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OpenBSD/mvme88k is a port of OpenBSD to the systems built upon Motorola's 88xxx-based VME motherboard family. The OpenBSD/mvme88k port has been discontinued after the 5.5 release. |
The Motorola 88k processor is said to be the best RISC processor ever devised. Its simplicity and elegance combine to make the mvme88k a hearty, robust platform.
Unfortunately, the first generation designs (88100) made use of companion chips for cache and virtual memory management, making hardware designs painfully complex (and expensive, at that time). The second generation (88110) addressed this issue, but was plagued with reliability issues. Eventually, Motorola seized the opportunity to drop the 88000 line in favour of the PowerPC as soon as possible, although some parts of the 88110 still exist in the PowerPC family processors today.
Nivas Madhur started the initial mvme88k port for the MVME187 card, building upon the CMU Mach code running on the 88100-based Omron Luna88k systems. However, he moved on to another employer before his work was ready to be imported into the OpenBSD source tree.
This integration work was completed by Dale Rahn, but he did not have enough time to continue working on the port. Steve Murphree, Jr., stepped up, and eventually completed the port to the MVME187 in November 1998.
Unfortunately, at the same time, a compiler upgrade from gcc 2.8.1 to egcs exposed a lot of problems in the mvme88k support in gcc, which could not be fixed in time for mvme88k to be a supported OpenBSD 2.5 release.
The lack of an in-tree toolchain did not prevent further work on the port, and a lot of changes were made to the codebase, such as revamped autoconf and on-board SCSI driver, greatly expanded VME bus support, a working install process that correctly creates a Motorola VID block on the disks, and support for MVME188 as well as improving support for MVME197.
During summer 2003, an effort to fix the toolchain eventually produced a working gcc 2.95 compiler, and allowed the port to be self-hosting again. With the help of Mark Kettenis, the toolchain effort eventually produced working binutils and gdb in late may 2004.
Work towards multiprocessor support on the MVME188 boards started in summer 2005 and, after a lot of tedious bugfixing, was eventually completed shortly after the 4.2 release in november 2007.
The next step was getting the 88110-based MVME197 designs to work. Single-processor kernels started to run reliably in december 2007; multiprocessor support was completed in march 2009, but kept triggering obscure bugs which eventually got tracked down to a processor errata, fixed for good in april 2010.
The long-awaited switch from the a.out binary format to ELF happened after the 5.3 release, with a compiler upgrade to gcc 3.3.6. This work paved the way for ELF shared libraries support.
Currently, MVME181, MVME187, MVME188 and MVME197 boards, as well as similar designs, are booting multi-user, supporting most of the on-board devices. There are still a few caveats; depending on your exact hardware setup, your mileage may vary.
Besides various Motorola complete systems (M8120, Series 900, etc), this port also runs on the MVME187-based Triton Dolphin System 100.
The last supported OpenBSD/mvme88k release was OpenBSD 5.5. Here are the OpenBSD/mvme88k 5.5 installation instructions.
As VME hardware is quite uncommon in the average retail place, and Motorola 881x0-based hardware is even more rare, this section is here to satisfy the well-founded curiosity about the mvme88k hardware.
A comprehensive reference about the m88k processor and the various designs built upon has been gathered by Paul Weissmann at badabada.
Pictures of a Motorola 900 modular chassis, with a 33MHz MVME187 CPU board, 32MB RAM, 4 MVME332XT serial boards, and an Archive 250MB QIC tape drive.
