This is a Apple machine, not a Hackintosh. Before Apple switched to APFS, you could put this inside a menu entry in GRUB:
set root=(your OS X partition) chainloader /System/Library/CoreServices/boot.efi
But that doesn't work with APFS, as GRUB can't read it, despite the EFI having drivers for AFPS.
Is there a way to have an option in the GRUB menu to boot MacOS? Some possibilities for how this might work:
- Somehow get GRUB to utilize the EFI's built-in APFS driver to load the MacOS bootloader
- Put the MacOS bootloader in a place where GRUB can read it
- Use GRUB to launch a 3rd-party EFI program that can load MacOS
exit in the GRUB console will load MacOS, but it's not consistent—it will sometimes power off the machine, load GRUB again, or load another OS that is installed.