arch/x86: Implement RESET_VECTOR_IN_RAM

Add support for devices with the reset vector pointing into DRAM.  This
is a specific implementation that assumes a paradigm of AMD Family 17h
(a.k.a. "Zen").  Until the first ljmpl for protected mode, the core's
state appears to software like other designs, and then the actual
physical addressing becomes recognizable.

These systems cannot implement cache-as-RAM as in more traditional
x86 products.  Therefore instead of reusing CAR names and variables,
a substitute called "earlyram" is introduced.  This change makes
adjustments to CAR-aware files accordingly.

Enable NO_XIP_EARLY_STAGES.  The first stage is already in DRAM, and
running subsequent stages as XIP in the boot device would reduce
performance.

Finally, add a new early_ram.ld linker file.  Because all stages run in
DRAM, they can be linked with their .data and .bss as normal, i.e. they
don't need to rely on storage available only at a fixed location like
CAR systems.  The primary purpose of the early_ram.ld is to provide
consistent locations for PRERAM_CBMEM_CONSOLE, TIMESTAMP regions, etc.
across stages until cbmem is brought online.

BUG=b:147042464
TEST=Build for trembyle, and boot to ramstage.
$ objdump -h cbfs/fallback/bootblock.debug
Idx ,Name          ,Size      ,VMA       ,LMA       ,File off  Algn
  0 ,.text         ,000074d0  ,08076000  ,08076000  ,00001000  2**12
  1 ,.data         ,00000038  ,0807d4d0  ,0807d4d0  ,000084d0  2**2
  2 ,.bss          ,00000048  ,0807d508  ,0807d508  ,00008508  2**2
  3 ,.stack        ,00000800  ,0807daf0  ,0807daf0  ,00000000  2**0
  4 ,.persistent   ,00001cfa  ,0807e2f0  ,0807e2f0  ,00000000  2**0
  5 ,.reset        ,00000010  ,0807fff0  ,0807fff0  ,0000aff0  2**0
  6 ,.debug_info   ,0002659c  ,00000000  ,00000000  ,0000b000  2**0
  7 ,.debug_abbrev ,000074a2  ,00000000  ,00000000  ,0003159c  2**0
  8 ,.debug_aranges,00000dd0  ,00000000  ,00000000  ,00038a40  2**3
  9 ,.debug_line   ,0000ad65  ,00000000  ,00000000  ,00039810  2**0
 10 ,.debug_str    ,00009655  ,00000000  ,00000000  ,00044575  2**0
 11 ,.debug_loc    ,0000b7ce  ,00000000  ,00000000  ,0004dbca  2**0
 12 ,.debug_ranges ,000029c0  ,00000000  ,00000000  ,00059398  2**3

Change-Id: I9c084ff6fdcf7e9154436f038705e8679daea780
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35035
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
7 files changed
tree: 5a005a84adce4b0771a6fbe76de257c25604c55f
  1. 3rdparty/
  2. configs/
  3. Documentation/
  4. LICENSES/
  5. payloads/
  6. src/
  7. util/
  8. .checkpatch.conf
  9. .clang-format
  10. .editorconfig
  11. .gitignore
  12. .gitmodules
  13. .gitreview
  14. AUTHORS
  15. COPYING
  16. gnat.adc
  17. MAINTAINERS
  18. Makefile
  19. Makefile.inc
  20. README.md
  21. toolchain.inc
README.md

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:

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.