coreboot-kgpe-d16/payloads/libpayload
Julius Werner 1143d08f7e libpayload: head.S: Avoid clearing BSS (and heap) again
3 out of 4 architectures currently zero out the payload BSS in early
assembly code, which is pointless since the code loading the payload has
already done that (with a more efficient memset). ARM64 has never had
any code like this and can run just fine without it. This also defeats
the new optimization of moving the heap out of the BSS, since all three
implementations assume that everything between _edata and _end is BSS.
We should just take this out.

Change-Id: I45cd2dabd94da43ff0f77e990f11c877cee6cda1
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/16091
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2016-08-13 02:46:19 +02:00
..
arch libpayload: head.S: Avoid clearing BSS (and heap) again 2016-08-13 02:46:19 +02:00
bin libpayload: Move base address, stack and heap size to Kconfig 2016-03-15 20:53:38 +01:00
configs libpayload: Add nyan config 2016-05-09 07:49:57 +02:00
crypto libpayload: Make Kconfig bools use IS_ENABLED() 2015-06-30 18:55:15 +02:00
curses libpayload: PDCurses: Remove trailing whitespace 2015-11-20 16:27:36 +01:00
drivers libpayload: split "Drivers" config section in Kconfig 2016-08-02 20:14:36 +02:00
gdb tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
include libpayload/pci: Correct MASK macro names 2016-06-21 20:41:06 +02:00
libc libpayload: Drop superfluous "continue" 2016-07-31 19:17:27 +02:00
libcbfs libpayload: cbfs: Fix minor memory leak in some edge cases 2016-08-12 22:52:22 +02:00
liblz4 cbfs: Add LZ4 in-place decompression support for pre-RAM stages 2016-02-22 21:38:37 +01:00
liblzma libpayload: lzma: Allocate scratchpad on the heap 2016-08-08 19:02:07 +02:00
libpci Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
sample Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
tests Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
Doxyfile
Kconfig libpayload: split "Drivers" config section in Kconfig 2016-08-02 20:14:36 +02:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
Makefile libpayload: update junit.xml target, clean up output 2016-03-25 18:18:27 +01:00
Makefile.inc libpayload: update junit.xml target, clean up output 2016-03-25 18:18:27 +01:00
README Remove empty lines at end of file 2015-06-08 00:55:07 +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.