> Trying to build a slightly trimmed down kernel for my IPC, I get:
> 
> ../../../../arch/sparc/dev/bwtwo.c:328: structure has no member named `sc_ovtype'

This is a known glitch in 1.2.1 patch-release source. Apply the following
diff to bwtwo.c:

===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/dev/bwtwo.c,v
retrieving revision 1.26.4.1
retrieving revision 1.26.4.2
diff -r1.26.4.1 -r1.26.4.2
1c1
< /*    $NetBSD: bwtwo.c,v 1.26.4.1 1996/12/10 19:24:43 mycroft Exp $ */
---
> /*    $NetBSD: bwtwo.c,v 1.26.4.2 1997/03/02 21:52:11 pk Exp $ */
328c328,336
<               if (sc->sc_ovtype == BWO_NONE)
---
> #if defined(SUN4)
>               /*
>                * XXX rcons doesn't seem to work properly on the overlay
>                * XXX plane.  This is a temporary kludge until someone
>                * XXX fixes it.
>                */
>               if ((fb->fb_flags & FB_PFOUR) == 0 ||
>                   (sc->sc_ovtype == BWO_NONE))
> #endif