Nice find! Every now and then, especially with older devices, a healthy one will fail to load maps on start up and present you wilh a screen without roads and showing only the vehicle icon. It might be only one in a hundred or many more boots when it happens and of course in an otherwise healthy device the next boot, whether done as a reset or normal boot, usually succeeds fully. I have a nuvi 765 US that's particularly prone to it. Now that little curious quirk can be used to advantage with a boot-looping device which will boot to 'Loading Maps' and then restart over and over, indicating a corrupt IMG file. By leaving it charging turned on for an extended period, maybe overnight or a day or even more, eventually it will fluke a boot without loading any .img files and you find the device fully booted but the Map screen showing no roads, only a lonely-looking vehicle icon. Then provided you don't let it reboot it will have MSM access and the offending map, which is nearly always a detail map, can be removed.

BTW, I didn't mean to look for .xmg too. I meant look for any instance of .img and change it to .xmg or it could be anything, .zzz or whatever provided it's not a used extension. It's just easier to substitute 'x' for the first letter that's all. It's really not surprising that the file extensions aren't in the Linux firmware but I've also checked multiple ways and you're right of course. If they were there us common folk would have been making cure fw for Linux devices years ago. Searching either as Unicode Latin or with a wildcard "." (i.e. ".I.M.G.") works with Garmin proprietary-OS firmwares and finds multiple references of ". I M G" and other common extensions which can cause 'bricking', such as gpi, gpx, vpm etc. Nobody bothers with that tedious method since the brilliant kunix came up with his Cure3 and QuickCure apps to simplify/automate making cures. Some more info here: [Only registered and activated users can see links. ]. I know for sure it can be done to make Linux cure fw but the guys who can do it just don't seem to post here anymore.