commit | 8f8cb95fe92170220ccf7ad44f22073fee561c40 | [log] [tgz] |
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author | Angel Pons <th3fanbus@gmail.com> | Tue Oct 20 23:03:45 2020 +0200 |
committer | Angel Pons <th3fanbus@gmail.com> | Thu Oct 22 20:06:54 2020 +0000 |
tree | a237f4f1aa620af8837ce1095004b965321b0417 | |
parent | 01490258bb26a1bbb7b41e0cf8100ec4d42082cb [diff] |
sec/intel/txt: Split MTRR setup ASM code into a macro If necessary, SCLEAN needs to run in early romstage, where DRAM is not working yet. In fact, that the DRAM isn't working is the reason to run SCLEAN in the first place. Before running GETSEC, CAR needs to be torn down, as MTRRs have to be reprogrammed to cache the BIOS ACM. Further, running SCLEAN leaves the system in an undefined state, where the only sane thing to do is reset the platform. Thus, invoking SCLEAN requires specific assembly prologue and epilogue sections before and after MTRR setup, and neither DRAM nor CAR may be relied upon for the MTRR setup. In order to handle this without duplicating the MTRR setup code, place it in a macro on a separate file. This needs to be a macro because the call and return instructions rely on the stack being usable, and it is not the case for SCLEAN. The MTRR code clobbers many registers, but no other choice remains when the registers cannot be saved anywhere else. Tested on Asrock B85M Pro4, BIOS ACM can still be launched. Change-Id: I2f5e82f57b458ca1637790ddc1ddc14bba68ac49 Signed-off-by: Angel Pons <th3fanbus@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/46603 Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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.
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.
coreboot supports a wide range of chipsets, devices, and mainboards.
For details please consult:
ANY_TOOLCHAIN
Kconfig option if you're feeling lucky (no support in this case).Optional:
make menuconfig
and make nconfig
)Please consult https://www.coreboot.org/Build_HOWTO for details.
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.
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
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.