The first batch of factory images for the recently announced Android 5.1 Lollipop operating system has been released by Google.
The factory images for the new Android are for certain devices under Google's Nexus line, namely the Nexus 5, the Nexus 7 (2012, Wi-Fi version) and the Nexus 10.
Factory images refer to the original factory firmware of devices, and are useful for developers that have flashed custom builds of Android on their devices and are looking to return the device to its default state.
The factory images can be flashed on Android devices using the fastboot tool, which can be accessed from either a compiled version of the Android Open Source Project or from the platform tools directory located in the Android software development kit.
The links to the Nexus factory images and detailed instructions on how to install them into Android devices were posted at the Google Developers page.
The rollout of the factory images of Android 5.1 Lollipop confirms the news reported last week that the new operating system was on the way to be pushed out to Nexus devices soon, as revealed by Artem Russakovskii, the founder of Android news website Android Police.
According to Russakovskii, the Android update will allow the mobile operating system to once again run "buttery smooth," as there have been many complaints regarding Android 5.0 Lollipop.
Google's official announcement of the Android 5.1 Lollipop operating system was also posted on the official Android blog by Dave Burke, the VP of the Android platform. According to the post, the update will address issues concerning performance and stability that was affected by Android 5.0 Lollipop, and will add some new features including support for multiple SIM cards, HD voice and device protection.
In addition to now allowing Android devices to support devices with more than one SIM card, Android 5.1 Lollipop now comes with Device Protection. The feature places stolen or lost Android devices in a locked state until its rightful owner signs in using his or her Google account. The lock does not release even if the device is flashed to reset to factory settings.
Android 5.1 Lollipop now also supports High Definition voice calling for devices and wireless networks that support the feature, such as the Nexus 6 and Verizon or T-Mobile.
The update also makes several other enhancements in the mobile operating system, including capabilities of joining Wi-Fi networks and controlling devices paired by Bluetooth to the mobile device directly from the Quick Settings menu.