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review.coreboot.org / coreboot / a6b60ebedbece7f2d008c57dc48bd492586989da
commita6b60ebedbece7f2d008c57dc48bd492586989da[log] [tgz]
authorMaulik V Vaghela <maulik.v.vaghela@intel.com>Wed Jun 09 11:36:20 2021 +0530
committerTim Wawrzynczak <twawrzynczak@chromium.org>Thu Jul 01 16:36:47 2021 +0000
tree3eb13d88444e14f91b95a6dbd34f403ffad47ed1
parent5bb7dc4e050b79390037a931681c6fbce639a052 [diff]
drivers/intel/gma: Move extended VBT just below opregion

Currently the flow for opregion init is as below:
1. Allocate memory for opregion first (cbmem_add(opregion))
2. Check if VBT size > 6 KiB (this requires extended VBT support)
3. In case of extended VBT requirement, we allocate another chunk
   of memory which is equal to size of VBT (cbmem_add(extended_vbt))
4. Pass physical address pointer to OS via RVDA

We can optimize the above flow to allocate single chunk of memory by
checking VBT size in earlier step. The new optimized flow for opregion
init is as below:
1. Check if VBT size > 6 KiB (this requires extended VBT support)
2. In case of extended VBT requirement, total memory to be allocated
   is calculated as sizeof(opregion) + sizeof (extended_vbt)
   In case where VBT size is < 6 KiB, total memory requirement would
   be equal to sizeof(opregion)
3. Based on above calculation, allocate single chunk of memory based on
   total size.

This will also be helpful for the case of virtualization where guest
users don't have access to physical address and when it needs relative
address of VBT compared to absolute address.

In case of opregion 2.1 spec, we need to pass relative address of
VBT from opregion base in RVDA. This optimization will help in meeting
this requirement since relative address of extended VBT is easy to get.
This change will ensure that it meets opregion specification
requirement and will be compatible with future versions as well.

BUG=b:190019970
BRANCH=None
TEST=check the address of extended VBT region and address is coming
correctly.

Change-Id: Ic0e255df63145409096b0b9312c6c51c05f49931
Signed-off-by: Maulik V Vaghela <maulik.v.vaghela@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55341
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
1 file changed
tree: 3eb13d88444e14f91b95a6dbd34f403ffad47ed1
  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.