coreboot-kgpe-d16/payloads/libpayload
Nico Huber 9c8f0424d6 libpayload: Add a Makefile for in-tree payloads
The new `Makefile.payload` can be included by the Makefiles of pay-
loads for in-tree builds. The basic idea is to use libpayload's
build results without the `make install` step, and to ensure that
incremental builds work. For instance, if libpayload's code changes,
a `make` for the payload would automatically update the libpayload
build and rebuild the payload. But if there are no code changes in
libpayload, only updated files of the payload will be re-built.

The configuration of libpayload is supposed to be automatically
generated from a `defconfig` file. If this `defconfig` changes,
libpayload and the payload will be re-built.

Change-Id: If5319f1bf0bcd09964416237c5cf7f8e59f487a2
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47633
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2021-02-07 16:22:45 +00:00
..
arch payloads/libpayload/arch/arm64/mmu.c: Fix typo in comment 2021-02-05 09:40:39 +00:00
bin
configs
crypto
curses
drivers
gdb
include
libc
libcbfs
liblz4
liblzma
libpci
sample
tests
.gitignore
Doxyfile
Kconfig
LICENSES
LICENSE_GPL
Makefile
Makefile.inc
Makefile.payload libpayload: Add a Makefile for in-tree payloads 2021-02-07 16:22:45 +00:00
README

README

-------------------------------------------------------------------------------
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.