bab0a0b577
Building libpayload with the PDCurses backend the following warning
is shown.
/src/coreboot/payloads/libpayload(master) $ make clean
/src/coreboot/payloads/libpayload(master) $ make
[…]
CC curses/pdcurses-backend/pdcscrn.libcurses.o
curses/pdcurses-backend/pdcscrn.c: In function 'PDC_scr_open':
curses/pdcurses-backend/pdcscrn.c:75:5: warning: "CONFIG_SPEAKER" is not defined [-Wundef]
[…]
The GCC documentation states [1]
In some contexts this shortcut is undesirable. The -Wundef option
causes GCC to warn whenever it encounters an identifier which is
not a macro in an ‘#if’.
and therefore use `#ifdef` [2] to silence this warning. No functional
change is done, as `CONFIG_SPEAKER` is assigned the value `Y` when
defined.
There was some discussion going on the list [3], but my points in there
turned out to be incorrect.
[1] http://gcc.gnu.org/onlinedocs/cpp/If.html
[2] http://gcc.gnu.org/onlinedocs/cpp/Ifdef.html
[3] http://www.coreboot.org/pipermail/coreboot/2013-March/075561.html
Change-Id: I8e9c9b5d01985b21ad05018986d614cf9bf2b439
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: http://review.coreboot.org/2934
Reviewed-by: Nico Huber <nico.huber@secunet.com>
Tested-by: build bot (Jenkins)
|
||
|---|---|---|
| .. | ||
| arch | ||
| bin | ||
| configs | ||
| crypto | ||
| curses | ||
| drivers | ||
| include | ||
| libc | ||
| libcbfs | ||
| liblzma | ||
| libpci | ||
| sample | ||
| tests | ||
| util | ||
| Config.in | ||
| Doxyfile | ||
| LICENSES | ||
| Makefile | ||
| Makefile.inc | ||
| 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 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.