coreboot/payloads/libpayload
Gabe Black 6bbb073cf6 libpayload: Use the same type for 32 bit data in readl as in uint32_t.
The compiler gets mad when the types are equivalent size but not necessarily
interchangeable because of strict aliasing checks. Since uint32_t is likely to
be used when trying to read 32 bit data, it makes sense for them to be the
compatible.

This change was originally written for ARM but applies to x86 as well.

BUG=None
TEST=Built and booted on link.
BRANCH=None

Change-Id: I91b5e39f40e516405b9802032c87d3b15ed52c23
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/169121
Reviewed-by: Ronald Minnich <rminnich@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@google.com>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
2013-09-14 18:30:17 +00:00
..
arch arm: libpayload: Make cache invalidation take pointers instead of integers 2013-08-29 22:48:54 +00:00
bin libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
configs beltino: add libpayload config file 2013-09-13 22:18:56 +00:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
curses libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
drivers libpayload: ehci: Cache management is hard, let's go copying... 2013-09-14 01:31:18 +00:00
include libpayload: Use the same type for 32 bit data in readl as in uint32_t. 2013-09-14 18:30:17 +00:00
libc libpayload: ehci: Cache management is hard, let's go copying... 2013-09-14 01:31:18 +00:00
libcbfs cbfs: Fix overwalk on file scan 2013-08-19 17:29:35 -07:00
liblzma libpayload: Make lzma truncation non-fatal. 2013-08-19 19:04:35 -07:00
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: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
util libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
Config.in libpayload: Drop PowerPC architecture 2013-06-13 15:50:38 -07:00
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: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
Makefile.inc libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
README libpayload, superiotool: README: Prepend coreboot/ to path of change directory line 2013-04-04 17:22:15 +02:00

-------------------------------------------------------------------------------
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 http://coreboot.org for details on coreboot.


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

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

 $ cd coreboot/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.