coreboot-kgpe-d16/payloads/libpayload
Marc Jones 5f145faff8 Don't do a call as the first instruction in libpayload.
Doing a call before the payload has set up its stack is risky. The stack may
not be in a favorable location. Normally this is not an issue with coreboot
or other well behaved callers.

Change-Id: Ie6f6748a471324b29ebad045c807dfc9f4b92034
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: http://review.coreboot.org/240
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2011-10-11 11:47:06 +02:00
..
arch Don't do a call as the first instruction in libpayload. 2011-10-11 11:47:06 +02:00
bin Add lib/ to the default library path of lpgcc, so -l works 2011-03-01 07:12:08 +00:00
configs libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
crypto Use coreboot build system for libpayload, too. 2011-06-30 20:40:10 +02:00
curses libpayload: Add PDCurses and ncurses' libform/libmenu 2011-08-04 08:10:41 +02:00
drivers libpayload: Add get_option_from() 2011-09-14 07:42:20 +02:00
include libpayload: Add get_option_from() 2011-09-14 07:42:20 +02:00
lib
libc libpayload: Some more compatibility (for flashrom) 2011-08-17 16:26:20 +02:00
libcbfs libpayload: export get_cbfs_header() 2011-08-18 22:02:53 +02:00
liblzma libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
libpci Reduce warnings/errors in libpayload when using picky compiler options 2011-06-30 20:41:23 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
util Fix libpayload xconfig script to find coreboot utils xgcc. 2010-06-22 19:12:58 +00:00
Config.in libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSES Since some people disapprove of white space cleanups mixed in regular commits 2010-04-27 06:56:47 +00:00
Makefile Fixes to the libpayload build system 2011-07-03 14:47:48 +02:00
Makefile.inc libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
README Update repo path in libpayload readme. 2011-03-29 19:29:01 +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 http://coreboot.org for details on coreboot.


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

 $ svn co svn://coreboot.org/coreboot/trunk/payloads/libpayload

 $ cd libpayload

 $ make menuconfig

 $ make

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

As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.


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 http://www.coreboot.org/Libpayload.

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


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

See LICENSES.