Sony recently rolled out the Android 4.1.2 Jelly Bean update, with base firmware 12.0.A.2.245 for HSPA+ and LTE variants of the Xperia SP with model number C5302 and C5303 respectively.

The official build brings several notable features including a transparent notification bar/menu bar, a few settings in the notification bar, new UI, and a number of small apps. Besides, it addresses bug issues spotted in the previous firmware update. 

Xperia SP
Sony has released Android 4.1.2 software update for Xperia SP.

Click here for our guide to install Android 4.1.2 (12.0.A.2.245) Jelly Bean on Xperia SP  

Xperia SP users who wish to root their devices running on Android 4.1.2 may follow our step-by-step guide. The tutorial uses kernel with root file released by senior XDA member, alivanov79.

Kernel root file features

zImage 12.0.A.2.245

Insecure ramdisk

Autoroot

init.d

busybox

/rootfs and /system mounted as rw

Persistent adb

IBTimes UK reminds its readers that it will not be held responsible for any damage to the device. Users are also advised to verify that their devices meet the following requirements.  

Pre-requisites

1) Install USB Driver for Sony Xperia SP to connect the Android device with computer.

2) Enable USB Debugging Mode on phone to connect it with computer and use Android SDK with it. [Press Menu>> Settings>> Applications. From there navigate and click on Development option then check USB Debugging Mode.]  

3) As the tutorial might wipe out all data of the phone, create a backup. If the device is having any custom recoveries such as CWM/TWRP already installed then backup data using recovery.  

4) The bootloader of Xperia SP should be unlocked. Head over to Sony official site for instructions to unlock bootloader.     

5) The phone should have above 80% of battery charge. 

6) Rooting the phone will void of its manufacturer's warranty. Users can reclaim the warranty by unrooting the device later. 

7) The kernel with root file work only on Sony Xperia SP running on Android 4.1.2 (12.0.A.2.245) Jelly Bean. As, flashing this on incorrect variant might brick the device, verify the model number of device by navigating to Settings>> About device>> Model number.    

Steps to root Sony Xperia SP on Android 4.1.2 (12.0.A.2.245) Jelly Bean

Step-1: Download stock kernel with root for Xperia SP to the computer

File name: kernel.elf [900MB]

Step-2: Set up fastboot in the computer [Click here for a guide to setup ADB and Fastboot driver with Android SDK.]  

Step-3: Copy adb.exe, AdbWinApi.dll from C:android-sdk-windowsplatform-tools and fastboot.exe in C: android-sdk-windowstools to a new folder at the desktop. Rename it as fastboot

Step-4: Copy the downloaded kernel.elf file to the fastboot folder on desktop

Step-5: Switch off the phone

Step-6: Enter Fastboot Mode by connecting the phone to the computer using USB cable while pressing Volume Up button

Step-7: Open Command Prompt windows in the computer [To open Command Prompt, go to Windows logo then type CMD in search box and press Enter.]

Step-8: Type cd C:fastboot in the command prompt windows to navigate to the fastboot folder

Step-9: Type fastboot flash boot kernel.elf to flash the kernel file on the phone

Step-10: Press and hold Power button to turn off the phone  

Provided all the aforementioned instructions are followed strictly, the Xperia SP should now be rooted successfully on Android 4.1.2 (12.0.A.2.245) Jelly Bean official firmware.

[Source: Android Teen