An Android 4.1.2 (Jelly Bean) test firmware, XXLSJ, was recently leaked for the Samsung Galaxy S2 (I9100, international version). Now, XDA developer, CQNSTANT!NE, has released a custom ROM based on that leak, called Rainbox v5. This file is for the Galaxy S2 (I9100, international version) only. For a full list of new features and other relevant details, visit the development page.
Galaxy S2 users looking to update to the Rainbox ROM may follow this tutorial. IBTimes UK reminds its readers it will not be held responsible for damage to the device during installation.
- Ensure appropriate USB drivers are installed and enable USB debugging mode
- Ensure device is rooted and ClockWorkMod Recovery is installed
- Ensure back-up of all important data before proceeding
- Ensure battery carries at least 80 percent of charge
To Install Rainbox Android 4.1.2 (Jelly Bean) on Galaxy S2 I9100
- Download Android 4.1.2 Rainbox ROM to the computer
- Connect device to computer with USB cable and copy downloaded file to SD card in device, without extracting files
- Disconnect device and switch it off
- Re-start in Recovery mode (to do so, press Volume Up, Home and Power buttons until screen turns on. Alternatively, try entering Recovery mode without key combination)
- Perform Nandroid backup of existing ROM by selecting Backup and Restore and then the Backup option. Return to the main Recovery menu after the process is over
- Perform a data wipe by selecting Wipe Data/Factory Reset. Return to the main Recovery menu after the process is over
- Scroll to Install Zip from SD Card and select using Power. Press Power again to select Choose Zip from SD Card
- Now, browse to and locate Jelly Bean ROM saved earlier. Select using Power and confirm installation on next screen
- After installation, return to main Recovery menu and select Reboot System Now (the phone should boot into the customised Android 4.1.2 ROM but this step will take a few minutes)
- Note: To restore previous ROM, boot into Recovery, select Backup and Restore and select ROM from the list
The pre-rooted custom ROM, Rainbox (based on Android 4.1.2 (Jelly Bean)) firmware is now installed and running on the Samsung Galaxy S2. To ensure the rooted Rainbox ROM is correctly installed, verify root permission with Root Validator.
[Source: Android Jinn]