coreboot-kgpe-d16/payloads/libpayload
Hung-Te Lin 4708612061 fmap: Add FMAP_AREA_PRESERVE
When updating firmware, we may need to preserve some sections like VPD,
calibration data, ... etc. The logic can be hard-coded in updater as a
list of known names, but a better solution is to have that directly
declared inside FMAP area flags.

To do that, the first step is to apply the changes in flash map
(http://crosreview.com/1493767). A new FMAP_AREA_PRESERVE is now
defined and will be set in future with new syntax in FMD parser.

BUG=chromium:936768
TEST=make; boots an x86 image.

Change-Id: Idba5c8d4a4c5d272f22be85d2054c6c0ce020b1b
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://review.coreboot.org/c/31676
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
2019-03-04 13:25:01 +00:00
..
arch libpayload: arm64: Add GDB support 2018-10-12 20:17:48 +00:00
bin
configs libpayload: Remove unused timer/serial drivers 2018-12-05 14:07:17 +00:00
crypto
curses Fix typos involving "the the" 2018-12-18 13:24:28 +00:00
drivers libpayload: i8042: Only test PS/2 AUX port when enabled 2019-03-02 06:17:49 +00:00
gdb libpayload: gdb: Factor out gdb_handle_reentrant_exception() from arm32 2018-10-12 20:17:40 +00:00
include fmap: Add FMAP_AREA_PRESERVE 2019-03-04 13:25:01 +00:00
libc libpayload: add memchr to libc 2019-02-11 23:17:37 +00:00
libcbfs libpayload: cbfs: Check decompressed size when loading files 2019-02-28 13:56:45 +00:00
liblz4
liblzma
libpci libpayload: Add pci_free_dev() and some boilerplate 2017-12-07 21:51:24 +00:00
sample
tests
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: keyboard: Add option to ignore failures during init 2019-03-02 06:17:36 +00:00
LICENSES
LICENSE_GPL
Makefile libpayload: Make libpayload compile using gnu11 2018-07-16 07:44:03 +00:00
Makefile.inc
README Use git HTTP URLs without `/p` in it 2018-04-17 10:38:06 +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

 $ sudo make install (optional, will install into /opt per default)

As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.


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.