Android System Architecture

To give you a better understanding of how the Android system works, let's look at its system architecture first.
Android can be roughly divided into four-tier architecture, five-block areas.
1. Linux Kernel layer
The Android system is based on the Linux 2.6 kernel, which provides a base for the various hardware of Android devices
Drivers, such as display drivers, audio drivers, camera drivers, bluetooth drivers, Wi-Fi drivers, power management, and more.
2. System Runtime Layer
This layer provides key feature support for Android systems through a number of C + + libraries. such as SQLite Cuiti
Supported by the database, the Opengl|es library provides support for 3D drawings, and the Webkit library provides a browser core
Support and so on.
Also on this tier is the Android runtime Library, which mainly provides core libraries that allow developers to
Use the Java language to write Android apps. In addition, the Dalvik virtual machine is included in the Android Runtime library.
It allows each Android app to run in a separate process, with a Dalvik virtual
Machine instance. Compared to Java virtual machines, Dalvik is specifically tailored for mobile devices,
CPU performance is limited and so on the situation has been optimized processing.
3. Application Framework Layer
This layer provides the core of the various api,android that may be used when building the application
Applications are done using these APIs, and developers can build their own applications by using these APIs.
4. Application Layer
All applications installed on the phone belong to this layer, such as the system comes with the contact person, SMS, etc.
program, or a mini-game you download from Google play, and of course your own program.

Android System Architecture