1. Device Driver_Skeleton

2. a. Device Driver skeleton.c #include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/major.h>
MODULE_LICENSE("GPL");
int result;
int skeleton_open(struct inode *inode, struct file *filp) {
printk("Device Open!!\n");
return 0; }
int skeleton_release(struct inode *inode, struct file *filp) {
printk("Device Release!!\n");
int skeleton_read(struct file *filp, const char *buf, size_t count, loff_t *f_pos){
printk("Device Read!!\n");
int skeleton_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) {
printk("Device Ioctl!!\n");

3. a. Device Driver skeleton.c
int skeleton_write(struct file *filp, unsigned int *buf, size_t count, loff_t *f_pos) {
printk("Device Write!!\n");
return 0; }
struct file_operations skeleton_fops = {
.open = skeleton_open,
.release= skeleton_release,
.read = skeleton_read,
.unlocked_ioctl = skeleton_ioctl,
.write = skeleton_write, };
static int skeleton_init(void)
printk("skeleton module init!!\n");
result = register_chrdev(0, "skeleton!!", &skeleton_fops);
printk("major number=%d\n", result);
static void skeleton_exit(void)
printk("skeleton module exit!!\n");
module_init(skeleton_init);
module_exit(skeleton_exit);

4. a. Device Driver Makefile
CC := /usr/local/CodeSourcery/Sourcery_G++_Lite/bin/arm-none-eabi-gcc
KDIR := /Smart4412Linux/Development/Source/Kernel/kernel_4412
obj-m := skeleton.o
build :
make -C $(KDIR) SUBDIRS=$(PWD) modules
clean :
rm -rf *.o *.ko *.mod.c *.order *.symvers

5. a. Device Driver userapp.c #include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
int main() {
int fd;
fd = open("/dev/skeleton", O_RDWR);
printf("Device Driver Test Application\n");
read(fd, 0, 0);
ioctl(fd, NULL, 0);
close(fd);
return 0; }

6. a. Device Driver
Applicaton Build
# make

7. a. Device Driver DeviceDriver module Build
# arm-linux-gnueabihf-gcc userapp.c –o userapp

8. a. Device Driver insmod # insmod skeleton.ko
# mknod /dev/skeleton c 248 0
# ./userapp
# lsmod
# dmesg