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Aprende What a Device Driver Is and How the Kernel Uses It | Foundations of Device Drivers
C Device Drivers Basics

bookWhat a Device Driver Is and How the Kernel Uses It

A device driver is a specialized program that allows the Linux kernel to communicate with hardware devices. Its core purpose is to translate generic kernel commands into device-specific operations, so the operating system can control and interact with a wide variety of hardware without needing to know the intricate details of each device. Device drivers act as a bridge between the kernel and the physical components of a computer, such as disks, network cards, or USB peripherals. By providing a standard interface, drivers enable the kernel to manage devices efficiently and securely.

minimal_driver.c

minimal_driver.c

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#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> // Initialization function static int __init minimal_driver_init(void) { printk(KERN_INFO "Minimal driver loaded\n"); return 0; } // Exit function static void __exit minimal_driver_exit(void) { printk(KERN_INFO "Minimal driver unloaded\n"); } module_init(minimal_driver_init); module_exit(minimal_driver_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Your Name"); MODULE_DESCRIPTION("A minimal example device driver");

The kernel interacts with device drivers through specific entry points, most notably the initialization and exit functions. When a driver is loaded, the kernel calls the function registered with module_init, which is responsible for setting up the driver, registering devices, and preparing resources. When the driver is unloaded, the function registered with module_exit is called to clean up and free any resources. In the minimal driver example above, minimal_driver_init and minimal_driver_exit serve these roles, providing a controlled way for the kernel to manage the driver's lifecycle.

log_message_driver.c

log_message_driver.c

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#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> static int __init log_message_driver_init(void) { printk(KERN_INFO "Hello from the kernel driver!\n"); return 0; } static void __exit log_message_driver_exit(void) { printk(KERN_INFO "Goodbye from the kernel driver!\n"); } module_init(log_message_driver_init); module_exit(log_message_driver_exit); MODULE_LICENSE("GPL");
question mark

Which function is used to log messages from a kernel module to the kernel log?

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Sección 1. Capítulo 1

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bookWhat a Device Driver Is and How the Kernel Uses It

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A device driver is a specialized program that allows the Linux kernel to communicate with hardware devices. Its core purpose is to translate generic kernel commands into device-specific operations, so the operating system can control and interact with a wide variety of hardware without needing to know the intricate details of each device. Device drivers act as a bridge between the kernel and the physical components of a computer, such as disks, network cards, or USB peripherals. By providing a standard interface, drivers enable the kernel to manage devices efficiently and securely.

minimal_driver.c

minimal_driver.c

copy
123456789101112131415161718192021
#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> // Initialization function static int __init minimal_driver_init(void) { printk(KERN_INFO "Minimal driver loaded\n"); return 0; } // Exit function static void __exit minimal_driver_exit(void) { printk(KERN_INFO "Minimal driver unloaded\n"); } module_init(minimal_driver_init); module_exit(minimal_driver_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Your Name"); MODULE_DESCRIPTION("A minimal example device driver");

The kernel interacts with device drivers through specific entry points, most notably the initialization and exit functions. When a driver is loaded, the kernel calls the function registered with module_init, which is responsible for setting up the driver, registering devices, and preparing resources. When the driver is unloaded, the function registered with module_exit is called to clean up and free any resources. In the minimal driver example above, minimal_driver_init and minimal_driver_exit serve these roles, providing a controlled way for the kernel to manage the driver's lifecycle.

log_message_driver.c

log_message_driver.c

copy
1234567891011121314151617
#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> static int __init log_message_driver_init(void) { printk(KERN_INFO "Hello from the kernel driver!\n"); return 0; } static void __exit log_message_driver_exit(void) { printk(KERN_INFO "Goodbye from the kernel driver!\n"); } module_init(log_message_driver_init); module_exit(log_message_driver_exit); MODULE_LICENSE("GPL");
question mark

Which function is used to log messages from a kernel module to the kernel log?

Select the correct answer

¿Todo estuvo claro?

¿Cómo podemos mejorarlo?

¡Gracias por tus comentarios!

Sección 1. Capítulo 1
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