In 2006 the company of Open Firmware inventor Mitch Bradley, Firmworks, Inc, released their Open Firmware implementation under a BSD license. This code shares some code with SUN's OpenBOOT implementation. It supports the x86 architecture and runs, amongst others, as a LinuxBIOS payload. It is the firmware implementation on the OLPC.
You can browse the source code online.
The repository is available through Subversion:
You can check it out as follows:
$ svn co svn://openbios.org/openfirmware/
if you want a specific revision:
$ svn co svn://openbios.org/openfirmware -r 35
$ svn co https://www.openbios.org/openfirmware-svn/ openfirmware
You should change openfirmware/cpu/x86/pc/biosload/config.fth:
Index: config.fth =================================================================== --- config.fth (revision 599) +++ config.fth (working copy) @@ -2,14 +2,14 @@ purpose: Establish configuration definitions create pc \ Demo version for generic PC -\ create pc-linux \ Demo version for generic PC and Linux +create pc-linux \ Demo version for generic PC and Linux \ create pc-serial \ Demo version for generic PC \ --- The environment that "boots" OFW --- \ - Image Format - Example Media - previous stage bootloader \ - (Syslinux) COM32 format - USB Key w/ FAT FS - Syslinux -create syslinux-loaded +\ create syslinux-loaded \ - Linux kernel format - USB Key w/ FAT FS - LinuxBIOS w/ stripped Linux payload \ create bzimage-loaded @@ -19,10 +19,10 @@ \ create etherboot-variant \ Enable additional tweaks for Etherboot \ - ELF format (no pheader) - ROM - LinuxBIOS direct -\ create linuxbios-loaded +create linuxbios-loaded \ Load and run in qemu -\ create qemu-loaded +create qemu-loaded [ifdef] pc-serial create serial-console @@ -47,7 +47,7 @@ \ the point where Linux starts using the MMU. It isn't strictly \ necessary to use virtual mode if you just want to boot Linux \ and then have OFW disappear. -create virtual-mode +\ create virtual-mode create pc create linux-support [then]
qemu-0.9.0 + ROMSIZE-patch Open Firmware rev. >= 500 coreboot >= v2
Patch and build qemu
Get the patch from http://www.freimann.org/qemu_biossize.patch and apply it against qemu-0.9.0.
Make sure that you have gcc-3.x installed, then
./config && make && make install
Build Open Firmware
Get Open Firmware from Subversion
Change to the build directory of the biosload build.
create linuxbios-loaded create qemu-loaded
Comment out the line with
Now change to the build directory and type "make"
cd build make
After make is finished there should be a file "ofwlb.elf" in the same directory. Copy this to your coreboot-v[x] directory.
Follow the instructions in the coreboot documentation. Make sure that you use the ofwlb.elf file as your payload. It is also very imortant that the ROMSIZE for coreboot and qemu correspond with each other.
qemu -L coreboot-v3/build -hda path/to/disk.img -serial `tty` -nographic