coreboot/payloads/libpayload
Julius Werner 02a2fe7907 Merge coreboot and libpayload <endian.h> into commonlib
We've accumulated a number of endianness-handling and related macros
that are duplicated between coreboot and libpayload. This patch reduces
duplication by merging them into a commonlib header. This has the added
side-benefit of bringing the coreboot implementation of beXXenc/dec()
functions to libpayload, which lead to better code generation by
avoiding https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92716.

Keep the htobell()-style functions in libpayload only since they're not
needed in coreboot and not preferred. Keep the cpu_to_beXX()-style
functions in coreboot only -- maybe we should deprecate those
eventually.

This patch is explicitly copying and relicensing some of the code I
originally added as GPLv2 in commit e8e92d60c4 ("endian.h: Add
be32dec/be32enc family of functions") to BSD-3.

Change-Id: I5eb83d44a98b3aa59bba65b8e22df668874d2668
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90308
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2025-12-11 08:43:16 +00:00
..
arch libpayload: arm64: Fix asynchronous exception routing in payload 2025-11-25 16:49:56 +00:00
bin libpayload: Add x86_64 (64-bit) support 2024-05-26 01:26:31 +00:00
configs libpayload: configs: Add new config.featuretest to broaden CI 2024-12-04 22:25:34 +00:00
crypto payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
curses tree: Replace union {0} initializers with {} for C23 compliance 2025-08-11 16:40:34 +00:00
drivers libpayload/drivers/pci_qcom: Fix address during ATU config 2025-07-30 17:54:17 +00:00
gdb libpayload: gdb: Make die_if() format string a literal 2024-03-19 22:50:03 +00:00
include Merge coreboot and libpayload <endian.h> into commonlib 2025-12-11 08:43:16 +00:00
libc libpayload: Add CBMEM_ID_MEMINFO to sysinfo 2025-11-22 18:55:00 +00:00
libcbfs libpayload: Remove legacy CBFS API 2024-02-22 21:18:39 +00:00
liblz4 payloads/libpayload: Support legacy LZ4 compression format 2025-11-13 23:45:02 +00:00
liblzma payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
libpci payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
sample libpayload: Add mock architecture 2021-10-11 12:59:57 +00:00
tests payloads/libpayload: Support legacy LZ4 compression format 2025-11-13 23:45:02 +00:00
vboot libpayload: Add x86_64 (64-bit) support 2024-05-26 01:26:31 +00:00
.gitignore .gitignore: Split into subdirectory files 2020-10-30 07:05:27 +00:00
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: Use Kconfig instead of weak symbol for arch_ndelay() 2025-05-22 19:27:30 +00:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
Makefile tree: Replace scan-build by clang-tidy 2025-07-01 01:12:32 +00:00
Makefile.mk payloads/libpayload/Makefile.mk: Replace nm with $(NM) 2025-06-05 13:37:27 +00:00
Makefile.payload libpayload/Makefile.payload: Add lto flags 2024-08-27 09:08:07 +00:00
README payloads/libpayload: Update a Makefile for sample libpayload 2019-06-21 09:16:36 +00:00

-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------

libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().

Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


Usage
-----

Here's an example of a very simple payload (hello.c) and how to build it:

 #include <libpayload.h>

 int main(void)
 {
     printf("Hello, world!\n");
     return 0;
 }

Building the payload using the 'lpgcc' compiler wrapper:

 $ lpgcc -o hello.elf hello.c

Please see the sample/ directory for details.


Website and Mailing List
------------------------

The main website is https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.