The ROM images on /usr/share/qemu-kvm/rhel6-*.rom come from the

Red Hat Enterprise Linux 6.4 package gpxe-roms-qemu-0.9.7-6.16.el6.noarch.rpm.

The source code for those images can be downloaded from:

http://ftp.redhat.com/pub/redhat/linux/enterprise/6Server/en/os/SRPMS/gpxe-0.9.7-6.16.el6.src.rpm

For more information on how to obtain source code for Red Hat Enterprise Linux

software, you can refer to Chapter 1. Obtaining Red Hat Enterprise Linux of the

Red Hat Enterprise Linux Installation Guide.