The Symbian OS (Symbian Books)

The Symbian OSArchitectureSourcebookThe Symbian OSArchitectureSourcebookDesign and Evolution of a MobilePhone OSByBen MorrisReviewed byChris Davies, Warren Day, Martin de Jode, Roy Hayun,Simon Higginson, Mark Jacobs, Andrew Langstaff, DavidMery, Matthew O’Donnell, Kal Patel, Dominic Pinkman,Alan Robinson, Matthew Reynolds, Mark Shackman,Jo Stichbury, Jan van BergenSymbian PressHead of Symbian PressFreddie GjertsenManaging EditorSatu McNabbCopyright  2007Symbian Software, LtdJohn Wiley & Sons, Ltd The Atrium, Southern Gate, Chichester,West Sussex PO19 8SQ, EnglandTelephone (+44) 1243 779777Email (for orders and customer service enquiries): cs-books@wiley.co.ukVisit our Home Page on www.wileyeurope.com or www.wiley.comAll Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system ortransmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning orotherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms ofa licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP,UK, without the permission in writing of the Publisher.

Requests to the Publisher should be addressed tothe Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, WestSussex PO19 8SQ, England, or emailed to permreq@wiley.co.uk, or faxed to (+44) 1243 770620.Designations used by companies to distinguish their products are often claimed as trademarks. Allbrand names and product names used in this book are trade names, service marks, trademarks orregistered trademarks of their respective owners.

The Publisher is not associated with any product orvendor mentioned in this book.This publication is designed to provide accurate and authoritative information in regard to the subjectmatter covered. It is sold on the understanding that the Publisher is not engaged in renderingprofessional services. If professional advice or other expert assistance is required, the services of acompetent professional should be sought.Other Wiley Editorial OfficesJohn Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USAJossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USAWiley-VCH Verlag GmbH, Boschstr.

12, D-69469 Weinheim, GermanyJohn Wiley & Sons Australia Ltd, 42 McDougall Street, Milton, Queensland 4064, AustraliaJohn Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809John Wiley & Sons Canada Ltd, 6045 Freemont Blvd, Mississauga, Ontario, L5R 4J3, CanadaWiley also publishes its books in a variety of electronic formats. Some content thatappears in print may not be available in electronic books.Anniversary Logo Design: Richard J. PacificoLibrary of Congress Cataloging-in-Publication DataMorris, Ben, 1958The Symbian OS architecture sourcebook : design and evolution of amobile phone OS / by Ben Morris.p. cm.Includes bibliographical references.ISBN-13: 978-0-470-01846-0ISBN-10: 0-470-01846-11.

