Google unveiled the Android 4.1 (Jelly Bean) last month during its 2012 Google I/O, and rolled out the Jelly Bean 4.1.1 update to its Nexus lineup a few weeks back. Today, Google on its Developers sited posted the factory images of Android 4.1.1.
Google has yet to post a changelog for Android 4.1.1, but the most notable changes in Jelly Bean include "Project Butter and Google voice search."
"This page contains binary image files that are provided for use in restoring your Nexus device's original factory firmware," Google stated on its Developers website.
Adding, "These files are for use only on your personal Nexus devices and may not be disassembled, decompiled, reverse engineered, modified or redistributed by you or used in any way except as specifically set forth in the license terms that came with your device," Google said.
In order to restore you have to unlock the bootloader before installing the factory image. Google recommends to lock it again afterwards for security reasons.
Google states that if you have used the AOSP project, the Android Open Source Project and you had a custom build installed on your device these factory images will be the key to returning to the way Google wanted the software to be aka default; the Jelly Bean binaries have been available since three weeks ago on the Android Open Source Project.
"You will find these files useful if you have used the Android Open-Source Project, flashed custom builds on your device, and wish to return that device to its factory state.
In order to use these files, you need to have the fastboot tool in your PATH. That tool is compiled as part of every configuration of the Android Open-Source Project and is the tool used to flash custom builds on your device. On GNU/Linux systems, this also implies that you have configured USB access as mentioned in the machine setup instructions.
Your device needs to be in fastboot mode, with the bootloader unlocked. The relevant key combinations and commands are documented on the page about building for devices.
You need to uncompress each download before use, which creates a new directory for that exact download. That directory contains a ./flash-all.sh script, which handles the various operations, installs the necessary bootloader, baseband firmware(s), and operating system. Note that this operation deletes all user data by default.
After restoring a factory image, it is recommended that you lock the bootloader, for security reasons," Google explained.
Check out Android 4.1.1 Jelly Bean Factory Images for Nexus Devices here.