1. Symbian Operating System
CS-550: Operating System
Presented By,
Himal Prasad Humagain
15th Dec, 2005
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Himal P. Humagain Fall Symbian OS

2. Himal P. Humagain Fall 2005 Symbian OS
History
Symbian established as a private independent company in June 1998, owned by Ericsson, Nokia, Motorola and Psion.
Symbian is a software licensing company that develops and supplies the advanced, open, standard operating system – Symbian OS – for data-enabled mobile phones.
Versions of Symbian OS:
Release v , · Release v6.2 Q1/2002, · Release v7 200
Release v including Multimedia Framework (MMF)
Release v allowing manufacturers to build Symbian OSRelease v supporting the latest generation of ARM-based processors
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Himal P. Humagain Fall Symbian OS

3. Himal P. Humagain Fall 2005 Symbian OS
Features of Symbian V9
Browsing: full web browser support and WAP stack for mbile browsing
Messaging: support MMS, EMS, SMS, POP3, IMAP4, SMTP, MHTML; standard attachments; fax
Multimedia: shared access to screen, keyboard, fonts and bitmaps; audio recording and playback, and image related functionality (support common audio and image formats), including API for graphics acceleration, streaming and direct screen access
Communication protocols: including TCP, IP version 4, IP version 6 and WAP, IrDA, Bluetooth, USB
Mobile telephony: abstract API for cellular standards.
Data synchronization: over-the-air (OTA) synchronization support using SyncML. Supported over serial, infrared, Bluetooth and USB links. Provides synchronization : PIM data, transfer of files, and document conversion to and from non-Symbian OS formats.
Security: full-strength encryption and certificate management, secure communications protocols (including HTTPS, WTLS and SSL), WIM framework and certificate-based application installation
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Himal P. Humagain Fall Symbian OS

4. Application platforms
Series 60 is a UI for mobile phones that are single-handed operated. In addition to voice communication, multimedia messaging, content browsing and application downloading are the main features of this platform.
Series 80 is a UI for devices with larger horizontal screens. It is used in clamshell devices with a keyboard.
UIQ is a customizable pen-based user interface platform for media-rich mobile phones based on Symbian OS.
Symbian OS is also being used in the new Series 90 platform, which is being introduced in the Nokia 7700
phone. With a pen input user interface, a horizontal screen and an optional television tuner, the Nokia 7700
brings mobile multimedia to a new level.
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Himal P. Humagain Fall Symbian OS

5. Himal P. Humagain Fall 2005 Symbian OS
Processor Modes
ARM Processor
32 bit registers in Privileged mode
17 bit in user mode
Supervisor mode:
kernel owns device drivers
implements the scheduling & synchronization policy
does power management
allocates memory to itself and user-mode (that is, unprivileged) processes.
User mode: Runs user level application like: file server and windows server.
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6. Himal P. Humagain Fall 2005 Symbian OS
Memory Management
Supports RAM maximum of 2GB.
Applications share RAM with operating system but has exclusive access to their allocated memory area
Flash and expansion card memory is used for storage.
The kernel runs within its own protected address space. So a programs memory leak or stack over-run can't overwrite the kernel's stack or heap which would cause a system crash.
Symbian OS presents a virtual machine model to all running programs.
Programs use linear virtual memory environment facilitated by the use of the MMU.
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Himal P. Humagain Fall Symbian OS

7. Himal P. Humagain Fall 2005 Symbian OS
File Management
File server provides the access
The drive, directory and file hierarchy is VFAT, thus making the file system naturally compatible with desktop PCs.
It provides local file systems (ROM, RAM and removable media), and an interface to allow dynamically installable file systems, such as those required to communicate with remote disks over a network.
File Manager: File handling application.
Browse the structure of internal storage, Memory stick storage space. It can be used for
File management operations like Copy, Move, Delete, Rename, View properties Change file attributes, and more. Folders and files can also be managed and opened in appropriate viewers.
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8. Himal P. Humagain Fall 2005 Symbian OS
Processes and Threads
Supports multitasking and multithreading.
Only one application can have access to UI.
A process can have one or more threads.
Uses preemptive multitasking.
The thread with the highest priority being ready to run will be scheduled next.
All user processes have their own memory address spaces and all threads within the same process share the same memory address space.
Each Process and threads have their own stack and heaps.
Thread Priorities
Absolute: Ignoring the priority of a process owning the thread
Relative: Overall priority of a thread is defined as a priority of the process owning the thread plus the relative priority value.
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Himal P. Humagain Fall Symbian OS

9. Mutual Exclusion & Synchronization
Semaphore: Global or Local
Wait(){count--; if(count<0) the calling thread is put in waiting state;}
Signal(){if(count<0) Mark the first thread waiting for this semaphore ready to run; count--;}
Mutexe: Global or Local.
Critical Section: Critical sections are used for synchronizing exclusive access to shared resources within a single process
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10. Himal P. Humagain Fall 2005 Symbian OS
Success
Technical
Symbian Has large software development community.
Symbian OS maintains its position as the industry’s leading development platform for phones designed for 3G networks
Symbian OS™ Real Time Compatibility Layer (RTCL)
Modularity: runtime linking between dynamically linked shared librariy
Commercial
Q shipments of Symbian OS™ phones rise 131% (Symbian OS, 2005)
Symbian OS worldwide installed base reaches almost 48 million phones.
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11. Himal P. Humagain Fall 2005 Symbian OS
Threats
PC nature: User can install software .
Symbian OS has been subject to a variety of viruses, the best known of which is Cabir.
Critics also argue that Symbian is trying to replace PC.
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12. Himal P. Humagain Fall 2005 Symbian OS
Bibliography
Symbian OS,
Nokia Corporation (2005). “Symbian OS: Threads Programming”
Wikipedia,
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