http://refit.sourceforge.net/

Installing rEFIt on a non Mac system was always a litle hard.
Debian derived distributins already had the rEFIt as a package to install.
rEFIt is a nice bootlaoder for all efi/uefi based boards (like my hp 6930p)
the ebuild for this nice bootmanager is located in my linamh overlay

Simply emerge -av sys-boot/refit

This ebuild depends on that your efi partition is mountet under /boot/efi