Okay, I'd like to make a few comments about the i386 install:

	* It is possible to do an install inside a prescribed
	  partition.  If you can't get it to work in cylinder mode
	  (either because your NetBSD partition is first on the disk
	  and you need to leave a track free at the beginning, or
	  because you entered the native disk geometry and the MBR
	  partition table is using a translated geometry), use sector
	  mode.

	* If your filesystems aren't cylinder-aligned according to the
	  NetBSD disklabel's idea of what a cylinder is, FFS will just
	  drop a little bit of space on the floor.  No reason to lose
	  sleep.

	* I'm wary of just using the faked-up disklabel for a disk
	  with a real NetBSD partition on it.  I introduced mapping
	  the BIOS partitions as e, f, g, and h in the fake disklabel
	  mainly so that you could easily mount a DOS partition on a
	  disk with no NetBSD partition (there's some grossness
	  involved here because we don't have an "unknown" disklabel
	  filesystem type, but that's a separate issue).  But that's
	  four very prime disklabel slots taken up by entries you're
	  not generally very interested in.

	  Moreover, there's an inconsistency (which dates from long
	  before I did anyf hacking on the code) between where the
	  faked-up disklabel and the standard installed disklabel puts
	  the NetBSD partition (the faked-up disklabel puts it in the
	  first slot; the installation procedure puts it in the third
	  slot).

	  Finally, I don't think it's hard to do right now without an
	  editor:

		disklabel wd0 > /tmp/label
		disklabel -r -R wd0 /tmp/label

	  or ("disklabel wd0 | disklabel -r -R wd0 /dev/stdin" if you
	  really don't want a writable temporary filesystem.)

	* fdisk will do computations based on the existing MBR
	  partition table to intuit the translated geometry.  These
	  computations pretty much always work unless the partition
	  table is empty.  Right now, fdisk is not present on the i386
	  installation disks.

	* The installation could productively use the fake disklabel
	  to find the NetBSD partition (simply by looking at the first
	  entry), but it can't find out the translated geometry of the
	  disk.  So it will tend to lose space in partitions unless
	  you ask the user for the translated disk geometry, or make
	  fdisk part of the i386 installation (not trivial at the
	  moment).

I currently maintain an MIT-specific single-disk installation
procedure (it relies on an NFS server) which does all sorts of song
and dance, offering to create your partition for you if you leave room
in the MBR partition table, asking you for partition sizes in
megabytes, etc..  The existing tools are quite good enough (apart from
the lack of a scheme to copy an image from a floppy into a memory
filesystem, and FFS's neanderthal attention to disk geometries); the
problem is in how they are put together into the installation
procedure.