huang lin 7b9bca0b2b libpayload: mmu: Initialize the base 4GiB as device memory
This allows to accommodate different platforms' default
configurations, memory configuration is fine tuned later during boot
process.

BUG=chrome-os-partner:51537
BRANCH=none
TEST=none yet, the full stack of patches boots fine on EVB

Change-Id: I39da4ce247422f67451711ac0ed5a5e1119ed836
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 97a9a71ade4df8a501043f9ae58463a3135e2a4f
Original-Change-Id: I39da4ce247422f67451711ac0ed5a5e1119ed836
Original-Signed-off-by: huang lin <hl@rock-chips.com>
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/332384
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/13914
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2016-04-05 13:34:47 +02:00
..
2016-03-16 17:56:32 +01:00
2016-03-15 18:22:58 +01:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +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.