coreboot/payloads/libpayload
Gabe Black 59df109d56 libpayload: Add a new "die" function to fatally signal programming errors.
If a programming error is detected, die can be used to print a message and
stop execution similar to failing an assert. There's also a "die_if" function
which is conditional.

die functions, like asserts, should be used to trap programming errors and not
when the hardware does something wrong. If all code was written perfectly, no
die function would ever be called. In other words, it would be appropriate to
use die if a function was called with a value that was out of bounds or if
malloc failed. It wouldn't be appropriate if an external device doesn't
respond.

In the future, the die family of functions might print a stack trace or show
other debugging info.

BUG=None
TEST=Used the die_if function in other code and verified that it stops
execution, prints messages like printf, shows file, line, and function
information, and is correctly gated by its condition.
BRANCH=None

Change-Id: I653fc8cb0b4e459522f1b86f7fac280836d57916
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/178000
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
2013-11-27 01:46:00 +00:00
..
arch arm: Remove exception_test() 2013-11-20 06:51:13 +00:00
bin ARM: Generalize armv7 as arm. 2013-10-02 09:18:44 +00:00
configs kirby is dead. long live the arm pit. 2013-11-07 23:42:47 +00:00
crypto libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
curses libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2013-08-14 17:05:33 -07:00
drivers libpayload: ehci: Fix byte count in dump_td() 2013-10-30 01:04:52 +00:00
include libpayload: Add a new "die" function to fatally signal programming errors. 2013-11-27 01:46:00 +00:00
libc libpayload: Add a new "die" function to fatally signal programming errors. 2013-11-27 01:46:00 +00:00
libcbfs cbfs: Fix overwalk on file scan 2013-08-19 17:29:35 -07:00
liblzma libpayload: Make lzma truncation non-fatal. 2013-08-19 19:04:35 -07:00
libpci libpayload: minor cleanups 2012-04-04 00:40:31 +02:00
sample fix compilation of hello.elf example payload. 2010-08-28 23:23:47 +00:00
tests libpayload: Change CONFIG_X86_SERIAL_CONSOLE to CONFIG_8250_SERIAL_CONSOLE 2013-09-27 14:05:53 +00:00
util Set check-lxdialog.sh mode properly 2013-10-22 21:41:24 +00:00
Config.in ARM: Generalize armv7 as arm. 2013-10-02 09:18:44 +00:00
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 ARM: Generalize armv7 as arm. 2013-10-02 09:18:44 +00:00
Makefile.inc ARM: Generalize armv7 as arm. 2013-10-02 09:18:44 +00:00
README libpayload, superiotool: README: Prepend coreboot/ to path of change directory line 2013-04-04 17:22:15 +02:00

-------------------------------------------------------------------------------
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 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.