coreboot-kgpe-d16/payloads/libpayload
Nico Huber a160d93dda libpayload/keyboard: Revise keyboard_cmd() error handling
Even if we are careful, it's still possible that we read spurious
data from the keyboard, e.g. keystrokes. Namely, when we send the
reset/disable command, there is a race before the command is pro-
cessed.

So we should always process data from the keyboard in a loop. We
break it, when an ACK (0xfa) or a NAK (0xfe) is received, and warn
on unexpected data unless it might be due to the mentioned race.

This also gives us the opportunity to use command-specific timeouts
which we take from Linux: 1s for the keyboard self-test (as there
are keyboards that perform the test before acking the command) and
200ms for all other commands.

Change-Id: I60a2643a8ff4b9231c63bf970c8749c97c7d8926
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47083
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
2020-12-24 08:18:41 +00:00
..
arch libpayload: Provide API to expose MMU memery ranges for ARM64 2020-12-05 09:45:34 +00:00
bin libpayload: Add compiler.h to compiler parameters 2020-11-08 11:37:04 +00:00
configs Delete mainboard/google/cheza 2020-11-12 01:43:09 +00:00
crypto payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
curses libpayload/curses: Use <stdbool.h> 2020-10-26 06:57:21 +00:00
drivers libpayload/keyboard: Revise keyboard_cmd() error handling 2020-12-24 08:18:41 +00:00
gdb libpayload: gdb: Condition video console init on LP_VIDEO_CONSOLE 2020-06-22 12:24:42 +00:00
include libpayload/i8042: Add API to get/set kbd translation state 2020-12-23 03:29:16 +00:00
libc coreboot tables: Add SPI flash memory map windows to coreboot tables 2020-12-08 22:56:09 +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 payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
libpci libpayload/libpci: Introduce device class attribute in pci_dev 2020-10-17 16:33:55 +00:00
sample treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
tests
.gitignore .gitignore: Split into subdirectory files 2020-10-30 07:05:27 +00:00
Doxyfile
Kconfig libpayload/keyboard: Revise scancode set and translation config 2020-12-23 03:29:32 +00:00
LICENSES
LICENSE_GPL
Makefile treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
Makefile.inc libpayload: Add compiler.h to compiler parameters 2020-11-08 11:37:04 +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.