coreboot-kgpe-d16/payloads/libpayload
Nico Huber d1cc812799 libpayload: Add comments on virtual pointers in lib_sysinfo
After another incident related to virtual pointers in lib_sysinfo (and
resulting confusion), I decided to put some comments on the matter into
the code.

Remember, we decided to always use virtual pointers in lib_sysinfo, but
it's not always obvious from the code, that they are.

See also:
425973c libpayload: Always use virtual pointers in struct sysinfo_t
593f577 libpayload: Fix use of virtual pointers in sysinfo

Change-Id: I886c3b1d182cba07f1aab1667e702e2868ad4b68
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/2878
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2013-03-22 16:20:08 +01:00
..
arch libpayload: Add comments on virtual pointers in lib_sysinfo 2013-03-22 16:20:08 +01:00
bin libpayload: fix compiler flags 2013-02-15 06:51:52 +01:00
configs libpayload: Update configs/defconfig file 2012-12-18 15:05:36 +01:00
crypto Change TARGET_I386 to ARCH_X86 2012-11-30 23:20:54 +01:00
curses PDcurses: Delete automatically created (and unused) files 2012-12-20 14:46:29 +01:00
drivers libpayload: Make keycode constants available outside of curses.h. 2013-03-18 20:45:48 +01:00
include libpayload: Add comments on virtual pointers in lib_sysinfo 2013-03-22 16:20:08 +01:00
libc libpayload: Generalize and redistribute timekeeping code 2013-03-14 04:53:33 +01:00
libcbfs cbfs: Change false ERROR print to a WARNING. 2013-03-21 23:23:31 +01:00
liblzma libpayload: Don't do unaligned accesses during LZMA decompression 2013-03-13 23:42:09 +01:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
tests libpayload: initial test case + tiny "framework" 2013-03-22 00:35:32 +01:00
util libpayload: Start using only internal and compiler headers. 2013-03-13 22:04:44 +01:00
Config.in libpayload: Make whether or not there's an IO address space configurable 2013-03-13 23:02:05 +01:00
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 libpayload: Fix the config file dependency in the Makefile template 2013-03-18 20:46:09 +01:00
Makefile.inc libpayload: Fix the config file dependency in the Makefile template 2013-03-18 20:46:09 +01:00
README libpayload: Update README with Git repository URL and directory location 2013-01-30 17:36:22 +01:00

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
------------

 $ git clone http://review.coreboot.org/p/coreboot.git

 $ cd payloads/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.