b3182fbb00
This patch changes the vboot EC sync code to use the new CBFS API. As a consequence, we have to map the whole EC image file at once (because the new API doesn't support partial mapping). This should be fine on the only platform that uses this code (Google_Volteer/_Dedede family) because they are x86 devices that support direct mapping from flash, but the code was originally written to more carefully map the file in smaller steps to be theoretically able to support Arm devices. EC sync in romstage for devices without memory-mapped flash would be hard to combine with CBFS verification because there's not enough SRAM to ever hold the whole file in memory at once, but we can't validate the file hash until we have loaded the whole file and for performance (or TOCTOU-safety, if applicable) reasons we wouldn't want to load anything more than once. The "good" solution for this would be to introduce a CBFS streaming API can slowly feed chunks of the file into a callback but in the end still return a "hash valid/invalid" result to the caller. If use cases like this become pressing in the future, we may have to implement such an API. However, for now this code is the only part of coreboot with constraints like that, it was only ever used on platforms that do support memory-mapped flash, and due to the new EC-EFS2 model used on more recent Chrome OS devices we don't currently anticipate this to ever be needed again. Therefore this patch goes the easier way of just papering over the problem and punting the work of implementing a more generic solution until we actually have a real need for it. Signed-off-by: Julius Werner <jwerner@chromium.org> Change-Id: I7e263272aef3463f3b2924887d96de9b2607f5e5 Reviewed-on: https://review.coreboot.org/c/coreboot/+/52280 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .editorconfig | ||
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| AUTHORS | ||
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| MAINTAINERS | ||
| Makefile | ||
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| README.md | ||
| gnat.adc | ||
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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.