Files
system76-coreboot/payloads/libpayload
Furquan Shaikh e4a642c867 libpayload arm64: Allow board to define upper address limit on DMA
Instead of forcing boards to have DMA region below 4GiB, provide
Kconfig option DMA_LIM_EXCL that a board can use to set the upper
limit in MiB units on the address range reserved by DMA. By default,
this value is 0x1000 i.e. 4GiB limit on the DMA upper address.

BUG=None
BRANCH=None
TEST=Compiles successfully for rush. Default value is seen as 0x1000.

Change-Id: Ie35d3844a0989486ae022f8922fdd4c9d7d57fb4
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 6716cf312a103bc0440a558fc43c8c77869816e3
Original-Change-Id: I3ecbb4ec90995ab1568cb0924d5ce9467492697d
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/245250
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/8800
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
2015-03-23 13:11:24 +01:00
..
2015-03-21 18:54:34 +01:00
2012-04-04 00:40:31 +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.