Search line in /etc/grub.d/40_custom is not generic

[bengtfredh]

Can be good idea to put instruction that you need to adjust the search line in 40_custom for your system. Most easy is probably to find out what search line is on your system with something like this:

# grep "set=root" `find /boot -name "grub.cfg"` | tail -1

output: search --no-floppy --fs-uuid --set=root 00000000-0000-0000-0000-000000000000

40_custom can look like this:

search --no-floppy --fs-uuid --set=root 00000000-0000-0000-0000-000000000000
chainloader (${root})/EFI/custom/apple_set_os.efi
boot

Confirmed to work on:

• MacBookPro11,4 (Retina Iris Pro)
• Big Sur
• Fedora 33 btrfs Workstation
• Kernel 5.10.12