9boot(8) is the place to start. 9boot replaces 9pxeload but is more persistent. 9load and 9loadusb should behave much as the old ones did, though I hope that the new ones will run on more machines. One can boot through any PCI ethernet interface for which we have a kernel driver now.
We are using 9boot to boot virtually all of our machines, including those running amd64 kernels. Thanks to my very patient beta testers, David du Colombier, John Floren and the lsub crew. Gorka contributed new CD booting code and I swiped Russ Cox's old decompressing executable header.
