Mathias Krause 898de6111a libpayload: multiboot - support meminfo flag
Some simple implementation of the MultiBoot protocol may not pass a
memory map (MULTIBOOT_FLAGS_MMAP missing in the flags) but just the two
values for low and high memory, indicated by the MULTIBOOT_FLAGS_MEMINFO
flag.

Support those kind of boot loaders too, instead of falling back to the
hard-coded values in lib_get_sysinfo().

Tested with a multiboot enhanced version of FILO.

Change-Id: I22cf9e3ec0075aff040390bd177c5cd22d439b81
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Reviewed-on: https://review.coreboot.org/18350
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
2017-02-17 18:20:38 +01:00
..
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2017-01-25 17:58:48 +01:00
2015-06-08 00:55:07 +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.