Patched firmwares for JNX files

AlexWhiter · 25th October 2011, 10:01 AM

I'm afraid I'm not too good in the cryptography.
When (or if) the public keys used to produce valid GMA certificates are made available, we'll surely can use them.

But if you mean to change the RSA key in the firmware itself, then this requires the patching anyway.
And the current JNX loader patching gives us more flexible solution, because it allows loading of both "official" JNX (created in BaseCamp for the activated devices), and of the hand-made ones, independetly of their signatures, CRCs etc.

**kunix** · 25th October 2011, 10:27 AM

Loader patch is good. But is the signature invariant across various devices and firmware versions?
As opposite, RSA public key signature should be the same everywhere, it's a big fat plus. Of course original JNX would have to be re-signed with new private key to work correctly with new public key.
Okay, don't pay too much attention, I'm just dreaming.

**radiopelissanne** · 9th November 2011, 11:28 PM

Can someone help me. I am a little afraid of patching my new gpsmap 62sc because of the warranty.I have FW 2.40.I am not sure having very well understood how to do:I put the patched gupdate.gcd in garmin folder, and after I switch on the gps without usb cable. And if I want to come back to the non patched firmware, I replace patched gupdate.gcd with the non patched gupdate.gcd. Is it right or wrong? Is there anything else to do?
Thanks for your help

**angelozip** · 10th November 2011, 02:28 AM

The procedure is correct. Before changing the FW, save a copy of your gupdate.gcd version 2.40. I also recommend that before you change the fw, update your 62sc to the latest version 2.60 by webupdater. Before removing the cable to reinitializes it, applies the firmwarepathcher in gupdade.gcd that you just downloaded. Then remove the cable and reboot the machine to the upgrade. If you need to return to the original for some reason, for example, to take technical assistance, simply replace the original gupdate.gcd in Garmin folder and restart the gps for to the original fw. It's a simple process ..

**radiopelissanne** · 10th November 2011, 10:07 AM

Originally Posted by angelozip

The procedure is correct. Before changing the FW, save a copy of your gupdate.gcd version 2.40. I also recommend that before you change the fw, update your 62sc to the latest version 2.60 by webupdater. Before removing the cable to reinitializes it, applies the firmwarepathcher in gupdade.gcd that you just downloaded. Then remove the cable and reboot the machine to the upgrade. If you need to return to the original for some reason, for example, to take technical assistance, simply replace the original gupdate.gcd in Garmin folder and restart the gps for to the original fw. It's a simple process ..

Thanks for your answer. It's clear. But if I patch the 2.60 fw, does the firware patcher give a new number of the version or not. If not, when I return to the original version, with the same number in gupdate.gcd, does it works also.

**angelozip** · 10th November 2011, 03:36 PM

The fimwarepather v2.9 offers the option to change the firmware version, for example 2.59, considering that you have already installed the 2.60. To automatically update to the original version 2.60 simply update directly from the Garmin WebUpdater. This procedure is even easier than suggested in the previous post.

**radiopelissanne** · 10th November 2011, 09:44 PM

I have first tried to patch fw 2.40: if I don't check "adjust firmware version", no upgrade. If I put "1", it's good: "patched firmware" appears in the gps, and I can load jnx files in the birdseye folder, they appear activated in "digital globe" with demo.jnx. It's marvellous for me. I also tried to downgrade to original gupdate 2.40. It works, but the data is lost. No matter. Now, I'll try with fw 2.60, but I am not yet sure that firmwarepatcher v2.90 works with it, in order to see jnx files.
Great thanks

**radiopelissanne** · 11th November 2011, 10:24 AM

FW 2.60 in GPSMAP 62SC patched with Firmwarepatcher 2.90 works nice. I must only adjust the firmware version in it. But, if I downgrade to original version, I don't understand why all the maps which are on my 8gb SD card as desactivated become activated, so it take quite a long time to load.