coreboot/payloads/libpayload
Aaron Durbin 6026ca5ad0 libpayload: arm64: don't modify cbtable entries
The framebuffer structure lives in the coreboot tables. Those
tables have a checksum calculation applied over all the entries.
Therefore, one shouldnot be modifying fields within the coreboot
table entries because the calculated checksum would be wrong.

BRANCH=none
BUG=chrome-os-partner:31936
TEST=On ryu, confirmed dev screen still works as well as cbmem utility
     once booted.

Change-Id: Ic9c164ded03d10d6f6f3ce15e9b38b1f6ce61a91
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/230471
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Commit-Queue: Furquan Shaikh <furquan@chromium.org>
2014-11-18 21:11:52 +00:00
..
arch libpayload: arm64: don't modify cbtable entries 2014-11-18 21:11:52 +00:00
bin libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
configs Revert "ryu: libpayload: Set fb address in dc register" 2014-11-14 19:39:26 +00:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
curses libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
drivers Revert "ryu: libpayload: Set fb address in dc register" 2014-11-14 19:39:26 +00:00
gdb libpayload: Let GDB stub read/write memory with aligned MMIO words 2014-07-22 01:24:00 +00:00
include libpayload: Add support for parsing RAMOOPS range from coreboot 2014-11-14 01:42:31 +00:00
libc libpayload: Add support for parsing RAMOOPS range from coreboot 2014-11-14 01:42:31 +00:00
libcbfs libpayload: Fix pointer related casts 2014-05-14 00:25:48 +00:00
liblzma libpayload: Make lzma truncation non-fatal. 2013-08-19 19:04:35 -07:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
tests libpayload: Change CONFIG_X86_SERIAL_CONSOLE to CONFIG_8250_SERIAL_CONSOLE 2013-09-27 14:05:53 +00:00
util libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
Config.in ryu: libpayload: Add CONFIG_LP_TEGRA_VIDEO_CONSOLE_INIT 2014-11-01 01:27:53 +00:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2014-06-13 20:37:29 +00:00
LICENSES libpayload: Introduce new Kconfig to explicitly allow GPL code 2014-06-13 20:37:29 +00:00
Makefile libpayload: Add support for arm64 in libpayload 2014-06-07 01:28:57 +00:00
Makefile.inc Change GDB_DEBUG to SOURCE_DEBUG 2014-10-08 05:07:21 +00:00
README libpayload, superiotool: README: Prepend coreboot/ to path of change directory line 2013-04-04 17:22:15 +02:00

-------------------------------------------------------------------------------
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 http://coreboot.org for details on coreboot.


Installation
------------

 $ git clone http://review.coreboot.org/p/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 http://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at http://coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.