1. Start by booting to macOS Big Sur and opening a Terminal application window. You could try entering the command given below. If the command was accepted, then SIP would be disabled on the next boot. 

        sudo nvram csr-active-config=%7f%00%00%00

    However, the command will not be accepted. Certain misspellings will be accepted, such as in the command given below.

        sudo nvram Asr-active-config=%7f%00%00%00

    Enter the above command, then proceed to the next step.

 2. Shutdown macOS. In the `Setting` window for the virtual machine, select 
`Startup Disk`. Hold down the <kbd>option</kbd> key and select the `Restart to Firmware…` button, as shown below.

    [![][1]][1]

    Select the `EFI Internal Shell`, as shown below.

    [![][2]][2]

    If desired, enter the command below to get full use of the window.

        mode 128 40

 3. Set the current filesystem to the EFI volume. This should be the mapped `fs0` filesystem, so you would enter the following

        fs0:

    Next, verify the label is `EFI` by entering the command below.

        vol

    If wrong, then try `fs1:`, `fs2:`, `fs3:`, ....

 4. Enter the command below to save the `Asr-active-config` variable to the file `csr.bin`.

        dmpstore Asr-active-config -s csr.bin

    >Note: For more information on this command enter `help -b dmpstore`.

    Next, enter the command below to edit the `csr.bin` file. You will need to correct the spelling by replacing the letter `A` with the letter `c`. The can be done by typing a `63` over the `41` on the first line.

        hexedit csr.bin

    The corrected file will appear as shown below. When finished save the changes and exit.

    >Note: The value of the variable is stored in the last 4 bytes of this file.

    [![][3]][3]

    Enter the command below to create the `csr-active-config` variable in NVRAM.

        dmpstore -l csr.bin

    SIP will now be disabled on the next boot of Big Sur. If desired, enter the command below to remove the `Asr-active-config` variable from NVRAM.

        dmpstore -d Asr-active-config

 5. Enter the command below to leave the command shell.

        exit

    From the `Boot Manager`, select `Mac OS X` to boot Big Sur.

Format of the `csv.bin` File
-------

|Offset in Hex|Size in Decimal |Description|
|------------:|---------------:|:----------| 
| 00-03 |  4 |  Length of variable name|
| 04-27 | 36 |  Variable name stored as null terminated UTF-16LE string|
| 28-37 | 16 |  GUID of the variable |
| 38-3B |  4 |  Attributes stored as 4 byte integer (See below) |
| 3C-3F |  4 |  Length of the data|
| 40-43 |  4 |  The 4 byte integer that comprises the data |

| Attribute| Value| Description |
|----------|------|-------------|
| NV | 1 | Non-volatile |
| BS | 2 | Boot service Access |
| RT | 4 | Runtime Access |
| HR | 8 | Hardware Error Record |

  [1]: https://i.sstatic.net/GtT1v.png
  [2]: https://i.sstatic.net/muLxs.png
  [3]: https://i.sstatic.net/vKW6Z.png