coreboot-kgpe-d16/payloads/libpayload
Julius Werner 9665d389e4 libpayload: dma_malloc: Prevent warm reboot problems and add debugging
Since the DMA memory is allocated by Coreboot (outside of the payload's
linker script), it won't get zeroed upon loading like the heap.
Therefore, a warm reboot that doesn't reset memory may leave stale
malloc cookies lying around and misinterpret them as memory that is
still in use on the next boot. After several boots this may fill up the
whole DMA memory and lead to OOM conditions.

Therefore, this patch explicitly wipes the first cookie in
init_dma_memory() to prevent that from happening. It also expands the
existing memory allocator debugging code to cover the DMA parts, which
was very helpful in identifying this particular problem.

Change-Id: I6e2083c286ff8ec865b22dd922c39c456944b451
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/169455
Reviewed-by: Stefan Reinauer <reinauer@google.com>
(cherry picked from commit 8e5e1784638563b865553125cd5dab1d36a5d2cb)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6645
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2014-08-14 23:41:44 +02:00
..
arch arm: libpayload: Add cache coherent DMA memory definition and management 2014-08-13 00:04:14 +02:00
bin libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
configs libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
curses libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
drivers libpayload: xhci: Make XHCI stack usable on ARM 2014-08-14 23:41:21 +02:00
include libpayload: dma_malloc: Prevent warm reboot problems and add debugging 2014-08-14 23:41:44 +02:00
libc libpayload: dma_malloc: Prevent warm reboot problems and add debugging 2014-08-14 23:41:44 +02:00
libcbfs cbfs: Fix overwalk on file scan 2014-08-10 22:25:07 +02:00
liblzma LZMA: Add a version of ulzma which takes the input and output buffer sizes. 2014-08-10 22:29:51 +02:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample libpayload/sample: Use settings from .xcompile file to build. 2013-10-17 01:54:43 +02:00
tests libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
util Set check-lxdialog.sh mode properly 2014-08-09 17:30:33 +02:00
Config.in libpayload: Drop PowerPC architecture 2013-11-26 00:08:39 +01:00
Doxyfile Run doxygen -u on doxygen configuration files 2010-06-28 10:40:38 +00:00
LICENSES Since some people disapprove of white space cleanups mixed in regular commits 2010-04-27 06:56:47 +00:00
Makefile libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
Makefile.inc libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
README libpayload, superiotool: README: Prepend `coreboot/` to path of change directory line 2013-04-04 17:22:15 +02:00

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 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.