Galaxy S2 I9100 users are in for a double treat, as Samsung's latest official Jelly Bean firmware release (Android 4.1.2 XXMS1) is followed by the CyanogenMod 10.1 (CM10.1) custom ROM release for the latest Android 4.2.2 Jelly Bean firmware. Although, the popular custom firmware does not bring any major feature upgrades over its previous iteration (Android 4.2.1 release), it does pack a punch with improved security feature along with a host of custom tweaks and apps for the discerning, power users.
NOTE: As the CM10.1 ROM is a nightly release, it may harbour a few untested bugs or broken features. However, all issues are expected to be fixed in the upcoming updates as development progress.
Key Points to Note
- CyanogenMod 10.1 ROM and the instructions given in this guide are limited to Galaxy S2 I9100 model only and will not work with any other device. Verify the device's model number by navigating to Settings > About Phone.
- Backup the important data and settings on the phone to avoid data loss during firmware installation.
- Verify that the correct USB drivers are installed for Galaxy S2 on computer (download USB drivers).
- Ensure that the phone has at least 80 percent battery charge to prevent unexpected device shutdown during firmware installation.
- Make sure that USB Debugging mode is enabledon 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 or later, then do the following steps:
- Go to Settings > About Phone
- Scroll down to the bottom 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.
- Ensure that the phone is rooted with ClockworkMod (CWM) recovery installed on it.
- If the device is stuck at booting or experiencing boot loop issues, then perform Wipe Cache Partition and Wipe Dalvik Cache a few more times before rebooting.
- Allow the newly installed ROM to stabilise for five minutes before working on it.
- The instructions provided in this guide are meant for reference purpose only. IBTimes UK will not be held liable if the device is damaged or bricked during or after the firmware installation. Users must proceed at their own risk.
How to Install Android 4.2.2 Jelly Bean on Galaxy S2 I9100 with CyanogenMod 10.1 Nightly ROM
1. Connect the Galaxy S2 to computer with the USB cable.
2. Without extracting, copy the downloaded ROM and Google Apps zip files to the root folder on phone's SD card.
3. Unplug the USB cable from computer and then switch off the phone.
4. Now, boot the phone into CWM recovery by pressing and holding Volume Up, Power and Home buttons together until the Samsung logo appears on screen. Then release all three buttons for half a second and hold them again. Now, the device boots into ClockworkMod recovery screen. Use Volume keys to browse between options and Power key to select an option in recovery.
5. Take a Nandroid backup of current ROM on the phone, so that it can be restored later if the new ROM fails to work or if you want to return to the original ROM. To do a backup, choose Backup and Restore, then hit Backup on next screen. Return to main recovery menu once backup is done..
6. Now, perform full data wipe task. To do so, choose Wipe Data/Factory Reset, then click Yes on next screen to confirm. Wait for a few minutes until the data wipe process completes. Now, return to CWM recovery main menu. Click Wipe Cache Partition and once wiping process is done, choose Wipe Dalvik Cache under advance option.
7. Choose Install zip from SD card and then click Choose zip from SD card. Now, browse and select the cm-10.1-20130217-NIGHTLY-i9100.zip file copied earlier in Step 2 and select it by tapping Power button. Confirm the ROM installation by choosing Yes on the next screen and the installation will begin.
8. After the ROM installation is complete, repeat the step 7 but choose the gapps-jb-20121212-signed.zip file instead of ROM zip to install Google apps.
9. Once both the ROM and Google apps are installed, return to the main recovery menu and hit Reboot System Now to reboot the phone into newly installed Android 4.2.2 CM10.1 Jelly Bean ROM. The first boot may take some time. So, leave it alone.
10. Restoring to Previous ROM: To return to previous ROM, boot into recovery, choose Backup and Restore then restore your previous ROM by selecting it from the list.
Congratulations! Galaxy S2 I9100 is now running the latest Android 4.2.2 CM10.1 Jelly Bean ROM. Go to Settings > About Phone to verify the firmware version installed.
[Source: Android Jinn]