coreboot/payloads/libpayload
Patrick Georgi 9de060fd34 libpayload: Use volatile pointers in {read,write}{8,16,32,64}
This is already the case on x86 but not on the ARM platforms, and
{read,write}[bwl] are using volatile pointers, too, so follow suit.

Change-Id: I6819df62016990e12410eaa9c3c97b8b90944b51
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50918
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
2021-02-20 17:01:09 +00:00
..
arch payloads/libpayload/arch/arm64/mmu.c: Fix typo in comment 2021-02-05 09:40:39 +00:00
bin libpayload/lpgcc: Drop redundant linker path 2021-01-11 23:33:03 +00:00
configs Delete mainboard/google/cheza 2020-11-12 01:43:09 +00:00
crypto payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
curses libpayload/curses: Use <stdbool.h> 2020-10-26 06:57:21 +00:00
drivers libpayload/i8042: Add API to peek on keyboard input queue 2020-12-24 08:29:18 +00:00
gdb libpayload: gdb: Condition video console init on LP_VIDEO_CONSOLE 2020-06-22 12:24:42 +00:00
include libpayload: Use volatile pointers in {read,write}{8,16,32,64} 2021-02-20 17:01:09 +00:00
libc coreboot tables: Add SPI flash memory map windows to coreboot tables 2020-12-08 22:56:09 +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 payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
libpci libpayload/libpci: Introduce device class attribute in pci_dev 2020-10-17 16:33:55 +00:00
sample libpayload: Move .xcompile into $(obj) 2021-01-01 21:30:44 +00:00
tests Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
.gitignore .gitignore: Split into subdirectory files 2020-10-30 07:05:27 +00:00
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload/keyboard: Revise scancode set and translation config 2020-12-23 03:29:32 +00:00
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: Move .xcompile into $(obj) 2021-01-01 21:30:44 +00:00
Makefile.inc libpayload: Keep a copy of .config in the build dir 2021-01-01 21:31:29 +00:00
Makefile.payload libpayload: Add a Makefile for in-tree payloads 2021-02-07 16:22:45 +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.