The early history is not very clear. Apparently the first work was done by CMU as part of their Mach project. The initial hardware was the DEC R2000/R3000-based DECstations. This code was later used by both the Sprite and BSD groups. The 4.4BSD code, known as the `pmax' port, was made freely available in mid '93. It was merged into the NetBSD tree by a variety of people, but has never been very stable, reliable, or complete. Compiler toolkit problems have plagued the port because the standard a.out executable format is an imperfect match to the MIPS architecture.
Per Fogelström became familiar with the code after porting it to a home-built IDT R3081 based board. Subsequently he added R4400 support when porting it to the MIPS R4400 Acer PICA board. Willowglen Singapore purchased a second PICA board for Theo de Raadt so that he could improve the port for use as a development system for an internal project. Since then Theo, Per and others have completed the port.
The Acer PICA is a dead platform. Acer no longer makes the machine, but even worse the machines are very rare. But the Acer PICA was just one of a whole family of similar machines built by other companies like MIPS, Deskstation, NEC, Olivetti. These machines were known as ARC machines, built according to the Advanced RISC Computing specification. No new ARC BIOS machines for MIPS will likely be manufactured. Microsoft has announced that it will no longer support MIPS after NT 4.0. OpenBSD/arc provides a good alternative to NT, especially now that no more OS updates for NT MIPS will happen. Deskstation has ceased business operations, so there will be no more ARC MIPS machines from them.
As a result, the code has been modified to make it more versatile, and eventually it should support a larger whole range of ARC machines. Hopefully a port will result that can run on the full range of MIPS processors: R4000, R4xx, R43xx, R4400, R46x0, R4700, R5000, R8000 and R10000.
The people working the most on OpenBSD/arc currently consists of Per Fogelström, Theo de Raadt, Niklas Hallqvist, Warner Losh, and a few others. Of course, others are very welcome!
The ARC port is complete, including everything you can expect on any OpenBSD port.
Snapshots are made available from time to time.
Send mail to Warner Losh and Per Fogelström.