How can I create a NetBoot image using command line tools?

Is it possible to create a NetBoot image entirely using command line tools?
(That is, without using the System ImageUtility)
If so, are there reasonable instructions posted somewhere?

I don't believe I can use System ImageUtility with my current setup,
but I would be happy to hear how I could:

I have a set of Xserve clusternodes but without optical drives or video cards.
One node acts as the head, running DHCP, DNS, OpenDirectory, Xgrid.
They are wired to a gigabit switch.
I have a PowerBook connected on the subnet which has ServerAdmin Tools installed.

I don't think when I run System ImageUtility on my PowerBook that I can successfully image one of the clusternodes disks over the network.

I have tried to start one node in target(Firewire) mode, connect it via Firewire
to the head node, and run hdiutil from the head node to make a complete disk image of the clusternode's drive.
But a NetBoot image requires the whole nbi file, right?

Could I then use copy this disk image to my PowerBook and use System ImageUtility on my PowerBook to create a NetBoot image from it?


I really have tried to read the PDFs, but I found the section on System Imaging in the Command Line Reference rather unhelpful.

Thanks for anyones help.
dmaus


Mac OS X (10.4.4)