Training > Linux Kernel Development > Linux Kernel Internals and Development (LFD420)
INSTRUCTOR-LED COURSE

Linux Kernel Internals and Development (LFD420)

Learn how to develop for the Linux kernel. In this instructor-led course you’ll learn how Linux is architected, the basic methods for developing on the kernel, and how to efficiently work with the Linux developer community. If you are interested in learning about the Linux kernel, this is the definitive course on the subject.

Who Is It For

This course is designed to provides experienced programmers with a solid understanding of the Linux kernel. Students should be proficient in the C programming language, basic Linux (UNIX) utilities such as ls, grep and tar, and be comfortable with any of the available text editors (e.g. emacs, vi, etc.).
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What You’ll Learn

In this course you will learn how Linux is architected, how kernel algorithms work, hardware and memory management, modularization techniques and debugging, how the kernel developer community operates and how to efficiently work with it, and much more.
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What It Prepares You For

You will come away from this course with a detailed understanding of the theory and philosophy behind the Linux kernel, and the ability to develop and debug Linux kernel code.
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Course Outline
Introduction
Objectives
Who You Are
The Linux Foundation
Linux Foundation Training
Certification Programs and Digital Badging
Linux Distributions
Platforms
Preparing Your System
Using and Downloading a Virtual Machine
Things change in Linux
Documentation and Links
Course Registration
Preliminaries
Procedures
Kernel Versions
Kernel Sources and Use of git
How to Work in OSS Projects **
Overview on How to Contribute Properly
Stay Close to Mainline for Security and Quality
Study and Understand the Project DNA
Figure Out What Itch You Want to Scratch
Identify Maintainers and Their Work Flows and Methods
Get Early Input and Work in the Open
Contribute Incremental Bits, Not Large Code Dumps
Leave Your Ego at the Door: Don’t Be Thin-Skinned
Be Patient, Develop Long Term Relationships, Be Helpful
Kernel Architecture I
UNIX and Linux **
Monolithic and Micro Kernels
Object-Oriented Methods
Main Kernel Tasks
User-Space and Kernel-Space
Kernel Mode Linux **
Kernel Programming Preview
Error Numbers and Getting Kernel Output
Task Structure
Memory Allocation
Transferring Data between User and Kernel Spaces
Linked Lists
String to Number Conversions
Jiffies
Labs
Modules
What are Modules?
A Trivial Example
Compiling Modules
Modules vs Built-in
Module Utilities
Automatic Loading/Unloading of Modules
Module Usage Count
The module struct
Module Licensing
Exporting Symbols
Resolving Symbols **
Labs
Kernel Architecture II
Processes, Threads, and Tasks
Process Context
Kernel Preemption
Real Time Preemption Patch
Dynamic Kernel Patching
Run-time Alternatives **
Porting to a New Platform **
Labs
Kernel Initialization
Overview of System Initialization
System Boot
Das U-Boot for Embedded Systems**
Kernel Configuration and Compilation
Installation and Layout of the Kernel Source
Kernel Browsers
Kernel Configuration Files
Kernel Building and Makefiles
initrd and initramfs
Labs
System Calls
What are System Calls?
Available System Calls
How System Calls are Implemented
Adding a New System Call
Labs
Kernel Style and General Considerations
Coding Style
kernel-doc **
Using Generic Kernel Routines and Methods
Making a Kernel Patch
sparse
Using likely() and unlikely()
Writing Portable Code, CPU, 32/64-bit, Endianness
Writing for SMP
Writing for High Memory Systems
Power Management
Keeping Security in Mind
Mixing User- and Kernel-Space Headers **
Labs
Race Conditions and Synchronization Methods
Concurrency and Synchronization Methods
Atomic Operations
Bit Operations
Spinlocks
Seqlocks
Disabling Preemption
Mutexes
Semaphores
Completion Functions
Read-Copy-Update (RCU)
Reference Counts
Labs
SMP and Threads
SMP Kernels and Modules
Processor Affinity
CPUSETS
SMP Algorithms – Scheduling, Locking, etc.
Per-CPU Variables **
Labs
Processes
What are Processes?
The task_struct
Creating User Processes and Threads
Creating Kernel Threads
Destroying Processes and Threads
Executing User-Space Processes From Within the Kernel
Labs
Process Limits and Capabilities **
Process Limits
Capabilities
Labs
Monitoring and Debugging
Debuginfo Packages
Tracing and Profiling
sysctl
SysRq Key
oops Messages
Kernel Debuggers
debugfs
Labs
Scheduling
Main Scheduling Tasks
SMP
Scheduling Priorities
Scheduling System Calls
The 2.4 schedule() Function
O(1) Scheduler
Time Slices and Priorities
Load Balancing
Priority Inversion and Priority Inheritance **
The CFS Scheduler
Calculating Priorities and Fair Times
Scheduling Classes
CFS Scheduler Details
Labs
Memory Addressing
Virtual Memory Management
Systems With and Without MMU and the TLB
Memory Addresses
High and Low Memory
Memory Zones
Special Device Nodes
NUMA
Paging
Page Tables
page structure
Kernel Samepage Merging (KSM) **
Labs
Huge Pages
Huge Page Support
libhugetlbfs
Transparent Huge Pages
Labs
Memory Allocation
Requesting and Releasing Pages
Buddy System
Slabs and Cache Allocations
Memory Pools
kmalloc()
vmalloc()
Early Allocations and bootmem()
Memory Defragmentation
Labs
Process Address Space
Allocating User Memory and Address Spaces
Locking Pages
Memory Descriptors and Regions
Access Rights
Allocating and Freeing Memory Regions
Page Faults
Labs
Disk Caches and Swapping
Caches
Page Cache Basics
What is Swapping?
Swap Areas
Swapping Pages In and Out
Controlling Swappiness
The Swap Cache
Reverse Mapping **
OOM Killer
Labs
Device Drivers**
Types of Devices
Device Nodes
Character Drivers
An Example
Labs
Signals
What are Signals?
Available Signals
System Calls for Signals
Sigaction
Signals and Threads
How the Kernel Installs Signal Handlers
How the Kernel Sends Signals
How the Kernel Invokes Signal Handlers
Real Time Signals
Labs
Closing and Evaluation Survey
Evaluation Survey

** These sections may be considered in part or in whole as optional. They contain either background reference material, specialized topics, or advanced subjects. The instructor may choose to cover or not cover them depending on classroom experience and time constraints.
Reviews
Jan 2021
I learned lots of new things, and got insight into things where I had only scratched the surface so far.
Dec 2020
The training materials are kept up to date.
Dec 2020
The labs and the lab solutions.
Dec 2020
The instructor is an expert in the area, and I really learned a lot from it.
Dec 2020
A good overview over most relevant kernel aspects. The course and material given is a good starting point for deeper self-study.
Dec 2020
I have already written some drivers, but some of the kernel internals were ambiguous for me. This course helped me to really get a better understanding of some of the kernel internals.
Dec 2020
I learned a lot of new stuff, and feel much more confident with the technology.
Dec 2020
General overhaul, great answers to questions, competent instructor, and chilled course.
Dec 2020
The course covers a wide range of Linux kernel internals, with practical lab exercises.
Dec 2020
Trainer was very helpful and kind.