Chapter 7 -- Reading and Writing Data

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Chapter 7

All the infrastructure I've described so far in this book leads up to this chapter, where I finally cover how to read and write data from a device. I'll discuss the service functions you call to perform these important operations on a device plugged in to one of the traditional buses, such as PCI (Peripheral Component Interconnect). Since many devices use a hardware interrupt to notify system software about I/O completion or exceptional events, I'll also discuss how to handle an interrupt. Interrupt processing normally requires you to schedule a deferred procedure call (DPC), so I'll describe the DPC mechanism, too. Finally, I'll tell you how to arrange direct memory access (DMA) transfers between your device and main memory.