How to prevent installation of a new firmware

Discussion related to the Garmin GPSMAP 66s/st GPSr
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g66
Posts: 135
Joined: Wed Jul 03, 2019 1:48 pm

How to prevent installation of a new firmware

Unread post by g66 »

Did someone try to rename a textfile to gupdate.gcd

It should not work, but will not overwrite with a newer version

Or is there any other trick.

As my unit is BT-Connected, update will be loaded automatically :roll:
Art
Posts: 83
Joined: Sat Nov 10, 2018 9:14 am

Re: How to prevent installation of a new firmware

Unread post by Art »

By editing the file GarminDevice.xml to reflect a much higher firmware version than will ever become available prevents Garmin Webupdater ever writing a new firmware file to the unit. I don’t know if this would affect a BT connection.
I have an SD card pretending to be a garmin device with fw version 5.00 so it will always get the latest update.<SoftwareVersion>500</SoftwareVersion>

This won’t stop the unit asking you if you want to update if a GUPDATE.GCD file somehow does make it onto the unit.
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GPSrChive
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Re: How to prevent installation of a new firmware

Unread post by GPSrChive »

Unfortunately, the GarminDevice.xml file is re-written every time the device boots.
g66
Posts: 135
Joined: Wed Jul 03, 2019 1:48 pm

Re: How to prevent installation of a new firmware

Unread post by g66 »

I know there is an option if i upgrade with a
gupdate.gcd
version modified by a patcher and the version is much higher afterwareds.

But i do not know how to downgrade.
Is there an option to downgrade?
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GPSrChive
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Re: How to prevent installation of a new firmware

Unread post by GPSrChive »

You can load any version firmware version GCD file you like, and the GPSr will install it. However, when installing a firmware older than what is currently on the device, all settings will be reset to factory defaults.
g66
Posts: 135
Joined: Wed Jul 03, 2019 1:48 pm

Re: How to prevent installation of a new firmware

Unread post by g66 »

Oh yes, i remember now - forgot this info already :roll:
Thank you!
Art
Posts: 83
Joined: Sat Nov 10, 2018 9:14 am

Re: How to prevent installation of a new firmware

Unread post by Art »

At the time of writing... August 22,
If you make 10.20 firmware look like 10.30, and write that to the device, then when 10.30 really comes out you don’t
get asked by the device if you want to update (or downgrade) to the same version firmware....
but you have a problem when the real 10.40 comes out, is that right? :D
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GPSrChive
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Re: How to prevent installation of a new firmware

Unread post by GPSrChive »

No problem, anything above 10.30 will load.
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