coreboot-kgpe-d16/payloads/libpayload
Vadim Bendebury e63990ef34 libpayload: provide basic 64bit division implementation
These functions are usually provided by gcc lib, which is not supposed
to be included on embedded platforms. This patch adds a no thrills C
implementation.

Other than MIPS platforms are happy using the gcc library provided
implementation, but in case of Chrome OS MIPS toolchain the libraries
are compiled with the small GOT, such that the entire data segment
does not fit.

With this implementation mips, arm and x86 targets build fine.

BRANCH=none
BUG=chrome-os-partner:31438

TEST=checked the logic by incorporating this code into a C file and
     running a loop continuously comparing random inputs' division and
     left and right shift results.

     The test ran for extended periods of time without failure.

Change-Id: I468acd2fdbcdd493a76758a394e79cad35f9535a
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 2cc5f8668dd2609408af8da5a74c5a3d063fc0d3
Original-Change-Id: Ib46616d7eb0b2b497199270057514f730bb1cb0b
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/232232
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8742
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2015-03-21 01:39:59 +01:00
..
arch libpayload: move MRC processing to x86 path and remove ACPI_GNVS duplication 2015-03-20 15:33:47 +01:00
bin libpayload: Do not include gcclib for mips targets 2015-03-20 10:02:04 +01:00
configs libpayload: Add Rock Chip drivers 2015-01-12 05:55:30 +01:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
curses libpayload/PDcurses: avoid NULL deref 2015-01-03 23:58:22 +01:00
drivers libpayload/usb: wait a millisecond to work around device bugs 2015-03-19 23:24:44 +01:00
gdb libpayload: Let GDB stub read/write memory with aligned MMIO words 2015-01-12 05:56:16 +01:00
include libpayload: provide basic 64bit division implementation 2015-03-21 01:39:59 +01:00
libc libpayload: provide basic 64bit division implementation 2015-03-21 01:39:59 +01:00
libcbfs libpayload: Fix pointer related casts 2014-12-31 18:57:35 +01:00
liblzma LZMA: Add a version of ulzma which takes the input and output buffer sizes. 2014-08-10 22:29:51 +02:00
libpci
sample libpayload: Fix missed CONFIG_ -> CONFIG_LP_ substitutions 2014-10-17 11:24:15 +02:00
tests libpayload: Change CONFIG_X86_SERIAL_CONSOLE to CONFIG_8250_SERIAL_CONSOLE 2014-08-28 01:40:48 +02:00
util libpayload: Add support for arm64 in libpayload 2015-01-09 07:04:28 +01:00
Config.in libpayload: Add Rock Chip drivers 2015-01-12 05:55:30 +01:00
Doxyfile
LICENSES libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
Makefile libpayload: Add support for arm64 in libpayload 2015-01-09 07:04:28 +01:00
Makefile.inc libpayload: Add remote GDB support 2015-01-09 07:06:51 +01:00
README libpayload, superiotool: README: Prepend `coreboot/` to path of change directory line 2013-04-04 17:22:15 +02:00

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 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.