Install shim by entering the following commands in the terminal:
sudo apt update sudo apt install shim
Description:
boot loader to chain-load signed boot loaders under Secure Boot
This package provides a minimalist boot loader which allows verifying signatures of other UEFI binaries against either the Secure Boot DB/DBX or against a built-in signature database. Its purpose is to allow a small, infrequently-changing binary to be signed by the UEFI CA, while allowing an OS distributor to revision their main bootloader independently of the CA.
Version: 13-0ubuntu2
Section: admin