Package: grub-rescue-pc In README.Debian we see: How to write the images to bootable media: sudo dd if=/usr/lib/grub-rescue/grub-rescue-floppy.img of=/dev/fd0 bs=32k sudo wodim /usr/lib/grub-rescue/grub-rescue-cdrom.iso # or just use your favourite CD burning program However no instructions are provided for USB.