Recently, the Galaxy S2 I9100G received a flurry of Android 4.2.2 custom ROMs including CyanogenMod 10.1 (CM10.1) Nightly ROM, AOKP Build 4 ROM and Vanilla RootBox ROM, with due credit to industrious Android custom ROM developers. As Samsung is unlikely to release any further Jelly Bean updates for its Galaxy series anytime soon, users may try their hands on the latest Android 4.2.2 custom firmware based on a highly stable CM10.1 M2 ROM.

Key Points to Note

  • CyanogenMod 10.1 M2 ROM and the instructions given in this guide are applicable to the Galaxy S2 I9100G model only and will not work on any other device. Verify the device's model number by navigating to Settings > About Phone.
  • Verify that the correct USB drivers are installed for the Galaxy S2 on computer (download USB drivers).
  • Back up important data and settings on the phone to avoid unexpected data loss during firmware installation. It is recommended that you use either ClockworkMod (CWM) or TWRP recovery for data backup, as it creates a complete image of the existing phone setup.
  • Make sure that the device is rooted with CWM recovery installed.
  • Ensure that USB Debugging 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 do the following steps:
    • Go to Settings > About Phone
    • Scroll down to the bottom and select Build Number.
    • Now, tap the Build Number for seven times to unlock or reveal the hidden Developer Options under Settings. Then enable or select the checkbox for USB Debugging mode under Settings > Developer Options.
  • Verify that the phone has at least 85 percent battery charge to prevent unexpected device shutdown during firmware installation.
  • Do a Dalvik Cache Wipe before continuing from Recovery mode.
  • Samsung KIES will not recognise your device after installing Android 4.2.2 CM10.1 M2 ROM, as it is a custom release.
  • The instructions provided in this guide are meant for reference purpose only. IBTimes UK will not be held liable if you damage or brick your device during or after firmware installation. Users must proceed at their own risk.

How to Install Android 4.2.2 Jelly Bean Update on Galaxy S2 I9100G with CyanogenMod 10.1 M2 ROM

Step 1 - Download Android 4.2.2 CM10.1 M2 ROM and Google Apps for Galaxy S2 I9100G on your computer.

Step 2 - Connect and mount the Galaxy S2 USB mass storage on computer with the USB cable.

Step 3 - Without extracting, copy the downloaded CyanogenMod 10.1 M2 ROM and Google Apps zip files to the root folder of your phone's SD card.

Step 4 - Power off the phone and disconnect its USB cable from computer.

Step 5 - Press and hold Volume Up, Menu and Power buttons together until the device boots into Recovery mode.

Step 6 - In ClockworkMod recovery, do a full data wipe first. Then navigate to Flash zip from SD card option and hit the Power button to choose it.

Step 7 - Tap the Power button again and click Choose zip from SD card.

Step 8 - Use the volume keys to navigate to Android 4.2.2 CM10.1 ROM zip file that you copied earlier to your phone's SD card and select it by tapping the Power button. Confirm the ROM installation on the next screen and the installation process will begin.

NOTE: Repeat this step for installing Google Apps as well.

Step 9 - Once the ROM is completely installed, hit Go Back and reboot the phone by clicking Reboot System Now in the Recovery menu. The phone will reboot and its first boot may take about five minutes to complete. So, please be patient.

The Galaxy S2 I9100G is now successfully updated to Android 4.2.2 Jelly Bean via CyanogenMod 10.1 M2 ROM. Go to Settings > About Phone to verify the firmware version installed.

[Source: Team Android]