Today I tried to install Ubuntu on my mac and screwed up the drive and now In recovery I can't even erase my drive it says missing efi partition and failed to unmount when I choose one partition. I tried going to single user mode and repairing the drive but that didn't work I have a 2013 Haswell i7 13 Air. I'm going to try and boot from a Bootable mavericks Recovery USB and see if that helps to erase the whole SSD. Can anyone give me some tips.