Google has started to push out the Android 5.1.1 Lollipop update to three devices under its Nexus line, namely the Nexus 4, Nexus 5 and LTE version of the Nexus 9.
In addition to the launch of the over-the-air updates to take the devices to Android 5.1.1 Lollipop, Google has also uploaded the factory images of the latest version mobile operating system for the Nexus devices, along with that for the Nexus 7.
The factory images are available at the Nexus Factory Images page under the Google Developers website. The Nexus devices that have the Android 5.1.1 Lollipop factory image uploaded are the following:
- Nexus 4
- Nexus 5, GSM/LTE
- Nexus 7 2013, Wi-Fi
- Nexus 7 2013, Mobile
- Nexus 7, Wi-Fi
- Nexus 7, Mobile
- Nexus 9, LTE
- Nexus 9, Wi-Fi
- Nexus 10
- Nexus Player
Users who are not willing to wait for their Nexus devices to receive the Android 5.1.1 Lollipop operating system as an over-the-air update can download and install these factory images. However, it should be noted that installing operating systems are more complicated and require many more steps compared to simply waiting for the over-the-air update to arrive in the user's device. In addition, installing a new system image will delete all the user data in the Nexus device, which would require the user to first back up all the data in the device.
To flash a factory image into a Nexus device, users will require the latest version of the fastboot tool, which can be acquired either as a compiled version from the Android Open Source Project or through the platform tools directory of the Android SDK.
To begin, users should download the corresponding factory image for their Nexus device, which should be connected to a computer through a USB cable. Users are then required to start the Nexus device in fastboot mode, which can be done in two ways. The user can either use the adb tool or use the specific key combo for the device, which differs between the Nexus devices. For example, to enter the fastboot option for the Nexus 5, upon powering on the device, users will have to press the Volume Up, Volume Down and Power buttons.
If required, users should then unlock the bootloader of the device by running the "fastboot oem unlock" command, which erases all the data on the device. The user can then open a terminal, navigate to where the factory image of Android 5.1.1 Lollipop was saved, and then run the flash-all script.
Upon completing the script, the Nexus device will re-boot and power on into Android 5.1.1 Lollipop. For additional security, the user should lock the bootloader of the device by entering the fastboot mode once more then executing the "fastboot oem lock" command.
