coreboot-kgpe-d16/payloads/libpayload
Yu-Ping Wu b086728094 libpayload: cbgfx: Add draw_line()
Add a function draw_line() to draw either a horizontal or vertical line
segment.

Theoretically a horizontal line can also be drawn by calling
draw_rounded_box() with dim_rel.x being the line length and dim_rel.y
being the line width. However, due to the truncation in integer division
when converting relative coordinates to absolute ones, this will
potentially produce inconsistent line widths, depending on the value of
pos_rel.y.

It is guaranteed that draw_line() will produce consistent line widths,
regardless of the position of the line. Also, when the thickness
argument is zero, this function is able to draw a line with 1-pixel
width, which is not achievable by draw_rounded_box().

BRANCH=puff
BUG=b:146399181, b:161424726
TEST=emerge-puff libpayload

Change-Id: I2d50414c4bfed343516197da9bb50791c89ba4c2
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43508
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Joel Kitching <kitching@google.com>
2020-07-23 05:09:31 +00:00
..
arch libpayload: allow nonblocking delay and more than one delay 2020-07-16 16:48:42 +00:00
bin treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
configs trogdor: add support for Bubs variant 2020-04-15 19:57:59 +00:00
crypto treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
curses treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
drivers libpayload: cbgfx: Add draw_line() 2020-07-23 05:09:31 +00:00
gdb libpayload: gdb: Condition video console init on LP_VIDEO_CONSOLE 2020-06-22 12:24:42 +00:00
include libpayload: cbgfx: Add draw_line() 2020-07-23 05:09:31 +00:00
libc libpayload: Add simple 32.32 fixed-point math API 2020-07-09 00:32:11 +00:00
libcbfs treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
liblz4 lz4: Fix out-of-bounds reads 2020-03-02 15:03:03 +00:00
liblzma treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
libpci treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
sample treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
tests Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: cbgfx: Replace bilinear resampling with Lanczos 2020-07-09 00:32:17 +00:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
Makefile treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
Makefile.inc treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
README payloads/libpayload: Update a Makefile for sample libpayload 2019-06-21 09:16:36 +00:00

README

-------------------------------------------------------------------------------
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 https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


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 https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.