The document discusses the architecture of the Android operating system. It describes the five layers that make up the Android stack: 1) the Linux kernel, 2) the Hardware Abstraction Layer, 3) libraries and runtime, 4) the application framework, and 5) Android applications. The Linux kernel handles low-level system tasks like memory management. Above this is the HAL which provides interfaces to hardware. Libraries and runtime include components like WebKit and SQLite. The application framework contains services for location, telephony, and resources. Finally, applications interact directly with users at the top layer.

1. Android Architecture
Srinivas Devarapalli
nivasdevarapalli@gmail.com
Fall June 2013

2. Android Stack

3. 
Android Stack Contains 5 Layers :

1) Linux Kernel.

2) HAL(Hardware Abstraction Layer).

3) Libraries & Android Run Time.

4) Android Application FrameWork.

5) Android Applications.
Srinivas Devarapalli
nivasdevarapalli@gmail.com

4. Linux Kernal
•
Linux Kernel not interact with user &
Developer,performs :
•
Memory Management Programs, Security
Settings,Power Management Software,
Network Stack,Support for Shared
Libraries,Hardware Drivers.

5. Linux Kernel For Android Versions
•
Android 1.0 ----------- 2.6.25.
•
Android 1.5 ----------- 2.6.27.
•
Android 1.6 ----------- 2.6.29.
•
Android 2.0 ----------- 2.6.29.
•
Android 2.2 ----------- 2.6.32.
•
Android 2.3 ----------- 2.6.35.
•
Android 3.0 ----------- 2.6.36.
•
Android 4.0+ ----------- 3.0.1.
•
Android 4.1+----------- 3.0.31.

6. Android Libraries
•
Libraries developed with C,having
•
Surface Manager: composing windows on the
screen.
•
WebKit : Browser.
•
Sqlite : DataBase.
•
libc (System C libraries).

7. Dalvik Virtual Mechine(DVM)
Android Runs on its Own
Process.
It is optimized for low memory requirements.
Allow Multiple instance,run at once.
Peocess Management.
Thread Support.
Operates On dex files.
Srinivas Devarapalli
nivasdevarapalli@gmail.com

8. Android Application Frame Work
Our applications directly interact with these blocks of the Android architecture. These
programs manage the basic functions of phone like resource management, voice call
management etc.
Location Manager: Location management, using GPS or cell tower.
Telephony Manager: Manages all voice calls. We use telephony manager if we want to
access voice calls in our application.
Resource Manager: Manage the various types of resources we use in our Application

9. Android Application
Top Layer o Android stack is Application Layer.
User interacting with this layer only.
Blue Color : Developed with JAVA.
Green Color : Developed with C.
To Interface C & JAVA,need to JNI.
Srinivas Devarapalli,
nivasdevarapalli@gmail.com,
Fall June 2013.