The ultimate objective of this project is to develop the next generation Text to Speech software for regional Indian languages like Hindi and Bengali which is called Embedded Shruti. The keyword here is "next generation"

The device drivers are included in every Windows CE operating system image are responsible for direct communication to devices.

A device is a physical or logical entity that requires:

a) Control

b) Resource Management

c) Both (a) and (b) from Operating System

1. Device

2. Protocol

3. Service

File system drivers are example of virtual device drivers.

Typically one can characterize drivers by the device interface they expose. In the simplest case there is one interface exposed downward to hardware and one interface upwards to the applications.
Interface to Hardware  Hardware interface or bus interface

Interface to Application  Device interface or client interface

Application, other drivers or the device manager can manipulate the device interfaces. The provider of the interface determines how these modules manipulate the client interface.

Buses are responsible for loading the drivers for the devices on their buses. Bus enumeration is the process of examining the bus and then loading appropriate drivers. Root bus driver is a registry enumerator.

Different processes load different drivers. The following tables show the processes that load drivers and what drivers they load.

Process	Drivers
Graphics, Windowing and Event Subsystem(GWES)	Battery drivers Display drivers Notification LED drivers Printer drivers
Device Manager (Device.exe)	Audio drivers, Keyboard drivers, Mouse driver, Serial drivers, PC card drivers, USB devices and any other driver that exposes the stream interface.
File System (Filesys.exe)	File System Drivers

Device driver source code:

1. The device driver source code is separated into platform dependent code.

2. CPU support package (CSP) drivers.

3. Common drivers.

2.1.2.7 Creating a Board Support Package

Windows CE provides the basic infrastructure that allows one to rapidly and easily create BSPs. Different device driver libraries like Microprocessor-native libraries are shipped in Platform Builder.

Microprocessor Native Libraries:

The microprocessor native libraries consist of device drivers for high integration microprocessors and their native peripherals. For example Strong-Arm microprocessor and its companion chip integrated many peripherals on microprocessor such as LCD, serial port, USB etc.

A SDB that uses a specific microprocessor will use the same set of microprocessor native drivers.

2.1.2.8 Thin Client example revisited

In the Thin Client example discussed above a configuration was chosen after carefully studying the hardware characteristics of the Thin Client. Do the following steps after opening the Platform Builder:

1. From the file menu, choose new platform, and new platform wizard will appear.

2. Choose next and select one or more available BSPs.

3. On the BSP page choose next and in the platform configuration dialog box, enter a name for the platform.

4. Select a platform configuration from the available configuration area which in this case will be Windows Thin Client with browser for this particular example.

The OS image will be built based on the platform that has been configured. To build an Operating System image select retail or debug build configuration, modify the platform settings as needed, such as enabling kernel debugger, and then build the image.

After the platform is configured, the platform can be built using the platform builder integrated development environment (IDE).

Platform builder creates an Operating System image in four stages:

1. Sysgen phase.

2. Feature build phase.

3. Release copy phase.

Build system generates header files, links modules, copies the resulting modules to a release directory, and generates a binary image file.

Static library as well as code supplied by the developer or the third party vendors is combined into a binary file and that is downloaded onto the device.
Sysgen Phase: Each feature selected from catalog has a corresponding sysgen variable. If a feature is included in platform, IDE sets the corresponding sysgen variable during the sysgen phase of the build process.

Build system uses these variables to link the corresponding static libraries into modules.

The system also filters the system header files, creating headers that only contain prototypes for the functions exported by the developer’s platform. Import libraries for the system modules are also created during this phase.

Feature Build Phase: After sysgen phase, feature build phase is run. During this phase, all user features including platform builder project (.pbp) files, source files and makefile (.mak) files are compiled and built.
Release Copy Phase: Build system copies all the files needed to make an OS image to the release directory. The modules and files created during the sysgen phase are copied to the directory first, followed by the files created by the feature build phase.
Make Image Phase: The project specific files which includes

Project.bib

Project.dat

Project.db

Project.reg

are copied into Release directory.

Now information in BIBInfo tab of the platform setting dialog box is then added for each module or file. During this phase, the files in the release directory are combined in binary image file Nk.bin. If some modification is done, then the image should be made again.
Platform Downloading

After the platform is built, the OS image associated with the platform will be downloaded to a target device. The IDE gives a mechanism that allows downloading using a number of types of communication hardware, an OS image to target device.

To download an Os image to a target device, there should be connection from development workstation to target device.

Target menu in the IDE provides functionality that allows the developer to download an OS image to a target device. Before downloading configure a connection to the target device. To download using Ethernet, the development workstation and the target device must be on the same subnet. If the subnets will differ then the target device cannot be connected and debugging the OS image will not be possible.

When included in the platform under development, the standard software development kit (SDK) for Microsoft® Windows® CE provides a common subset of features that allow an application written to conform to the standard SDK to run on a display-based Windows CE platform. To maintain compatibility with the standard SDK, an application must function with only the features provided in the standard SDK. Using additional features will make the application incompatible with the standard SDK. To implement the standard SDK on a Windows CE platform, the standard SDK for a Windows CE feature must be added to a display-based platform. The standard SDK is not compatible with headless devices and is therefore limited to display-based platforms. When added to an operating system (OS) image, the standard SDK will automatically include any features associated with the standard SDK as well as their dependencies. It will also add a registry flag to the image that indicates that the standard SDK has been implemented on that image. This allows any application written for the standard SDK to verify that a particular Windows CE platform supports the standard SDK.

