lib/cbfs: Add cbfs_preload()

This API will hide all the complexity of preloading a CBFS file. It
makes it so the callers simply specify the file to preload and CBFS
takes care of the rest. It will start a new thread to read the file into
the cbfs_cache. When the file is actually required (i.e., cbfs_load,
etc) it will wait for the preload thread to complete (if it hasn't
already) and perform verification/decompression using the preloaded
buffer. This design allows decompression/verification to happen in the
main BSP thread so that timestamps are correctly reflected.

BUG=b:179699789
TEST=Test with whole CL chain, verify VGA bios was preloaded and boot
time was reduced by 12ms.

Logs:
Preloading VGA ROM
CBFS DEBUG: _cbfs_preload(name='pci1002,1638.rom', force_ro=false)
CBFS: Found 'pci1002,1638.rom' @0x20ac40 size 0xd800 in mcache @0xcb7dd0f0
spi_dma_readat_dma: start: dest: 0x021c0000, source: 0x51cc80, size: 55296
took 0 us to acquire mutex
start_spi_dma_transaction: dest: 0x021c0000, source: 0x51cc80, remaining: 55296
...
spi_dma_readat_dma: end: dest: 0x021c0000, source: 0x51cc80, remaining: 0
...
CBFS DEBUG: _cbfs_alloc(name='pci1002,1638.rom', alloc=0x00000000(0x00000000), force_ro=false, type=-1)
CBFS: Found 'pci1002,1638.rom' @0x20ac40 size 0xd800 in mcache @0xcb7dd0f0
waiting for thread
took 0 us
CBFS DEBUG: get_preload_rdev(name='pci1002,1638.rom', force_ro=false) preload successful
In CBFS, ROM address for PCI: 03:00.0 = 0x021c0000
PCI expansion ROM, signature 0xaa55, INIT size 0xd800, data ptr 0x01b0
PCI ROM image, vendor ID 1002, device ID 1638,
PCI ROM image, Class Code 030000, Code Type 00
Copying VGA ROM Image from 0x021c0000 to 0xc0000, 0xd800 bytes

$ cbmem
  ...
  40:device configuration                              5,399,404 (8,575)
  65:Option ROM initialization                         5,403,474 (4,070)
  66:Option ROM copy done                              5,403,488 (14)
  ...

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I879fc1316f97417a4b82483d353abdbd02b98a31
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56491
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
3 files changed
tree: 8b9f622e925831ad2cdcf788ca001c005af18baa
  1. 3rdparty/
  2. configs/
  3. Documentation/
  4. LICENSES/
  5. payloads/
  6. spd/
  7. src/
  8. tests/
  9. util/
  10. .checkpatch.conf
  11. .clang-format
  12. .editorconfig
  13. .gitignore
  14. .gitmodules
  15. .gitreview
  16. AUTHORS
  17. COPYING
  18. gnat.adc
  19. MAINTAINERS
  20. Makefile
  21. Makefile.inc
  22. README.md
  23. 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.