Files
system76-coreboot/payloads/libpayload
Julius Werner 7b58319e9c libpayload: cbgfx: Show square images on portrait displays
CBGFX currently doesn't support portrait screens at all. This will have
to be fixed eventually but might take a bit of effort. As a first step
to make devices with a portrait panel somewhat usable, this patch will
just force a square canvas on these panels and keep the bottom part of
the screen black.

Also switch set_pixel to calculate framebuffer position via
bytes_per_line instead of x_resolution. This is supposed to be the
canonical way to do that and may differ in cases where the display
controller requires a certain alignment from framebuffer lines.

Change-Id: I47dd3bf95ab8a7d8b7e1913e0ddab346eedd46f1
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/19279
Tested-by: build bot (Jenkins)
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
2017-04-17 18:12:02 +02:00
..
2017-04-07 21:33:19 +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
2017-01-25 17:58:48 +01:00
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.