In order to optimize systems for OS X, many users of non-Gigabyte motherboards flash a modified UEFI. For users of Asus H77, B75 and certain Z77 boards without the USB Flashback feature, there is now a method to allow you to flash modified roms. Thanks to Flashrom and SJ_UnderWater's DPCIManager, we can now extract the rom from the motherboard, and flash modified roms all from within the comfort of OS X.
The new method will be necessary if you have one of the Asus 7 series boards without USB Flashback, and for users with Intel 1155 boards wishing to use a modified rom. It requires users to upload their own extracted roms for patching. Please note that flashing a modified file onto your motherboard can be risky- your board is your responsibility.
Official Guide: How to flash modified roms on unsupported boards
DPCIManager 1.1 w/ Kext Suggestions and BIOS ROM Flashing
Modified UEFI Rom FAQ
Asus 1155 Patched BIOS Repository
MSI, Asrock and Foxconn 1155 Patched Bios Thread