Mobile Operating Systems
Lesson 05
Windows CE
• A 32 bit OS from Microsoft
• Customized for each specific hardware and processor in order to fine-tune the performance
• Compatible with a variety of processor architectures
• Compiled for a specific set of hardware, its performance is very finely tuned
Windows CE
• User─ personal-computer-like feel and Windows-like GUIs
• Large number of Windows-based applications available at the device
Windows CE 4.x
• Adds improved security, GUIs, VUIs, telephony libraries, and standard
interfaces for access to the external SD cards for the files
Windows CE 5.x
• Supports a non-volatile file system using flash memory
• Flash nowadays used instead of persistent battery-backed RAM
Windows CE 5.x
• Windows CE supports a new file system that supports larger file sizes, removable media encryption, and larger storage
media
• The flash file system saves the files and data in case the battery charge is
Windows Embedded CE 6.0
• Open, scalable, 32-bit operating system (OS) with small-footprint and advanced Windows technologies
• Provides hard real-time capabilities, with a redesigned kernel and
Windows Embedded CE 6.0 devices
• For home as well as work places • Provisions for media and shared
presentations
Windows Mobile 6 platform
• For mobile devices such as PocketPC
• for managing Visual C# and Visual Basic .NET codes
• Based on Windows CE and hardware such as personal digital assistants
Windows Mobile 6 platform
• Microsoft Visual Studio 2005
• Windows Mobile SDK for creating software for the platform
Windows Mobile
• Windows CE 5.0 with a set of specific applications
• GUIs/VUIs and for a specific set of processors
• Windows Mobile 5.xall user data in
persistent (flash) memory and RAM to be used only for running applications
Windows CE Memory
• Memory requirement large
• Minimum footprint of Windows CE is 350 kB
• Windows Mobile 5.x all user data in
persistent (flash) memory and RAM to be used only for running applications
• Scales to the requirement of the device peripherals
Processes in Windows CE
• Device based on CE 6.0 can run a larger number of complex applications and can run as many as 32,000 simultaneous
processes
• Windows CE 6.0 provisions for each
simultaneously running process─2 GB of virtual memory space
• Minimum footprint of Windows CE 350 kB
Thread
• Basic unit of computation
• A process─ any number of threads • Threads run concurrently
Windows Mobile
• Deployed in (i) Smart phone, (ii)
handheld PocketPC which features the digitizer in the human computer interface (HCI), and (iii) portable media player
• PDA with Microsoft Smartphone phone device, touch screen, touchpad, or
PocketPC
• Has digitization software which converts (i) analog signals to digital ones to enable
scanning of photos and video recordings for storage or transmission
(ii) audio analog sources into digital form to enable speech processing, voice, or music for creatring records and files which are
Windows CE
• Kernel divided into two sublayers
• One sublayer consists of large part of the OS
• Then the OS is adjusted according to the device hardware by adding the remaining part of the OS
• Second sublayer called hardware abstraction layer
Windows CE
• Shared source licensed with controlled
access to full or limited parts of the source code for a product
• Windows CE 5.x developers have the
freedom to modify down to the kernel level without the need to share their changes
Windows CE
• A component-based, embedded, real-time operating system with deterministic
interrupt latency
• Can be configured as a real-time operating system for handheld Smart phone,
PocketPC, computers, and embedded systems
Windows CE
• Modular/componentized to provide the foundation of several classes of devices and supports addition of features of other components for Windows, DCOM, and
Windows CE
• Data format─ database or object file • File automatically compresses when
stored and decompresses when loaded • Visual C/C++ platform integrates use of
web
GUIs development support
• Using markup language as well as C/C++ language
• Embedded complex APIs
• Gives the user a PC-like feel and
Windows-like GUIs (window resizing not provided)
VUIs development support
• Built-in microphone for voice recording • VUIs (in PocketPC and automotive PC),
buttons, shortcut icons, menus, scroll bar, dialogs, forms, and tables
Display
• High resolution colour/ display • Touch screen
• Stylus keypad with Windows layout of
desktop programs displayed on coloured touch screen
Software
• Desktop for Windows
• Other essential software • PIM
• Contacts • Task-to-do • Smart phone
• Multimedia applications such as playing music
Desktop Programs
• Owner
• Number of messages not read • Tasks
Desktop Programs
• Button and tool bar for task start menu • Today calendar, contacts, Internet
explorer, messages, phone, pocket
MSN, album, MSN messenger, camera, programs, settings, and help], phone
mode indicator (on/off), signal strength status, speaker status (on/off), and time
Soft buttons
• Two context-sensitive soft buttons at the bottom of the screen
• Can be mapped to hardware buttons on any specific device
Ports
• USB and infrared port support for
communication of a device with mobile
phones and for synchronizing a PC using ActiveSync after resolving the conflicts
due to different versions of object files during data exchange.
• Bluetooth • TCP/IP
ActiveSync
• Synchronization of mobile device data
with PC using a USB, Bluetooth, and PC infrared port
Connectivity to other devices
• A cradle connects to PC
• USB 2.0 in Windows CE 5.0 PocketPC conform as the USB mass storage class, the storage on device can be accessed, and drag and drop menu can be used from any USB port of PC, which
considers the handheld device just another flash drive
Third party support
• Very large support (about 20000) for games, applications, mobile
Window CE device three states
(i) ON with clock frequency lowered in idle state
(ii) suspend with power to unused system units and port peripherals disconnected, memory data persistent, CPU idle till
next interrupt, and clock running (iii) dead with power disconnected
Windows CE deficiencies
• Cooperative running of multi-threading does not support simultaneous
multi-modal user interfaces (data by multiple modes, for example, text as well as
Poor Adaptability
• Adapts to different sorts of hardware limits mainly because of two reasons(i)
compiled for a specific set of hardware for very fine-tuned Windows CE performance, (ii) large parts of OS offered in the form of source code first and then adjusted to the hardware by the manufacturer
Summary
• A 32 bit real time OS from Microsoft
• Customized for each specific hardware and processor in order to fine-tune the performance
• Compatible with a variety of processor architectures
• User─ personal-computer-like feel and Windows-like GUIs …
… Summary
• Large number of Windows-based applications available at the device
• Kernel consisting of source code and hardware abstraction sublayer
• Shared source and source code access • Memory requirement large but scales to
the requirement of the device peripherals …
… Summary
• Memory space partitioned
• Data formats database and object file • File automatically compresses when
stored and decompresses when loaded • Visual C/C++ platform integrates use of
web
End of Lesson 05 Windows CE─ Part 1
