coreboot-kgpe-d16/payloads/libpayload
Julius Werner ae096be00c libpayload: memmove: Don't make expectations of architecture memcpy
default_memmove() calls memcpy() when (src > dst). This is safe for the
default_memcpy() implementation, but just calling memcpy() may invoke an
architecture-specific implementation. Architectures are free to
implement memcpy() however they want and may assume that buffers don't
overlap in either direction. So while this happens to work for all
current architecture implementations of memcpy(), it's safer not to rely
on that and only rely on the known implementation of default_memcpy()
for the forwards-overlapping case.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I7ece4ce9e6622a36612bfade3deb62f351877789
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44691
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2020-08-24 09:24:06 +00:00
..
arch libpayload: Cache physical location of CBMEM entries 2020-08-24 09:13:30 +00:00
bin treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
configs libpayload/defconfig: Set default heap size to 1MiB 2020-08-17 06:10:49 +00:00
crypto treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
curses payloads/libpayload/curses/menu/eti.h: Remove unneeded whitespaces 2020-07-25 01:25:16 +00:00
drivers libpayload: Cache copy of `cb_framebuffer` struct 2020-08-24 09:13:16 +00:00
gdb libpayload: gdb: Condition video console init on LP_VIDEO_CONSOLE 2020-06-22 12:24:42 +00:00
include libpayload: Cache physical location of strings 2020-08-24 09:13:35 +00:00
libc libpayload: memmove: Don't make expectations of architecture memcpy 2020-08-24 09:24:06 +00:00
libcbfs treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
liblz4 lz4: Fix out-of-bounds reads 2020-03-02 15:03:03 +00:00
liblzma treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
libpci treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
sample treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
tests
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: cbgfx: Replace bilinear resampling with Lanczos 2020-07-09 00:32:17 +00:00
LICENSES
LICENSE_GPL
Makefile treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
Makefile.inc treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
README payloads/libpayload: Update a Makefile for sample libpayload 2019-06-21 09:16:36 +00:00

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 https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


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 https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.