CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. CentOS conforms fully with the upstream vendor's redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.) CentOS is free. http://www.centos.org
Please see here about EFI-enabled images
http://lists.centos.org/pipermail/centos-announce/2012-September/018887.html