Debootstrap Bootable Trisquel System to USB Using Shell Script?

Hi everyone,

I am trying to make an unattended shell script that allows the ability to do the following in order:

0) Login as root
1) Format USB as ext4, then mount it without noexec or nodev
2) Debootstrap a minimal Trisquel system onto the drive
3) Install GRUB, unmount. Done!

Does anyone know where to find such script? Or can anyone make a script? Thanks.