coreboot-kgpe-d16/payloads/libpayload
Nico Huber 5e0db58533 libpayload: Cache copy of `cb_framebuffer` struct
Our AArch64 code supports dynamic framebuffer allocation which
makes it necessary to change the framebuffer information during
runtime. Having a pointer inside `libsysinfo` made a mess of it
as the pointer would either refer to the original struct inside
the coreboot table or to a new struct inside payload space. The
latter would be unaffected by a relocation of the payload.

Instead of the pointer, we'll always keep a copy of the whole
struct, which can be altered on demand without affecting the
coreboot table. To align the `video/graphics` driver with the
console driver, we also replace `fbaddr` with a macro `FB` that
calls phys_to_virt().

Change-Id: I3edc09cdb502a71516c1ee71457c1f8dcd01c119
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43578
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2020-08-24 09:13:16 +00:00
..
arch libpayload: Cache copy of `cb_framebuffer` struct 2020-08-24 09:13:16 +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 copy of `cb_framebuffer` struct 2020-08-24 09:13:16 +00:00
libc libpayload: Cache copy of `cb_framebuffer` struct 2020-08-24 09:13:16 +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.