OS in Mobile DevicesInstructing Computing Devices : Operating Systems

1

Saturday, 29th Nov 2014 yatharthagg@gmail.com

OS in Markets2

85%

12%

2%

0%

1%

Shipment in Q2 2014

Android

iOS

Windows

PhoneBlackBerry

OS

History………..

In July 2005, Google acquired Android Inc., a small startup company based

in Palo Alto, CA. Android's co-founders who went to work at Google.

included :

Andy Rubin (co-founder of Danger),

Rich Miner (co-founder of Wildfire Communications, Inc.),

Nick Sears (once VP at T-Mobile), and

Chris White (one of the first engineers at WebTV).

On 5 November 2007, the Open Handset Alliance(OHA), a consortium ofseveral companies which include Google, HTC, Intel, Motorola, Qualcomm, T-Mobile, Sprint Nextel and NVIDIA, was unveiled with the goal to develop open

standards for mobile devices.

The OHA also unveiled their first product, Android , an open source mobile

device platform on the same day.

3

Android Architecture

Can be divided into Four Layers:

The kernel

The libraries and runtime

The application framework

The application layer

4

The Kernel

The architecture is based on the Linux 2.6 kernel.

This layer is core of android architecture. It provides service like

power management, memory management, security etc.

It helps in software or hardware binding for better communication.

5

The Libraries

Android has its own libraries, which is written in C/C++. These

libraries cannot be accessed directly. With the help of

application framework, we can access these libraries.

There are many libraries like web libraries to access web browsers, libraries for android and video formats etc.

6

and Runtime

Core Libraries are written in the Java programming language.

The core library contains all of the collection classes, utilities, IO,

all the utilities and tools that you’ve come to expected to use.

7

Runtime continued…….

Dalvik Virtual machine is extremely low-memory based virtual machine,

which was designed especially for Android to run on embedded systems

and work well in low power situations.

The Dalvik VM creates a special file format (.DEX) that is created through

build time post processing. Conversion between Java classes and .DEX

format is done by included “dx” tool.

8

The Application Framework

Application Framwork is written in JAVA

It is a toolkit that all applications use, ones which come with

mobile device like Contacts or SMS box, or applications written by

Google and any Android developer.

9

• Activity manager:-It manages the lifecycle of applications. It enable propermanagement of all the activities. All the activities are controlled by activity manager.

• Window manager:-It is use to create views and layouts.

• Content Providers:-It allows applications to share their data with other applications.

• View System:-It contains things like buttons and lists, all the building blocks of the UI.It also handles things like event dispatching, layout drawing.

• Package manager:-It is use to retrieve the data about installed packages ondevice.

• Telephony manager:-It is use to handle settings of network connection and allinformation about services on device.

• Resource manager:-It provides access to non-code resources such as graphics etc.

• Location manager:-It fires alerts when user enters or leaves a specifiedgeographical location.

• Notification manager:-It enables all applications to display custom alerts in statusbar.

10

The Application Layer

The Application Layer used used by the final user.

By installing different applications, the user can turn his mobile

phone into the unique, optimized and smart mobile phone.

All applications are written using the Java programming language.

These applications works with end user with the help of

application framework to operate.

11

The Android complete……

12

An example/13

It all starts with init()14

Linux Kernel

Init

daemons runtimedaemonsdaemons

Service

manager

Zygote Dalvik VM

System

Server

Surface

flinger

Surface

flinger

System

ServerTelephony

services

Booting process

Processes

Threads

Applications

Tasks

Activity

An activity is an application component that provides a screen with which

users can interact in order to do something, such as dial the phone, take a

photo, send an email, or view a map.

Each activity is given a window in which to draw its user interface.

15Application anatomy…

Activity Lifecycle

onCreate() : The initial method to set up anActivity.

onStart() : The application process typechanges to visible and the activity is about tobe visible to the user.

onDestroy():The counterpart to onCreate()

onResume() : This method is called if theActivity is visible in the foreground and readyto get and process user input.

onPause() : The method has to quickly saveuncommitted data and stop CPU intensivework to prepare the Activity to lose the focusand going to background.

onRestart() : This method has to restore apreviously saved state of the Activity, as it iscalled after an activity was completelystopped and is needed again

16

Navigation of applications17

Home

System Processes

HomeHOME

Mail

Mail List

Mail List Message

Message

Browser

Browser

Browser

Maps

Map

Map

18

Map

HomeHOME

System Processes

Browser

Browser

MapsMap

Browser

Mail

Message

Message

https.refrences.links.com

http://os.itec.kit.edu/downloads/sa_2010_braehler-stefan_android-

architecture.pdf

http://androidgroup.googlecode.com/files/Introduction%20to%20Android.pdf

http://davidehringer.com/software/android/The_Dalvik_Virtual_Machine.pdf

http://androidteam.googlecode.com/files/Anatomy-Physiology-of-an-

Android.pdf

Love you wikipedia

19

. . Thank You . .

By ~

yatharth aggarwal [72511]

gourav kalbalia [72373]

kaustabh barman [72530]