Advanced Linux: The Linux Kernel

Course details

Upskill as a Linux developer, network engineer, or DevOps professional. In this hands-on course, instructor Kevin Dankwardt provides an overview of the role and functionality of the Linux kernel, including setup and how to write, compile, and insert loadable kernel modules. Along the way, find out why configuring and building custom kernels can help to illuminate the kernel's breadth of functionality as well as provide insights on the kernel's capabilities.

Learning objectives
Configure and build a Linux kernel.
Write, compile, and insert loadable kernel modules.
Navigate the Linux kernel source code.
Describe and explain key actions by the Linux kernel during booting.

Concepts

Introduction

Working with the Linux kernel
Using the exercise files
Prerequisites and takeaways
What is the Linux kernel

Surveying the Linux Kernel

Discover and control hardware
Challenge - Hardware
Solution - Hardware
System calls in-depth
Challenge - System calls (syscalls)
Solution - System calls (syscalls)
Read messages from the kernel and proc
Challenge - kernel messages and proc
Solution - kernel messages and proc
Introduction to sys
Challenge - sysfs
Solution - sysfs
Device drivers and device files
Challenge - Drivers and device files
Solution - Drivers and device files

Booting

Understanding the bootloader GRUB
Configuring GRUB
Kernel command line parameters
Demo kernel command line args
Process 1 and start-up services
Challenge - GRUB, command line parameters, boot sequence
Solution - GRUB, command line parameters, boot sequence

Working with Loadable Kernel Modules

Loadable kernel modules (LKMs)
Finding the LKMs
Challenge - Finding LKMs
Solution - Finding LKMs
Using LKM Commands
Challenge - Working with LKM commands
Solution - Working with LKM commands
LKM Dependencies & Use Count
Challenge - Working with module dependencies and counts
Solution - Working with module dependencies and counts
How LKMs and writing LKMs work
Challenge - How LKMs work
Solution - How LKMs work

Examining Linux Kernel Source Code

Getting Linux kernel source code
Explore the kernel makefile
Examine and build kernel documentation
Search the kernel source
Demonstration of kernel source and searching
Examine kernel driver source
Demonstration - kernel source
Additional selected subdirectories
Challenge - Linux kernel source code
Solution - Linux kernel source code

Configuring and Building a Linux Kernel

Using make menuconfig
Using make xconfig
Explore kernel config files
Build and install modules and kernel
Demonstration configuing and building
Challenge - Configuring and building a kernel
Solution - Configuring and building a kernel

Conclusion

Next steps