内核及设备驱动实验报告.doc

内核及设备驱动实验报告1、 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。2、 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。3、 实验记录与分析程序清单：1. 驱动程序 #include #include #include #include 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 80 static int Major; static int Device_Open = 0; static char msgBUF_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 %dn, Major); return Major; printk(I was assigned major number %d. To talk ton, Major); printk(the driver, create a dev file withn); printk(mknod /dev/hello c %d 0.n, Major); printk(Try various minor numbers. Try to cat and echo ton); printk(the device file.n); printk(Remove the device file and module when done.n); return 0;void cleanup_module(void) int ret = unregister_chrdev(Major, DEVICE_NAME); if (ret i_rdev);printk(Major number=%dn, 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 (Sorry, this operation isnt supported.n); return -EINVAL;2. Makefile文件 KSRC = /lib/modules/uname -r/build PWD = $(shell pwd) obj-m = chardev.o default: make -C $(KSRC) SUBDIRS=$(PWD) modules clean: $(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 #include int main() int fd, n; char buff80; fd = open(./dev/chrdev, O_RDONLY); if(fd 0) printf(Open File Failedn); return -1; printf(Open File Successedn); n = read(fd, buff, 40); buffn=0; printf(%sn, buff); close(fd); return 0;8253应用程序1驱动程序#include#include#include#include#include#include#include#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 8253static 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)(freq8),0x42); break; case STOP: outb_p(0x00,0x61); break; default: printk(INVALID 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 #include #include #include #include #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:1,2,3,4,5,6,7n); printf(stop :Ctrl+cn);for(i=0;i10000;i+) char b; b = getchar(); switch(b) case 1: ioctl(fd,DATA,freq0);break; case 2: ioctl(fd,DATA,freq1);break; case 3: ioctl(fd,DATA,freq2);break; case 4: ioctl(fd,DATA,freq3