Kyösti Mälkki 48e9eb89fa libpayload: Fix to properly disable serial console
With coreboot builds with serial console disabled, there is no
CB_TAG_SERIAL entry in coreboot tables. We ended up with
lib_sysinfo.serial == NULL and serial_hardware_is_present == 1.

Change-Id: I9a2fc0b55bf77769f2f2bfbb2b5476bee8083f7d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5723
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2014-05-17 14:56:06 +02:00
..
2014-01-08 13:24:43 +01:00
2012-04-04 00:40:31 +02:00
2013-11-25 23:36:27 +01:00

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