Android Marshmallow

Android 6.0 "Marshmallow"^[3] is the latest version of the Android mobile operating system, released in October 2015.^[4]
Marshmallow primarily focuses on improving the overall user experience of Lollipop,^[5] introducing a new permissions architecture, new APIs for contextual assistants (a feature notable leveraged by "Google Now On Tap"—a new capability of the Google Search app), a new power management system that reduces background activity when a device is not being physically handled, native support for fingerprint recognition and USB Type-C connectors, the ability to migrate data to and utilize a secondary storage device as primary storage, as well as other internal changes.

History

The Android "M" developer preview was unveiled and released at Google I/O on May 28, 2015, for the Nexus 5 and Nexus 6 phones, Nexus 9 tablet, and Nexus Player set-top box, under the build number MPZ44Q.^[5][6] The third developer preview (MPA44G) was released on August 17, 2015 for the Nexus 5, Nexus 6, Nexus 9 and Nexus Player devices,^[7] and was updated to MPA44I that brought fixes related to Android for Work profiles.^[8] Android "Marshmallow" was officially announced as the release's name the same day.^[3]
On September 29, 2015, Google unveiled launch devices for Marshmallow; the LG Electronics-produced Nexus 5X, the Huawei-produced Nexus 6P, and the in-house Pixel C tablet.^[9][10] Android 6.0 updates and factory images for Nexus 5, 6, 9, and Player were released on October 5, 2015.^[11] On October 14, 2015, LG announced that it planned to release Marshmallow for its flagship LG G4 in Poland the following week, marking the first third-party device to receive an update to Marshmallow.^[12]

Features

User experience

A new "Assist" API allows information from a currently-opened app, including text and a screenshot of the current screen, to be sent to a designated "assistant" application for analysis and processing. This system is used by the Google Search app feature "Google Now on Tap", which allows users to perform searches within the context of information currently being displayed by holding the "Home" button or using a voice command. The search generates on-screen cards overlaid onto the app, which display information, suggestions, and actions related to the content.^[13] "Direct Share" allows Share menus to display combinations of contacts and an associated app to be displayed, as opposed to selecting an app and then choosing a target within the app itself.^[13]
When inserting a new SD card or other secondary storage into an Android device, users are now prompted to designate it as either "Portable" or "Secondary" storage. "Portable" maintains the default behavior of previous Android versions, treating the media as a secondary storage device for storage of user files, and normal operation of the device does not depend on its presence.^[13] When designated as "Internal" storage, the media is "adopted" by Android as the primary storage device, and is reformatted with an encrypted ext4 file system. Existing data (including applications and "private" data folders) are migrated to the external storage. However, normal operation of the device becomes dependent on the presence of the media; apps and operating system functions will not function properly if the adopted storage device is removed. If user loses access to the SD card, the adopted storage can be "forgotten", which makes the data permanently inaccessible.^[13]

Platform

Android Marshmallow introduces a redesigned application permission model: there are now only eight permission categories, and applications are no longer automatically granted all of their specified permissions at installation time. An opt-in system is now used, in which users are prompted to grant or deny individual permissions (such as the ability to access the camera or microphone) to an application when they are needed for the first time. Applications remember the grants, which can be revoked by the user at any time.^[14] The new permission model will be used only by applications compiled for Marshmallow using its software development kit (SDK), and all other applications will continue to use the previous permission model.^[5][15]
Marshmallow introduces a new power management scheme known as "Doze"; when running on battery power, a device will enter a low-power state if it is inactive and not being physically handled. In this state, network connectivity and background processing is restricted, and only "high-priority" notifications are processed.^[13]
Android Marshmallow provides native support for fingerprint recognition on supported devices via a standard API, allowing third-party applications to implement fingerprint-based authentication. Fingerprints can be used for unlocking devices and authenticating Play Store and Android Pay purchases. Android Marshmallow supports USB Type-C, including the ability to instruct devices to charge another device over USB. Marshmallow also introduces "verified links" that can be configured to open directly in their specified application without further user prompts.^[5][15] User data for apps targeting Marshmallow can be automatically backed up to Google Drive over Wi-Fi. Each application receives up to 25 MB of storage, which is separate from a user's Google Drive storage allotment.^[13]
As of Marshmallow, all devices capable of doing so at a sufficient access speed must encrypt device data by default, and have a secure boot system, in order to be deemed officially compatible with the specifications of the Android Compatibility Definition Document—a condition that must be met in order to license Google Mobile Services software. This change was originally intended to take effect on Lollipop, but was delayed due to performance issues.^[16][17]