Linux® Kernel Primer, The: A Top-Down Approach for x86 and PowerPC Architectures

Chapter 5. Input/Output

In this chapter

• 5.1 How Hardware Does It: Busses, Bridges, Ports, and Interfaces 255

• 5.2 Devices 260

• Summary 281

• Project: Building a Parallel Port Driver 281

• Exercises 293

The Linux kernel is a collection of code that runs on one or more processors. The processors' interface to the rest of the system is through the supporting hardware. At its lowest machine-dependent layer, the kernel communicates with these devices with simple assembly-language instructions. This chapter explores the relationship of the kernel to the surrounding hardware, focusing on file I/O and hardware devices. We illustrate how the Linux kernel ties together software and hardware by discussing how we go from the highest level of a virtual filesystem down ...