Understanding devices in Linux

As already stated on several occasions in this book, everything in Linux is a file. This also includes devices. Device files are special files in Unix and Linux operating systems. Those special files are interfaces to device drivers, and they are present in the filesystem as a regular file.

With no further ado, let’s see how Linux abstraction layers work. This will give you an overview of how hardware and software are related and interconnected.

Linux abstraction layers

Now is as good a time as any to discuss Linux system abstraction layers and how devices fit into the overall picture. Any computer is generally organized into two layers (or levels) – the hardware and the software levels:

• Hardware level: This level contains the hardware components of your machine, such as the memory (RAM), central processing unit (CPU), and devices, including disks, network interfaces, ports, and controllers.
• Software level: For all these...