I have a OSM map for Garmin that was created by www.gmaptool.eu and is in the *.gmap format and can be used in Garmin MapInstall and MapManager programs and from there loaded onto a Garmin device. I was wondering if there is any application for Linux that can take this map format and turn it into a *.img format that could then be manually installed on a Garmin device? A simple command line tool is fine. Thanks for your help.
You can try Mapsource or BaseCamp/Mapinstall with wine.