The SPL_TABLE_FILE and SPL_RW_AB_TABLE_FILE Kconfig options provide a way to override the default SPL file configured in the SoC's fw.cfg file by passing the '--spl-table' parameter to amdfwtool which will then use the override instead of the SPL file from the fw.cfg file. When SPL*_TABLE_FILE is an empty string, the corresponding add_opt_prefix call in the makefile will result in no '--spl-table' parameter being passed to amdfwtool, so it'll use the default SPL file from fw.cfg. In order to not pass an SPL override by default, remove the default from the SPL_TABLE_FILE in the SoC's Kconfig. The SoC default pointed to the same SPL file as in fw.cfg file anyway. Now only when a mainboard sets this option to point to a file, that file will be used as an override. This override is used to include a special SPL file needed for the verstage on PSP case on the Chromebooks. Since SPL_TABLE_FILE is an empty string by default, neither the SPL_TABLE_FILE Kconfig option nor it being evaluated in the Makefile need to be guarded by HAVE_SPL_FILE, so remove the dependency in the Kconfig and the ifeq in the Makefile. Before this patch, the HAVE_SPL_FILE option controlled two things that shouldn't be controlled by the same Kconfig option: Only when HAVE_SPL_FILE was set to y, the SPL_TABLE_FILE override was taken into account, and it also controls if spl_fuse.c got added to the build which when added will send the SPL fusing command to the PSP. So the case of needing an SPL file override, but not updating the SPL fuses wasn't supported before. The SPL file in the amdfw part will be used by the PSP bootloader for the anti-rollback feature which makes sure that the SPL file version isn't lower than what is in the SPL fuses. For this the SPL file needs to be present in the PSP directory table. The SPL version check happens way before we're running code on the x86 cores. The SPL fusing PSP command that can be sent by coreboot will tell the PSP to update the SPL fuses so that the fused minimal SPL version will be updated to the current SPL version. Since the former HAVE_SPL_FILE option now only controls if the SPL fusing command will be sent to the PSP mailbox, rename it to PERFORM_SPL_FUSING to clarify what this will do and update the help text correctly describe what this does. TEST=With INCLUDE_CONFIG_FILE set to n, timeless builds for both Birman with Phoenix APU and Skyrim result in identical binaries. Signed-off-by: Felix Held <felix-coreboot@felixheld.de> Change-Id: I6cec1f1b285fe48e81a961414fbc9978fa1003cc Reviewed-on: https://review.coreboot.org/c/coreboot/+/78178 Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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3rdparty | ||
configs | ||
Documentation | ||
LICENSES | ||
payloads | ||
spd | ||
src | ||
tests | ||
util | ||
.checkpatch.conf | ||
.clang-format | ||
.editorconfig | ||
.gitignore | ||
.gitmodules | ||
.gitreview | ||
.mailmap | ||
AUTHORS | ||
COPYING | ||
gnat.adc | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc | ||
README.md | ||
toolchain.inc |
coreboot README
coreboot is a Free Software project aimed at replacing the proprietary firmware (BIOS/UEFI) found in most computers. coreboot performs the required hardware initialization to configure the system, then passes control to a different executable, referred to in coreboot as the payload. Most often, the primary function of the payload is to boot the operating system (OS).
With the separation of hardware initialization and later boot logic, coreboot is perfect for a wide variety of situations. It can be used for specialized applications that run directly in the firmware, running operating systems from flash, loading custom bootloaders, or implementing firmware standards, like PC BIOS services or UEFI. This flexibility allows coreboot systems to include only the features necessary in the target application, reducing the amount of code and flash space required.
Source code
All source code for coreboot is stored in git. It is downloaded with the command:
git clone https://review.coreboot.org/coreboot.git
.
Code reviews are done in the project's Gerrit instance.
The code may be browsed via coreboot's Gitiles instance.
The coreboot project also maintains a mirror of the project on github. This is read-only, as coreboot does not accept github pull requests, but allows browsing and downloading the coreboot source.
Payloads
After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot.
See https://doc.coreboot.org/payloads.html for a list of some of coreboot's supported payloads.
