Samsung recently rolled out its latest Android 4.1.2 (Jelly Bean) based XWLSN official firmware for Galaxy S2 I9100 users. The new official firmware is a follow-up release to XWLSJ official firmware that was released a few days ago.

Galaxy S2 users who have already updated their device to the official firmware can now root their phones using the Siyah Kernel Root package with this guide. The package includes ClockworkMod (CWM) recovery with auto-installation option, and hence a separate installation for it is not needed. The root method used in this guide makes use of ODIN flash tool, and so the use of CWM recovery is limited to data backup purpose only.

Galaxy S2 I9100
How to Root Galaxy S2 I9100 on Official Android 4.1.2 XWLSN Jelly Bean Firmware

Note: Siyah Kernel Root package and the instructions provided in this guide are meant for reference purpose only. IBTimes UK will not be held liable if the device is damaged during or after the root installation. Users are advised to proceed at their own risk.


  • Siyah Kernel Root package and the instructions given in this guide are limited to the international variant Galaxy S2 I9100 model only and will not work on any other device. Verify the device's model number by navigating to Settings > About Phone.
  • Back up important data and settings on phone using one of the recommended custom recovery tools such as ClockworkMod (CWM) or TWRP, as it creates a complete image of the existing phone setup.
  • Make sure that the phone has at least 80 per cent battery charge to prevent unexpected device shutdown (due to battery drain) during firmware installation, as this may inadvertently brick or damage the device.
  • Verify that the correct USB drivers are installed for the phone on computer (download Samsung Galaxy S2 I9100 USB drivers).
  • Ensure that USB Debugging mode is enabled on the phone navigating to Settings > Developer Options (if the device is running on Android 4.0 or later) or Settings > Applications > Development (if the phone is running on Android 2.3 or earlier).
  • Double check to see that the device is factory unlocked (not locked to a specific carrier) with CWM recovery installed on it.

How to Root Galaxy S2 I9100 on Official Android 4.1.2 XWLSN Jelly Bean Firmware

Galaxy S2 I9100
How to Root Galaxy S2 I9100 on Official Android 4.1.2 XWLSN Jelly Bean Firmware.

Step 1 - Download Siyah Kernel Root I9100XWLSN for Galaxy S2 on the computer.

Step 2 - Download ODIN v1.85 which is needed to root the official firmware on the phone.

Step 3 - Power off the phone and boot it into Download Mode by pressing and holding Volume Down, Home and Power buttons together, until the construction Android robot icon with a triangle appears on screen. Hit the Power button again to confirm entry into Download Mode.

Step 4 - Launch ODIN on computer and connect the phone to it while the phone is still in Download Mode.

Step 5 - When the phone connects successfully, one of the ID: COM boxes will indicate yellow with the corresponding COM port number. This process may take about five minutes. So, leave it alone.

Step 6 - Choose the files that must be flashed or installed on the phone, which can be found among the downloaded files in Step 1.

  • Select the 'PDA' checkbox and click the file 'Siyah-s2-v6.0b4.tar'.

Step 7 - In ODIN, enable Auto Reboot and F. Reset Time options.

Step 8 - Hit Start button in ODIN and the root installation process will begin. This will take just a few minutes to complete.

Step 9 - Once the root installation process completes, the phone will automatically reboot. Finally, when the home screen appears, just disconnect the phone from computer.

Samsung Galaxy S2 I9100 is now rooted on official Android 4.1.2 XWLSN Jelly Bean firmware. Check for the Superuser app in the phone's apps list to verify if root installation is successful. Alternatively, download and install Root Checker app (click to download) from Google Play Store to confirm root access to the phone is working correctly.

[Source: Team Android]