coreboot-kgpe-d16/payloads/libpayload
Julius Werner 879ea7fce8 endian: Replace explicit byte swapping with compiler builtin
gcc seems to have some stupid problem with deciding when to inline byte
swapping functions (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92716).
Using the compiler builtin instead seems to solve the problem.

(This doesn't yet solve the issue for the read_be32()-family of
functions, which we should maybe just get rid of at some point?)

Change-Id: Ia2a6d8ea98987266ccc32ffaa0a7f78965fca1cd
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37343
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2019-12-06 15:08:50 +00:00
..
arch arm64: Bump exception stack size to 2KB 2019-12-05 17:58:05 +00:00
bin Remove MIPS architecture 2019-11-20 10:10:48 +00:00
configs trogdor: libpayload USB support 2019-12-05 17:57:31 +00:00
crypto payloads: Replace all IS_ENABLED(CONFIG_XXX) with CONFIG(XXX) 2019-03-07 17:15:30 +00:00
curses libpayload: Enable -Wimplicit-fallthrough 2019-07-21 17:17:42 +00:00
drivers Change all clrsetbits_leXX() to clrsetbitsXX() 2019-12-04 14:11:17 +00:00
gdb libpayload: gdb: Factor out gdb_handle_reentrant_exception() from arm32 2018-10-12 20:17:40 +00:00
include endian: Replace explicit byte swapping with compiler builtin 2019-12-06 15:08:50 +00:00
libc lib/coreboot_table: Add CBMEM_ID_VBOOT_WORKBUF pointer to coreboot table 2019-12-02 13:00:45 +00:00
libcbfs payloads: Replace all IS_ENABLED(CONFIG_XXX) with CONFIG(XXX) 2019-03-07 17:15:30 +00:00
liblz4
liblzma
libpci
sample Remove MIPS architecture 2019-11-20 10:10:48 +00:00
tests
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig Remove MIPS architecture 2019-11-20 10:10:48 +00:00
LICENSES
LICENSE_GPL
Makefile Remove MIPS architecture 2019-11-20 10:10:48 +00:00
Makefile.inc Remove MIPS architecture 2019-11-20 10:10:48 +00:00
README payloads/libpayload: Update a Makefile for sample libpayload 2019-06-21 09:16:36 +00:00

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.