iMac G3 - YDL 3.0.1 won't boot

[Alex]

Hello,
i am using a iMac G3 with YDL 3.0.1. There is no Mac Os or other stuff 
on the mashine.
The install was sucessfull (I installed as bootloader "yaboot" <- 
default). But after the restart, the system doesn't boot from the 
harddisc. There appears a smiley and a "?" every second. I tried to 
change some settings in the firmware:
like "setenv boot-device hd:1,\\:tbxi"
but all numbers between 0 and 10 doesn't work. With gentoo and Mandrake 
9.1 (install disc) I checked my partitions:
hda2, hda3 and hda4 but I am not able to find anything like "boot".
What is wrong?

Best regards
Alex Wirth