Files
system76-coreboot/payloads/libpayload
Ionela Voinescu b29a67d8c8 libpayload: pistachio: fix timer implementation
timer_raw_value must return the number of CPU ticks, and not
the time obtained by dividing the ticks by the CPU frequency.
The CPU counter is increased at every 2 CPU clocks
and therfore the number of ticks will be the counter value
multiplied by 2.

BUG=chrome-os-partner:31438
TEST=tested on Pistachio FPGA; it works properly.
BRANCH=none

Change-Id: Iae62cb328e882f84822250bdf72146321ca9bbe0
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 7ab25ce7dcaffb453ee774d870963a56444d46af
Original-Change-Id: I74408950900463a2c054d5aebd3edb005a325adb
Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/242393
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/8744
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-03-21 11:08:33 +01:00
..
2012-04-04 00:40:31 +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.