Google started to give OTA images for Nexus devices
Google was already giving factory images for its Nexus devices, but they chose to limit the users by requiring an unlocked put loader to flash the devices. However, now it has been changed. You no longer need to do that. If you have one of the supported devices ( Nexus Devices ), you can download OTA images to your phone or tablet without having a put loader.
The advantage of this system is that you no longer need to wipe your data. However, it is highly recommended to back up your device, just in case.
If you want to download the OTA image of Android 6.0.1 to your nexus device, then here is a quick tutorial for you.
- Download the appropriate update image for your device below, then unzip it to a safe directory.
- Verify the checksum of the image: the OTA mechanism has a built-in validation feature, however verifying would save you some time in case the file was incomplete. The last portion of the filename is the first 8 digits of its SHA256 checksum; the full SHA256 checksum is also shown next to the download link.
- With the device powered on and USB debugging enabled, execute:
adb reboot recovery
The device is now in recovery mode and an Android logo with red exclamation mark should appear on the screen.
Powerbutton and press
Volume Uponce, and a menu will be shown. Select the option of
Apply update from ADB
- Run the following command:
adb sideload (ota file.zip)
where (ota file.zip) is replaced with the file you have downloaded and verified.
- Once the update finishes, you should reboot the phone by choosing:
Reboot the system now
For device security, you should disable USB debugging when it is not being updated.
Source – Google Developers