makefs -t cd9660 vs. mkisofs

I've played a bit with NetBSD's (latest -current) "makefs -t cd9660" and 
mkisofs tonight, but didn't really get a bootable CD going. I have a a 
setup similar to [1] in isodir.hf, and tried the following commands:

1) mkisofs -b cdboot -no-emul-boot -o nb.iso isodir.hf
2) obj.i386/tooldir.NetBSD-2.0-i386/bin/nbmakefs -t cd9660 -o \
 	"rockridge,bootimage=i386;isodir.hf/cdboot,no-emul-boot" \
 	nb.iso isodir.hf

Booting the file from 1) in qemu gives the expected results, i.e. the 
kernel gets loaded and the wonders how to go on. For 2), qemu loads 
something (what?), prints "NetBSD/i386 cd9660 Primary Bootstrap" (see 
[2]), then hangs.

There's no difference if I give qemu a harddisk file or not, and the fact 
that that everything works with mkisofs, I wonder how to go on from there?


  - Hubert


[1] http://mail-index.netbsd.org/tech-install/2005/06/22/0013.html
[2] http://www.feyrer.de/Misc/qemu2.gif