# clone iPXE
git clone git://git.ipxe.org/ipxe.git
cd ipxe/src

# build ipxe rom
make bin/8086100e.rom    # e1000
make bin/virtio-net.rom  # virtio
make bin/10ec8139.rom    # rtl8139 
make bin/10222000.rom
make bin/80861209.rom
make bin/10500940.rom

# now copy into /usr/share/kvm. Backup the old copies first.
cp bin/8086100e.rom /usr/share/kvm/pxe-e1000.rom
cp bin/virtio-net.rom /usr/share/kvm/pxe-virtio.rom
cp bin/10ec8139.rom /usr/share/kvm/pxe-rtl8139.rom
cp bin/10222000.rom /usr/share/kvm/pxe-pcnet.rom
cp bin/80861209.rom /usr/share/kvm/pxe-eepro100.rom
cp bin/10500940.rom /usr/share/kvm/pxe-ne2k_pci.rom