Update: The boot partition was formatted and all the old configs restored with TestDisk but the system seems to be damaged by some earlier fstab changes adding gid=0 to the /root dir fstab entry. All I feel is pain ( I don't have a root password, archiso it is ) 

Yesterday I got a warning saying I should fsck my xbootldr partition. This is why you should'nt ignore warnings. Had to put the partition on life support and relabel it.