Samsung Galaxy S2 I9100G
CM10.1 based on Android 4.2 custom ROM is available for Galaxy S2 I9100G. XDA Developers

XDA developer codeworkx has released a CM10.1 custom ROM for the Samsung Galaxy S2 (I9100G). The firmware is based on Android 4.2 (Jelly Bean) and is similar to an earlier release for the Nexus. It should be noted the release for the Galaxy S2 is an experimental build and bugs, therefore, are likely.

This is a tutorial to update the Galaxy S2 (I9100G) with CM10.1 Android 4.2 custom firmware. IBTimes UK reminds its readers it will not be held liable for any damage to the device during installation. The CM10.1 ROM is compatible only with Samsung Galaxy S2 I9100G.


  • Ensure appropriate USB drivers for the Samsung Galaxy S2 (I9100G) are installed and enable USB debugging mode
  • Ensure a back-up of all important data
  • Ensure device rooted and ClockWorkMod (CWM) Recovery is installed
  • Ensure device is running Ice Cream Sandwich (ICS) bootloaders [Note: If unsure, then flash official ICS ROM before proceeding]
  • Ensure battery has at least 80 percent charge

To Install CM10.1 Android 4.2 Firmware on Galaxy S2 (I9100G)

  • Download CM10.1 Android 4.2 ROM to computer (an alternative link can be found here)
  • Download Google apps package
  • Connect device to computer with USB cable and copy downloaded files to SD card [do not extract files]
  • Disconnect device and switch it off
  • Re-start in Recovery mode (to do so, press Volume Up, Home and Power buttons until screen flashes) / as an alternative, try entering Recovery without key combinations)
  • Perform Nandroid backup of existing ROM by selecting Backup and Restore and then Backup again and return to Recovery menu after backup is completed
  • Perform data wipe by selecting Wipe Data/Factory Reset and then select Yes on next screen to confirm action (wait till process is over and return to Recovery menu)
  • Select Install Zip from SD card using Power button and then select Choose Zip from SD Card to confirm installation
  • After installation of ROM, repeat above selection steps to install apps package
  • After installation, return to main Recovery menu and select Reboot System Now to reboot into customised Android 4.2 ROM (first boot may take a few minutes)
    • Note: To restore previous ROM, boot into Recovery mode, select Backup and Restore and select previous ROM from list

CM10.1 custom ROM, based on Android 4.2, is now installed and running on the Samsung Galaxy S2 (I9100G). This may be verified by navigating to Settings > About Phone.

[Source: Android Jinn]