libpayload/Makefile.payload: Revise config strategy

Payloads often just use one of the defconfigs for libpayload. When
the `Makefile.payload` was introduced, it also added dependencies
to pass a `make oldconfig` or `make defconfig` for the payload on
to libpayload. Turned out, this creates some dependency madness
when, for instance, `make oldconfig` gets called without a libpay-
load `.config` available, or when we try to include the `.config`
in the `Makefile`.

To make things worse, Kconfig's `Makefile` that is imported from
Linux contains some rarely used paths that are generally incompa-
tible to our environment. So let's get rid of the hard-to-control
automatism.

Payloads that don't want to use a libpayload defconfig need to
clear the `$(LIBPAYLOAD_DEFCONFIG)` variable and manually run
the respective config target to generate a `.config`. To fully
support this, the rule to create a `.config` via `defconfig` is
guarded by `$(LIBPAYLOAD_DEFCONFIG)`. Otherwise we'd have a
spurious, broken recipe when the variable is unset.

We keep the option to call libpayload targets with an `lp-` prefix
for convenience. The existing, explicit targets `lp-defconfig` and
`lp-oldconfig` are replaced with a pattern match, so all config
and other targets should work.

Change-Id: Ie3fcce58d98e248c7182cd47f2a797fe066dd18a
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62273
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Thomas Heijligen <src@posteo.de>
1 file changed
tree: 1735ab9ca5b7cfd6da5d7e98fa8de6d08d3b437b
  1. 3rdparty/
  2. configs/
  3. Documentation/
  4. LICENSES/
  5. payloads/
  6. spd/
  7. src/
  8. tests/
  9. util/
  10. .checkpatch.conf
  11. .clang-format
  12. .editorconfig
  13. .gitignore
  14. .gitmodules
  15. .gitreview
  16. .mailmap
  17. AUTHORS
  18. COPYING
  19. gnat.adc
  20. MAINTAINERS
  21. Makefile
  22. Makefile.inc
  23. README.md
  24. 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:

  • 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.