/usr/lib/ipxe/eepro100.rom is in ipxe-qemu 1.0.0+git-20150424.a25a16d-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ipxe/qemu/pxe-eepro100.rom
/usr/lib/ipxe/qemu/pxe-eepro100.rom