Installing:

  On non-Mac UEFI sytems make sure you have 'efibootmgr' before installing,
  and make sure you booted in UEFI mode. Then the install should set things
  up correctly.

  On Mac EFI systems there several options - see also
  https://help.ubuntu.com/community/UEFIBooting#Make_the_firmware_launch_GRUB2_.28U.29EFI_as_default
  After installing the grub2-efi rpm:

    0. prepare the EFI directory:

      boot_root=$(df /boot | awk '/^\// {print $6}')
      efi_dir=$(readlink -f ${boot_root}/EFI)  # will be /boot/EFI or /EFI
      mkdir $efi_dir

    1. If you have rEFIt:

      mv -T /boot/grub2 $efi_dir/grub2
      ln -s $efi_dir/grub2 /boot/grub2

    2. Otherwise if you are using the Apple bootloader:

      mv -T /boot/grub2 $efi_dir/BOOT
      ln -s $efi_dir/BOOT /boot/grub2

      mv /boot/grub2/{grub.efi,BOOTIA32.EFI}   # if on i386
      mv /boot/grub2/{grub.efi,BOOTX64.EFI}    # if on x86_64

  For further configuration see the above UEFIBooting wiki page.