coreboot-kgpe-d16/payloads/libpayload
Yu-Ping Wu e5824ff2a9 libpayload: cbgfx: Clear screen by memcpy
Instead of setting each pixel in the framebuffer, use memcpy() to clear
screen faster. As this method should be fast enough, remove the fast
path using memset().

The speed of clear_screen() on brya (x_resolution = 1920,
bytes_per_line = 7680):

- Using memset(): 15ms
- Setting each pixel: 25ms
- Using memcpy(): 14ms

Also remove set_pixel_raw() since it's now used in only one place.

BUG=none
TEST=emerge-brya libpayload
TEST=Saw developer screen on brya
BRANCH=none

Change-Id: I5f08fb50faab48d3db6b61ae022af3226914f72b
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58128
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
2021-10-07 14:11:56 +00:00
..
arch
bin
configs libpayload: Enable UART driver for sc7280 2021-10-06 23:57:20 +00:00
crypto
curses libpayload: curses: Only call `serial_set_color()` with initialized values 2021-07-14 08:22:05 +00:00
drivers libpayload: cbgfx: Clear screen by memcpy 2021-10-07 14:11:56 +00:00
gdb
include driver/intel/pmc_mux/conn: Move typec_orientation enum to coreboot_tables.h 2021-10-04 17:15:47 +00:00
libc coreboot tables: Add type-c port info to coreboot table 2021-10-04 17:12:48 +00:00
libcbfs
liblz4
liblzma
libpci
sample
tests
.gitignore
Doxyfile
Kconfig
LICENSES
LICENSE_GPL
Makefile libpayload: Move EXTRA_CFLAGS to enable option override 2021-09-01 19:34:20 +00:00
Makefile.inc libpayload: Move EXTRA_CFLAGS to enable option override 2021-09-01 19:34:20 +00:00
Makefile.payload util/kconfig: Uprev to Linux 5.13's kconfig 2021-07-13 20:28:14 +00:00
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 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.