OpenBSD landisk

OpenBSD/landisk runs on machines related to the IO-DATA USL-5P, using a Hitachi/Renesas SH-4 CPU.
This platform comes in a variety of models:

  • IO-DATA USL-5P, using CF storage (Japan; as shown)
  • IO-DATA HDL-U, HDL-AV, HDL-W and HDLM-U series (Japan)
  • SuperTank LAN Tank (SOTO-HDLWU) (Japan)
  • IO-DATA UHDL-160U and UHDL-300U (May be found in USA)
  • Plextor PX-EH16L, PX-EH25L and PX-EH40L

Note: The "Giga-landisk" and HDL-F machines are ARM-based (both Intel XScale & Marvell), some of which were supported by the defunct armish architecture.



OpenBSD/landisk is the 1st OpenBSD port to a Hitachi/Renesas SH-4 based machine. It is hoped that other SH-4 based machines will show up which are interesting enough for our user and development community, but the SH-4 processor is normally used only in true embedded products.

This processor architecture is the first 32-bit successor of a series of extremely bizarre 8 and 16 bit processors by Hitachi. It has a very strange instruction set and MMU, and developers find it quite a challenge to map their knowledge of Unix low-level ideas to the processor architecture.

Current status

Hardware support is mostly complete and quite stable.

Supported hardware

For a complete system component and device driver listing for this architecture, see intro(4/landisk).

Getting and installing

The latest supported OpenBSD/landisk release is OpenBSD 7.3. Here are the OpenBSD/landisk installation instructions.

Snapshots are made available from time to time, in this location as well as on a few mirrors. Here are the OpenBSD/landisk snapshot installation instructions as well. usl5p serial

Serial cable connection

All of these machines require a special serial cable which does voltage conversion, and can hopefully be purchased along with the card. This cable normally contains a little max232 or similar chip which converts from the 3.3V signals to +/-12V. The IO-DATA cable has pins which can grip the inside of the holes. Or you can attempt to build your own using some Japanese instructions.

The IO-DATA cable converts from a DB9 connector to a 5-pin header (3.3V Tx Rx GND NC). Note that the Rx and Tx pins on the board are swapped compared to the ARM-based machines made by IO-DATA. All the board models have a 5-pin connector (called CN7) which the cable can plug into -- except for the USL-5P which has a 4-pin header (thus requiring removal of the spare pin).

A USL-5P is shown with a modified IO-DATA cable. In this case the cable has been shortened significantly and the DB9 connector is glued into a slot carefully cut into the plastic between the ethernet and a USB port.