Marc Jones ccee6256b4 Fix libpayload alloc() size and gcc pointer optimization problems.
The previous commit was incomplete and missed setting the entire
alloc area.

There are also additional problems with gcc optimizations of the
pointer math. The "auto" casting by gcc wouldn't return warnings,
but it was causing the optimization to be incorrect. We are now
very explicit in the casting in the pointer math.

Change-Id: I020808c8d1dda544fe862b9efb0e5345eeab5aab
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: http://review.coreboot.org/804
Tested-by: build bot (Jenkins)
Reviewed-by: Peter Stuge <peter@stuge.se>
2012-03-21 21:03:24 +01:00
..
2012-01-07 11:49:57 +01:00
2011-08-04 08:11:21 +02:00
2011-08-04 08:11:21 +02:00
2011-12-21 16:27:01 +01:00
2011-08-04 08:11:21 +02:00
2011-07-03 14:47:48 +02:00
2011-08-04 08:11:21 +02:00
2011-03-29 19:29:01 +00:00

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

 $ 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.