identify the device that the /boot/efi partition is mounted on, umount it and then use gdisk to delete that partition and create a new one with the code AF00 for HFS+. Write the changes out in gdisk and then execute mkfs.hfsplus on the device to format it. Now change the boot/efi entry in fstab to have 'hfsplus defaults', remount the boot/efi partition and just execute the 'update-efi-booter' script.
Afterwards the /boot/efi subdirectory will contain...
# cd /boot/efi/
# ls -lR .
.:
total 4
-rw-r--r-- 1 root root 34 Dec 16 23:04 mach_kernel
drwxr-xr-x 1 root root 3 Dec 16 23:04 System
./System:
total 0
drwxr-xr-x 1 root root 3 Dec 16 23:04 Library
./System/Library:
total 0
drwxr-xr-x 1 root root 4 Dec 16 23:04 CoreServices
./System/Library/CoreServices:
total 1968
-rw-r--r-- 1 root root 2009088 Dec 16 23:04 boot.efi
-rw-r--r-- 1 root root 380 Dec 16 23:04 SystemVersion.plist
and where the boot.efi is now blessed on a HFS+ filesystem. This allows the option key boot selector on Macs to display the Ubuntu operating system with a customized icon. Thus rEFind is no longer needed to be able to switch between other installed OS releases.
Tested on a fresh install of Ubuntu 16.10 x86_64 by...
gcc -o disable_journal disable_journal.c
chmod ugo+x update-efi-booter
install disable_journal update-efi-booter /usr/local/bin
identify the device that the /boot/efi partition is mounted on, umount it and then use gdisk to delete that partition and create a new one with the code AF00 for HFS+. Write the changes out in gdisk and then execute mkfs.hfsplus on the device to format it. Now change the boot/efi entry in fstab to have 'hfsplus defaults', remount the boot/efi partition and just execute the 'update-efi-booter' script.
Afterwards the /boot/efi subdirectory will contain...
# cd /boot/efi/
# ls -lR .
.:
total 4
-rw-r--r-- 1 root root 34 Dec 16 23:04 mach_kernel
drwxr-xr-x 1 root root 3 Dec 16 23:04 System
./System:
total 0
drwxr-xr-x 1 root root 3 Dec 16 23:04 Library
./System/Library:
total 0
drwxr-xr-x 1 root root 4 Dec 16 23:04 CoreServices
./System/ Library/ CoreServices:
total 1968
-rw-r--r-- 1 root root 2009088 Dec 16 23:04 boot.efi
-rw-r--r-- 1 root root 380 Dec 16 23:04 SystemVersion.plist
and where the boot.efi is now blessed on a HFS+ filesystem. This allows the option key boot selector on Macs to display the Ubuntu operating system with a customized icon. Thus rEFind is no longer needed to be able to switch between other installed OS releases.