coreboot-kgpe-d16/payloads/libpayload
Julius Werner 2e0bca011a arm64: Bump exception stack size to 2KB
To avoid trampling over interesting exception artifacts on the real
stack, our arm64 systems switch to a separate exception stack when
entering an exception handler. We don't want that to use up too much
SRAM so we just set it to 512 bytes. I mean it just prints a bunch of
registers, how much stack could it need, right?

Quite a bit it turns out. The whole vtxprintf() call stack goes pretty
deep, and aarch64 generally seems to be very generous with stack space.
Just the varargs handling seems to require 128 bytes for some reason,
and the other stuff adds up too. In the end the current implementation
takes 1008 bytes, so bump the exception stack size to 2K to make sure it
fits.

Change-Id: I910be4c5f6b29fae35eb53929c733a1bd4585377
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37464
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
2019-12-05 17:58:05 +00:00
..
arch arm64: Bump exception stack size to 2KB 2019-12-05 17:58:05 +00:00
bin Remove MIPS architecture 2019-11-20 10:10:48 +00:00
configs trogdor: libpayload USB support 2019-12-05 17:57:31 +00:00
crypto
curses libpayload: Enable -Wimplicit-fallthrough 2019-07-21 17:17:42 +00:00
drivers Change all clrsetbits_leXX() to clrsetbitsXX() 2019-12-04 14:11:17 +00:00
gdb
include mmio: Add clrsetbitsXX() API in place of updateX() 2019-12-04 14:10:37 +00:00
libc lib/coreboot_table: Add CBMEM_ID_VBOOT_WORKBUF pointer to coreboot table 2019-12-02 13:00:45 +00:00
libcbfs
liblz4
liblzma
libpci
sample Remove MIPS architecture 2019-11-20 10:10:48 +00:00
tests
Doxyfile
Kconfig Remove MIPS architecture 2019-11-20 10:10:48 +00:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
LICENSE_GPL
Makefile Remove MIPS architecture 2019-11-20 10:10:48 +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.