Aaron Durbin 82683ab9d4 libpayload: provide missing cbfs symbol
The generic cbfs code relies on the libpayload_init_default_cbfs_media
symbol. However, none was provided for ARM. Provide an empty
implementation that returns an error as there is no generic way
to locate the default cbfs media.

Old-Change-Id: Ie0d06fbe6fc790c9d92434cd2d60922908acdc69
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/56805
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
(cherry picked from commit d3410c28ef9f37b832e2fa2d18351dda332bc9f7)

libpayload: place dummy_media.c in correct object list

The commit introducing dummy_media.c was placed in the
libc object list. This wasn't correct. It should be in the
libcbfs object list as well as guarded by CONFIG_CBFS.

Old-Change-Id: Iace43fff8f85f60ecac5e6eb8350cd1f3ee9d35e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/56925
(cherry picked from commit 7937c7c5e95a934593bc0cedd5f4496b4770c303)

Squashed two related commits.

Change-Id: I84cd132b44cc2ea5b29acf109a3562baaeede9c6
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6411
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
2014-07-31 18:32:37 +02:00
..
2012-04-04 00:40:31 +02:00
2013-11-25 23:36:27 +01:00

-------------------------------------------------------------------------------
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.