hey m new to the kernel programming, am trying to build a simple hello world kernel module. when i executed the make file its working well even i can insert and remove module in kernel modules. but when i try to compile module with gcc its giving errors.

am using boss os and kernel version is 3.0, latest gcc is also installed in my system.

my hello world program is:

vim hello.c
#include<linux/init.h>
#include<linux/module.h>
#include<linux/kernel.h>

static int start_mod()
{
printk("initialize kernel module\n");
printk("hello world!\n");
return 0;
}
static void end_mod()
{
printk("kernel module unloaded.\n");
}

module_init(start_mod);
module_exit(end_mod);

and
my make file is:

vim Makefile
obj-m+=hello.o
all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

Since you received gcc error giving up that info would have been good.

However, lots of folks do this and this link will tell you exactly what you need to do. Whether or not it is advisable I cannot say, kernel hacking is not a forte of mine, but the folks at this link do it all the time. You could do well to have a good read. Their code for something similar is different than yours, since the outcome will be the same you should probably go with these kernel hackers.

First, bring up the file init/main.c in your favorite editor
Find the calibrate_delay(void) function in the file.

The first lines are declarations of a few variables, and will look something like this:

unsigned long ticks, loopbit;
int lps_precision = LPS_PREC;

Now, type in the following line just below them:

printk("*** I am a kernel hacker! ***\n");

Just a taster for you, read the whole page. If you want Kernel Hacking this place works.

http://www.linuxchix.org/content/cou...acking/lesson5

Bon chance

------------------------------------------------------------------------------------------------------------
Give me pat on the back if it works for you

1 members found this post helpful.

The link build must point to a location like
/usr/src/linux/ or /usr/src/3.0/ ,
to find e.g. /usr/src/3.0/include/linux/init.h


Your code compiles OK with the standard Makefile :

Am using debian os ,kernel version 3.0 and its latest gcc and headers are also installed in my computer.
when i try to compile my simple kernel module hello world program using gcc its giving error.

hello.c:1:23: error: linux/init.h: No such file or directory
hello.c:2:25: error: linux/module.h: No such file or directory
hello.c:16: warning: data definition has no type or storage class
hello.c:16: warning: parameter names (without types) in function declaration
hello.c:17: warning: data definition has no type or storage class
hello.c:17: warning: parameter names (without types) in function declaration

my hello world program is
#include<linux/init.h>
#include<linux/module.h>
#include<linux/kernel.h>

static int start_mod()
{
printk("initialize kernel module\n");
printk("hello world!\n");
return 0;
}
static void end_mod()
{
printk("kernel module unloaded.\n");
}

module_init(start_mod);
module_exit(end_mod);

and my Makefile is
obj-m+=hello.o
all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

Please edit posts #1 and #4 to use CODE tags :
Write [/code] at code end, and [code] at code text start.
Or use the # button in the 'Advanced Editor'.
http://www.linuxquestions.org/questi....php?do=bbcode

Your Makefile works OK
... So I guess your link /lib/modules/`uname -r`/build
is not pointing to /usr/src/linux-3.0/

.