Files
system76-coreboot/payloads/libpayload
Lee Leahy e32b6e7196 libpayload: PCI bus scan - Eliminate endless loop
Don't attempt to scan the PCI bus if the bridge is disabled.  When
the PCI bridge is not setup and enabled, it is possible for the
secondary bus register to contain the value zero (0).  In this case
the usb_scan_pci_bus routine gets into an infinite recursive loop
which ends only when the heap or stack is exhausted.  This patch
verifies that the PCI bridge is enabled by verifying that it is
enabled for either memory or I/O operations.  When enabled, the
secondary bus is scanned.

BRANCH=none
BUG=None
TEST=Build and run on Samus

Change-Id: I6826dc1d73b7c24729de5ac7c4d3534922ca73c5
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 63d04b47934761351b54c847a2692bdef81ce54f
Original-Change-Id: I855240c52fa3eba841e6754816ebbcb824abc4cd
Original-Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/236382
Original-Commit-Queue: Leroy P Leahy <leroy.p.leahy@intel.com>
Original-Tested-by: Leroy P Leahy <leroy.p.leahy@intel.com>
Original-Reviewed-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/8734
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-04-09 21:44:33 +02:00
..
2012-04-04 00:40:31 +02:00
2015-04-08 09:32:21 +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.