coreboot-kgpe-d16/payloads/libpayload
Julius Werner 5c0e72ff99 libpayload: arm64: Make exception handling closer to arm32
This patch reworks the arm64 exception handling to be more similar to
how it works on arm32. This includes a bunch of features like actually
saving and restoring more exception state in the exception_state
structure and supporting the same sort of partial reentrancy that is
useful for GDB. Since there's no instruction to directly load into or
store out of SP on arm64, we can't do quite the same thing where we use
that to read an exception_state_ptr variable right after exception entry
when no other register is available. But we can do something very
similar by (ab-)using the "high" stack pointer (SP_EL2) as a pointer to
the exception_state struct and providing a function to change it.

Change-Id: Ia16a1124be1824392a309ae1f4cb031547d184c1
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/29018
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2018-10-12 20:17:28 +00:00
..
arch libpayload: arm64: Make exception handling closer to arm32 2018-10-12 20:17:28 +00:00
bin libpayload: Move base address, stack and heap size to Kconfig 2016-03-15 20:53:38 +01:00
configs libpayload: cheza - fix config for chromium chroot build 2018-06-22 13:11:06 +00:00
crypto libpayload: Make Kconfig bools use IS_ENABLED() 2015-06-30 18:55:15 +02:00
curses payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
drivers libpayload/drivers/usb: Fix leaks 2018-10-01 16:58:29 +00:00
gdb libpayload/gdb: fix unused variable warning 2017-04-29 07:34:08 +02:00
include libpayload: arm64: Make exception handling closer to arm32 2018-10-12 20:17:28 +00:00
libc libpayload/libc/time: Add an arch_ndelay() 2018-09-12 14:15:18 +00:00
libcbfs cbfs: Rename CBFS_TYPE_PAYLOAD to CBFS_TYPE_SELF 2018-05-04 10:30:24 +00:00
liblz4 Rename __attribute__((packed)) --> __packed 2017-07-13 19:45:59 +00:00
liblzma libpayload: lzma: Allocate scratchpad on the heap 2016-08-08 19:02:07 +02:00
libpci libpayload: Add pci_free_dev() and some boilerplate 2017-12-07 21:51:24 +00:00
sample Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
tests Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: disable mouse on CHROMEOS 2018-05-18 16:00:18 +00:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
Makefile libpayload: Make libpayload compile using gnu11 2018-07-16 07:44:03 +00:00
Makefile.inc copy & update test routines from what-jenkins-does 2017-08-11 15:24:56 +00:00
README Use git HTTP URLs without /p in it 2018-04-17 10:38:06 +00:00

-------------------------------------------------------------------------------
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

 $ sudo make install (optional, will install into /opt per default)

As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.


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.