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43dcbfd855
cherry-pick from Chromium, commit 8fbe1e7 On Braswell and Baytrail devices, by userland 'perf top', observed demanding clocks on __vdso_clock_gettime() since chromeos_3.18 kernel; besides, evaluated massive calling of clock_gettime() cost, up to 700 ns in average. It turns out that Linux kernel of map_vdso() first call of remap_pfn_range() does not fall into reserve_pfn_range() due to size parameter, instead it relies on lookup_memtype() and potentially be failed to be identified as eligible RAM resource because the function of pat_pagerange_is_ram() actually walks through root's sibling. Meanwhile, on current BSW (and BYT) firmware implementation makes System RAM resources located on child leaf, combining all of these factors makes the kernel treat the vvar page of vdso as a uncached-minus one leading slow access in result. This patch recollects TOLM accessing; as Aaron recalled some core_msr_script turns off access to TOLM register, he suggests to store tolm to avoid getting back a zero while setting acpi nvs space. Original-Change-Id: Iad4ffa542b22073cb087100a95169e2d2a52efcd Original-Signed-off-by: Harry Pan <harry.pan@intel.com> Original-Reviewed-on: https://chromium-review.googlesource.com/368585 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Change-Id: Idc9765ec5c0920dc98baeb9267a89bec5cadd5a0 Signed-off-by: Matt DeVillier <matt.devillier@gmail.com> Reviewed-on: https://review.coreboot.org/20060 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> |
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| configs | ||
| Documentation | ||
| payloads | ||
| src | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| COPYING | ||
| gnat.adc | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
| toolchain.inc | ||
------------------------------------------------------------------------------- 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: * https://www.coreboot.org/Supported_Motherboards * https://www.coreboot.org/Supported_Chipsets_and_Devices 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_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this case). * iasl (for targets with ACPI support) Optional: * doxygen (for generating/viewing documentation) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig' and 'make 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: https://www.coreboot.org 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.