This post is about upgrading your Nexus 7 from any custom ROM or recovery in Jelly Bean 4.2.1 to 4.3 while keeping your root access intact. We do this by going through 4.2.2 in between.
The reason I start from 4.2.1 is because many people ( myself included) had not been able to get the OTA update from google to install automatically. I believe this is because of a change in the bootloader from 4.2.1 to 4.2.2. However I maybe wrong, so check that out and let me know as well if you wish.
I am assuming, that if you have rooted and flashed a ROM on your nexus through your recovery, you’ll find the following method very basic and easy. However I will elaborate it just in case it makes a difference to anyone.
Step 1: For those running 4.2.1
Check your build. if it’s 4.2.1, you need to flash the 4.2.2 zip.
You can grab the file here
To check if your ROM is odexed or not, install a root explorer go to /system/apps, if you see no .odex files there (.odex.bak don’t count), you’re running a deodexed ROM. you can download the deodexed file from the above link on to your storage, and flash it by going into your recovery, like you would flash any other zip.
Factory wipe isn’t necessary as your data will be preserved in this update. This basically saves you time as the real objective is to update to 4.3
Reboot into your system check your android version. It should be listed as 4.2.2
Step 2 : for those with 4.2.2
Again, you just need to flash a zip which will preserve your root.
grab your file from here
Or check out this page. It’s from the creator of these files.
It is important to do a factory reset and a wipe cache and wipe dalvik cache.After that flash the zip using your recovery.
Reboot into 4.3.
Use root checker to check root access.
It should be preserved.
PS- All credit to the developers of those two files. Make donations if it helps you.