How to Update Galaxy S2 I9100G with Jellybean 4.2 Cyanogen Mod Firmware

Galaxy S2 LogoSamsung Galaxy S II GT I9100G is the next smartphone in developer’s radar for release of Jellybean 4.2 firmware and in the due course of this article we will be checking out on how you can apply the same. Please note that unfortunately as of now Samsung hasn’t disclosed any plans on by when there we will be an official firmware update of Jellybean 4.2 for Galaxy S2 GT I9100G but is a custom ROM firmware which is based on the Cyanogen mod 10 firmware which ropes in the magic of Jellybean 4.2 firmware. So, before we proceed to the tutorial on how to update Galaxy S2 with jellybean 4.2 firmware, you will have to go through the detailed pre requisite instructions and then to the detailed instructions to update. For your convenience, we have also mentioned the screen captures on ho this firmware looks like.

There will be many more versions of Jellybean 4.2 firmware which we will be checking out in the coming days. Since this is a custom ROM firmware, there might be some issues which will be solved in the coming days.

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Quick Pre Requisites:

  • Over the process of installing this update, there is a probability that the data might get lost or corrupted, so with the help of below mentioned steps you will have to create a backup of all your data. Don’t backup with the help of ROM Manager or with KIES.

SMS – Use “SMS Backup & Restore app”,
Contacts – Sync with the Gmail application,
Call Log - Call Log and Restore
Images, Songs, Videos, Files – Copy to internal / External SD Card,
APN and MMS Settings – Note down from the path “Applications > Settings > Wireless and Network > Mobile Networks > Access Point Names

  • From the path “Settings > Applications > Development > USB debugging”, enable the USB Debugging, ensure that the USB debugging option is ticked. Also, make sure that the battery life in your Galaxy S2 GT I9100G is not less than 40% as this may turn off the device in the middle of firmware update. Also, make sure that your computer has active USB ports with Full Read / Write Access.

Disclaimer: Follow all the instructions mentioned in this article as if there is any damage caused due to not following instructions then we shall not be held liable or responsible. Just in case if you face any issues then we will try our level best to address the same.

To check on whether your device is rooted or not, you will have to download the “Root Checker” app from the Google PLAY Store. Just in case if the device is not rooted, with the help of below instructions you can root the device.

How to Update Galaxy S2 GT I9100G with Official ICS 4.0.3 XXLPQ Firmware

How to Root Samsung Galaxy S2 GT I9100G on ICS XXLPQ 4.0.3 Firmware

Assuming that you are done with all the instructions mentioned above, you can now head over to the next step where we have summed up a detailed instructions on how to apply this firmware update.

  • Rocky

    Hi Neal,

    My phone is I9100 and not I9100G. My present ROM is official 4.1.2 downloaded from this website itself. But I want to move to CM10 stable build. Can I use this ROM for my phone as well? Any risks?

  • Rocky

    Hi Pradeep,

    I have GT i9100. Even the stable version of GTi9100G is out but not GTi9100. So can I install this ROM on my device? Will it be safe? Please suggest.
    I’m currently running official 4.1.2 downloaded from your website itself.


    • Pradeep Neela

      apply i9100g SPECIFIC UPDATES FOR THE DEVICE, DONT APPLY THE FIRMWARE OF I9100 variant to i9100g

  • VIP007

    i am using samsung galaxy S2 I9100G model

  • VIP007

    I am having the built 7 slimbean 4.2 issue that not able to use facebook and other software as getting storage full error while installing them even have 1+ GB free ROM and 9+GB in SD card…

  • VIP007

    It now easy now as apply butter on bread, i can now apply any custom ROM on my SGS2 i9100G after 4.1.2 now i applied CM 10.1 4.2.2 than slimbean 4.2.2 …thanks for usefull guidence…

  • Samuscle

    Is photosphere unlocked?

    • Pradeep Neela

      yes it is unlocked

  • LG KE850 Prada

    Thank you for the good writeup. It in truth was once a amusement account it. Glance complicated to more added agreeable from you! By the way, how can we keep in touch?

  • Rahmat Khan

    I’ve joeldroid 4.1.2 installed. Can i flash it on it or is it necessary to have ics 4.0.3 for this update?
    Please reply fast.

    • Pradeep Neela

      yes you can very well apply this update

  • hasan


  • Romit

    Swoftware update

  • MR10

    GT-I9100 ???? 4.2 ???? :((

    • Pradeep Neela

      yes its the custom ROM

  • amao

    Impossible to follow the instructions, as after downloading super user and installing it, the Rom Manager is stating: Your telephone must be rooted in order to use ROM Manager.impossible to find superuser in “system/bin/su” or”system/xbin/su”. Use google to find how you can root your telephone.
    Does any one know that?