to make shell's '-u' happy.

This allows us to pass in e.g. -j

to work around #887892

vmdebootstrap wants UEFI for arm64 and we can use the Debian kernel when we
only run in qemu.

We don't have a single board using it and we can easily bring it back if
needed.

We had files gone missing already

Leave it disabled for now by default

always handy

Not needed during boot

This ensures better sepration and we can use it from differen scripts