Block Drivers

  • Article

Block device drivers read or write data to block devices in fixed-size blocks. Block devices do not allow you to read or write individual bytes of data. Common block sizes are 512 bytes, 1 kilobyte (KB), 2 KB, and 4 KB. Block devices are ideally suited for mass storage and persistent storage applications, such as disk drives or nonvolatile RAM disks. Some common types of block devices are hard disks and Advanced Technology Attachment (ATA) flash memory disks in miniature card, PC Card, and Compact Flash card form factors.

If you want your driver to interface with the file allocation table (FAT) file system or file system driver (FSD) Manager, your block driver should expose the stream interface. For more information about the stream interface, see Stream Interface Drivers. The Device Manager manages drivers that expose the stream interface. For more information about the Device Manager, see Device Manager. The stream interface exposes file I/O functions so it can interact with applications. The XXX_IOControl function is the most important of the I/O functions for block device drivers. This function handles all I/O requests to block devices.

See Also

Driver Categories | Block Driver Architecture | Block Driver Samples | Block Driver Registry Settings | Creating FSDs | Loading FSDs | Storage Manager | Partition Manager

 Last updated on Tuesday, May 18, 2004

© 1992-2003 Microsoft Corporation. All rights reserved.