Files
system76-coreboot/payloads/libpayload
Gabe Black 6149776e73 libpayload: ARM: Don't leave alignment checking on after the exception test
Currently, the exception handling code on ARM in libpayload turns on alignment
checks as an easy way to generate an exception for testing purposes. It was
leaving it on which disabled unaligned accesses for other, unlreated code
running later. This change adjusts the code so the original value of the
alignment bit is restored after the test exception.

Built and booted into depthcharge on pit with an unaligned accesses added
after the call to exception_init in the depthcharge's main. Before this
change, the access caused an exception. After this change, the access
completed successfully.

Change-Id: If92cab3cc8eabca7c5b0560ce88a8796a27fe3b2
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/59372
Reviewed-by: Stefan Reinauer <reinauer@google.com>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: http://review.coreboot.org/4255
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)
2013-12-03 02:35:56 +01:00
..
2013-11-26 00:08:39 +01:00
2012-04-04 00:40:31 +02:00
2013-11-25 23:36:27 +01:00
2013-11-26 00:08:39 +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.