Paul> I've managed to install NetBSD 1.5.1 from a CD image onto a G4 Cube.  I

Paul> should put ofwboot.xcf and the netbsd kernel on the HFS+ partition ...
Paul> is this right?

(1) put ofwboot.xcf onto HFS+ partition

Try 
(2) boot hd:,ofwboot.xcf 

for the first time. If you have one HFS+ and one NetBSD, 
it probably works.

In the case you have several partitions, you may need
(3) boot hd:xx,ofwboot.xcf  hd:yy
where xx and yy is the partition number for HFS+ 
and netbsd root respectively. The first MacOS partition usually
starts 9 (See following partition d:).
So xx usually  9 and yy will probably 10 in that case.

In my case (Machine is iBook/SE,1999), and disklabel wd0
(after NetBSD booted), shows following.

 a:    262144  11638280  4.2BSD   # (Cyl. 11545*- 11805*) 13
 b:    761856  11900424    swap   # (Cyl. 11805*- 12561*) 
 c:  39070080         0  unused   # (Cyl.    0 - 38759)
 d:   2048000      1544     HFS   # (Cyl.    1*- 2033*)    9
 e:   8192000   2049544     HFS   # (Cyl. 2033*- 10160*)  10
 f:   1331200  10241544     HFS   # (Cyl. 10160*- 11480*) 11
 g:   1047389  12662280  4.2BSD   # (Cyl. 12561*- 13600*) 
 h:     65536  11572744     HFS   # (Cyl. 11480*- 11545*) 12
 i:  25360384  13709669  4.2BSD   # (Cyl. 13600*- 38759*) 
 j:        27  39070053 unknown   # (Cyl. 38759*- 38759)  

With this partiotion, I am using
  boot-device	hd:12,ofwboot.xcf
  boot-file     hd:13
or 
  boot hd:12,ofwboot.xcf hd:13
is my boot string.
---
(Makoto Fujiwara), Chiba Japan
http://www.ki.nu/software/NetBSD/iBook2/