E- OS

By

Ajal A JAssistant Professor (Guest) , ECE Department

EMBEDDED OPERATING SYSTEM

EMBEDDED OPERATING SYSTEM

• An embedded operating system is an operating system for embedded computer systems.

• These operating systems are designed to be compact, efficient, and reliable.

• E-OS are frequently also real-time operating systems, and the term RTOS is often used as a synonym for embedded operating system.

E- OS vs desktop operating systems

• An important difference between most embedded operating systems and desktop operating systems is that the application, including the operating system, is usually statically linked together into a single executable file.

• Unlike a desktop operating system, the embedded operating system does not load and execute applications. This means that the system is only able to run a single application.

What makes a good Embedded OS? • Modular• Scalable• Configurable• Small footprint• CPU support• Device drivers• etc, etc, etc...

Examples

Android , Symbian•In the small and rapidly growing world the need of mobiles and its applications are obvious.

• To meet the users embedded OS are playing the vital.

•Android is much advanced and provides more value to the end users.

•Symbian needs updates its features.

Example I

ANDROID OS ARCHITECTURE

ANDROID ARCHITECTURE

• Use a colour of font that contrasts sharply with the background– Ex: blue font on white background

• Use colour to reinforce the logic of your structure– Ex: light blue title and dark blue text

• Use colour to emphasize a point– But only use this occasionally

Applications

• Set of core applications including an email client, SMS program, calendar, maps, browser, contacts.

• All applications are written using the Java programming language.

• Built in and user apps.• Can replace built in apps.

Application Framework• Access location information, run background services,

set alarms, add notifications to the status bar, and much, much more.

• Build an application, including lists, grids, text boxes, buttons, and even an embeddable web browser

• Providing access to non-code resources such as localized strings, graphics, and layout files.

• Activity manager – manages application life cycle.

Android Runtime

• Includes a set of core libraries of JAVA that provides most of the functionality

• Runs in its own process, with its own instance of the Dalvik Virtual Machine

• The Dalvik VM executes files in the Dalvik Executable (.dex) – Compact and efficient than class files– Limited memory and battery power

Dalvik Virtual Machine

• All applications written in Java and converted to the Dalvik

executable .dex.

• Every android app runs its own process, with its own instance of the

Dalvik virtual machine.

• Not a traditional JVM, but a custom VM designed to run multiple

instances efficiently on a single device.

• VM uses Linux kernel to handle low-level functionality including

security, threading, process and memory managemet.

Linux Kernel

• Acts as an abstraction layer between the hardware and the rest of the software stack.

• Relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model.

• Works as a HAL

Libraries

System C library - implementation of the C library (libc).Media Libraries - based on PacketVideo's Open CORE.Surface Manager - composites 2D and 3D graphic layers LibWebCore - a modern embeddable web view.SGL - the underlying 2D graphics engine.3D libraries - based on OpenGL ES 1.0 APIs; the libraries use

hardware 3D acceleration.FreeType - bitmap and vector font renderingSQLite - a powerful and lightweight relational database engine .

Android Software Updates

• Android 1.1 • Android 1.5 – Cupcake• Android 1.6 – Donuts (CDMA)• Android 2.0 – Éclair • Android 2.2 – Froyo• Android 2.3 - Gingerbread • Android 3 - Honeycomb• API Levels used by apps to identify software version on the

device• Android apps are generally forward compatible with newer

version, but not necessarily backwards compatible

Example II

SYMBIAN OS ARCHITECTURE

Example of Applications where the Symbian OS is being used

• Nokia Series 80 interface

• UIQ interface(Used for PDAs such as Sony Ericsson P800 )

• Nokia S60 interface

SYMBIAN OS…(INTRODUCTION)

Symbian OS is one of Nokia's mobile operating system for mobile devices and smartphones, with associated libraries, user interface, frameworks and reference implementations of common tools, originally developed by Symbian Ltd.

HISTORY

• Psion founded by David Potter inn 1980 launched the Psion Organizer,

the world's first volume-produced handheld computer in 1984.

• In June 1998 - Symbian is established as a private independent company

and is owned by Ericsson, Nokia, Motorola and Psion. From this point

onwards has EPOC OS been called Symbian OS.

• In February 2004 - Symbian OS v8.0 is announced.

• In February 2005 - Symbian OS v9 is announced.

• In May 2006 - 100th commercial phone model ships.

HISTORY Contd..

• In November 2006 - 100 million Symbian smartphones shipped.

• In 2008, the former Symbian Software Limited was acquired by Nokia and a

new independent non-profit organization called the Symbian Foundation

was established.

• The platform has been designated as the successor to Symbian OS,

following the official launch of the Symbian Foundation in April 2009.

• The Symbian Platform was officially made available as open source code in

February 2010.

CHARACTERISTICS..

• PROCESSING THREAD BASED• MEMORY MANAGEMENT• INPUT/OUTPUT

KERNEL EXTENSIONDEVICE DRIVERSDMA(DIRECT MEMORY ACCESSBLOCKING I/OSTOAGE MEDIA

MEMORY MANAGEMENT

How Symbian OS Addresses Memory– Symbian OS is a 32-bit operating system, addresses

can range up to 4 GB– Symbian OS divides memory into virtual pages and

physical frames– Symbian OS adopts a two-level page table strategy

MEMORY MANAGEMENT

FEATURES

1. CLIENT SERVER ACHITECTURE2. EVENT MANAGEMENT3. OBJECT ORIENTED DESIGN4. POWER MANAGEMENT5. ROBUST AND DEPENDABLE6. MULTI TASKING7. AN OPEN OPERATING SYSTEM8. MEMORY MANAGEMENT

STRENGTHS AND WEAKNESS

STRENGTH•MEMORY MANAGEMENT•EXECUTION IN ONE PLACE

WEAKNESS•NO VITUAL MEMORY

SYMBIAN ACHITECTURE

• Symbian has a microkernel architecture, which means that the minimum necessary is within the kernel to maximise robustness, availability and responsiveness.

• Symbian is designed to emphasise compatibility with other devices, especially removable media file systems.

• There is also a large volume of User Interface (UI) Code. • Symbian includes a reference user-interface called

"TechView". • It is very similar to the user interface from the Psion Series 5

personal organiser and is not used for any production phone user interface.

MORE DETAILED ARCHITECTURE

PLATFORM SECURITY

Trust•Access to private dataSecurity•Cost control•Compromise important telephone functionalityProtection•Software ownership•DRM

PLATFORM SECURITY

ADVANTAGES

• Greater range of applications.

• High quality games.

• Better inbuilt wap browser.

• Connectivity is lot more easier and faster.

• Real Player, Smart movie player etc. sort of application are not available

with java phones.

• You can install software and applications of any type

• You can download big files through your phone easily with 3G around.

DISADVANTAGE

• The OS is not available for PCs .

• The Symbian OS can be easily affected by a

Virus.

COMPARSION OF SYMBIAN & ANDROID

• OPERATING SOFTWARE or FIRMWARE• FLASHING Your phone with new FIRMWARE• CHANGING PHONE FEATURES• PROCESSOR and its SPEED• MODIFICATIONS