Operating systems (Computers) 2. Symbian OS (Computer file) I.Title.QA76.76.O63M6835 2007005.4 32 – dc222006103533British Library Cataloguing in Publication DataA catalogue record for this book is available from the British LibraryISBN: 978-0-470-01846-0Typeset in 10/12pt Optima by Laserwords Private Limited, Chennai, IndiaPrinted and bound in Great Britain by Bell & Bain, GlasgowThis book is printed on acid-free paper responsibly manufactured from sustainableforestry in which at least two trees are planted for each one used for paper production.To Philippa, with love.ContentsAbout this AuthorAcknowledgementsxiiixvGlossary of TermsxviiIntroductionxixPart 1: The Background to Symbian OS1 Why Phones Are Different1.11.21.31.41.51.6The Origins of Mobile PhonesFrom 2G to 3GMobile Phone EvolutionTechnology and Soft EffectsDisruption and ComplexityThe Thing About Mobile Phones2 The History and Prehistory of Symbian OS2.12.22.32.42.52.62.72.8The State of the ArtIn the BeginningThe Prehistory of PsionThe Beginnings of Symbian OSThe Mobile OpportunityBackground to the First Licensee ProjectsDevice FamiliesOperating System Influences33567910151517202226273137viiiCONTENTS3 Introduction to the Architectureof Symbian OS3.13.23.33.43.53.63.73.8Design Goals and ArchitectureBasic Design Patterns of Symbian OSWhy Architecture MattersSymbian OS Layer by LayerThe Key Design PatternsThe Application PerspectiveSymbian OS IdiomsPlatform Security from Symbian OS v94 Introduction to Object Orientation4.14.24.34.44.5BackgroundThe Big AttractionThe Origins of Object OrientationThe Key Ideas of Object OrientationThe Languages of Object Orientation4545494952566571838787889092100Part 2: The Layered Architecture View5 The Symbian OS Layered Model5.15.25.35.45.5IntroductionBasic ConceptsLayer-by-Layer Summary of the Symbian OS v9.3ModelWhat the Model Does Not ShowHistory6 The UI Framework Layer6.16.26.36.46.56.66.7IntroductionPurposeDesign GoalsOverviewArchitectureA Short History of the UI ArchitectureComponent Collections7 The Application Services Layer7.17.27.37.47.57.67.7IntroductionPurposeDesign GoalsOverviewLegacy Application EnginesArchitectureComponent Collections111111111117119119121121122123123124128129133133134134135137137149CONTENTS8 The OS Services Layer8.18.28.38.48.58.68.78.8IntroductionPurposeDesign GoalsOverviewArchitectureGeneric OS Services BlockMultimedia and Graphics Services BlockConnectivity Services Block9 The Comms Services Block9.19.29.39.49.59.69.79.89.9IntroductionPurposeDesign GoalsOverviewArchitectureComms FrameworkTelephony ServicesNetworking ServicesShort-link Services10 The Base Services Layer10.110.210.310.410.510.6IntroductionPurposeDesign GoalsOverviewArchitectureComponent Collections11 The Kernel Services and Hardware InterfaceLayer11.111.211.311.411.511.611.711.8IntroductionPurposeDesign GoalsOverviewEKA1 and EKA2Singleton Component CollectionsKernel Architecture BlockKernel Architecture Component Collections12 The Java ME Subsystem12.112.212.312.4IntroductionRequirements of the Java ME SubsystemDesign Goals for the Java ME SubsystemEvolution of Java on Symbian OSix165165166168170171171177192199199201204206206210220230245255255255256257258270279279280281283283284285295301301302302303xCONTENTS12.512.6ArchitectureComponent Collections13 Notes on the Evolution of Symbian OS13.113.213.313.413.5The State of the ArtSummary of Symbian OS v6 ReleasesSummary of Symbian OS v7 ReleasesSummary of Symbian OS v8 ReleasesSummary of Symbian OS v9 Releases306311319319319321324326Part 3: Design Case Studies14 The Use of Object-oriented Designin Symbian OS14.114.214.3IntroductionPioneering the Object Approach in PsionA Thoroughly Object-oriented Operating System15 Just Add Phone15.115.215.315.415.5333333334353367IntroductionAnatomy of a PhoneThe Phone Operating SystemTelephonyMessaging: It’s Different on a Phone36736736837838616 One Size Does Not Fit All: The Radical UserInterface Solution39716.116.216.316.416.516.616.716.816.916.10IntroductionBackground to the Eikon GUIEikon Design PointThe Device Family StrategyQuartzPearlNightingaleHow to Develop a World-class GUISymbian OS User Interface ArchitectureFuture Directions17 System Evolution and Renewal17.117.217.317.417.517.6IntroductionDesign LifetimeRenewal in Symbian OSEvolution in the KernelTelephony EvolutionSound and Vision Evolution397402404410416417418420425426429429430434436440443CONTENTS17.717.8Defining the SkinMoving Towards Standard C++18 Creative Zoo or Software Factory?18.118.218.318.418.5xi444446453IntroductionThe Software ProblemToo Many DragonsSoftware Development ApproachesWhat Making Software Is Really About453453455456459Appendix A: Symbian OS Component Reference475Appendix B: Interviewee Biographies573References579Index583About the AuthorBen Morris joined Psion Software in October 1997, working in thesoftware development kit team on the production of the first C++ andJava SDKs for what was at that time still the EPOC32 operating system.

