Custom ROMs are nice but nothing beats the original flavor of things. We're presenting a bit of a paradox to you with this ROM because it allows you to enjoy the pure vanilla taste of Android 4.1 Jelly Bean but your AT&T Samsung Galaxy S2 SGH-I777 won't be quite the same phone. A lot of this ROM's features have been cherry-picked from the CyanogenMod Team's and TeamKang's source codes. The SuperNexus ROM, developed by XDA Developers member Faryaab, gives you the pure Android experience many Nexus users enjoy.

This ROM has nothing excluded from AOSP, as it was completely built from Google's AOSP source, so that means it gives you the stock Jelly Bean look and feel. The ROM is also deodexed, zipaligned and is rooted with BusyBox installed. The SuperNexus ROM is also very light, since there are no third-party apps and it has zero bloatware. The developer claims that it may not be buttery smooth just yet, but other than that, there are no major bugs.

In this guide, learn how to upgrade the Galaxy S2 I777 to Android 4.1.1 Jelly Bean via the SuperNexus custom ROM.

Warning

• The instructions in this guide are intended for use with the AT&T Samsung Galaxy S2, model number SGH-I777. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• AT&T Samsung Galaxy S2 SGH-I777 with custom recovery (e.g., ClockworkMod Recovery) installed
  • You can check out our guide on how to root and flash ClockworkMod Recovery to your AT&T Samsung Galaxy S2 SGH-I777.
• Download the following files to your computer:
  • SuperNexus ROM file (SuperNexus-I777-BUILD2-20120812.zip, md5sum: 243ABBD878A0DC1395D07FE63D7DC51E).
  • Google Apps package file (gapps-jb-20120726-signed.zip, md5sum: f62cfe4a827202899919fd932d5246d7).
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.

Instructions

1. Copy the SuperNexus ROM file and the Google Apps package file to the root of  your AT&T Galaxy S2′s internal SD card.
2. Turn off your AT&T Galaxy S2.
3. Boot into Recovery Mode. You can do this by pressing and holding down the Volume Up, Volume Down, and Power buttons. Keep holding them down until the screen flashes a second time. Let them go and the phone should boot into Recovery Mode.
4. Make a NANDroid backup of your current ROM. Go to Backup and Restore and select Backup.
5. Select Wipe data/factory reset. Confirm the action on the next screen.
6. Select Install ZIP from SD card. Select Choose ZIP from SD card and select the SuperNexus ROM file.
7. Once the SuperNexus ROM file has finished flashing, repeat step 6 and flash the GApps package.
8. Select Go back.
9. Select Reboot system now.

Fantastic! You now have the SuperNexus ROM file installed on your AT&T Samsung Galaxy S2 SGH-I777. Enjoy your pure Jelly Bean'd Nexus experience.