Android

1. Hardware

2. Development

2.1. Update schedule

Android版本历史

2.2. Linux kernel

Android's kernel is based on one of the Linux kernel's long-term support (LTS) branches. Since April 2014, Android devices mainly use versions 3.4 or 3.10 of the Linux kernel. The specific kernel version depends on the actual Android device and its hardware platform; Android has used various kernel versions since the version 2.6.25 that was used in Android 1.0.

2.3. Software Stack

Android's Architecture Diagram

2.3.1. Linux kernel

On top of the Linux kernel, there are the middleware, libraries and APIs written in C, and application software running on an application framework which includes Java-compatible libraries based on Apache Harmony. Development of the Linux kernel continues independently of other Android's source code bases.

2.3.2. Android Runtime

Android 4.4 introduced Android Runtime (ART) as a new runtime environment, which uses ahead-of-time (AOT) compilation to entirely compile the application bytecode into machine code upon the installation of an application. In Android 4.4, ART was an experimental feature and not enabled by default; it became the only runtime option in the next major version of Android, 5.0.

2.3.3. Android's Standard C Library

2.3.4. Application Framework

Includes Java-compatible libraries based on Apache Harmony.

http://developer.android.com/guide/index.html: how to build apps using Android's various APIs(APIs Docs)

2.3.5. Applications

2.4. Open-source community

3. Security and Privacy

4. Relatives

5. Reference


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