://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:

https://www.coreboot.org

You can contact us directly on the coreboot mailing list:

https://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.