Samsung rolled out yet another official Jelly Bean firmware, Android 4.1.2 UHMS9, for the Galaxy S2 I9100 just a while ago. S2 users who have already updated to the aforementioned official firmware can now root their device using this guide. The root method used in this guide employs ODIN flash tool along with Siyah Kernel to install root access on the device. However, the root package will also automatically install ClockworkMod (CWM) recovery, as part of the installation.

It is imperative to root the phone, as root access is lost soon after installing the official firmware. In addition, root access is essential for installing third-party root apps, custom ROMs and latest system tweaks on the Galaxy S2.

NOTE: Although the newly released Android 4.1.2 UHMS9 firmware is officially meant for Russia, it can still be installed and rooted on any unlocked Galaxy S2 I9100, as the firmware itself is not carrier dependent. Check out our step-by-step guide to install Android 4.1.2 UHMS9 official firmware on Galaxy S2 I9100 here.

Key Points to Note

  • Siyah Root Kernel and the instructions given in this guide are compatible with 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 the phone using one of the recommended custom recovery tools such as CWM or TWRP recovery, as it creates a complete image of the existing phone setup.
  • Verify that the correct USB drivers are installed for the Galaxy S2 on computer (download Galaxy S2 I9100 USB drivers)
  • Ensure that USBDebugging mode is enabled on the phone by navigating to Settings > Developer Options (if the device is running Android 4.0 or later) or go to Settings > Applications > Development (if the phone is running Android 2.3 or earlier). Otherwise, if the device is running Android 4.2, then perform the following steps:
    • Go to Settings > About Phone
    • Scroll down to the bottom of screen and select Build Number
    • Tap the Build Number seven times to unlock or reveal the hidden Developer Options under Settings. Then select the checkbox to enable USB Debugging mode under Settings > Developer Options.
  • Make sure that the device has at least 85 per cent battery charge
  • Verify that the phone is factory unlocked (not locked to a specific carrier) before proceeding with root installation
  • 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 the firmware installation. Users must proceed at their own risk.


How to Root Galaxy S2 I9100 on Official Android 4.1.2 UHMS9 Jelly Bean Firmware

Galaxy S2 I9100
Root Galaxy S2 I9100 on Official Android 4.1.2 UHMS9 Jelly Bean Firmware .

Step 1 - Power 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 confirm entry into Download Mode.

Step 2 - Launch ODIN on computer and connect the phone to it while the phone is still in Download Mode.

Step 3 - When the phone connects successfully, one of the ID: COM boxes indicates yellow with the corresponding COM port number. This step may be time-consuming (take about five to seven minutes). So, leave it alone.

Step 4 - Choose the files that need to be flashed or installed on the phone, which can be found among the downloaded files above.

  • Click the 'PDA' checkbox and choose the file 'Siyah-s2-v6.0b4.tar'.

Step 5 - In ODIN, enable Auto Reboot and F. Reset Time options.

Step 6 - Hit Start button in ODIN and the root installation process will begin. It should take just a few minutes to complete.

Step 7 - Once the root installation completes, the phone will reboot. Finally, when the home screen appears, disconnect the phone from computer.

Samsung Galaxy S2 I9100 is now rooted on latest Android 4.1.2 UHMS9 Jelly Bean official firmware. Check for the Superuser app in the phone's apps list to verify if the installation is successful.

To ensure that the installed root access is working correctly, verify with Root Checker app downloaded from Google Play Store.

[Source: Team Android]