Google recently started rolling out Android 4.2.1 (Jelly Bean) OTA update (Over-The-Air) for it’s Nexus series of devices (Nexus 4, 7, 10 and Galaxy Nexus). Every Android update brings a new challenge to the Android community developers, to push out a root access patch for the latest version as early as possible, so that the users who’re installing those updates on their device could enjoy the benefits without much delay. Fortunately, it didn’t take them long to gain root access successfully on the Nexus devices, updated to the latest Android version 4.2.1. The method involves flashing a custom recovery image, and installing SuperUser binaries on the device. Here’s how you could do it on your device.
NOTE: This method has been tested successfully on many devices, but any method that involves flashing always bear the risk of bricking your device, no matter how proven or safe the method is. If you plan to proceed with flashing your device by following the instructions given below, please do it at your own risk. We can’t be held responsible if something happens to your device.
Step 1: Check for Prerequisites
Before Rooting your Android 4.2.1 powered Nexus device, you need to make sure you have a few things already in place.
- Bootloader on your device should be unlocked. If you haven’t, you may follow the instructions here to unlock bootloader (same for all Nexus devices). Unlocking bootloader voids your device warranty, but so does rooting. However, there’s also a way to re-lock bootloader (instructions on the same page).
- Backup your Data (Contacts, SMS, Call Logs, Wireless/APN Settings etc.) in-case something goes wrong.
- At least 70-80% remaining charge on your device.
- Android USB Debugging mode should be enabled on your device (Settings >> Developer Options >> USB Debugging)
Step 2: Download Files
You need to download a few files, and install/extract them before proceeding further.
- Download and Install Android SDK on your computer.
- Download SuperSU binaries ZIP file.
- Download and extract Fastboot in “platform-tools” directory of your Android SDK.
- Download and extract ClockworkMod Recovery image in “platform-tools” directory of your Android SDK.
Step 3: Place SuperSU binaries on device
Connect your Nexus device to your PC using the USB cable, and copy the SuperSU binaries ZIP file, you downloaded, to the root location of your internal memory. Now, reboot your device (still connected to PC) into the bootloader mode, by pressing the Volume Down and Power button at the same time, for a few seconds.
Step 4: Flash ClockworkMod Recovery
Now, open Command Prompt on your PC (Terminal on Linux), and navigate to the platform-tools directory of your Android SDK. Run the following command (assuming you didn’t change the filename of the recovery image)
fastboot flash recovery recovery-clockwork-220.127.116.11-grouper.img
Step 5: Flash SuperSU binaries using ClockworkMod Recovery
After you’ve flashed ClockworkMod Recovery by executing the command in the previous step, select “Recovery” from Fastboot menu on your device. That’ll take you to the ClockworkMod screen (Use Volume Up/Down for navigation, and Power key to select).
Now, select “Install ZIP from SD Card”, followed by “Choose ZIP from SD Card”. Navigate to the SuperSU ZIP file, and select it (using Power key). Confirm your selection on the next screen, to flash the file on your device. After flashing, “Go back” to the ClockworkMod menu, and select “Reboot System now” to reboot your device.
And, that’s it. If everything goes as per the above steps, you’ve successfully gained root access on your Android 4.2.1 powered Nexus device.