| # Open Firmware |
| ## Introduction |
| |
| In 2006 the company of Open Firmware inventor Mitch Bradley, [Firmworks, |
| Inc](http://firmworks.com/), released their Open Firmware implementation |
| (OFW) under a BSD license. This code shares some code with SUN's |
| OpenBOOT implementation. The open source OFW supports x86, PowerPC, and |
| ARM architectures. Other architectures, including SPARC and MIPS, may be |
| added as time and interest dictate. |
| |
| The x86 version is used on the OLPC "XO" computer. The x86 version can |
| be configured for numerous other environments, including |
| |
| - Direct QEMU ROM (replacing the "bios.bin" that is supplied with QEMU |
| - Coreboot payload |
| - Loadable on directly on top of a conventional PC BIOS (booted from |
| floppy or hard disk like an OS). In this configuration it can run on |
| an arbitrary PC, or on an emulator like QEMU, VirtualBox, or VMWare. |
| |
| OFW can boot Linux directly from a disk file (FAT, ext2, ISO9660, or |
| jffs2 filesystems) without the need for an intermediate bootloader like |
| LILO or GRUB. The Linux image can be in either ELF format (as created by |
| the first phase of the Linux kernel compilation process) or in the |
| "bzImage" format that "wraps" the ELF image. When booting an ELF image, |
| OFW can read the ELF symbol table so OFW's assembly language debugger |
| can resolve kernel symbols. |
| |
| OFW can also boot other ELF standalone images, providing to them |
| rudimentary "libc" capability. That facility has been used for booting, |
| for example, Minix, ReactOS, Plan9, Inferno and SqueakNOS. The OLPC |
| system ROM includes several such "standalone client programs", including |
| MicroEMACS, memtest86, and NANDblaster (a facility for fast OS updates |
| over multicast wireless). |
| |
| On the OLPC system, OFW emulates enough legacy BIOS "real mode INTs" to |
| boot Windows XP. On another system, OFW supports booting Windows CE. |
| |
| ## Download |
| |
| You can [browse the source code |
| online](https://github.com/openbios/openfirmware). |
| |
| The repository is available through git: |
| |
| You can check it out as follows: |
| |
| $ git checkout https://github.com/openbios/openfirmware.git |
| |
| ## Building Different Versions |
| |
| - Direct QEMU ROM: see [Building OFW for QEMU](Building_OFW_for_QEMU) |
| - Coreboot: see [OFW as a Coreboot Payload](OFW_as_a_coreboot_Payload) |
| - OLPC: see [Building OFW for OLPC](Building_OFW_for_OLPC) |
| - BIOS-loaded: see [Building OFW to Load from BIOS](Building_OFW_to_Load_from_BIOS) |
| - ARM: see [Building OFW for ARM](Building_OFW_for_ARM) |
| |
| ## Mailing List |
| |
| There's an Open Firmware mailing list at: |
| |
| - <http://www.openfirmware.info/mailman/listinfo/openfirmware>. |
| |
| The mailing list archive is also available: |
| |
| - <http://www.openfirmware.info/pipermail/openfirmware/> |
