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This change configures PCIE_RST1_L as GPO driven low on the sleep path. This is required to keep PERST# asserted to devices until coreboot deasserts it on S3 resume path. Without this change, on S3 resume, PCIE_RST1_L gets deasserted sooner than required resulting in violation of PCIe reset timings. With this change, the behavior of PCIE_RST1_L is as follows: 1. GPIO27 is configured as NF (PCIE_RST1_L) in coreboot bootblock/romstage and driven high. 2. On S3 entry, GPIO27 is configured as GPO driven low. * Boot out of G3: Timing should be met since GPIO_27 is pulled down by default until coreboot configures it. * S3 resume: Timing should be met since GPIO_27 is configured as GPO low and it retains state across S3 entry/exit. So, should be low until coreboot configures it. * Warm reset: Timing should be met since it is configured as NF. So, hardware guarantees the reset timing as seen in "warm reset.jpg" in #46. BUG=b:152582706 Signed-off-by: Furquan Shaikh <furquan@google.com> Change-Id: Ia0ad1522edc438fd054d927ef4a2ab5c27329c00 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2261116 Reviewed-by: Aaron Durbin <adurbin@google.com> Commit-Queue: Furquan Shaikh <furquan@chromium.org> Tested-by: Furquan Shaikh <furquan@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/42934 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> |
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| LICENSES | ||
| configs | ||
| payloads | ||
| src | ||
| tests | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| AUTHORS | ||
| COPYING | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README.md | ||
| gnat.adc | ||
| 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_TOOLCHAINKconfig 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 menuconfigandmake 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:
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.