Question

Kernal Modul Programing

Quenstion : Implement the following 4 conditions in kernel module programming.

1. Implement a timer module using the timer function provided by the file LINUX/timer.h
2. In module_init, the timer is initialized using setup_timer and called mod_timer to start the timer.
3. Call back function my_timer_callback when timer expires.
4. When you remove a module, delete the timer.

Answer 1

/**

* @file    hello.c

* @author Akshat Sinha

* @date 16 oct 2020

* @version 0.1

* @brief An introductory "Hello World!" loadable kernel

* module (LKM) that can display a message in the /var/log/kern.log

* file when the module is loaded and removed. The module can accept

* an argument when it is loaded -- the name, which appears in the

* kernel log files.

*/

#include <linux/module.h>     /* Needed by all modules */

#include <linux/kernel.h>     /* Needed for KERN_INFO */

#include <linux/init.h>       /* Needed for the macros */

  

///< The license type -- this affects runtime behavior

MODULE_LICENSE("GPL");

  

///< The author -- visible when you use modinfo

MODULE_AUTHOR("Akshat Sinha");

  

///< The description -- see modinfo

MODULE_DESCRIPTION("A simple Hello world LKM!");

  

///< The version of the module

MODULE_VERSION("0.1");

  

static int __init hello_start(void)

{

    printk(KERN_INFO "Loading hello module...\n");

    printk(KERN_INFO "Hello world\n");

    return 0;

}

  

static void __exit hello_end(void)

{

    printk(KERN_INFO "Goodbye Mr.\n");

}

  

module_init(hello_start);

module_exit(hello_end);