Hello,

> No go:
> 
> tadpole# disklabel -r /dev/wd0c
> disklabel: /dev/wd0c: Device not configured
> tadpole# ls -l /dev/wd0*
> brw-r--r--  1 root  daemon  12, 0 Apr  8 03:00 /dev/wd0a
> brw-r--r--  1 root  daemon  12, 1 Apr  8 03:00 /dev/wd0b
> brw-r--r--  1 root  daemon  12, 2 Apr  8 03:00 /dev/wd0c
> brw-r--r--  1 root  daemon  12, 3 Apr  8 03:01 /dev/wd0d
> brw-r--r--  1 root  daemon  12, 4 Apr  8 03:01 /dev/wd0e
> brw-r--r--  1 root  daemon  12, 5 Apr  8 03:01 /dev/wd0f
> brw-r--r--  1 root  daemon  12, 6 Apr  8 03:01 /dev/wd0g
> brw-r--r--  1 root  daemon  12, 7 Apr  8 03:01 /dev/wd0h

Found it. The major device number needs to be declared in sys/arch/sparc/conf/majors.sparc. The entry for wd was commented out as sparc64-only.
Here's a new test kernel that should work with the above /dev/ entries:
http://macallan.homeunix.org:6704/stuff/BSD/sparc/SPARCbook3GX_04_08.bz2
Besides that it's a lot less noisy :)

have fun
Michael