coreboot-kgpe-d16/payloads/libpayload
Julius Werner 456314fcf8 libpayload: Let GDB stub read/write memory with aligned MMIO words
Looks like we got our first SoC that actually insists on using
word-sized accesses for its MMIO registers with the Rk3288. This patch
changes the GDB command handler for reading and writing memory to always
perform word-sized accesses. This isn't really perfect since the remote
GDB interface is just not really meant to interact with MMIO (e.g. you
shouldn't use this on something with read side effects), but for most
of our purposes it should be good enough.

BUG=chrome-os-partner:18390
TEST=Remote GDB works on Veyron even when writing MMIO registers.

Original-Change-Id: I2ae52636593499f70701582811f1b692c1ea8fcc
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/208554
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 028940934e6b45a02122b61bb859588bf8671938)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I4185a6efe9a5211525781acd0a167b821e854211
Reviewed-on: http://review.coreboot.org/8130
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
2015-01-12 05:56:16 +01:00
..
arch libpayload arm64: Add gdb stub for arm64 2015-01-09 07:08:08 +01:00
bin libpayload: Add support for arm64 in libpayload 2015-01-09 07:04:28 +01:00
configs libpayload: Add Rock Chip drivers 2015-01-12 05:55:30 +01:00
crypto
curses libpayload/PDcurses: avoid NULL deref 2015-01-03 23:58:22 +01:00
drivers libpayload: Add Rock Chip drivers 2015-01-12 05:55:30 +01:00
gdb libpayload: Let GDB stub read/write memory with aligned MMIO words 2015-01-12 05:56:16 +01:00
include libpayload: Expand setbits_le32() and fix readl() const-ness 2015-01-12 05:56:01 +01:00
libc libpayload: improve us timer accuracy 2015-01-12 05:55:45 +01:00
libcbfs libpayload: Fix pointer related casts 2014-12-31 18:57:35 +01:00
liblzma
libpci
sample libpayload: Fix missed CONFIG_ -> CONFIG_LP_ substitutions 2014-10-17 11:24:15 +02:00
tests
util libpayload: Add support for arm64 in libpayload 2015-01-09 07:04:28 +01:00
Config.in libpayload: Add Rock Chip drivers 2015-01-12 05:55:30 +01:00
Doxyfile
LICENSES libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
Makefile libpayload: Add support for arm64 in libpayload 2015-01-09 07:04:28 +01:00
Makefile.inc libpayload: Add remote GDB support 2015-01-09 07:06:51 +01:00
README

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 http://coreboot.org for details on coreboot.


Installation
------------

 $ git clone http://review.coreboot.org/p/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 http://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at http://coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.