As we start to see more UEFI firmware become available, one would guess we'll find more exciting weirdness like what Matthew Garrett found. For whatever reason, the firmware in a Lenovo Thinkcentre M92p only wants to boot Windows or Red Hat Enterprise Linux (and, no, it is not secure boot related): "Every UEFI boot entry has a descriptive string. This is used by the firmware when it's presenting a menu to users - instead of "Hard drive 0" and "USB drive 3", the firmware can list "Windows Boot Manager" and "Fedora Linux". There's no reason at all for the firmware to be parsing these strings. But the evidence seemed pretty strong - given two identical boot entries, one saying "Windows Boot Manager" and one not, only the first would work."