commit | 1d9f8b0c428885cfe807752716716f656eb018e5 | [log] [tgz] |
---|---|---|
author | Michael Niewöhner <foss@mniewoehner.de> | Tue Apr 20 18:51:42 2021 +0200 |
committer | Patrick Georgi <pgeorgi@google.com> | Fri Apr 30 06:41:08 2021 +0000 |
tree | 987dfc6323ad0b1bdc27121b5dc73e3513054157 | |
parent | 3f36a8c7e15233a1b516f06bfa1b068f7bb34147 [diff] |
cpu/x86/msr: introduce helpers msr_read, msr_write The existing helpers for reading/writing MSRs (rdmsr, wrmsr) require use of the struct `msr_t`, which splits the MSR value into two 32 bit parts. In many cases, where simple 32 bit or 64 bit values are written, this bloats the code by unnecessarly having to use that struct. Thus, introduce the helpers `msr_read` and `msr_write`, which take or return `uint64_t` values, so the code condenses to a single line or two, without having to deal with `msr_t`. Example 1: ~~~ msr_t msr = { .lo = read32((void *)(uintptr_t)0xfed30880), .hi = 0, }; msr.lo |= 1; wrmsr(0x123, msr); ~~~ becomes ~~~ uint32_t foo = read32((void *)(uintptr_t)0xfed30880); msr_write(0x123, foo | 1) ~~~ Example 2: ~~~ msr_t msr = rdmsr(0xff); uint64_t msr_val = (msr.hi << 32) | msr.lo; ~~~ becomes ~~~ uint64_t msr_val = msr_read(0xff); ~~~ Change-Id: I27333a4bdfe3c8cebfe49a16a4f1a066f558c4ce Signed-off-by: Michael Niewöhner <foss@mniewoehner.de> Reviewed-on: https://review.coreboot.org/c/coreboot/+/52548 Reviewed-by: Nico Huber <nico.h@gmx.de> Reviewed-by: Felix Held <felix-coreboot@felixheld.de> Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org> 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.