coreboot-kgpe-d16/payloads/libpayload
Yu-Ping Wu 52889c9c9f libpayload: cbgfx: Clear screen by sequential access
Currently clear_screen() calls set_pixel() to set all pixels. However,
the actual order of pixels being set depends on the framebuffer
orientation. With NORMAL orientation, the framebuffer is accessed
sequentially; with LEFT_UP/RIGHT_UP orientation, it is accessed back and
forth, leading to performance drop (>1 second on bugzzy).

Therefore, ensure sequential access to the framebuffer, regardless of
the orientation.

BUG=b:194967458
TEST=emerge-cherry libpayload
BRANCH=dedede

Change-Id: Iecaff5b6abc24ba4b3859cbc44c0d61b2a90b2d9
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57104
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2021-08-27 02:53:38 +00:00
..
arch payloads/libpayload/arch/arm64/mmu.c: Fix typo in comment 2021-02-05 09:40:39 +00:00
bin
configs libpayload: Support herobrine 2021-04-15 19:08:23 +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 sequential access 2021-08-27 02:53:38 +00:00
gdb
include nvs: Add Chrome OS NVS (CNVS) information to coreboot tables 2021-06-18 18:38:14 +00:00
libc nvs: Add Chrome OS NVS (CNVS) information to coreboot tables 2021-06-18 18:38:14 +00:00
libcbfs
liblz4
liblzma
libpci
sample
tests
.gitignore
Doxyfile
Kconfig libpayload: i8042: Enable keyboard translation by default on exit 2021-05-03 15:55:52 +00:00
LICENSES
LICENSE_GPL
Makefile util/kconfig: Uprev to Linux 5.13's kconfig 2021-07-13 20:28:14 +00:00
Makefile.inc
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.