coreboot-kgpe-d16/payloads/libpayload
Julius Werner e9808b145f cbgfx: Use memset() for faster screen clearing if possible
cbgfx currently makes a separate function call (recomputing some values)
for every single pixel it draws. While we mostly don't care that much
about display speed, this can become an issue if you're trying to paint
the whole screen white on a lowly-clocked Cortex-A53. As a simple
solution for these extreme cases, we can build a fast path into
clear_screen() that just memset()s the whole framebuffer if the color
and pixel format allow it.

BUG=chrome-os-partner:54416
TEST=Screen drawing speed on Kevin visibly improves (from 2.5s to 3ms).

Change-Id: I22f032afbb86b96fa5a0cbbdce8526a905c67b58
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/15524
Tested-by: build bot (Jenkins)
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2016-07-02 03:22:51 +02:00
..
arch arm64: Add stack dump to exception handler 2016-05-24 20:51:28 +02:00
bin libpayload: Move base address, stack and heap size to Kconfig 2016-03-15 20:53:38 +01:00
configs libpayload: Add nyan config 2016-05-09 07:49:57 +02:00
crypto
curses libpayload: PDCurses: Remove trailing whitespace 2015-11-20 16:27:36 +01:00
drivers cbgfx: Use memset() for faster screen clearing if possible 2016-07-02 03:22:51 +02:00
gdb tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
include libpayload/pci: Correct MASK macro names 2016-06-21 20:41:06 +02:00
libc libpayload/libc: Fix memset/sizeof usage 2016-04-06 13:33:07 +02:00
libcbfs libpayload: cbfs: Add cbfs_handle API for more fine-grained accesses 2016-05-17 22:48:28 +02:00
liblz4 cbfs: Add LZ4 in-place decompression support for pre-RAM stages 2016-02-22 21:38:37 +01:00
liblzma
libpci
sample
tests
Doxyfile
Kconfig libpayload: ipq40xx: Introduce timer and uart driver 2016-05-09 08:53:24 +02:00
LICENSES
LICENSE_GPL
Makefile libpayload: update junit.xml target, clean up output 2016-03-25 18:18:27 +01:00
Makefile.inc libpayload: update junit.xml target, clean up output 2016-03-25 18:18:27 +01:00
README

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 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.