I've prepared a set of patches to make OpenBSD's ipmi(4) work with ipmitool via /dev/ipmi*, following what FreeBSD did. I'd like to hear feedback from developers and users.
https://github.com/uebayasi/openbsd-ipmi I'm also looking for someone whose machine supports BT (block transfer) interface. I believe the BT support is broken. Need testers to fix it.