Linux Device Driver Programs

Welcome to the Linux Device Driver Programs repository! This repository contains a collection of device drivers written for the Linux kernel. These programs serve as examples and educational resources for understanding and developing Linux kernel modules and device drivers.

Table of Contents

• Introduction
• Header Files
• Getting Started
• Prerequisites
• Step-by-Step Program Execution
• Contributing

Introduction

Device drivers are essential components of the Linux kernel, enabling the system to interact with hardware devices. This repository contains various examples of Linux device drivers, from basic "Hello World" modules to more advanced drivers interfacing with hardware.

Header Files

Each Linux device driver program in this repository utilizes various kernel header files. Below is a list of commonly used header files in the programs:

• <linux/module.h>: Provides the core functions and macros needed to create a loadable kernel module, such as module_init and module_exit.
• <linux/kernel.h>: Contains kernel-specific functions and macros, including logging functions like printk.
• <linux/init.h>: Used for module initialization and cleanup functions.
• <linux/fs.h>: Provides the file system interface and structures such as file_operations.
• <linux/uaccess.h>: Used for safely copying data between user space and kernel space.
• <linux/cdev.h>: Provides character device registration functions and structures.
• <linux/gpio.h>: Provides functions and macros for interacting with General-Purpose Input/Output (GPIO) pins.
• <linux/interrupt.h>: Used for handling hardware interrupts.

Getting Started

These instructions will guide you through setting up your environment to compile and run the device driver programs in this repository.

Prerequisites

Before you start, ensure that you have the following installed on your Linux machine:

• Linux Kernel Headers: Required for compiling kernel modules.

  sudo apt-get install linux-headers-$(uname -r)
  
  

Step-by-step Program Execution

Each program is contained in its own directory. Navigate to the directory of the program you want to compile: file will be found in tutorial_1 directory.

  mkdir Driver
  cd Driver
  touch first_drive.c Makefile

• Examine the Source Code

Before compiling, you may want to review the source code. Each program typically includes a .c file and a Makefile. The .c file contains the driver code, and the Makefile defines how to compile the module.

sudo make first_drive.c

This will produce a .ko file (e.g., hello_world.ko), which is the compiled kernel module.

• Insert the Kernel Module Load the module into the kernel using insmod:

sudo insmod first_driver.ko

Replace first_driver.ko with the name of the module you compiled.

• Verify the Module Loading Check the kernel messages to verify that the module has been loaded successfully:

dmesg | tail

This should show output related to your module.

• Interact with the Module (if applicable) If the module creates a device file (e.g., in /dev/), you can interact with it using standard file operations like cat, echo, or custom programs.

• Remove the Kernel Module When you’re done, unload the module from the kernel:

sudo rmmod first_driver

Replace first_driver with the name of the module you loaded.

• Clean Up Remove the generated files from the directory:

make clean

This will delete the .o, .ko, and other temporary files.

Summary

• The Header Files section lists the commonly used headers in your Linux device driver programs.

• The Step-by-Step Program Execution section provides a detailed guide to compiling, loading, interacting with, and cleaning up after running the programs.

This README.md should serve as a comprehensive guide for anyone looking to understand, compile, and run the Linux device driver programs in your repository.