[x86 drive program]helloworld

墨蓝 2021-09-22 16:24 322阅读 0赞

Referce: [https://www.cnblogs.com/amanlikethis/p/4914510.html][https_www.cnblogs.com_amanlikethis_p_4914510.html]

1.Compile drive program

Add hello.c hellotest.c Makefile in a total directory. Then input "make"  to compile.

2.Compile appication program

gcc hellotest.c -o hellotest

3. Install mudule.

sudo insmod hellomodule.ko

Then input "dmesg", will see the message of mudule prinf, as below:

![20181224091037360.png][]

See mudle if install succedful: use command cat /proc/modules

![20181221164839222.png][]

or just use command

lsmod

4.Creat Node

sudo mknod /dev/hellodev c 231 0

If success, as bellow:

![20181221165745724.png][]

5.Run the application.

![2018122116591236.png][]

6.Remove mudule

sudo rmmod hellomodule

# Appendix: Source file #

hello.c

#include <linux/module.h>
    #include <linux/kernel.h>
    #include <linux/fs.h>
    #include <linux/init.h>
    #include <linux/delay.h>
    
    #define    HELLO_MAJOR     231
    #define    DEVICE_NAME     "HelloModule"
    
    static int hello_open(struct inode *inode, struct file *file){
        printk(KERN_EMERG "hello open.\n");
        return 0;
    }
    	
    static ssize_t hello_write(struct file *pFile, const char __user * buf, size_t count, loff_t *ppos){
        printk(KERN_EMERG "hello write.\n");
        return 0;
    }
    
    static struct file_operations hello_flops = {
        .owner  =   THIS_MODULE,
        .open   =   hello_open,     
        .write  =   hello_write,
    };
    
    static int __init hello_init(void){
        int ret;
        
        ret = register_chrdev(HELLO_MAJOR,DEVICE_NAME, &hello_flops);
        if (ret < 0) {
          printk(KERN_EMERG DEVICE_NAME " can't register major number.\n");
          return ret;
        }
        printk(KERN_EMERG DEVICE_NAME " initialized.\n");
        return 0;
    }
    
    static void __exit hello_exit(void){
        unregister_chrdev(HELLO_MAJOR, DEVICE_NAME);
        printk(KERN_EMERG DEVICE_NAME " removed.\n");
    }
    
    module_init(hello_init);
    module_exit(hello_exit);
    MODULE_LICENSE("GPL");

Makefile:

ifneq ($(KERNELRELEASE),)
    MODULE_NAME = hellomodule
    $(MODULE_NAME)-objs := hello.o
    obj-m := $(MODULE_NAME).o
    else
    KERNEL_DIR = /lib/modules/`uname -r`/build
    MODULEDIR := $(shell pwd)
    
    .PHONY: modules
    default: modules
    
    modules:
    	make -C $(KERNEL_DIR) M=$(MODULEDIR) modules
    
    clean distclean:
    	rm -f *.o *.mod.c .*.*.cmd *.ko
    	rm -rf .tmp_versions
    endif

Application program:

hellotest.c

#include <fcntl.h>
    #include <stdio.h>
    
    int main(void)
    {
        int fd;
        int val = 1;
        fd = open("/dev/hellodev", O_RDWR);
        if(fd < 0){
            printf("can't open!\n");
        }
        write(fd, &val, 4);
        return 0;
    }

(end)

[https_www.cnblogs.com_amanlikethis_p_4914510.html]: https://www.cnblogs.com/amanlikethis/p/4914510.html
[20181224091037360.png]: /images/20210920/ae344831734e43d4b7c9c6da7b9ccd6b.png
[20181221164839222.png]: /images/20210920/11d348f00316433da6f1ea9aad6af7b8.png
[20181221165745724.png]: /images/20210920/2fbf8682dc2f4ac19f4e0da2f58de5a8.png
[2018122116591236.png]: /images/20210920/71b85798b27b46298f201f05be5be6b6.png