Microsoft® Windows® Powered Pocket PC 2002 is a personal companion for mobile device users. It offers users the following:

• 
  An easy, seamless setup experience
  
• 
  An intuitive user interface
  
• 
  Powerful information management
  
• 
  A robust communications platform
  
• 
  Customizable user interface
  
• 
  Best companionship to Microsoft Outlook®
  

The Microsoft® Windows® Powered Pocket PC 2002 SDK includes a new emulation environment. This environment provides a virtual computer running Pocket PC 2002 software compiled for the Intel x86 processor. The virtual computer duplicates hardware that runs Microsoft Windows CE on an x86-based PC.

• 
  ActiveSync
  

• 
  Windows CE Messaging
  

• 
  Connection Manager
  

• 
  HTML Control
  

• 
  MIDI
  

• 
  Object Exchange (OBEX)
  

• 
  Telephony
  

• 
  Assisted TAPI. Allows applications to make telephone calls without requiring the details of the services of the full Telephony API.
  
• 
  Extended TAPI. Extends wireless functionality to include such things as asking for signal strength, choosing the cellular network, and more.
  
• 
  Phone API. Provides the functionality to access a call log and creates a custom report from the information in that log.
  
• 
  Subscriber Identity Module (SIM) Manager. Allows access to information stored on the SIM card.
  
• 
  Short Message Service (SMS). Enables wireless devices to send and receive short messages through an SMS Center.
  
• 
  Telephony Service Provider. Supports communications device control through a set of exported service functions.
  

Microsoft® Windows® CE operating system version 3.0 for Windows Powered Pocket PC 2002 provides a powerful and easily portable platform for mobile professional users. It combines the power of a personal information manager (PIM), a compact

Software package fully compatible with Windows-based desktop computers, and a Windows development environment. Pocket PC 2002 allows users to keep their personal and business information up to date and close at hand by using a sophisticated hardware design to fill the need for a more portable and less expensive device than traditional laptop or palmtop computers.

Pocket PC 2002 is designed to quickly access, record, and transmit information at any time. The software bundled with Pocket PC 2002 manages contacts, appointments, and other personal and business information. By using the Voice Recorder application, users can capture ideas and thoughts as they occur. Pocket PC 2002 software can also store telephone numbers and short messages, and it can send and receive e-mail messages by using Internet technologies. All these features are fully compatible with the user's Windows-based desktop applications.

Pocket PC 2002 gives the developer access to a rich development environment. The Windows CE operating system is based on the Microsoft Win32® application programming interface. The applications can be created by using Microsoft eMbedded Visual Tools (eVT) 3.0, which are special versions of the familiar Microsoft Visual Studio® tools that the developers may have used to write applications for desktop Windows. The developer can choose to develop applications by using Microsoft eMbedded Visual C++® or Microsoft eMbedded Visual Basic®. Embedded Shurti is developed using Microsoft eMbedded Visual C++®.

Pocket PC 2002 supports a variety of input technologies, including freestyle drawing, handwriting character recognition, or a graphical representation of a keyboard for use on a touch screen.

Original equipment manufacturers (OEMs) have a variety of hardware options when building Pocket PC 2002 devices. The following illustration shows the different hardware components available for a typical Pocket PC 2002.

• 
  Touch screen
  

• 
  Stylus and keyboard
  

The stylus is a pointer for accessing a touch screen and input methods. The stylus has a smaller point than a user's finger, yet will not scratch the touch screen.

The OEM or a user can add additional input methods. For example, an independent software vendor (ISV) could create an input method for tapping in Morse code. The user could purchase the Morse code input method and install it at home.

• 
  Navigation controls
  

Navigation control	Description
On/off	Turns Pocket PC 2002 on and off
Action button	Acts as the ENTER key
Record button	Activates the Voice Recorder application
Program button(s)	Launches an application
Up	Acts as an UP ARROW key
Down	Acts as a DOWN ARROW key

Some OEMs may add a silkscreen region, which is an extension of the resistive touch panel, to cover a non-LCD region of a Pocket PC 2002 case. This region is usually directly below the LCD. It is called a silkscreen region because it often has buttons applied by using a silkscreen process. While a silkscreen button is technically a software control, Pocket PC 2002 software does not distinguish between a silkscreen button and other navigation controls; both types of buttons send the same virtual key messages. The OEM is responsible for the driver that handles the silkscreen region.

• 
  Audio input
  

For devices that support audio, a built-in microphone is included. It is usually located on the front of the device, so that a user can view the screen while recording. The hardware supports 16-bit sampling at 8 kHz, and codec, the compression and decompression software, compresses the recording to 2.4 Kbps. The codec software is identical to a desktop computer's audio compression manager (ACM). OEMs may add a microphone jack for an external microphone. The jack is transparent to the software.

• 
  Audio output
  

• 
  Printing
  

• 
  Notification options
  

• 
  Power
  

• 
  CPU
  

• 
  Memory
  

Because it is important to conserve memory on a Pocket PC 2002, many Pocket PC 2002 operating system (OS) components are compressed in ROM. When a user needs a component, the operating system decompresses that component and transfers it to RAM. Because of the time required for decompression and transfer, compressed files slow performance.

• 
  Built-in serial port
  

• 
  Infrared communications serial port