coreboot-kgpe-d16/payloads/libpayload
Patrick Rudolph bc744f5893 drivers/smmstore: Implement SMMSTORE version 2
SMMSTORE version 2 is a complete redesign of the current driver. It is
not backwards-compatible with version 1, and only one version can be
used at a time.

Key features:
* Uses a fixed communication buffer instead of writing to arbitrary
  memory addresses provided by untrusted ring0 code.
* Gives the caller full control over the used data format.
* Splits the store into smaller chunks to allow fault tolerant updates.
* Doesn't provide feedback about the actual read/written bytes, just
  returns error or success in registers.
* Returns an error if the requested operation would overflow the
  communication buffer.

Separate the SMMSTORE into 64 KiB blocks that can individually be
read/written/erased. To be used by payloads that implement a
FaultTolerant Variable store like TianoCore.

The implementation has been tested against EDK2 master.

An example EDK2 implementation can be found here:
eb1127744a

Change-Id: I25e49d184135710f3e6dd1ad3bed95de950fe057
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Christian Walter <christian.walter@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40520
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
2020-10-22 12:29:47 +00:00
..
arch libpayload/arch/x86: Introduce pacc pointer in sysinfo_t struct 2020-10-20 20:35:24 +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 payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
curses payloads: Drop unneeded empty lines 2020-09-21 16:20:57 +00:00
drivers libpayload/storage/ahci: Use pci_dev struct in ahci_initialize() 2020-10-20 20:39:30 +00:00
gdb libpayload: gdb: Condition video console init on LP_VIDEO_CONSOLE 2020-06-22 12:24:42 +00:00
include drivers/smmstore: Implement SMMSTORE version 2 2020-10-22 12:29:47 +00:00
libc libpayload: use PRIu64 type to print u64 2020-09-30 10:16:44 +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 treewide: Remove "this file is part of" lines 2020-05-11 17:11:40 +00:00
tests
Doxyfile
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.