Another way, if you still have the Big Sur installer on the disk, is manually creating another 12GB virtual disk and creating a Big Sur installer on it, then using that installer to fix the boot sequence.Īgain, the problem is probably very minor and I'm giving these hacky solutions so I don't have to look into, but it's probably the source of the issue and it's probably very simple to fix it.

The proper solution would be fixing Big Sur's boot settings, or, if the VM has nothing on it, deleting the VM and making a new one, then upgrading to Big Sur when it's the only attached bootable disk so the boot sequence doesn't get complicated. Keeping the installer attached and editing the second and third run (1 5) to run (2 5) or run (3 5) so it skips the first one or two disks (I can't remember if the installer has an EFI partition I think it doesn't so you only need to skip one partition in the EFI Internal Shell).Then, switch the Type drop-down option to Mac OS X and Version to Mac OS X (64-bit). If the boot menu appears, select 'Boot Manager' and then 'EFI Internal Shell' and then allow the startup. This boots into the EFI Internal Shell or the boot menu. Use the name of your macOS version to name your virtual machine for example, Monterey. When resetting or powering up the VM, immediately press Esc when the VirtualBox logo appears. Click New to create your new virtual machine.

Permanently attaching an empty HFS disk so Big Sur is the second disk again. Install VirtualBox on your Windows PC by following the instructions in the installation wizard.

However if you don't feel like delving into macOS boot internals, you can try: Since Big Sur boots with the Catalina installer disk attached but fails if it's the only disk, the problem is definitely minor and probably somewhere in.

Startup.nsh macos virtualbox