Keep gupdate.gcd on-board after update?

[osiris4isis]

Some Garmin devices automatically delete the internal GCD file after updating from it. This is particularly true with most outdoor devices, but not so with automotive devices.

So always delete .gcd (where is it located at?) on unit BEFORE doing anything. And after update is done, no need to keep it around; so delete it, right?

[Butters]

Where it's located is device-dependent, for MSM-capable devices it's either in Garmin folder of older models or .System folder of newer. There's only need to delete it, if present, before updating manually by RGN or with GCD on media card. Other 'conventional' updating done via GarminExpress or WebUpdater will simply overwrite any existing GUPDATE.GCD file as will of course manually copying one to the correct folder in MSM. Leaving it on the device after updating causes no issues if the device doesn't automatically delete it after updating from it.

[Scyllo]

There's only need to delete it, if present, before updating manually by RGN or with GCD on media card.

Hello!

How to manage the deletion of a GUPDATE.gcd on the device (I also do not know if it even exists!), if the device is in a boot loop and is no longer recognized by the PC?

So I can no longer access the device at all.

[osiris4isis]

What's "MSM?" Also it's safe to delete after done to prevent any future issue, right? I'm asking these "silly" questions because I'm working on a proggy to be as "safe" as possible. So what "triggered" the updating of .gcd? How does .rgn gets updated? Is it wise to backup/dump of certain regions before doing an .rgn update? Taking a break from NNG hacking to obtained these knowledge needed for my Garmin update proggy.

[Butters]

Ah! A 'silly question' specialist. That's great because I specialize in silly answers with overtones of sarcasm ....

• MSM is mass storage mode (Boy, I bet you feel real silly now, huh?).
• Sure, it's ok to delete it after it's been used.
• I don't know the 'how' of device being triggered to use the GCD file other than it recognizes that the file is for a different version firmware than the one already loaded. The GCD itself is a bit like a self-loading EXE file, simplistically, in that it contains the same data as an RGN file and additionally (I suppose) a 'header' that directs loading of the new data to the appropriate regions.
• RGN files are a 'stripped-down' version of a GCD and must be loaded manually in preboot mode using Updater.exe.
• You should make a backup of the device's nonvol region at the very least regardless of how you intended to update it initially and keep the backup for the life of the device. Ideally, a full dump of all possible regions should be done at least once. Some are protected from copying but most aren't. The visible file system for MSM-capable devices is located in either rgn48 or rgn83 from recollection, so that very large region can be skipped if you have a copy/paste copy already of all files and folders. Possible region numbers are 1 to 255 but nowhere near all are populated and it varies between device models.

You'll have to insert your own sarcasm for the last 4 answers, I'm tired now.

[osiris4isis]

Sorry no sarcasm, I must focus and get this done ASAP. On my 255W under Garmin\Diag directory there are 3 files: FT.bin, GarminError.xml, sys_log1.bin
GarminError.xml file contained data:
<PCB>nuvi 2W series S2 V4 2GB
that is in conflict of what is shown in the diagnostic screen (S4 board)
What does this mean?

The only .gcd files before the update are under the Garmin\RemoteSW directory (two .gcd and one .bin files) I've updated the 255W using Garmin Express; dodge a brick event because I was downloading the non-MTK version and almost did manual update with it (HWID was 1091)

[Butters]

Sorry no sarcasm, I must focus and get this done ASAP. On my 255W under Garmin\Diag directory there are 3 files: FT.bin, GarminError.xml, sys_log1.bin
GarminError.xml file contained data:
<PCB>nuvi 2W series S2 V4 2GB
that is in conflict of what is shown in the diagnostic screen (S4 board)
What does this mean?

Not sure it's a direct conflict as such, rather it's more an example of using conflicting [or inconsistent] terms. Maybe someone else can comment more learnedly on that.

The only .gcd files before the update are under the Garmin\RemoteSW directory (two .gcd and one .bin files)

Only the GCD file in your 255W's Garmin folder is to do with the main system software (firmware). The RemoteSW folder's files update other minor software.

I've updated the 255W using Garmin Express; dodge a brick event because I was downloading the non-MTK version and almost did manual update with it (HWID was 1091)

That's why it so important to name the RGN file safely. i.e. XXXX01000xxx.rgn where XXXX is the contained firmware's HWID (should be the same as the device's correct HWID) and xxx is the fw version. If Updater.exe detects that the device HWID differs to the one in that naming convention it will stall and report 'no update available'. Other naming, such as out.rgn or even leaving one of the central digits out will result in a forced flash. Handy for sensible modding but disastrous if used indiscriminately.

Maybe a Mod will move these posts to a Discussion thread as they're OT here and your "coder-level" question will get better attention from the right ppl.
Above posts moved from thread: [Only registered and activated users can see links. ]

[osiris4isis]

I was going to manually obtained the .gcd file and do the update. I'd picked non-MTK because I didn't know what my 255W was. Only after I decided to be "safe" and use Garmin Express that it picked the "correct" file. I did post analysis and found out that the unit was MTK based on HWID from .xml !!!
Lets say after identifying the unit and getting the .gcd file from perry, what do I do next to update the unit? Do I have to convert it to .rgn and use Updater.exe? Or can I update the .gcd file directory by just putting it under Garmin directory and reboot? Which method is "safer?"

[Butters]

Using a safely-named RGN and Updater.exe is less risky than using a GCD imho.

[osiris4isis]

Given a HWID, how do I find out what device it is? How do I know 1091 is nuvi255W_MTK and 872 is nuvi255W?