This Architecture Guide provides fundamental technical information about Windows Phone OS 7.0. With the goal of supporting a rich consumer experience, Windows Phone OS 7.0 is designed to provide exceptional hardware and software integration on a platform engineered for optimal performance, quality, and hardware differentiation.

This architectural guide serves as a roadmap to the components and core fundamentals of the Windows Phone OS 7.0 architecture. It is intended for software developers, hardware engineers, and anyone interested in operating system internals. The guide provides a high-level view of core architectural components and systems, including:

• Hardware components

• Software components, comprising kernel-mode and user-mode areas such as the kernel, board support package, drivers, OEM Adaptation Layer (OAL), and other systems

• Security, and startup and shutdown processes
  Windows Phone OS 7.0 System Overview

  The Windows Phone OS 7.0 architecture is based on the Windows Embedded CE 6.0 kernel and is logically layered into three main component areas: kernel-mode and user-mode components (the software layer), and hardware components. The following diagram shows the structure and primary components of the architecture.

  Hardware Components

  The hardware requirements and recommendations for Windows Phone 7 have been chosen based on market research and discussions with suppliers. The goal has been to complement the software with an iconic and component-rich hardware platform.

  A summary of basic hardware components and some phone functionality is found below. However, engineers and designers should consult the Windows Mobile "7" Performance Chassis Requirements Specification for complete hardware requirements.

  Summary of Hardware Components

  Hardware components chosen to be included in Windows Phones include the following:

  • ARMv7-based applications processor

  • Hardware acceleration for the DirectX® application programming interface

  • Capacitive multi-touch screen

  • Digital camera

  • Bluetooth and Wi-Fi connectivity

  • FM radio receiver

  • A-GPS

  • Accelerometer, magnetometer, light, and proximity sensors

  Performance Chassis

  Windows Phone OS 7.0 targets focused classes of mobile devices. Each device class is defined by a set of hardware specifications for a device chassis.

  For example, the performance chassis architecture features a large WVGA multi-touch screen and incorporates all of the components listed in the above list. User navigation and input on this hardware can be completed by way of “gestures”—finger-based movements upon the capacitive-touch screen. Also included are four sets of sensors and assisted GPS functionality. These hardware elements leverage mobile application development, allowing for intuitive and exciting user experiences.

  The following diagram illustrates a possible layout for a performance chassis design.

  Software Components

  Windows Phone OS 7.0 consists of two areas—kernel-mode and user-mode.

  Kernel-Mode Areas

  The kernel-mode elements of the OS architecture are described in more detail in the following topics:

  • Kernel for Windows Phone OS 7.0 provides extensive coverage of the kernel, including trap and interrupt handling, thread and process scheduling, and memory management.

  • BSP for Windows Phone OS 7.0 covers the device driver architecture, the Kernel Independent Transport Layer (KITL) architecture, and the OEM Adaptation Layer (OAL) architecture.

  • Networking in Windows Phone OS 7.0 describes the overall networking architecture. It then provides more information on the four main networking areas: IP Core, CellCore, Bluetooth core, and Connection Manager.

  • File System for Windows Phone OS 7.0 provides an in-depth look at the file system architecture including partitions, the file system stack, and the user store.

  • Windows Phone Update in Windows Phone OS 7.0 explains the mechanism by which the OS is updated—either with critical updates, or with non-critical updates to phone features, components, and applications.

  User-Mode Components

  The user-mode elements of the OS architecture are described in User-Mode Components in Windows Phone OS 7.0. This topic has coverage of the user-mode architecture such as user-mode drivers and the platform for application development.

  Security, Startup, and Shutdown

  The security and startup and shutdown architecture is described in the following topics:

  • Security Overview for Windows Phone OS 7.0 discusses the chambered security model, as well as an in-depth look at chamber types and privileges.

  • Startup in Windows Phone OS 7.0 provides information on phone startup architecture.