ed6f7e4a65
As part of boot time optimization, one of the culprit was CSE where response to End Of Post (EOP) command used to take ~60ms. Earlier patch was pushed to delay the EOP to reduce response time to ~5-7 ms. During this stage overall platform boot time was ~1.15 seconds. Once boot time was optimized to ~ 1 seconds, CSE EOP time again increased to ~80 ms since coreboot used to send EOP at the time where CSE was busy. This created some back and forth moving of sending EOP command function within coreboot sequence. Upon debugging using traces, it was found that coreboot used to send EOP late where CSE was busy loading other IP payload, so it might take more time to respond. In order to avoid delayed response, coreboot has to send EOP in stage when CSE is done with firmware init and it will be ready to serve EOP as soon as possible. This also aligns with previous flow where FSP used to send EOP once silicon init is done and coreboot used to rely on FSP to send this message. Moving EOP to earlier stage (From SoC) meets the requirement and CSE EOP time reduces from ~60 ms to ~20 ms on Brya board. Note that once SoC code sends EOP, coreboot common code won't send it again since common code already has check in case EOP is sent earlier. BUG=b:211085685 BRANCH=firmware-brya-14505.B TEST=Tested on Brya system before and after the changes. Observed ~40ms savings in boot time. Change-Id: I9401d5e36ad43cdc0dfe947aabc82528d824df9b Signed-off-by: MAULIK V VAGHELA <maulik.v.vaghela@intel.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/62272 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Subrata Banik <subratabanik@google.com> Reviewed-by: Ronak Kanabar <ronak.kanabar@intel.com> Reviewed-by: Sridhar Siricilla <sridhar.siricilla@intel.com> |
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| Documentation | ||
| LICENSES | ||
| configs | ||
| payloads | ||
| spd | ||
| src | ||
| tests | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| .mailmap | ||
| 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.