Galaxy S2 was launched in 2011. It is powered by a 1 GHz dual core processor and 1 GB RAM. It had 16/32 GB internal storage options which could be further expanded by 32 GB via microSD card. It also had a 8 MP rear camera and a 2 MP front facing camera. It originally ran on Android 2.3.4 and was later upgradable to Android 4.1.
The CyanogenMod team have developed an Android 5.1.1 based ROM for the Galaxy S2. This ROM has been developed based on the changelog released by Google. The OS will be Android 5.1 but there will be some of the features of Android 5.1.1. To install this ROM on Galaxy S2, follow the guide below.
Disclaimer: Follow the instructions at your own risk. If the device gets damaged, the writer or the owner of the site must not be held responsible.
Pre-requisites and Backing up your S2:
- Create a Nandroid Backup
- Backup and Restore your Android smartphone via Desktop PC
- Backup/Sync and Restore contacts on Android smartphone
- Backup WhatsApp messages on Android Smartphone and Email
Steps to install CM 12.1 on S2:
- Create a Nandroid backup from recovery, in case anything goes wrong.
- Download the CM 12.1 zip file and Gapps zip file and transfer it to the phone.
- Switch off the phone and boot the phone into Recovery mode.
- Next, wipe the cache and the dalvik cache.
- Now go to “Install zip” and then “Select zip”. Choose the CM 12.1 zip file.
- Now again clear cache and dalvik cache.
- Go to ”Install zip”, then “Select zip”. Choose the Gapps zip file.
- Then perform full data wipe task. To do so, click “Wipe Data/Factory Reset”, then choose “Yes” on next screen to confirm.
- After the process is complete, reboot the phone.