Linux's simplest Driver Model: helloworld!

Linux's simplest Driver Model: helloworld! -- Linux general technology-Linux programming and kernel information. The following is a detailed description. 1. The file hello. c contains the following content:
# Ifndef _ KERNEL __
# Define _ KERNEL __
# Endif
# Ifndef MODULE
# Define MODULE
# Endif

# Include /* Printk */
# Include
# Include /* Module_init module_exit */

Static int _ init hello_init (void)
{
Printk ("hello world, my god! \ N ");
Return 0;
}

Static void _ exit hello_exit (void)
{
Printk ("bye, my god! \ N ");
}

Module_init (hello_init );
Module_exit (hello_exit );
MODULE_LICENSE ("GPL ");

2. Compile the driver
2.1 hardware environment Introduction:
2.1.1> redhat9 [linux-2.4.20-8] In vmwarevm
2.1.2> putty.exe remote ssh login to linux on vmware
2.1.3> Use winscp.exe in windows XP and copy remote small files from linux in vmware
2.1.4> vmware-> files-> Settings-> options-> sharing large files [/mnt/hgfs/] [gliethttp]
2.2 Preparation:
Since I'm using a linux testing system as a linux-2.4.20-8, first make sure that/usr/src/linux-2.4.20-8 exists
If it does not exist, download the linux-2.4.20-8 kernel source code, put it in any directory, just put the downloaded linux-2.4.20-8 kernel source code, put in
In the/usr/src directory, the preparation is complete.
2.3 compile
[Root @ gliethttp] # gcc-c hello. c-I/usr/src/linux-2.4.20-8/include
After success, the system generates hello. o in the same directory as hello. c.
2.4 execution
[Root @ gliethttp] # insmod hello. o
Hello world, my // display
[Root @ gliethttp] # lsmod // view the hello driver Unit
[Root @ gliethttp] # rmmod hello // remove from the system
Bye, my // display
NOTE: If it is executed in putty, the putty will not show the results, but the [gliethttp] will be displayed in vmware's tty.