coreboot-kgpe-d16/payloads/libpayload
Caveh Jalali eaa219b5bb libpayload: drivers/usb: add a USB pre-poll hook
This adds a hook so that a payload can optionally perform USB service
functions in conjunction with regular USB port status polling. In
particular, this allows depthcharge to control the state of an
external USB mux. Some SoCs like Tiger Lake have a USB mux for Type-C
ports that must be kept in sync with the state of the port as reported
by the TCPC. This can be achieved by hooking into the poll routine to
refresh the state of the USB mux.

BUG=b:149883933
TEST=booted into recovery from Type-C flash drive on volteer

Change-Id: Ic6c23756f64b891b3c5683cd650c605b8630b0fb
Signed-off-by: Caveh Jalali <caveh@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42072
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2020-06-06 01:49:52 +00:00
..
arch treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +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: drivers/usb: add a USB pre-poll hook 2020-06-06 01:49:52 +00:00
gdb libpayload: gdb: Factor out gdb_handle_reentrant_exception() from arm32 2018-10-12 20:17:40 +00:00
include libpayload: drivers/usb: add a USB pre-poll hook 2020-06-06 01:49:52 +00:00
libc payloads/libpayload/libc: Avoid NULL pointer dereference 2020-05-28 09:34:37 +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
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
LICENSES
LICENSE_GPL
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.