Linux Device Driver

 

 

Overview

This course deals with the issues of developing drivers in the Linux environment, with a discussion of broader operating systems issues for developers.

The course covers the key issues in Linux device drivers. Questions such as: how do I develop a character device, how do I debug a driver,

how do I use task queues are examined. Upon completion of this course, you will have the information and technical understanding of how file systems work

and device drivers developed in Linux environment.

 

Target Audience

Students with a need to understand or develop Linux drivers and file systems drivers on Linux.

 

Prerequisite

Familiarity with basic usage of Linux and “C” programming language.

No knowledge of any previous device driver development is required.

 

COURSE OUTLINE:

 

BASICS

Operating System Fundamentals

X86 Architecture and Windows

Kernel Mode Vs User Mode

Linux Architecture Overview

Security Issues

Version Numbering

License Terms

 

AN INTRODUCTION TO DEVICE DRIVERS

The Role of the Device Driver

            Splitting the Kernel

Classes of Devices and Modules

 

BUILDING AND RUNNING MODULES

Kernel Modules Versus Applications

Compiling and Loading

The Kernel Symbol Table

Initialization and Shutdown

Using Resources

Automatic and Manual Configuration

Doing It in User Space

 

Tracing and Debugging

printk for debugging

Device information in /proc

strace to track system calls

ksyms and ksymoops

Debuggers, e.g., gdb, and kgdb

 

Character Devices

Classes of device files

Major and minor numbers

Creating device files with mknod

Registering character device file

Listing character device driver methods

 

Data: User To/From Kernel

Important functions for accessing user space

Shared Memory

Kiobufs

 

IOCTLs

What is ioctl

Using ioctl commands to interact with a device

Implementing IOCTL in drivers

 

Memory management

The Real Story of kmalloc

Memory allocation with kmalloc and kfree

Lookaside Caches

get_free_page and Friends

vmalloc and Friends

Boot-Time Allocation

Page-oriented memory allocation

Memory allocation in the virtual address space

The mmap() method.

 

JUDICIOUS USE OF DATA TYPES

Use of Standard C Types

Assigning an Explicit Size to Data Items

Interface-Specific Types

Other Portability Issues

Linked Lists

 

Block Device Read/Write

Block vs Char Read/Write 

Block Device Global Variables 

Request Handing 

Creating a RAM Disk

 

Blocking and Wait Queues

Multi-tasking

Schedule()

Wait Queues

Save sleeping

Poll()

 

Synchronization

Race conditions

Atomic access

Dead lock

Spinlocks

The Kernel Lock

Disabling interrupts

Creating Virtual File System Driver

            Registering

            Readdir Lookup Semantics

            Organization of Code

            Adding entry into the proc file system

 

Writing Mouse Device Driver

 

Understanding Linux Source Tree

            Physical Layout of Linux Kernel Source

 

Project

 

Trainer Details:

This course will be conducted by a hard-core systems developer with experience of developing file systems for Linux.