Last editied: January 17, 2020
Wanna try OpenCore but can't boot UEFI based sources? Well don't fret, there's hope for you! OpenCore supports DuetPkg which emulates a UEFI environment for legacy systems.
To start, you need the following:
Install source(MacOS Journaled + GUID, size of USb depends on the version of macOS. 16GB recommended for catalina)
Within your OpenCore build folder, navigate to
Utilities/BootInstall. Here you'll find a file called
BootInstall.command. What this does is install DuetPkg to your desired drive.
Now you'll want to run
BootInstall.command, do note that you may need
sudo for this to work correctly on newer versions of macOS
This will give you a list of available disks, choose yours and you will be prompted to write a new MBR. Choose yes
[y] and you'll be finished.
This will provide you with an EFI partition with a
boot file, this is where we'll add our OpenCore EFI.
Note: You will need AppleUsbKbDxe.efi for picker support