Gabe Black c324794cb0 libpayload: Make the symbols in memory.c weak so they can be overridden.
The implementations for various stdlib functions in libc/memory.c are very
generic and should work under just about any circumstances. They are
unfortunately also very slow. This change makes them weak symbols so that
faster versions can be defined on a per architecture basis which will
automatically take the place of the slow versions.

Change-Id: Ia1ac90d9dcd45962b2a15f61ecc74b0a4676048d
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: http://review.coreboot.org/1725
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)
2012-11-07 18:30:56 +01:00
..
2011-08-04 08:11:21 +02:00
2012-11-07 18:30:11 +01:00
2011-08-04 08:11:21 +02:00
2012-04-04 00:40:31 +02:00
2011-12-21 16:27:01 +01:00
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.