임베디드 Linux 소개 및 이것이 중요한 이유

#include  #include  #include  #include  #define DEVICE_NAME "my_device" #define BUF_SIZE 1024 static char buffer[BUF_SIZE]; static int major; static int my_device_open(struct inode *inode, struct file *file) { printk(KERN_INFO "Device opened "); return 0; } static int my_device_release(struct inode *inode, struct file *file) { printk(KERN_INFO "Device closed "); return 0; } static ssize_t my_device_read(struct file *file, char *buf, size_t count, loff_t *ppos) { if (copy_to_user(buf, buffer, count)) { return -EFAULT; } return count; } static ssize_t my_device_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { if (copy_from_user(buffer, buf, count)) { return -EFAULT; } return count; } static struct file_operations fops = { .open = my_device_open, .release = my_device_release, .read = my_device_read, .write = my_device_write, }; static int __init my_device_init(void) { major = register_chrdev(0, DEVICE_NAME, &fops); if (major < 0) { printk(KERN_ALERT "Failed to register device "); return major; } printk(KERN_INFO "Device registered with major number %d ", major); return 0; } static void __exit my_device_exit(void) { unregister_chrdev(major, DEVICE_NAME); printk(KERN_INFO "Device unregistered "); } module_init(my_device_init); module_exit(my_device_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Your Name"); MODULE_DESCRIPTION("A simple character device driver");