2023-08-09
installboot(8) is the program used during the OpenBSD install process to setup bootblocks and make your install bootable. There are a few gotchas when using it that I have run into and am documenting here.
A common error during install will be that installboot(8) could not find one of the boot programs. You need to point installboot(8) to /mnt/usr/mdec instead. After the install finishes but "fails" and drops you to a shell, enter the following, replacing sd0 for whatever your boot disk may be
installboot -r /mnt sd0
This points the root to /mnt instead of /. This should install the boot programs and get you into a bootable state!