Samsung Galaxy S2 I9100G
Android 4.1.2 custom firmware based on Android 4.1.2 available for Galaxy S2 I9100G. Samsung

After the release of CM10 nightly builds, based on Android 4.1.1 (Jelly Bean), the CyanogenMod team has now announced Android 4.1.2 (Jelly Bean) custom firmware, based on CM10, for several Android devices. This CM10 custom firmware is based on the official Android 4.1.2 release and offers several tweaks, options and customised features not available in stock ROMs.

This guide instructs owners of the Samsung Galaxy S2 I9100G in updating their device with the Android 4.1.2 CM10 custom firmware. IBTimes UK reminds its readers it will not be held liable for any damage to the device during installation and asks all users to ensure their device meets the minimum pre-requisites, listed below.


  • Install USB drivers for Samsung Galaxy S2 and enable USB debugging mode
  • Ensure back-up of all important data
  • Ensure battery carries at least 80 percent charge
  • Ensure device is rooted and ClockWorkMod (CWM) Recovery is installed

To Install CM10 Android 4.1.2 on Samsung Galaxy S2 I9100G

  • Download CM10 Android 4.1.2 (Jelly Bean) ROM to computer
  • Download Google Apps package
  • Connect phone to computer with USB cable and copy both downloaded zip files to SD card on phone
  • Disconnect device and switch it off
  • Place phone in Recovery mode (to do so, re-start device by pressing Volume Up, Home and Power buttons together)
  • Perform Nandroid backup of existing ROM (to do so, select Backup And Restore > Backup, and then return to main Recovery menu)
  • Perform complete data wipe (to do so, select Wipe Data/Factory Reset and tap Yes to confirm action. This may take a few minutes
  • Use Volume keys to scroll to Install Zip from SD Card and use Power button to select option
  • Press Power again to select Choose Zip from SD Card and now browse to Android 4.1.2 zip file on SD card. Select using Power and confirm installation on next screen
  • After ROM is installed, repeat procedure to install Google Apps package
  • After installation, return to main Recovery menu and select Reboot System Now. The device will take a few minutes to boot
    • Note: If you ever wish to return to previous ROM, boot into Recovery, select Backup and restore ROM by selecting from the list

The Android 4.1.2 custom firmware, based on CM10, is now installed on the Samsung Galaxy S2 I9100G. Check firmware by browsing to Settings > About Phone.