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review.coreboot.org / coreboot / bd503978d4fd57fe38cae3588748ee52b1bfdcae
commitbd503978d4fd57fe38cae3588748ee52b1bfdcae[log] [tgz]
authorAseda Aboagye <aaboagye@google.com>Tue Jun 15 23:24:26 2021 -0700
committerKarthik Ramasubramanian <kramasub@google.com>Sat Jun 19 00:08:20 2021 +0000
treec3f942e3d29b25bc7572c10311514bb7d49fb5ac
parent633560568d5cc24da52f1089f0ae4ca362f7de2f [diff]
mb/google/dedede: Configure CBI EEPROM WP

On dedede boards without Cr50, the CrOS Board Info (CBI) EEPROM write
protect signal is decoupled from the hardware write protect signal.
Instead, we'd like for it to mirror the software write protect status.
This commit simply checks the software write protect status of the SPI
flash and sets the CBI EEPROM write protect if it's enabled.  To prevent
changing the WP signal at run-time, the GPIO configuration is also
locked down after the level has been set.  If HW WP is deasserted, the
CBI EEPROM WP will be deasserted as well.

BUG=b:191189275,b:184592299
BRANCH=None
TEST=Build and flash lalala, disable SW WP by running `flashrom -p host
--wp-disable` from a root shell and verify that the GPIO is asserted
after a reboot.  Export the gpio via sysfs and verify that attempting to
change the value of the GPIO is futile. Enable SW WP via `flashrom -p
host --wp-enable` and reboot the DUT. Again, export the GPIO via sysfs
and verify that attempts to change the GPIO value are futile.

localhost ~ # iotools mem_read32 0xfd6e08d0
0x44000200
localhost ~ # cd /sys/class/gpio/
localhost /sys/class/gpio # echo 217 > export
localhost /sys/class/gpio # cd gpio217/
localhost /sys/class/gpio/gpio217 # echo out > direction
localhost /sys/class/gpio/gpio217 # cat value
0
localhost /sys/class/gpio/gpio217 # echo 1 > value
localhost /sys/class/gpio/gpio217 # cat value
1
localhost /sys/class/gpio/gpio217 # iotools mem_read32 0xfd6e08d0
0x44000200

Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Change-Id: Ic103037921ec7d2f96f86178675c11a3a1357d1b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55558
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
3 files changed
tree: c3f942e3d29b25bc7572c10311514bb7d49fb5ac
  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.