coreboot-kgpe-d16/payloads/libpayload
Subrata Banik 790b5cf442 {commonlib, libpayload}: Add "has_external_display" in coreboot table
This patch introduces a new coreboot table entry named
"has_external_display" to understand if external display is attached.

This information is useful to prevent graceful shutdown by payload
when the LID is closed but an external display is present.

This piece of the information will be gathered by coreboot and passed
into the payload using this new entry aka external_display because
payload (i.e., deptcharge) doesn't have any other way to determine
if external display is available.

BUG=b:299137940
TEST=Able to build and boot google/rex.

w/o this patch:

LID closed and external display attached (HDMI) in developer mode
  (GBB 0x39):

> System is powered off by depthcharge

w/ this patch:

LID closed and external display attached (HDMI) in developer mode
  (GBB 0x39):

> Booted to OS and device is alive/usable

Change-Id: I0fa7eee4c5a50371a7a66c6ca1ac2c7d046d010b
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77796
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2023-10-04 18:50:49 +00:00
..
arch libpayload: Skip unknown arguments to clang 2023-08-26 21:06:30 +00:00
bin
configs
crypto
curses payloads/libpayload: Don't use old style function definition 2023-08-28 17:09:46 +00:00
drivers libpayload/drivers/video: Add cursor movement support in console 2023-09-18 13:15:44 +00:00
gdb
include {commonlib, libpayload}: Add "has_external_display" in coreboot table 2023-10-04 18:50:49 +00:00
libc libpayload: Add vboot and reboot utility functions 2023-09-18 15:42:31 +00:00
libcbfs libpayload/libcbfs: Add VBOOT_CBFS_INTEGRATION support 2023-09-18 15:43:45 +00:00
liblz4
liblzma
libpci
sample
tests libpayload/vboot: Add vboot context initialization and management code 2023-09-18 15:40:40 +00:00
vboot libpayload/libcbfs: Add VBOOT_CBFS_INTEGRATION support 2023-09-18 15:43:45 +00:00
.gitignore
Doxyfile
Kconfig
LICENSES
LICENSE_GPL
Makefile
Makefile.inc
Makefile.payload
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.