| commit | ce51b34186b6eb7356c1bab752dcaccc66d96ab2 | [log] [tgz] |
|---|---|---|
| author | Patrick Rudolph <patrick.rudolph@9elements.com> | Mon Jan 11 09:21:58 2021 +0100 |
| committer | Patrick Georgi <pgeorgi@google.com> | Fri Jan 15 11:20:41 2021 +0000 |
| tree | aa38f2f800f7017725cf5d9a7827a2101b4758a5 | |
| parent | bc15e0195832e40b37df9fd6e658659e2982cfbd [diff] |
cpu/x86/mpinit: Serialize microcode updates for HT threads This change affects Intel CPUs only. As most platforms are doing uCode update using FIT, they aren't affected by this code either. Update microcode in MP-init using a single spinlock when running on a Hyper-Threading enabled CPU on pre FIT platforms. This will slow down the MP-init boot flow. Intel SDM and various BWGs specify to use a semaphore to update microcode on one thread per core on Hyper-Threading enabled CPUs. Due to this complex code would be necessary to determine the core #ID, initializing and picking the right semaphore out of CONFIG_MAX_CPUS / 2. Instead use the existing global spinlock already present in MPinit code. Assuming that only pre-FIT platforms with Hyper-Threading enabled and at most 8 threads will ever run into this condition, the boot delay is negligible. This change is a counterproposal to the previous published patch series being much more unsophisticated. Change-Id: I27bf5177859c12e92d6ce7a2966c965d7262b472 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/49303 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
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.