Patrick Georgi 5dc87fe470 libpayload/arm64: Mark existing framebuffer as DMAable
If a framebuffer is already configured by coreboot, libpayload's
MMU tables didn't mark its memory DMAable (unlike when libpayload
set up its own framebuffer memory).

BRANCH=none
BUG=chrome-os-partner:52826
TEST=depthcharge's recovery screen is not corrupted anymore on kevin

Change-Id: I228a861b3fdcf1298a3cfa0a054214c78ed55e70
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 889e8358a0f2f504abd9910549aa68f3992bb4e8
Original-Change-Id: I7ba79151ccc1eb605f82e1869a74b539a6be5e99
Original-Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/341092
Reviewed-on: https://review.coreboot.org/14685
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2016-05-09 08:30:56 +02:00
..
2016-05-09 07:49:57 +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.