Hi,
I have triple-boot system with Windows 8.1 Pro x64, OS X and Linux Mint 17 Cinnamon x64. As the main bootloader I am using Clover EFI and it loads Linux via Grub. If I have grubx64.efi in the EFI partition, it somehow manages to automatically be added UEFI to boot options. Say I remove all boot entries for Mint/Ubuntu with efibootmgr, reboot and Grub boot entry is back withing boot entries. How? This doesn't happen with other EFI loaders like Windows or Clover.
The main issue is that when grubx64.efi is present in the EFI partition, I keep getting duplicate \ broken boot entries for "ubuntu", duplicates for Windows or non-working entries titled "Hard drive" that sometimes shows up and remains after USB stick has been removed. It seems that something bad happens when Grub entry is added, though not sure if it is fault of UEFI firmware or Grub.
My specs:
MB: Asus Z97-Pro(Wi-Fi ac) with latest 1304 UEFI firmware
Storage: Samsung 840 EVO 500 GB SSD, WD Red 3TB (EFI partition and all three OS partitions are on the Samsung drive)
Here's a forum post with some pictures:
http://forums.linuxmint.com/viewtopic.php?f=46&t=183842
Regards,