Understanding device I/O fundamentals in Linux

In previous chapters, we saw how to schedule work on CPUs using processes and threads, and how to manage memory by controlling the memory layout of a program. In addition to the CPU and memory, the operating system also manages the system's hardware devices. Examples of hardware devices include keyboards, mice, hard disks, video adapters, audio cards, network adapters, scanners, cameras, and other USB devices. But the peculiarities of these physical hardware devices are hidden from the user programs by the operating system, using software modules called device drivers. Device drivers are indispensable software components for doing device I/O. Let's take a closer look at them.

What are device drivers?

Device drivers are shared libraries loaded into the kernel that contain functions to perform low-level hardware control. They communicate with the devices through the computer bus or communication subsystem to which the device...