Getting UEFI shell when trying to boot OS X in Virtual Box
You have to disable EFI boot in the machine settings. Then it will work, however, you will have to have Chameleon installed on the .cdr image.
- Type exit at the UEFI Shell Prompt
- Go to Boot Maintenance Manager
- Choose Boot From File
- Go to Preboot....
- Navigate through [Some GUID] -> System -> Library -> CoreServices
- Finally select boot.efi
Your machine should now boot up. Works for me for Big Sur.
This is not working in VirtualBox at the time of writing (2015-10-07).
Apple migrated the format of the partition table for El Capitan boot image from MBR to GPT and VirtualBox does not yet support HFS+ filesystems on GPT partitioned drives when starting from EFI.
Refer to this issue:
https://www.virtualbox.org/ticket/14490