[Shield Tablet General] Kasimodo:
Best way to update your K1 to 1.2 without loosing anything

For those who have deleted their TegraOTA.apk file, you could get it there

Just copy it into folder "/system/priv-app/TegraOTA/" (if folder TegraOTA doesn't exist anymore, just create it).

Then reboot your Tablet K1...

Prerequisites:

1. K1 is rooted.

2. K1 has TWRP custom recovery installed.

If you used "fastboot boot twrp-20151227-EXPERIMENTAL-shieldtablet-m.img" to root your tablet, before starting, you have to flash it with command "fastboot flash recovery twrp-20151227-EXPERIMENTAL-shieldtablet-m.img"

3. File manager (e.g. Total Commander).

FYI, i've tried with ES Exlorer with root access, and I was unabled to find the update file! So just download "Total Commander" on Google Play Store.

4. supersubeta.zip on your K1.

Update procedure:

1. Go to “System upgrade” menu screen (Settings->About tablet->System upgrade)

2. Enable full update image download. In the “System upgrade” menu window press dots on the far upper right corner and select “Advanced”. In the new meniu screen check the option “Check full upgrade”. Go back to previous screen.

3. Let the “System upgrade” window download the latest ROM image (1.2 was about 668 MB). When the file is downloaded, DOT NOT PRESS REBOOT/INSTALL.

4. OTA downloaded update files are stored deep in the system. You need to know where the downloaded OTA update file has landed. Open your file manager and navigate to “/data/data/com.nvidia.ota/app_download”. There you will find the downloaded OTA update zip file. Check for the size (it should around 668 MB in case of 1.2 update).

5. Move this file to a more manageable location, e.g. your downloads folder “/storage/emulated/0/download”.

6. Reboot K1 into TWRP recovery.

You have 2 choices. I prefere choice "b".

a. Press the power button on your K1, select “Reboot”. As soon as the screen goes dark, press Volume Down button on your K1. When the K1 has booted into black screen with small letters, navigate with Volume Down button to the meniu item “Recovery” and select it by pressing Power button on K1.

OR

b. if you are afraid to miss the recovery reboot, just install Quick Reboot from PhongIT

7. K1 reboots to the TWRP recovery.

8. Select “Install”. Navigate to the OTA downloaded zip file, which you copied/moved to the directory “/storage/emulated/0/download”.

9. Select that file. The tablet will seem to freeze, but it’s not. But if you will not touch the screen, the K1 will lock the screen. So, while the K1 is thinking, keep touching the screen in various places until you see a new menu with a slider to install the zip file.

10. When you see a menu with slider, slide it to the right to install the new ROM.

11. After the install is complete, select “Wipe cache/Dalvik cache” on the left.

12. After that, do not reboot the tablet yet. Navigate back to the install screen.

13. Select your “supersubeta.zip” file and install SuperSu binaries.

14. After that, reboot the tablet.

15. You could see that message from Nvidia asking for installing OTA 1.2 is always there. So, with your file explorer with root access, just rename "/system/priv-app/TegraOTA/TegraOTA.apk" to "/system/priv-app/TegraOTA/TegraOTA.apk.old"

16. If all went well, first boot should show it’s optimising Apps. It means, you successfully update your tablet. After the boot, check if SuperSu is present. If not, repeat the procedure into going to Recovery mode and installing the supersu.zip file again.

17. If you used xposed framework, it is no more enabled since update. So go back to TWRP recovery and flash "xposed-v81-sdk23-arm.zip"

18. Reboot to system.

Enjoy!

This tutorial was written by 0x6170 on Nvidia Shield Zone. I've just tested it successfully and report it there with some additions for Noobs like me ;)