diskless boot

I finally got my cats card into a box, no disks at all connected, just
a monitor and keyboard (temporarily) and a network card.

It has Cyclone 0.4 firmware.  How do I get it to boot diskless?

It comes to a boot> prompt, no bootable devices are available
according to the devices command.  The network card is mentioned
during boot and it shows carrier at the hub it is connected to.

I stumbled over a debian installation faq for ARM that mentioned 
boot> boot de0:
Does not work, I tried setting de0: in the boot enviroment variable
too, but no. Tried many other variants, le0, eth0 etc..  No go.
It likes to say "No such file or directory"

I have dhcpd on a Sparc/NetBSD that I have used in the past to boot
various sun3, sparc and hp300 machines.

Håkan