Excerpts from netbsd: 12-Aug-96 LKM support for many filesy..
rvb@IGW.TRUST.CS.CMU.EDU (640)

> So if I happen to boot /netbsd.foo when
> /etc/rc goes to modload my lkm (say afs), I die a horrible death.

Wolfgang Solfrank's solution looks much better, but
a cheap way to avoid these crashs is something like
ln -s /sys/arch/i386/compile/`uname -v|awk '{print $3}'|tr -d '()'`/netbsd /
in rc.local.
(if you keep all running kernels in the compile tree)

best regards
Matthias Drochner