Welcome to OpenBIOS
-------------------
OpenBIOS is a free, portable implementation of IEEE 1275-1994
(Open Firmware). Find detailed information about OpenBIOS at
http://www.openbios.org/
What is OpenBIOS?
-----------------
OpenBIOS can replace your system firmware (BIOS) partly or completely. It
can also be used as a bootloader to create an Open Firmware compatible
interface between legacy firmware and an operating system.
This is achieved by a modular concept that consists of a portable Forth
kernel and three interfaces for user interaction, device initialization
and client (operating system) control.
While far not all possible applications of OpenBIOS are implemented yet,
a lot of functionality is already there. OpenBIOS can be used to enhance
LinuxBIOS (http://www.linuxbios.org), or be booted from any multiboot
capable bootloader to bring Open Firmware to your machine. OpenBIOS can
also be used when an operating system is already running. It provides
the needed OpenFirmware functionality to MOL (MacOnLinux) to boot MacOS
9 and X on PPC machines, as well as Linux (all supported platforms)
OpenBIOS build options
---------------------
config/scripts/switch-arch <platform> - build for specified platform
Look in config/example for
platforms.
make - build all configured binaries
make run - run unix example.
How OpenBIOS works
------------------
The OpenBIOS forth core is split into a forth kernel written in portable
C and a forth dictionary which operated on by the kernel.
When building the forth core, you get different versions of
the forth kernel:
* a unix executable program
- to execute a forth dictionary from a file. This can be used for
easily testing and developing OpenBIOS on a unix host.
- to create a dictionary file. Such a dictionary file sets up
all of the forth language. Primitives are indexed to save relocations.
The default is to create a forth dictionary forth.dict from
forth/start.fs. This file includes all of the basic forth language
constructs from forth/bootstrap.fs and starts the interpreter.
To achieve this, the hosted unix version contains a basic set of
forth words coded in C that allow creating a full dictionary.
* a varying number of target specific binaries. On x86 you can start
openbios for example from GRUB or LinuxBIOS. They are all based on
the same forth engine consisting of a dictionary scheduler, primitive
words needed to build the forth environment, 2 stacks and a simple
set of console functions. These binaries can not be started directly
in the unix host environment.
Requirements
------------
* gcc
* gnu make
* OpenBIOS FCode Utils
Download with svn co svn://openbios.org/openbios/fcode-utils
* grub or any other multiboot loader to run the multiboot
binary "openbios.multiboot" with it's module "openbios-<platform>.dict"
* xsltproc
Building & Usage
----------------
* make
this builds "openbios.multiboot", the standalone image and "openbios-unix",
the hosted image. Additionally it creates a forth dictionary
file from forth/start.fs. All generated files are written to
the absolute directory held by the variable BUILDDIR, which defaults
to obj-[platform]. Some compile time parameters can be tweaked in
include/config.h
* use "openbios-unix" to create a forth dictionary on your own:
$ obj-x86/openbios-unix -Iforth start.fs
creates the file forth.dict from forth source forth/start.fs.
* use "openbios-unix" to run a created dictionary:
$ obj-x86/openbios-unix obj-x86/openbios-unix.dict
This is useful for testing
* booting openbios
You can boot openbios i.e. in grub. Add the following lines to
your menu.lst:
title openbios
kernel (hd0,2)/boot/openbios.multiboot
module (hd0,2)/boot/openbios-x86.dict
Note: change (hd0,2) to the partition you copied the openbios image and
openbios-x86.dict to.
To boot OpenBIOS from LinuxBIOS/etherboot, you can either use
"openbios-plain.elf" or "openbios-builtin.elf":
- openbios-plain.elf is the pure kernel that loads the dictionary from a
hardcoded address in flash memory (0xfffe0000)
- openbios-builtin.elf also includes the dictionary directly so that it
can be easily used from etherboot or the LinuxBIOS builtin ELF
loader without taking care of the dictionary
CREDITS
-------
OpenBIOS was developed by Stefan Reinauer, Samuel Rydh and Patrick Mauritz.
The OpenBIOS IDE driver was written by Jens Axboe.
For license details on this piece of software, see the file COPYING.
If you have patches, questions, comments, feel free to contact the OpenBIOS
mailinglist.
Regards,
the OpenBIOS team
