Create OpenCore Disk - mayankk2308/kryptonite GitHub Wiki

To use OpenCore, we need to set up a volume that the system can detect as bootable such that it loads OpenCore before loading the operating system. You can use an external USB drive, create your own volume on your internal drive, or use the EFI partition of your internal drive for this. Please note that the Kryptonite installer does not support working with EFI partitions, so if you are using that, your setup will have to be manual.

Prepare Volume on Internal Drive

  1. Launch Terminal and execute the following command: 
    tmutil deletelocalsnapshots /

# Do this for all other internal volumes as well
tmutil deletelocalsnapshots /Volumes/<Your Volume>
  2. Launch Disk Utility on macOS.
  3. Select your boot volume.
  4. Press Partition.
  5. You will be asked to choose Add Volume or Add Partition - choose Add Partition.
  6. Add a 256MB partition formatted as MS-DOS (FAT).

Prepare Volume on External Drive

  1. Launch Disk Utility on macOS.
  2. Select your external drive.
  3. Press Partition.
  4. If asked to choose Add Volume or Add Partition - choose Add Partition.
  5. Add a 256MB partition formatted as MS-DOS (FAT).

If you are unable to add a partition, you may need to format your external drive.

Using EFI Partition

Typically, OpenCore is installed on the EFI partition, but I prefer keeping everything stock and just having a separate disk for OpenCore created using the described procedures above. With EFI partition, weird things can happen. If you want to use the EFI partition, you can try these steps and then input the EFI partition as the installation disk in the install script.