How to invoke a UEFI Shell (v2.2) on a Fusion Player virtual machine with Big Sur installed?
I tested the following UEFI Shell v2.2 binaries. Many of these were suggested on Arch Linux wiki website &quot;Unified Extensible Firmware Interface&quot; under the section &quot;Obtaining UEFI Shell&quot;. Some binaries required extra effort to extract from the downloaded file.

Arch Linux: The shellx64.efi file in the root directory of the mounted archlinux-2021.03.01-x86_64.iso file. See here for a list of websites where the ISO file can be downloaded.

TianoCore EDK2 package: The Shell.efi file.

EDK2 package from Arch Linux: The Shell_Full.efi and Shell.efi files in the usr/share/edk2-shell folder of the expanded edk2-shell-202011-1-any.pkg.tar.zst file, which can be downloaded from this website.

rEFInd CD-R image: The shellx64.efi file in the EFI/tools folder of the mounted refind-cd-0.12.0.iso file. This ISO can be created by expanding the refind-cd-0.12.0.zip file, which can be downloaded from this website.

OpenCore package: The OpenShell.efi file in the X64/EFI/OC/Tools folder of the expanded OpenCore-0.6.7-RELEASE.zip file, which can be downloaded from this website.


All of the above shell binaries, except for OpenCore, either had an faulty edit command or failed to display output when boot directly from the client firmware Boot Manager.

The shell binary from the OpenCore 0.6.7 release was chosen for use in this answer.

The steps to install the new UEFI shell are given below.

Download an OpenCore package: Open the webpage containing this answer on the client. From this GitHub website, download the current release of the OpenCore package. Currently this is OpenCore-0.6.7-RELEASE.zip, which by default will become the OpenCore-0 folder in your Downloads folder on the client.

Mount the EFI volume: On the client, open a Terminal application window and enter the command given below.
sudo diskutil mount disk0s1


Put the shell in the EFI volume: On the client, copy the ~/Downloads/OpenCore-0/X64/EFI/OC/Tools/OpenShell.efi file to the root folder on the EFI volume. Rename this file to shellx64.efi.

Put the startup script in the EFI volume: This step is optional, however the script does create useful aliases and environment variables. Also, the display mode is set so the shell uses the entire console window.
Open this webpage on the client, then save the script given below as an ASCII text file named startup.nsh in the root folder on the EFI volume.
@echo -off
mode 128 40
set -v AppleEnv 7C436110-AB2A-4BBB-A880-FE41995C9F82
if x%uefishellversion% == x then
    # Startup commands for EFI 1.0 shells
    alias -v cv &quot;ver -s&quot;
    alias -v ush &quot;shellx64.efi -nomap -noversion -delay 0&quot;
    if &quot;x%StartupDelay%&quot; == x then
        set StartupDelay 0
    endif
    cls
else
    # Startup commands for UEFI 2.2 shells
    set -v ShellAlias 0053D9D6-2659-4599-A26B-EF4536E631A9
    set -v SEnv 158DEF5A-F656-419C-B027-7A3192C079D2
    alias -v csrutil &quot;setvar csr-active-config -nv -rt -bs -guid %AppleEnv%&quot;
    alias -v cv ver
    if &quot;x%ShellOpt%&quot; == x then
        setvar ShellOpt -nv -bs -guid %SEnv% =L&quot;-nomap -noversion -delay 0&quot; =0000
    endif
endif
cv


Restart to firmware: Shutdown the client. On the host, open the Startup Disk pane of Settings for the client. Hold down the option key and select the Restart to firmware… button.

Add boot option: From the client firmware menus, select Enter setup&gt;Configure boot options&gt;Add boot option, then select the EFI volume, as shown in the example below.

Next, select the shellx64.efi file. For a description enter UEFI Shell. and for options data enter -nomap -delay 0. The results should appear as shown below.

Next, select Commit changes and exit&gt;Exit the Boot Maintenance Manager. The window should appear as shown below.


Test the shell: Select UEFI Shell to boot to the UEFI shell. When finished, enter exit to return to the Boot Manager. If desired, select Shut down the system.