coreboot-kgpe-d16/payloads/libpayload
Gabe Black b4523bb691 libpayload: Change the measurement interval for get_cpu_speed to 2 ms.
The interval used to be about 55 ms which is excessively long. Coreboot only
waits for 2 ms and gets a reasonable answer. That should be good enough for us
as well.

Change-Id: I4d4e8b25b6ba540c9e9839ed0bbaa1f04f67cce1
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: http://review.coreboot.org/2520
Tested-by: build bot (Jenkins)
Reviewed-by: Anton Kochkov <anton.kochkov@gmail.com>
2013-02-26 07:38:41 +01:00
..
arch libpayload: Change the measurement interval for get_cpu_speed to 2 ms. 2013-02-26 07:38:41 +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 PDcurses: Delete automatically created (and unused) files 2012-12-20 14:46:29 +01:00
drivers libpayload: Fix license headers 2013-02-20 02:41:24 +01:00
include libpayload: Use the same type for 32 bit data in readl as in uint32_t. 2013-02-15 06:52:01 +01:00
libc libpayload: get time to compile cross-arch 2013-02-15 06:51:38 +01:00
libcbfs libpayload: cbfs: Fix CBFS max size calculation. 2013-02-22 09:23:43 +01:00
liblzma libpayload: Add liblzma, libcbfs 2011-08-04 08:11:21 +02:00
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
util Fix libpayload xcompile xgcc path 2013-02-01 20:15:47 +01:00
Config.in libpayload: only compile drivers/serial.c on machines that use it. 2013-02-16 04:48:51 +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: Initial ARMv7 port 2012-12-14 22:29:48 +01:00
Makefile.inc libpayload; put the ldscript into an arch-dependent directory path 2013-02-14 21:32:02 +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.