coreboot-kgpe-d16/payloads/libpayload
Julius Werner d61350c403 libpayload: malloc: Change memcpy() to memmove() in realloc
Our realloc() works (somewhat suboptimally) by free()ing the existing
allocation and then reallocating it wherever it fits. If there was free
space before the old location, this means the new allocation may be
before the old one, and if the free space block is smaller than the old
allocation it may overlap. Thus, we should be moving memmove() instead
of memcpy() to move the block over.

This is not a problem in practice since all our existing memcpy()s are
simple iterate and copy front to back implementations which are safe for
overlaps when the destination is in front of the source. but it's still
the more correct thing to do (in case we ever change our memcpy()s to do
something more advanced or whatever).

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I35f77a94b7a72c01364ee7eecb5c3ff5ecde57f6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40028
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2020-04-03 19:56:27 +00:00
..
arch libpayload: arm64: Keep instruction cache enabled at all times 2020-02-17 15:42:34 +00:00
bin Remove MIPS architecture 2019-11-20 10:10:48 +00:00
configs libpayload: Add uart/serial driver support for trogdor 2020-03-09 22:58:56 +00:00
crypto payloads: Replace all IS_ENABLED(CONFIG_XXX) with CONFIG(XXX) 2019-03-07 17:15:30 +00:00
curses libpayload: Enable -Wimplicit-fallthrough 2019-07-21 17:17:42 +00:00
drivers libpayload/drivers/nvram: Fix coding style 2020-03-23 08:35:56 +00:00
gdb
include libpayload/drivers/nvram: Add function to write RTC 2020-03-23 08:35:31 +00:00
libc libpayload: malloc: Change memcpy() to memmove() in realloc 2020-04-03 19:56:27 +00:00
libcbfs libpayload: cbfs: fix infinite loop in cbfs_get_{handle,attr} 2020-03-02 15:00:24 +00:00
liblz4 lz4: Fix out-of-bounds reads 2020-03-02 15:03:03 +00:00
liblzma libpayload: Fix out-of-bounds read 2020-02-24 12:53:25 +00:00
libpci libpayload: Make pci and endian handling -Wconversion safe 2020-02-05 21:48:36 +00:00
sample Remove MIPS architecture 2019-11-20 10:10:48 +00:00
tests
Doxyfile
Kconfig libpayload: Add uart/serial driver support for trogdor 2020-03-09 22:58:56 +00:00
LICENSES
LICENSE_GPL
Makefile Makefile: Remove romcc 2019-12-27 08:59:59 +00:00
Makefile.inc Remove MIPS architecture 2019-11-20 10:10:48 +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.