No description
5c9df70031
Add support and enalbe cache-as-ram paging for glk to work around a cache-as-ram corruption issue. glk executes verstage, romstage, and FSP-M directly out of cache-as-ram (just like apl). However, the front end on glk is very agressive about pulling cache lines into L1I for potential execution. When the snoops hit in the L1D and the cache lines are dirty the processor writes the line back. However, there is no backing store for the dirty lines to go. As such when the line is pulled back in the value is all 0xff's, corrupting cache-as-ram. To fix the issue one needs to enable paging with NX (no execute) permissions which prevents the above actions from happening because the TLB will indicate that shouldn't be fetched into the instruction cache since data will be marked no execute. The generated page tables are added to cbfs and only added to the COREBOOT cbfs as they are only consumed in the early cache-as-ram stages. The page tables generated with: $ go run util/x86/x86_page_tables.go \ --iomap_file=src/soc/intel/apollolake/glk_page_map.txt \ --metadata_base_address=0xfef00000 \ --pdpt_output_c_file=src/soc/intel/apollolake/pdpt.c \ --pt_output_c_file=src/soc/intel/apollolake/pt.c Merged address space: 00000000d0000000 -- 00000000fef00000 UC NX : 375 big 256 small 00000000fef00000 -- 00000000fef20000 WB NX : 0 big 32 small 00000000fef20000 -- 00000000fefc0000 WB : 0 big 160 small 00000000fefc0000 -- 00000000ff000000 WB NX : 0 big 64 small 00000000ff000000 -- 0000000100000000 WP : 8 big 0 small Total Pages of page tables: 5 Pages linked using base address of 0xfef00000. BUG=b:72728953 Change-Id: Icde9cc0bf5079bb5821f4e59eb61e939c13d7062 Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/25719 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Furquan Shaikh <furquan@google.com> |
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| 3rdparty | ||
| 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) * pkg-config * libssl-dev (openssl) 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.