Unable to load PReP boot image

[lists@naasa.net]

Hiho,

I'm trying to boot a IBM p615 with yaboot 1.3.13 packaged with Debian Sarge.
Till now without success. Here's my config:

# sfdisk -l | grep PPC
/dev/sdd1 * 0+ 3814 3815- 7813104 41 PPC PReP Boot

# cat /etc/yaboot.conf
boot=/dev/sdd1
partition=2
root=/dev/sdd2
timeout=30
install=/usr/lib/yaboot/yaboot

image=/boot/vmlinux
 label=linux
 read-only
 initrd=/boot/initrd.img
 initrd-size=8192

# ybin -v
ybin: Installing primary boostrap /usr/lib/yaboot/yaboot onto /dev/sdd1...
ybin: Installation successful

After selecting the the right disk in SMS, I get some rotating slash on the
screen for some seconds. Then it stops and says:

"Unable to load PReP boot image"

Do you have some hints for me? How can I debug this behaviour?
I've read something about addnote, and CHRP, but there doesn't
seem to be some helpful documentation.

Friendly,
Cajus Pollmeier