c语言Linux内核驱动
时间: 2024-01-27 08:41:16 浏览: 34
C语言是Linux内核驱动程序常用的编程语言之一。Linux内核驱动程序是一种特殊的软件,它允许操作系统与硬件进行交互,从而使计算机系统能够正常工作。以下是C语言在Linux内核驱动程序中的使用示例:
1. 设备驱动程序
设备驱动程序是Linux内核驱动程序的一种,它用于管理计算机系统中的硬件设备。设备驱动程序通常由C语言编写,以实现与设备的交互。例如,以下是一个简单的设备驱动程序示例:
```
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/device.h>
#define DEVICE_NAME "my_device"
static int major_number;
static struct class* device_class = NULL;
static struct device* device = NULL;
static int device_open(struct inode* inode, struct file* file)
{
printk(KERN_INFO "Device opened\n");
return 0;
}
static int device_release(struct inode* inode, struct file* file)
{
printk(KERN_INFO "Device closed\n");
return 0;
}
static struct file_operations device_fops =
{
.open = device_open,
.release = device_release,
};
static int __init device_init(void)
{
major_number = register_chrdev(0, DEVICE_NAME, &device_fops);
if (major_number < 0)
{
printk(KERN_ALERT "Failed to register device\n");
return major_number;
}
device_class = class_create(THIS_MODULE, DEVICE_NAME);
if (IS_ERR(device_class))
{
unregister_chrdev(major_number, DEVICE_NAME);
printk(KERN_ALERT "Failed to create device class\n");
return PTR_ERR(device_class);
}
device = device_create(device_class, NULL, MKDEV(major_number, 0), NULL, DEVICE_NAME);
if (IS_ERR(device))
{
class_destroy(device_class);
unregister_chrdev(major_number, DEVICE_NAME);
printk(KERN_ALERT "Failed to create device\n");
return PTR_ERR(device);
}
printk(KERN_INFO "Device registered\n");
return 0;
}
static void __exit device_exit(void)
{
device_destroy(device_class, MKDEV(major_number, 0));
class_unregister(device_class);
class_destroy(device_class);
unregister_chrdev(major_number, DEVICE_NAME);
printk(KERN_INFO "Device unregistered\n");
}
module_init(device_init);
module_exit(device_exit);
```
2. 文件系统驱动程序
文件系统驱动程序用于管理Linux文件系统中的文件和目录。文件系统驱动程序通常由C语言编写,以实现与文件系统的交互。例如,以下是一个简单的文件系统驱动程序示例:
```
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#define DEVICE_NAME "my_file"
static int device_open(struct inode* inode, struct file* file)
{
printk(KERN_INFO "File opened\n");
return 0;
}
static int device_release(struct inode* inode, struct file* file)
{
printk(KERN_INFO "File closed\n");
return 0;
}
static ssize_t device_read(struct file* file, char* buffer, size_t length, loff_t* offset)
{
printk(KERN_INFO "File read\n");
return 0;
}
static ssize_t device_write(struct file* file, const char* buffer, size_t length, loff_t* offset)
{
printk(KERN_INFO "File written\n");
return length;
}
static struct file_operations device_fops =
{
.open = device_open,
.release = device_release,
.read = device_read,
.write = device_write,
};
static int __init device_init(void)
{
register_chrdev(0, DEVICE_NAME, &device_fops);
printk(KERN_INFO "File registered\n");
return 0;
}
static void __exit device_exit(void)
{
unregister_chrdev(0, DEVICE_NAME);
printk(KERN_INFO "File unregistered\n");
}
module_init(device_init);
module_exit(device_exit);
```
这些示例程序只是Linux内核驱动程序的基础,实际的驱动程序可能会更加复杂和详细。