Alternative Way to Boot in Recovery Mode with Big Sur
--

Just to share my tryout after reading first post of David Anderson who helped me to find this.

The environment it's little different from VMW Fusion, actually it is this:
<br>Guest OS: Big Sur 11.6
<br>Host OS: Big Sur 11.6 on MBA 2020 (Intel)
<br>Hypervisor: Virtual Box 6.1.28

I have tried every way to boot in Recovery Mode, either using nvram, or through EFI Internal Shell, all with no success (within my environment). 
- `sudo nvram "recovery-boot-mode=unused"`  ==> With this old (Catalina) var, I even get “Error setting variable” in Big Sur.
- `sudo nvram internet-recovery-mode=RecoveryModeDisk` ==> when rebooting GuestOS, seems variable to be ignored as MBA don't actually boot in Recovery Mode.
- `dmpstore -l csr.bin` ==> returns “No matching variable found.”

And also booting in EFI Internal Shell and looking for CoreServices/boot.efi, I searched through all FS*N*: mapping table entries (all vols/partitions of local internal Disk of MBA), with no success. It seems System/Library/CoreServices is hidden or encrypted (SSV?)



Then, as suggested by t0rr3sp3dr0 [here in GitHub][1], tried to look for CoreServices boot.efi, this way and I did as follow:

 - In VirtualBox under VM Settings —> Storage, mount Big Sur Installation image. And check “Live CD/DVD” option.
- Start VM and press ESC key
- Choose Boot Manager —> EFI Internal Shell
- Look for Recovery Partition, in my environment under FS7, type:
<br>
`FS7:`
<br>
`vol`
<br>
to check for HFS+.
- Type:
<br>
`cd System/Library/CoreServices`
<br>
`boot.efi`
<br>
`ENTER`

[![enter image description here][2]][2]


Finally, my GuestOS (BigSur 11.6) boots in Recovery Mode!
<br>
Hope might help.


  [1]: https://github.com/geerlingguy/macos-virtualbox-vm/issues/46
  [2]: https://i.sstatic.net/ZP5pw.png