Heled the small team that produced the SDKs for the ER5 release of EPOC32and, when Psion Software became Symbian, he took over responsibilityfor expanding and leading the company’s system documentation team.In 2002, he joined the newly formed System Management Group in theSoftware Engineering organization of Symbian, with a brief to ‘definethe system’. He devised the original System Model for Symbian OS andcurrently leads the team responsible for its maintenance and evolution.He can be found on the Internet at www.benmorris.euAcknowledgementsSome people told me it would be hard to write this book in and aroundmy real job in the System Management Group at Symbian and a fewpromised me that it would be impossible. They were all right, of course,although none of them tried to stop me.Many thanks to Wiley and Symbian Press therefore for their patienceas I’ve stretched deadlines. Thanks to Fredrik Josephson for saying ‘yes’to my starting the book as a 10% task and for turning a blind eye whenit grew beyond that; and to Geert Bollen for being (almost) tolerant whenhe inherited the problem.

Thanks to Freddie Gjertsen of Symbian Pressfor getting me to the end and to Phil Northam for his part in making ithappen in the first place.My biggest thanks, though, are due to those who took the time to talkto me, agreed to my using a recording device and let me use their words.They are: Geert Bollen, Martin Budden, Andy Cloke, Charles Davies, BobDewolf, Morgan Henry, lan Hutton, Peter Jackson, Keith de Mendonca,Will Palmer, Howard Price, Murray Read, Martin Tasker, Andrew Thoelkeand David Wood. I have done my best to make sure they are happy withthe use to which I have put their words.I am also very grateful to my technical reviewers from across thecompany (and, in a few cases, from outside it): Jan van Bergen, ChrisDavies, Warren Day, Roy Hayun, Simon Higginson, Mark Jacobs, Martinde Jode, Andrew Langstaff, David Mery, Matthew O’Donnell, Kal Patel,Dominic Pinkman, Matt Reynolds, Alan Robinson, Mark Shackman, PhilSpencer, and Jo Stichbury.

Jeff Lewis provided a final review from acommercial perspective.Any errors which remain are mine, of course.A special thanks to Jawad Arshad for his help in constructing thereference material in Appendix A, and for his careful review of whatxviACKNOWLEDGEMENTSI did with it, and to Bob Rosenberg for his great work on the SystemModel graphics (which is present in the book in the form of the colorpull-out). Way back when, Martin Hardman was my original collaboratoron early versions of the System Model, and I would like to acknowledgehis contributionFinally, my family have put up with this book for longer than waspromised. Philippa, Nat, Jake and Henrietta – thanks.Glossary of TermsABIADTBALBIOCDMADFRDDRMDSPEDGEETSIFOMAGPRSIPCMOAPMTMMVCOBEXOMAOTAPANPIMPLPQoSRTOSRTPSIPApplication binary interfaceAbstract data typeBearer Abstraction LayerBearer-independent objectCode Division Multiple AccessDevice family reference designDigital rights managementDigital Signal ProcessorEnhanced Data Service for GSM EvolutionEuropean Telecommunications StandardsInstituteFreedom of Mobile AccessGeneral Packet Radio ServiceInterprocess communicationMobile Application PlatformMessage type moduleModel–view–controllerIrDA Object ExchangeOpen Mobile AllianceOver the airPersonal Area NetworkingPersonal information managerPsion Link ProtocolQuality of ServiceReal-time operating systemReal-time transport protocolSession initiation protocolxviiiSMILUARTUMTSVoIPVPNWAPWDPXIPGLOSSARY OF TERMSSynchronized Multimedia IntegrationLanguageUniversal AsynchronousTransmitter/ReceiverUniversal Mobile TelecommunicationsSystemVoice over IPVirtual Private NetworkWireless Application ProtocolWireless Datagram ProtocolExecute in placeIntroductionThis book is part description, part reference, part case study and parthistory.