So I'm playing around on a Soekris net4801 box, and decide
I want to be able to mount / read-only, so I removed /dev/console
so that init automatically does a MAKEDEV on an mfs filesystem.

However, I want to revert this temporarily, but have not found
a way of doing so: /bin/sh as init fails, probably because of
lack of /dev/console, and if I use normal /sbin/init I can't
umount /dev even in single user mode because of "device busy".
Similarly trying to mount /dev/wd0a, my root device, simultaneously
elsewhere gets "device busy".

How can I recreate /dev/console on the /dev/wd0a filesystem and thus
prevent an mfs /dev?

Neil.