coreboot-kgpe-d16/payloads/libpayload
Aaron Durbin a09760eb45 libpayload: add x86 ROM variable MTRR support
On x86, coreboot may allocate a variable range MTRR for enabling caching
of the system ROM. Add the ability to parse this structure and add the
result to the sysinfo structure.

An example usage implementation would be to obtain the variable MTRR
index that covers the ROM from the sysinfo structure. Then one would
disable caching and change the MTRR type from uncacheable to
write-protect and enable caching. The opposite sequence is required
to tearn down the caching.

Change-Id: I3bfe2028d8574d3adb1d85292abf8f1372cf97fa
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2920
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2013-03-29 20:10:14 +01:00
..
arch libpayload: add x86 ROM variable MTRR support 2013-03-29 20:10:14 +01:00
bin libpayload: fix compiler flags 2013-02-15 06:51:52 +01:00
configs libpayload: Update configs/defconfig file 2012-12-18 15:05:36 +01:00
crypto Change TARGET_I386 to ARCH_X86 2012-11-30 23:20:54 +01:00
curses libpayload: Fix prototype warnings in PDCurses 2013-03-26 19:37:33 +01:00
drivers libpayload: Fix unused function warning in EHCI stack 2013-03-26 19:07:53 +01:00
include libpayload: add x86 ROM variable MTRR support 2013-03-29 20:10:14 +01:00
libc libpayload: fix size_t handling 2013-03-26 19:35:28 +01:00
libcbfs libpayload: fix size_t handling 2013-03-26 19:35:28 +01:00
liblzma libpayload: Don't do unaligned accesses during LZMA decompression 2013-03-13 23:42:09 +01:00
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: initial test case + tiny "framework" 2013-03-22 00:35:32 +01:00
util libpayload: Start using only internal and compiler headers. 2013-03-13 22:04:44 +01:00
Config.in libpayload: Fix Config.in warning 2013-03-25 23:06:34 +01:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSES Since some people disapprove of white space cleanups mixed in regular commits 2010-04-27 06:56:47 +00:00
Makefile libpayload: Fix the config file dependency in the Makefile template 2013-03-18 20:46:09 +01:00
Makefile.inc libpayload: Fix the config file dependency in the Makefile template 2013-03-18 20:46:09 +01:00
README libpayload: Update README with Git repository URL and directory location 2013-01-30 17:36:22 +01:00

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


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

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

 $ cd 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.