内核及设备驱动实验报告一、实验目的1.学习Linux操作系统下内核程序的编写和应用。
2.学习可编程接口芯片的编程控制方法。
二、实验内容与要求1.完成一个内核模块的编写，实现内核模块的正确加载和卸载。
2.建立一个虚拟的字符设备驱动程序，至少要包含读、写功能，为用户程序提供内核空间与用户空间的数据交换，方案及实现过程自定。
3.在上面的基础上完成8253与自编的应用程序结合，实现特定的功能。
三、实验记录与分析程序清单：1.驱动程序#include <linux/kernel.h>#include <linux/module.h>#include <linux/fs.h>#include <asm/uaccess.h>int init_module(void);void cleanup_module(void);static int device_open(struct inode *, struct file *);static int device_release(struct inode *, struct file *);static ssize_t device_read(struct file *, char *, size_t, loff_t *);static ssize_t device_write(struct file *, const char *, size_t, loff_t *);#define SUCCESS 0#define DEVICE_NAME "chardev"#define BUF_LEN 80static int Major;static int Device_Open = 0;static char msg[BUF_LEN];static char *msg_Ptr;static struct file_operations fops = {.read = device_read,.write = device_write,.open = device_open,.release = device_release};int init_module(void){Major = register_chrdev(0, DEVICE_NAME, &fops);if (Major < 0) {printk ("Registering the character device failed with %d\n", Major);return Major;}printk("<1>I was assigned major number %d. To talk to\n", Major);printk("<1>the driver, create a dev file with\n");printk("'mknod /dev/hello c %d 0'.\n", Major);printk("<1>Try various minor numbers. Try to cat and echo to\n");printk("the device file.\n");printk("<1>Remove the device file and module when done.\n");return 0;}void cleanup_module(void){int ret = unregister_chrdev(Major, DEVICE_NAME);if (ret < 0) printk("Error in unregister_chrdev: %d\n", ret);}static int device_open(struct inode *inode, struct file *file){static int counter = 0;if (Device_Open) return -EBUSY;printk("major and minor device number=%x\n", inode->i_rdev);printk("Major number=%d\n", MAJOR(inode->i_rdev));Device_Open++;sprintf(msg,"I have already told you %d times Hello world!\n", counter++);msg_Ptr = msg;return SUCCESS;}static int device_release(struct inode *inode, struct file *file){Device_Open --;return 0;}static ssize_t device_read(struct file *filp,char *buffer, size_t length,loff_t *offset){int bytes_read = 0;if (*msg_Ptr == 0) return 0;while (length && *msg_Ptr){put_user(*(msg_Ptr++), buffer++);length--;bytes_read++;}return bytes_read;}static ssize_t device_write(struct file *filp,const char *buff,size_t len,loff_t *off){printk ("<1>Sorry, this operation isn't supported.\n");return -EINV AL;}2.Makefile文件KSRC = /lib/modules/`uname -r`/buildPWD = $(shell pwd)obj-m = chardev.odefault:make -C $(KSRC) SUBDIRS=$(PWD) modulesclean:$(MAKE) -C $(KSRC) SUBDIRS=$(PWD) clean执行make指令后生成chrdev.ko内核文件Insmod加载内核后，lsmod查看内核可以看到大小为6900的chardev，使用次数为0 通过mknod指令创建设备文件通过ls -l /dev查看设备文件3应用程序通过运行下面程序访问设备chrdev#include <stdio.h>#include <fcntl.h>int main(){int fd, n;char buff[80];fd = open("./dev/chrdev", O_RDONLY);if(fd < 0){printf("Open File Failed\n");return -1;}printf("Open File Successed\n");n = read(fd, buff, 40);buff[n]='\0';printf("%s\n", buff);close(fd);return 0;}8253应用程序1驱动程序#include<linux/kernel.h>#include<linux/init.h>#include<linux/module.h>#include<linux/fs.h>#include<linux/ioport.h>#include<asm/uaccess.h>#include<asm/io.h>#define TIMERIOMAGIC 250#define INIT _IOW(TIMERIOMAGIC,0,int)#define DAT _IOW(TIMERIOMAGIC,1,int)#define START _IOW(TIMERIOMAGIC,2,int)#define STOP _IOW(TIMERIOMAGIC,3,int)#define MAJOR 240#define NAME "8253"static int tyue_open(struct inode *,struct file *);static int tyue_ioctl(struct inode *,struct file *,unsigned int,unsigned long);static int tyue_close(struct inode *,struct file *);static int Device_open=0;static struct file_operations fops={.open= tyue_open,.ioctl= tyue_ioctl,.release= tyue_close,};int init_module(){int ret;ret=register_chrdev(MAJOR,NAME,&fops);return 0;}void cleanup_module(void){unregister_chrdev(TIMER_MAJOR,TIMER_NAME);}static int tyue_ioctl(struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg){ unsigned int freq=0;switch(cmd){case INIT:outb_p(0xb6,0x43);break;case START:outb_p(0x03,0x61);break;case DAT:freq=(unsigned int)arg;outb_p((char)(freq&0x00ff),0x42);outb_p((char)(freq>>8),0x42);break;case STOP:outb_p(0x00,0x61);break;default:printk("INV ALID COMMANDS!\n");}return 0;}static int tyue_open(struct inode *inode,struct file *file){if(Device_open) return -EBUSY;Device_open++;return 0;}static int tyue_close(struct inode *inode,struct file *file){Device_open--;outb_p(0,0x61);return 0;}2 应用程序2.应用程序#include <stdio.h>#include <unistd.h>#include <fcntl.h>#include <sys/types.h>#include <sys/ioctl.h>#define INIT _IOW(TIMERIOMAGIC,0,int)#define DAT _IOW(TIMERIOMAGIC,1,int)#define START _IOW(TIMERIOMAGIC,2,int)#define STOP _IOW(TIMERIOMAGIC,3,int)freq[]={0x237b,0x1f9f,0x1c2c,0x1a90,0x17b7,0x1521,0x12d1}; int main(){fd=open("8253",O_RDONLY);ioctl(fd,SINIT,0);int i;printf("vioce:1,2,3,4,5,6,7\n");printf("stop :Ctrl+c\n");for(i=0;i<10000;i++){char b;b = getchar();switch(b){case '1': ioctl(fd,DATA,freq[0]);break;case '2': ioctl(fd,DATA,freq[1]);break;case '3': ioctl(fd,DATA,freq[2]);break;case '4': ioctl(fd,DATA,freq[3]);break;case '5': ioctl(fd,DATA,freq[4]);break;case '6': ioctl(fd,DATA,freq[5]);break;case '7': ioctl(fd,DATA,freq[6]);break;default : break;}ioctl(fd,START,0);sleep（1）；ioctl(fd,STOP,0);sleep（0.1）；}}实验现象按键1,2,3,4,5,6,7控制音调，按键则发声，Ctrl+c退出程序。
