I want to use Asus Flashtool to restore stock firmware to my phone. The download page says I will need "RAW" firmware. What exactly is that? I have already downloaded the correct firmware file from Asus' own website. The site in question has a link to what it refers to as "RAW" firmware, but I would rather flash the firmware I've downloaded from an official source. Is there any difference? Is "RAW" firmware supposed to be something special?