Files
system76-coreboot/payloads/libpayload
Gabe Black 1b33c31cf3 libpayload: Make usb_initialize more efficient and fix style problems.
The usb_initialize function would scan for USB host controllers by brute force
iterating over all possible busses, devices, and functions. This change makes
it recursively scan busses only if it finds them on the other side of a bridge,
and only scan for functions beyond function 0 if the device claims to be
multifunction.

This change also takes the opportunity to clean up some style problems
throughout the file.

Change-Id: I0f5e8b9a454a42a76d30bccca898c8e1af770b2b
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: http://review.coreboot.org/1736
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)
2012-11-07 18:38:15 +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.