Windows API Reference: I/O Devices
This section provides comprehensive documentation on interacting with Input/Output (I/O) devices within the Windows operating system. Understanding how to manage and communicate with hardware devices is crucial for developing robust and efficient applications.
Core Concepts
Windows provides a layered architecture for device management, abstracting hardware complexities through a series of interfaces and drivers. Key components include:
- Device Drivers: Software components that translate generic I/O requests into device-specific commands.
- I/O Manager: The kernel-mode component responsible for managing I/O operations, I/O request packets (IRPs), and device objects.
- Device Objects: Kernel objects representing physical or logical devices.
- I/O Request Packets (IRPs): Data structures used to pass I/O requests from user mode to kernel mode and between driver layers.
Key APIs and Structures
The Windows API offers numerous functions for device interaction. Below are some fundamental areas:
Device Management
Functions for creating, opening, querying, and closing device handles.
CreateFile: Opens a handle to a specified device, file, or named pipe.DeviceIoControl: Sends a control code directly to a specified device driver to perform operations not included in the standard I/O functions.GetFileAttributes: Retrieves attributes for a specified file or directory.CloseHandle: Closes an open object handle.
I/O Control Codes (IOCTLs)
IOCTLs are used to communicate with device drivers using the DeviceIoControl function. They allow for custom commands beyond standard read/write operations.
Common IOCTL families include:
- Storage Device IOCTLs: For managing disks, partitions, and volumes.
- Network Device IOCTLs: For configuring network interfaces and querying network statistics.
- System Device IOCTLs: For interacting with various system-level devices.
Device Driver Development
For developers creating custom hardware drivers, the Windows Driver Kit (WDK) is essential. Key concepts include:
- Kernel-mode vs. User-mode drivers.
- DriverEntry function.
- Handling IRPs.
- INF files for driver installation.
Common Device Types
Windows supports a wide array of device types, each with specific APIs and driver models:
| Device Type | Description | Key APIs/Concepts |
|---|---|---|
| Storage Devices | Hard drives, SSDs, USB drives, CD/DVD drives. | CreateFile, DeviceIoControl (e.g., IOCTL_DISK_GET_DRIVE_GEOMETRY) |
| Network Devices | Ethernet adapters, Wi-Fi cards. | Winsock, NDIS, DeviceIoControl |
| Input Devices | Keyboards, mice, touchscreens. | Raw Input API, HID (Human Interface Device) drivers |
| Display Devices | Graphics cards. | DirectX, WDDM (Windows Display Driver Model) |
| Ports and Serial Devices | COM ports, LPT ports. | CreateFile (e.g., "COM1", "LPT1") |
Explore the sub-sections for detailed information on specific device types and advanced topics.