How to NetBoot powerPC?

I'm having a little trouble. I recently received an iMac PowerPC G5 with a busted HDD.

It has that infamous problem with the SuperDrive spitting every disk out, so I used dd on my linux box to put the Tiger image onto a 4gb pen-drive and booted it up through open-firmware via "boot ud:,\\:tbxi." I'm now successfully running Tiger.

However, support for Tiger is pretty poor and this guy meets the prereqs to run Leopard. Problem is, I don't have an 8gb pen-drive to hold that massive dual-layer image.

My setup is simple-- I have a Linux/PC dual-boot box and an iMac hooked together through a wired router. I don't care about security issues, I just need the simplest possible way to boot this thing over the network. I have the Leopard install image as a .dmg, but I can make it whatever format is best.

I found this guide--

http://koti.kapsi.fi/~jvaltane/mac/netinstall.html

But it's rather deprecated, and the explanation of tftp isn't very clear.

I've been researching dnsmasq, but I'm pretty clueless about which configuration options I need to setup to get this to work.

So!

Given a router, a linux/pc box, and a Mac, where do I need to put what to boot an install image in open-firmware?

Thanks!