Kill the kill switch - "ST - yy"

[Bogdacutu]

So I just need to delete the file right? I do not need to flash any custom recovery just the root the device right? If I may ask what is the path that I need to delete? thank you very much for this finding

You need to delete /system/app/TegraOTA (the entire folder).

 

[Shorty88jr]

Yes, but the OTA will reinstall TegraOTA, so you'll probably want to run my ZIP again afterwards

Ok I can easily do that. You are awesome not only did you find out how to stop the brick but you also fixed a security flaw

 

[Bogdacutu]

For those who are bricked, and since the APX drivers are not available.. would running Kali Linux distro or Wheelie help at all? perhaps going dirty with GRUB? save any chance of reviving a dead tablet?

APX drivers are available, but they aren't of much use, since nvflash requires the SBK which only Nvidia has. (and afaik wheelie doesn't work on our device, and even if it did, wheelie requires the device to work first so that it can get some blob from it)

 

[sinichi21]

You need to delete /system/app/TegraOTA (the entire folder).

so just delete the tegraOTA.apk right then that's it no more anything else

 

[Bogdacutu]

so just delete the tegraOTA.apk right then that's it no more anything else

Yes (forgot to mention that on KitKat system apps don't each have their own folder)

 

[Dashwood Foxe]

APX drivers are available, but they aren't of much use, since nvflash requires the SBK which only Nvidia has. (and afaik wheelie doesn't work on our device, and even if it did, wheelie requires the device to work first so that it can get some blob from it)

Not even Kali Linux or GRUB? If you'd like, I can throw my tablet into APX mode and see if I can get Kali to recognize (I find it hard for kali to not recognize anything since the distro can recognize a piece of rock and get it somehow to run.)

 

[Bogdacutu]

Not even Kali Linux or GRUB?

GRUB is a Linux bootloader that doesn't really have anything to do with our device (since first off it doesn't run on our device, and second, even if it did, you can't flash it because you can't get into fastboot), and Kali is just a Linux distro with some "hacking" tools preinstalled. So no, not really.

 

[Dashwood Foxe]

Well worst comes to worst, I use my new tablet.. and seal away my old one until the "OTA death package" ceases distribution.

 

[bluegizmo83]

Is there any way to get QuickCharge 2.0 working again on the new tablets? Ever since the 5.1.1 update from Nvidia on the old tablet (and now on the new tablet running 5.1.1) my quickcharge 2.0 charger is not charging at the faster rate anymore.

 

[Shorty88jr]

So this just deletes the file that contains the stuff for OTA updates which stops the kill switch correct? If it only removes the files but does not keep them from being installed what keeps Nvidia from updating a app for the tablet say the shield hub for example to add the files back to the tablet then kill the tablet?

 

[Dashwood Foxe]

Is there any way to get QuickCharge 2.0 working again on the new tablets? Ever since the 5.1.1 update from Nvidia on the old tablet (and now on the new tablet running 5.1.1) my quickcharge 2.0 charger is not charging at the faster rate anymore.

I believe Bogdacutu mentioned this feature was disabled since was it... 2.0? He looked into the source code of sorts which included a devnote from nvidia mentioning that QC was disabled to keep batteries from ballooning.

 

[bluegizmo83]

I believe Bogdacutu mentioned this feature was disabled since was it... 2.0? He looked into the source code of sorts which included a devnote from nvidia mentioning that QC was disabled to keep batteries from ballooning.

That could very well be.. Before the recall was announced I beleieve I was still running 2.0 or earlier, and then when I updated for recall is when I lost quickcharge... My battery never got even warm when using it though.

 

[Bogdacutu]

Well worst comes to worst, I use my new tablet.. and seal away my old one until the "OTA death package" ceases distribution.

If your old tablet was already hit by the OTA, it's too late

So this just deletes the file that contains the stuff for OTA updates which stops the kill switch correct? If it only removes the files but does not keep them from being installed what keeps Nvidia from updating a app for the tablet say the shield hub for example to add the files back to the tablet then kill the tablet?

Permissions. Theoretically, other apps don't have the permission to just download and install OTAs whenever they want.

 

[sinichi21]

Yes (forgot to mention that on KitKat system apps don't each have their own folder)

Thanks man your right I have forgot that on 5.0 and up all the system apk have there respective forlder now, I just rooted with king root 4.5 now with breezed and delete the whole folder tegraOTA folder along with the apk inside it. Thanks hope we are right about this and preserve our tablet.

 

[koop1955]

@Bogdacutu, thank you for all the work and research that you have put into this.
Great work.

 

[Bogdacutu]

I believe Bogdacutu mentioned this feature was disabled since was it... 2.0? He looked into the source code of sorts which included a devnote from nvidia mentioning that QC was disabled to keep batteries from ballooning.

Not sure of the exact version where it was disabled, but in any case here's the kernel commit that confirms it: http://nv-tegra.nvidia.com/gitweb/?...it;h=1d4f619763d3366e803a99927dbb80e751147641

 

[Dashwood Foxe]

If your old tablet was already hit by the OTA, it's too late

Old tablet still functional and kicking, I flashed your "fix" as a preventative measure. just in case. I may power down this tablet and retire her until a later time when it's safe.

Great work by the way getting this looked at with such attention to details.

Now if we can get a hold of the SBK... or someone talented enough to compile one..

 

[Shorty88jr]

If your old tablet was already hit by the OTA, it's too late



Permissions. Theoretically, other apps don't have the permission to just download and install OTAs whenever they want.

I am not talking about OTA files I am talking about reinstalling the files for the Nvidia OTA application. They could add a download that checks if the folder is there and if it's not it creates it. Apps are allowed to create file or folders and if it was there it could be enough to start the OTA update system. Maybe that's a really crazy scenario but if they couldn't get the files restored they could ask google to allow them to link a file in the app that kills the tablet when the app is updated.

 

[Bogdacutu]

Now if we can get a hold of the SBK... or someone talented enough to compile one..

The Secure Boot Key (SBK) is device-specific and burned onto the chip when it's fabricated, and can only be read by the hardware AES engine (which will gladly encrypt/decrypt for you, but won't give you the actual key), so I doubt that will happen anytime soon. We can still hope though

 

[Jackill]

As mentioned in the OP, the update doesn't get delivered immediately after you activate the new tablet. But yes, the old tablet shouldn't get the update before the new one is activated.

I think that might be also something triggered by the delivery company. Most of the replacements are delivered by UPS...so UPS knows exactly when each of the replacements were delivered...they tell nvidia "hey serial 123456 is now delivered", nvidia adds 2-5 days and triggers the switch...