Different GPUFS disk images have different root partitions that Linux needs to boot from. In particular, Ubuntu's new installer has a GRUB partition that cannot seem to be removed. Adding this as an option prevents needing to edit a config script to change one character each time a different disk image is used. Change-Id: Iac2996ea096047281891a70aa2901401ac9746fc Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71918 Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com> Maintainer: Matt Sinclair <mattdsinclair@gmail.com>