efibootmgr

Manipulate the UEFI Boot Manager (the Bootoptions). More information: https://manned.org/efibootmgr.

List the current settings / bootnums:

efibootmgr

List the filepaths:

efibootmgr -v

Add UEFI Shell v2 as a boot option:

sudo efibootmgr -c -d {{/dev/sda1}} -l {{\EFI\tools\Shell.efi}} -L "{{UEFI Shell}}"

Change the current boot order:

sudo efibootmgr -o {{0002,0008,0001,0005}}

Delete a boot option:

sudo efibootmgr -b {{0008}} --delete-bootnum