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review.coreboot.org / coreboot / 68305aa3b0fb5e8b3213baa99d48238e57bad2ad
commit68305aa3b0fb5e8b3213baa99d48238e57bad2ad[log] [tgz]
authorRonak Kanabar <ronak.kanabar@intel.com>Thu Feb 24 10:09:29 2022 +0530
committerFelix Held <felix-coreboot@felixheld.de>Tue Jun 14 13:37:31 2022 +0000
tree1885760d16e623b3b224099c30edcdd10813c526
parentf5c2f253a7dc8eced1c616ff9c79c6d196c86350 [diff]
soc/intel/common: Remove use of CPUID_EXTENDED_CPU_TOPOLOGY_V2

In x86 processor as per Software Developer's manual there are 2 ways to
get CPU topology by querying the processor. BIOS can use CPUID
instruction using CPUID_EXTENDED_CPU_TOPOLOGY (0x0B) as input or
CPUID_EXTENDED_CPU_TOPOLOGY_V2 (0x1F) as an input. Both will return
valid CPU topology data.

While CPUID_EXTENDED_CPU_TOPOLOGY (0x0B) returns data related to number
of threads, core and package, CPUID_EXTENDED_CPU_TOPOLOGY_V2 (0x1F)
provides more granular information regarding Die, package etc.

coreboot uses V2 to in order to query and return CPU topology data as of
now since that's the highest instruction of CPUID which is supported,
there is a mismatch in the way FSP processes the data.

FSP queries coreboot MP services to get CPU topology data which uses
structure which is either compatible with CPUID_EXTENDED_CPU_TOPOLOGY or
CPUID_EXTENDED_CPU_TOPOLOGY_V2. Since coreboot returns V2 data in
structure which is expecting data for CPUID_EXTENDED_CPU_TOPOLOGY, there
is hang observed on ADL_N CPUs.

To solve this problem coreboot should assign CPUID_EXTENDED_CPU_TOPOLOGY
data to processor_info_buffer->Location structure so remove use of
CPUID_EXTENDED_CPU_TOPOLOGY_V2

Ref EDK2 code: https://github.com/tianocore/edk2/tree/edk2-stable202202
Files:
MdePkg/Include/Protocol/MpService.h#L182
UefiCpuPkg/Library/MpInitLib/MpLib.c#L2127
UefiCpuPkg/Library/MpInitLib/MpLib.c#L2120
Ref doc: Software Developer’s Manual volume 3 CH 8.9

BUG=b:220652104
TEST=Build and boot ADL-N RVP with debug FSP and verify CPU topology
value and observe system boots (no hang).

Change-Id: I1e6832fb03fcc59d33df0ba1664019727185d10a
Signed-off-by: Ronak Kanabar <ronak.kanabar@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62323
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
1 file changed
tree: 1885760d16e623b3b224099c30edcdd10813c526
  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. .mailmap
  17. AUTHORS
  18. COPYING
  19. gnat.adc
  20. MAINTAINERS
  21. Makefile
  22. Makefile.inc
  23. README.md
  24. 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:

  • 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.