When I once installed Ubuntu 20.04.2 onto /dev/sda6 and reboot the machine, GNU Grub 2.04 doesn't show the boot menu, it shows the text “Minimal BASH-like …”. I press Esc, but it does nothing.
And I start into Ubuntu 20.04.2 Desktop LiveCD by USB drive, then install boot-repair. Once I click the “Recommended repair”, it says “Please enable a repository containing the [grub-efi] packages in the software sources of Ubuntu 20.04.2 LTS (sda6). Then try again.”
But I don't know what repository does it need to enable, and how to enable it.
EDIT 1: I tried:
sudo apt update
sudo apt install apt
sudo apt update
sudo apt install grub-efi
sudo apt update
