Quote Originally Posted by Swall View Post
Some time ago my vendor said that starting from the next map version current "license" is no more valid (as the map's FID value has increased) so each customer have to "renew" it individually according to the procedure. So I'd sent them ID of my unit and the vendor did responded with the .gma file generated. Actually, in order to get the map working, all I have to do is to place that .gma file next to gmapsupp.img in the ext. storage media. There are no other related files like .unl, etc. The .gma file missing results in auth error so the map is indeed protected. And that .gma file is the sole mean to unlock the map. I've no idea if that's right or wrong but it in my case it works in that manner.
No wonder.
An additional GMA-check was added to the firmware of modern devices for maps with FID > 2200.
As I mentioned before, the GMA file contains unlock codes that are digitally signed, so it was enough in your case.
However, many legacy devices don't have additional GMA-check and don't support GMA files at all, only UNL.


Quote Originally Posted by Swall View Post
Thanks for the quote from the official Overview. Could you provide a direct link to the related Garmin page?
Garmin does not publish such overviews on its pages available to the public.