[mkgmap-dev] Maps no longer working after firmware upgrade?

Fri Nov 16 18:12:45 GMT 2018

On Fri, Nov 16, 2018 at 05:48:43PM +0100, Felix Hartmann wrote:
> are you sure you're not sending maps with MapInstall 4.2.0?

That seems to be some sort of Windoze program. I am in a Microsoft free
zone :-(

I frequently install maps: I just place the *.img file into the sdhc
Garmin directory. I haven't actually checksummed it but I am sure
that it is correctly installed. It appears on the Map setup menu, and I
can enable/disable it. So it is seen by the Garmin firmware. And the
other contour maps (also *.img) are in there and working: I think that
they were built by mkgmap, but could be wrong.

> Meaning are you sure you did not destroy the .img files using Mapinstall
> 4.2.0? Use mkgmap itself to generate a gmapsupp.img (of a non unicode map
> just to be sure - maybe the firmware update crashes unicode maps but I've
> not heard of that for etrex 20/30)  and check if that works.

I may try that eventually, but for now have just used maps provided by
others.

> Can you not downgrade the firmware?

I very much hope so. I have a suspicion that I might have seen some
suggestions that that was not possible. At least not in a simple way.
Haven't looked at that yet, and any pointers to info on that would
be helpful. But it will need to work under linux if it requires support
from outside the Garmin.

I have only just discovered this problem and wanted to alert everyone
ASAP that there is/may be a problem, so others don't get hit.
Obviously I worry that Garmin might be trying to stop 3rd party
maps, although that would be incredibly stupid if that was really true.

ael