Daisuke Nojiri d66f1da846 libpayload: allow compression at file header level
Decompression is handled transparently within cbfs_get_file_content:

	const char *name = "foo.bmp";
	void *dst = cbfs_get_file_content(media, name, type, NULL);

To keep things consistent, a couple of API changes were necessary:
- cbfs_get_file_content always returns a copy of the data, even for
  uncompressed files. It's the callers responsibility to free the
  memory.
- same for cbfs_load_payload and cbfs_find_file.
- cbfs_load_optionrom doesn't take a "dest" argument anymore but always
  returns a copy of the data, for compressed and uncompressed files.
  Like with cbfs_get_file_content, the caller is responsible to free it.
  It also decompresses based on extended file attributes instead of the
  cbfs_optionrom subheader that libpayload specified but that (AFAIK)
  nobody ever used, given that there's not even tooling for that.

Change-Id: If959e3dff9b93c6ae45ec7358afcc7840bc17218
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10938
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
2015-09-17 18:52:56 +00:00
..
2015-09-07 15:54:50 +00:00
2015-05-21 20:50:25 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +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.