Thread: GCD RGN firmware update file differences

What device? For example, Oregon 6x0 is explained in Firmware page [Only registered and activated users can see links. ].

On garmin astro 220 and 320

I am not familiar with the Astro units. Hopefully someone else can help!

Originally Posted by gvp

1. what's the difference between these two file formats (when we use each one)

In simple terms they share common components or sections, in that both contain the same BIN files. A GCD file also contains additional data which tells the device to commence writing the BIN files to the relevant regions. For instance, fw_all.bin is flashed to region 14 (hex 0E). An RGN file on the other hand needs to be flashed manually using Updater.exe to write the BIN files to regions. Some very old Garmin devices which don't have access to Mass Storage Mode must be flashed with an RGN file either directly or using an EXE file which contains the relevant files.

GCD and RGN files can easily be converted from one to the other using RGN_Tool.exe or gfw.exe.

2. how we upgrade the unit using the one file and the other ?

A GCD file can be loaded to the device using WebUpdater or you may place the gupdate.gcd manually into the device's Garmin folder or, if there is a card slot, place it on a suitable media card in a Garmin root folder. The second and third methods require the file naming be 'gupdate', the first it doesn't matter provided the extension is ".gcd". Provided the device determines that the firmware version contained in the GCD file is newer than the version presently used by the device then it will flash the newer version on the next re-start.

An RGN file can only be flashed using Updater.exe with the device in preboot mode. Care must be taken with the naming of the file. Safe naming is XXXX01000xxx.rgn where 'XXXX' is the HWID of the firmware and 'xxx' is the SW Version (firmware version). Using that naming convention, should the firmware HWID and the device HWID differ then the flash will not proceed. In the case of Astro 320 firmware version 4.60 the safe naming would be 133901000460.rgn for example. Any other naming, out.rgn or even 13390100460.rgn, may force the flash regardless of a HWID mismatch. At worst that may unintentionally hard-brick the device.

A third method of flashing when a device has a card slot is utilising a card to flash the individual BIN files to the relevant regions via Ldr.bin (the boot.bin renamed) initiating commands in a file named Update.txt. That is often referred to as an "SD flash kit" or similar. The making of such kits is only for more advance users because the potential of permanent hard-bricking is high. Using the wrong boot.bin to make such a kit will usually end in disaster. More here on how this method works: [Only registered and activated users can see links. ].