I want to skip the GRUB loading screen or remove any other option besides Ubuntu.
I've installed another Linux distro on my other internal harddrive; however, I only want to be able to boot the other distro if I change boot-priority in the BIOS.
I did install GRUB on both harddrives.
I've tried editing /etc/default/grub
with
GRUB_HIDDEN_TIMEOUT=0
but it did not work, nor is it exactly what I want.