One question has been on the minds of millions Android users: when will we receive the official Android 4.1 updates? With the goal to bring the latest updates to all Android devices, independent developers such as the CyanogenMod team have been cooking the perfect ingredients to serve you the chewy Android 4.1 Jelly Bean.

XDA Developers member Entropy512 shares a preview build of the CyanogenMod 10 for your AT&T Samsung Galaxy S2 SGH-I777. Flashing this ROM will let you have a taste of Android 4.1.1 Jelly Bean on your mobile phone.

The CyanogenMod 10 ROM for the AT&T Galaxy S2 is still in its early stages and contains a lot of bugs. It is advised not to use this ROM as a daily driver until further updates are done.

Read on to learn how to upgrade the AT&T Galaxy S2 I777 to Android 4.1.1 Jelly Bean via CyanogenMod 10 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 ClockworkMod Recovery installed.
  • You may refer to our guide on how to root and flash ClockworkMod Recovery to your AT&T Samsung Galaxy S2 SGH-I777.
• Download the following files:
  • CyanogenMod 10 ROM (cm-10-20120803-UNOFFICIAL-i777.zip, md5sum: d94382091c11e17879b5633fbdbfbd76)
  • Jelly Bean GApps (Google Apps)package (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 CyanogenMod 10 ROM and the Jelly Bean GApps package to your phone's internal SD card.
2. Switch off your phone.
3. Reboot your phone into ClockworkMod Recovery Mode. You can do that by pressing and holding the Volume Up key, Volume Down key, and Power buttons simultaneously until recovery boots.
4. Create a NANDroid backup of your current ROM. From the main recovery menu, select Backup and Restore and select Backup on the next screen. Wait until the backup process is done.
5. Go back to the main menu and perform a full wipe:
   • Select Wipe data/factory reset and confirm the action on the next screen.
   • Select Wipe cache partition and confirm the action on the next screen.
   • Go back to the main menu and select Advanced. From there, select Wipe Dalvik cache and confirm the action on the next screen.
6. Go back to the main menu and select Install ZIP from SD card.
7. Select Choose ZIP from SD card and locate the cm-10-20120727-UNOFFICIAL-i777.zipfile. Confirm the action on the next screen to flash the ROM to your mobile phone.
8. Return to the main recovery menu and flash the Jelly Bean GApps package in the same manner as in steps 6 and 7.
9. Go back to the main menu and select Reboot system nowto restart your phone.

Hooray! You can now have a glimpse of how Android 4.1 Jelly Bean looks like by flashing CyanogenMod 10 on your AT&T Samsung Galaxy S2 SGH-I777.