Galaxy S2 GT-I9100 users can now enjoy an official or stock-based Jelly Bean experience with fully optimised features and bug-fixes, thanks to the release of Biftor v4.7 Final custom ROM. The ROM is based on the popular base Jelly Bean firmware, Android 4.1.2 XXLSJ, and introduces new apps and capabilities.
With minor changes to the stock interface and looks, the Biftor ROM preserves official firmware's basic features, while adding some new features for improved system stability, battery life and performance.
NOTE: Instructions provided in this guide are meant for reference purpose only. IBTimes UK reminds its readers that it will not be held liable if device is damaged during or after firmware installation. Users are advised to proceed at their own risk.
- The Biftor ROM and the instructions are meant for the Galaxy S2 GT-I9100 model only. Do not attempt installing this firmware on another variant or device, as it may inadvertently hard-brick or damage the device. Verify device model number by navigating to Settings > About Phone
- Back-up data and settings using a recommended custom recovery tool such as ClockworkMod (CWM) or TWRP
- Verify appropriate USB drivers are installed for the phone on computer (download Samsung Galaxy S2 I9100 USB drivers)
- Ensure USB debugging mode is enabled on phone by navigating to Settings > Developer Options (if device is running Android 4.0 or later) or Settings > Applications > Development (if device is running Android 2.3 or earlier). If device is running Android 4.2, perform the following steps:
- Go to Settings > About Phone
- Scroll to bottom of screen and select Build Number
- Tap phone's Build Number seven times to unlock or reveal hidden developer options under Settings. Then select checkbox to enable USB debugging mode under Settings > Developer Options
- Ensure phone has at least 80% battery charge to prevent unexpected device shutdown (due to battery drain) while installing ROM
- Ensure device is unlocked (not locked to specific carrier) and rooted with ClockworkMod Recovery (CWM) installed
- If device is stuck at booting or experiences boot loop issues,Wipe Cache Partition and Wipe Dalvik Cache a few more times before rebooting
- Allow newly installed ROM to stabilise for five minutes before using the device
- If a Status 7 error message flashes while installing firmware, it could be due to an incompatible device or absence of a necessary kernel (for instance, a Jelly Bean Kernel must be installed before installing any Jelly Bean ROM)
Download the appropriate Biftor ROM update for your phone based on the stock Jelly Bean firmware installed on it.
How to Install Bug-Fix Update for Galaxy S2 I9100 Running Stock Android 4.1.2 via Biftor ROM
- Connect and mount phone's storage or SD card on computer via USB cable
- Without extracting, copy downloaded ROM and Google Apps zip files to root folder on phone's SD card
- Once file transfer process completes, disconnect USB cable from computer and Power off phone
- Boot device into recovery mode by pressing and holding Volume Up, Home and Power buttons. Wait until screen flashes and then release all three buttons.
- Take Nandroid backup of current ROM, so it can be restored if new ROM fails to work or you want to return to original ROM. To do a backup, choose Backup and Restore and then click Backup on next screen. Return to main recovery menu once backup is complete.
- Perform a full data wipe task as follows: choose Wipe Data/Factory Reset and then click Yes on next screen to confirm. Wait for a few minutes until data wipe process completes. Return to CWM recovery main menu and click Wipe Cache Partition. Wait until wiping process completes and then choose Wipe Dalvik Cache under Advance options.
- Return to main recovery screen and select Install zip from SD card and then click Choose zip from SD card. Browse to Biftor ROM zip file that you copied to phone in Step 2 and select it by tapping Power. Confirm ROM installation by choosing Yes on next screen and installation will begin.
- Return to main recovery menu and tap reboot system now to reboot into newly installed Biftor ROM. The first boot may take some time (about 5 to 15 minutes).
Returning to Previous ROM
To restore previous ROM: boot into recovery, choose Backup and Restore and restore original ROM by selecting it from list.
The Galaxy S2 GT-I9100 is now successfully updated to stock Android 4.1.2 based Biftor ROM. Go to Settings > About Phone to verify firmware version installed.
[Source: Android Geeks]