Quote Originally Posted by babj615 View Post
Turns out locking maps is easy - It is done at the time of compiling.
Garmin locking method is very easy. It is changed A one opened flag is changed and info about levels is decoded with FID. If you got small knowledge about Garmin format you can see it by comparing locked and unlocked map. All that you need for reverse engineering to lock it is changing byte of the flag in HEX plus lock the level info in TRE section.