Boot linux from grub rescue

[thockman]

This is how I booted from a broken grub.
If your device is fine you can still boot. In my case I delete an old part that grub pointed to. I had a good install of ubuntu on another partition.
My part was /dev/sda7
At grub rescue>
ls to show devices
set prefix=(hd0,msdos7)
set root=hd0,msdos7
insmod linux
ls (hd0,msdos7)/boot
linux /boot/vmlinuz-3.0.0-15-generic ro root=/dev/sda7
initrd /boot/initrd.img-3.0.0-15-generic
boot