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  1. #1
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    Default Garmin encrypted firmwares - any details known?

    Garmin started to encrypt their firmware files. It started with the MARQ/Fenix updates and now also the firmware for the zumo XT is encrypted. Does anybody know anything about that? The MARQ/Fenixes encrypted binaries (inside the GCD) all start with 28 xx xx xx where the xx might indicate something. After that, the encrypted(?) firmware follows.

    The zumo XT update now breaks with the GCD/RGN tradition and is a file *.update.signed which is actually a tar archive that contains various encrypted files. Only the file "version" is readable and contains the firmware version.

    Any more info is appreciated!

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  3. #2
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    Thank' s for this information. I have a securitycopy of a B306500.update file (version is 6.4) for my Drive Smart 65 -D. Now i want downgrade the firmware from 8.7 to this older version. Have you informations, how i must proceed for downgrade ?. Can i copy the old file to replace the actualy file ? or will this breack the device ?
    additionaly i search version 7.* of file B306500.update.
    I have noticed, that filename is always the same for this device, only Filesize differs..

  4. #3
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    Quote Originally Posted by mbirth View Post
    The MARQ/Fenixes encrypted binaries (inside the GCD) all start with 28 xx xx xx where the xx might indicate something.
    The first four bytes are the length of the remaining file, i.e. this number + 4 is the total file length.

 

 

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