Android Architecture

Android Architecture

                      

1.  Android is not a single piece of hardware
2. It's a complete, end-to-end software platform that can be adapted to work on any number of hardware configurations.
3.  Everything is there, from the boot loader all the way up to the applications.

Operating System (Linux 2.6) :

• Linux kernel is a proven core platform.
• Reliability is more important than performance when it comes to a mobile phone, because voice communication is the primary use of a phone.
• Linux provides a hardware abstraction layer, letting the upper levels remain unchanged despite changes in the underlying hardware.
• As new accessories appear on the market, drivers can be written at the Linux level to provide support, just as on other Linux platforms.            
• Android uses Linux for its device drivers, memory management, process management, and networking

Libraries 

•  set of C/C++ libraries
• Interface through Java
•  2D and 3D graphics
•  Surface manager - Handling UI Windows
•  Media codec's, SQLite, Browser engine

Android Runtime

                     

                                  

• Core Libraries
• Dalvik VM

Core Libraries
                   Java Std edition
                  Collections, I/O etc…
Dalvik VM

 Every Android application runs in its own process, with its own instance of the Dalvik virtual machine

Android applications are compiled to Dalvik byte code

            

Application Framework

                         

• API interface
• Activity manager – manages application life cycle
• Android offers developers the ability to build extremely rich and innovative applications.
• Developers are free to take advantage of the device hardware, access location information, run background services, set alarms, add notifications to the status bar, and much, much more.

Applications

                            

                        

   Built in and user apps