General the chips are use for keeping code that will allow the nic to boot from a network. directly. You may want to investigate ipxe. The advatage is that if you can boot from the network, generally you do not need a local hard drive/ Many businesses use it with AOE and Iscsi now, We use ltsp,for diskless booting but vmware and other companies support the nic network boot. Novell with their servers first did it years ago.. Newer consumer nics no long have that removable . Nics that support ipxe are expensive. but there are ways around that.

I'd be worth a shot. Look at the removable chips and try to get a manufacturer name and model number off them. Then see if they're documented online. They might be ASICs, in which case they'd be more limited in their re-usefulness, or they might be general-purpose CPUs you could reprogram and embed somewhere else.