Essential Linux Device Drivers

Chapter 2. A Peek Inside the Kernel

In This Chapter

• Booting Up
• Kernel Mode and User Mode
• Process Context and Interrupt Context
• Kernel Timers
• Concurrency in the Kernel
• Process Filesystem
• Allocating Memory
• Looking at the Sources

Before we start our journey into the mystical world of Linux device drivers, let’s familiarize ourselves with some basic kernel concepts by looking at several kernel regions through the lens of a driver developer. We learn about kernel timers, synchronization mechanisms, and memory allocation. But let’s start our expedition by getting a view from the top; let’s skim through boot messages emitted by the kernel and hit the breaks whenever something looks interesting.

Booting Up

Figure 2.1 shows the Linux boot sequence ...