Supported Hardware
The coreboot project supports a wide range of architectures, chipsets, devices, and mainboards. While not all of these are documented, you can find some information in the Architecture-specific documentation or the SOC-specific documentation.
For details about the specific mainboard devices that coreboot supports, please consult the Mainboard-specific documentation or the Board Status pages.
Releases
Releases are currently done by coreboot every quarter. The release archives contain the entire coreboot codebase from the time of the release, along with any external submodules. The submodules containing binaries are separated from the general release archives. All of the packages required to build the coreboot toolchains are also kept at coreboot.org in case the websites change, or those specific packages become unavailable in the future.
All releases are available on the coreboot download page.
Please note that the coreboot releases are best considered as snapshots of the codebase, and do not currently guarantee any sort of extra stability.
Build Requirements and building coreboot
The coreboot build, associated utilities and payloads require many additional tools and packages to build. The actual coreboot binary is typically built using a coreboot-controlled toolchain to provide reproducibility across various platforms. It is also possible, though not recommended, to make it directly with your system toolchain. Operating systems and distributions come with an unknown variety of system tools and utilities installed. Because of this, it isn't reasonable to list all the required packages to do a build, but the documentation lists the requirements for a few different Linux distributions.
To see the list of tools and libraries, along with a list of instructions to get started building coreboot, go to the Starting from scratch tutorial page.
That same page goes through how to use QEMU to boot the build and see the output.
Website and Mailing List
Further details on the project, as well as links to documentation and more can be found on the coreboot website:
You can contact us directly on the coreboot mailing list:
https://doc.coreboot.org/community/forums.html
Copyrights and Licenses
Uncopyrightable files
There are many files in the coreboot tree that we feel are not copyrightable due to a lack of creative content.
"In order to qualify for copyright protection in the United States, a work must satisfy the originality requirement, which has two parts. The work must have “at least a modicum” of creativity, and it must be the independent creation of its author."
https://guides.lib.umich.edu/copyrightbasics/copyrightability
Similar terms apply to other locations.
These uncopyrightable files include:
- Empty files or files with only a comment explaining their existence. These may be required to exist as part of the build process but are not needed for the particular project.
- Configuration files either in binary or text form. Examples would be files such as .vbt files describing graphics configuration, spd files as binary .spd or text *spd*.hex representing memory chip configuration.
- Machine-generated files containing version numbers, dates, hash values or other "non-creative" content.
As non-creative content, these files are in the public domain by default. As such, the coreboot project excludes them from the project's general license even though they may be included in a final binary.
If there are questions or concerns about this policy, please get in touch with the coreboot project via the mailing list.
Copyrights
The copyright on coreboot is owned by quite a large number of individual developers and companies. A list of companies and individuals with known copyright claims is present at the top level of the coreboot source tree in the 'AUTHORS' file. Please check the git history of each of the source files for details.
Licenses
Because of the way coreboot began, using a significant amount of source code from the Linux kernel, it's licensed the same way as the Linux Kernel, with GNU General Public License (GPL) Version 2. Individual files are licensed under various licenses, though all are compatible with GPLv2. The resulting coreboot image is licensed under the GPL, version 2. All source files should have an SPDX license identifier at the top for clarification.
Files under coreboot/Documentation/ are licensed under CC-BY 4.0 terms. As an exception, files under Documentation/ with a history older than 2017-05-24 might be under different licenses.
Files in the coreboot/src/commonlib/bsd directory are all licensed with the BSD-3-clause license. Many are also dual-licensed GPL-2.0-only or GPL-2.0-or-later. These files are intended to be shared with libpayload or other BSD licensed projects.
The libpayload project contained in coreboot/payloads/libpayload may be licensed as BSD or GPL, depending on the code pulled in during the build process. All GPL source code should be excluded unless the Kconfig option to include it is set.
The Software Freedom Conservancy
Since 2017, coreboot has been a member of The Software Freedom Conservancy, a nonprofit organization devoted to ethical technology and driving initiatives to make technology more inclusive. The conservancy acts as coreboot's fiscal sponsor and legal advisor.