Thread: Running programs from SD on nuvi

Originally Posted by Raupe

............
So with the tool I have the files :
127.bin
158.bin
Just converted the hex addresses in the name of the files created by RNG tool to decimal.

The file 14.bin could not be generated in this way. These I brought as described in post #125 with rrgn from the device to the card.

What do you mean by it "could not be generated in this way"? RGN_Tool can extract fw_all (14.bin) from a GCD or RGN firmware file in exactly the same way as it can extract 127 & 158. Do you mean you've generated a firmware BIN file by dumping region 14 from the device using "rrgn,14,2/14bin"? If so, you'll be flashing back the exact same data for the main system software to region 14 (hex 0x0E) and if that's the case, what's the point?

From my point of view I have now everything together

The update.txt has this content :
....................
and is located in Garmin/updater/1772/update.txt
There is also the Ldr.bin .

Could this work, can I have made a mistake ?

Certainly the txt commands are correct to delete any gupdate.gcd file from .System, dump the nonvol memory to the card and rewrite data to the 3 fw regions from the card. So yes it will work provided you're using the right Ldr.bin in the HWID folder made from the correct 1772's boot.bin extracted from the appropriate firmware. However, again, what's the point? Even if the GCD in .System was corrupt, it's not being initiated anyway. If it was corrupt and initiated the device would be soft-bricked and stuck on the logo splash screen.

Please explain precisely what you wish to achieve as i must be missing something as to your ultimate intentions. If you're simply doing this as a practice exercise for updating future firmware versions it would be far simpler (and much safer) to do higher version updates with a GUPDATE.GCD in a Garmin folder on a microSD.

I see. But don't be embarrassed, that's nothing compared to the monumental cock-ups i did when learning about Garmin devices.

Firmware failure/corruption can manifest in 'soft-bricking', sometimes just freezing or spontaneous reboots during use but it doesn't cause that type of function loss in Garmin devices in practice, although i guess it's theoretically possible a software problem could disable USB access. It's worthwhile to hard reset/clear non-volatile memory as an immediate action when seeing any sudden weird behaviour, particularly best done just as a precaution after updating the device.

The fault you are experiencing is almost certainly due to a hardware failure. Maybe you should have reflowed the USB socket connections to the PCB while you had it apart anyway, despite the sound appearance of the traces. Sometimes the break is not easily seen even with magnification, but that's very rarely the case if the socket mountings are solid and not discernibly loose i.e. socket can't be 'wiggled' slightly. Also despite the good appearance of the socket's exterior you could also try cleaning by spraying it with dedicated electrical contact cleaner and letting it thoroughly drain and dry out before re-trying a PC connection. Complete checklist for common issues follows.

When there's a PC connection problem but the socket is not obviously loose or dirty/corroded (spray with cleaner as above if not sure), and nor can we see any damaged pin/s, initially we eliminate these potential causes:

• Use of incompatible USB cables. Even official Garmin ones can be problematic and a cable may work fine with one Garmin device but not another, so just try multiple cables to be sure;
• Use of USB3 ports instead of USB2 ports. That may result in intermittent or no connection at all despite the claim that USB3 is backwardly compatible;
• Use of front rather than rear USB ports on a desktop PC may result in fail to connect;
• Use of a USB hub rather than a direct connection is also potentially unreliable;
• Try another Windows PC if available (even an old and slow XP desktop will do, rather than a laptop). Avoid using a Mac at all.

If the above easy fixes don't help, open the device and carefully reflow the connections to the board anyway even if they seem ok. Use a fine tip and good-quality leaded solder if available and lots of flux to avoid bridges, taking the opportunity to reinforce the socket mounts because they aren't always properly done at the factory (they're robot soldered so a bit 'hit and miss' as to strength). Take care not to overheat the board.

Finally once all potential problems are eliminated, that leaves only a failed component on the PCB. Unless you or someone you know is into circuit testing of boards and microsoldering and can source the tiny component needed, that's not repairable. So all updates ongoing will need to be done via SD. A GarminDevice.xml file in a Garmin folder on SD can usually get the required updates from GarminExpress/WebUpdater and then the various files either transferred to the device's internal memory or used on a media card in the device.