Thread: *.gma - What's inside?!

Originally Posted by Cnfhbr

It's easy to verify via ImgTool or GMapTool.
The 25-digit unlock code is written to the MPS subfile of the map as a U-record.

You're right. It's there

Originally Posted by Cnfhbr

For most devices, the info on the successful authentication of the map is stored in non-volatile memory after the first success and kept there right down to the next hard/master reset or NonVol clearing.
For example, some tricks for temporary map authentication are based on this property.

Well, I think this security bug is by design. After all, Garmin's primary products are hardware devices so it's not seriously interested in closing all back doors