Here would be the supported ARM port for OpenBSD

ARM-based appliances (by Thecus, IO-DATA, and others) http://www.openbsd.org/armish.html

and not officially supported but being worked on

ARM-based devices, such as BeagleBone, BeagleBoard, PandaBoard ES, SABRE Lite, Nitrogen6x and Wandboard http://www.openbsd.org/armv7.html

one of the previous discussions: https://news.ycombinator.com/item?id=9482696