Galaxy S2 I9100 users in China recently received the latest official Jelly Bean update via Android 4.1.2 ZSLSE firmware from Samsung. Though the firmware is officially meant for Chinese users, it can be downloaded and installed on any unlocked Galaxy S2 I9100, using our step-by-step guide posted here.

Those who have already upgraded their Galaxy S2 with the latest ZSLSE official firmware can now root their device using the Siyah Kernel Root Package with this guide. The root package employed in this guide uses ODIN flash tool, which will automatically install ClockworkMod recovery as part of the installation. So, there is no need to install any custom recovery tool separately.

How to Root Galaxy S2 I9100 on Official Android 4.1.2 ZSLSE Jelly Bean Firmware [TUTORIAL]
Root Galaxy S2 I9100 on Official Android 4.1.2 ZSLSE Jelly Bean Firmware

Why Should You Root

Rooting the phone is essential to regain full system access (Super User access), as root access to the device is lost soon after installing the official firmware. In addition, rooting enables the user to install third-party root-based apps, custom ROMs and latest system tweaks.

NOTE: Rooting the device will void its hardware warranty. Just re-install any official firmware to restore the device warranty. 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.

Key Features of Android 4.1.2 ZSLSE Official Firmware

  • Buttery Smooth Performance & Great Stability (Thanks to Project Butter)
  • Full User Interface Revamp (Same UI as of the Galaxy S III and Galaxy Note II)
  • TouchWiz Nature UX
  • Samsung's S Cloud services
  • Improved Camera features
  • New Lockscreen With Many Customization Options
  • New Features like Direct Call, Smart Stay and Pop-up Play
  • New Widgets (From Galaxy S III)
  • 2 Home screen modes
  • New Notification bar With More Notification Toggles
  • Google Now


  • Siyah Kernel Root Package and the instructions given in this guide are applicable to the international variant Galaxy S2 I9100 model only. Do not attempt this procedure on any other device, else it may permanently damage or brick the hardware. Verify the device's model number by navigating to Settings > About Phone.
  • Make sure that the device is already running the latest Android 4.1.2 ZSLSE Jelly Bean official firmware before proceeding with root procedure.
  • Verify that the correct USB drivers are installed for the phone on computer (download Samsung Galaxy S2 I9100 USB drivers)
  • Back up important data and settings on the 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.
  • Verify that the USB Debugging Mode is enabled on the phone by navigating to Settings > Developer Options (if the device is running on Android 4.0 or later) or go to Settings > Applications > Development (if the phone is running on Android 2.3 or earlier).
  • Make sure that the phone has at least 85 percent battery charge.
  • Ensure that the phone is factory unlocked and not locked to a specific carrier.

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

How to Root Galaxy S2 I9100 on Official Android 4.1.2 ZSLSE Jelly Bean Firmware [TUTORIAL]
Root Galaxy S2 I9100 on Official Android 4.1.2 ZSLSE Jelly Bean Firmware Using Siyah Root Kernel with ODIN v1.85

Step 1 - Download Siyah Root Kernel I9100ZSLSE for Galaxy S2 on the computer.

Step 2 - Download ODIN v1.85 which is necessary for rooting the official firmware on Samsung Galaxy S2 I9100.

Step 3 - Turn off the phone and boot it into Download Mode. To do so, press and hold Volume Down and Home buttons together, and then tap the Power button until the construction Android robot icon with a triangle appears on screen. Hit the Power button again to progress 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 indicates yellow with the corresponding COM port number. This process may be time-consuming. So, please be patient.

Step 6 -
Choose the files that need to be flashed or installed on the phone, which can be found in the downloaded zip file in Step 1.

  • Click the 'PDA' checkbox and choose 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. It would take just a few minutes to complete.

Step 9 - Once the root installation is complete, the phone will reboot. When the home screen appears, disconnect the phone from computer.

Samsung Galaxy S2 I9100 is now rooted on Android 4.1.2 ZSLSE official 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 from Google Play Store to ensure that root access to the phone is working correctly.

[Source: Team Android]