hi all:
i followed the <The Linux Kernel Module Programming Guide>, and wrote a
module hello-1.c:
[code]
#include <linux/module.h>
#include <linux/kernel.h>

int init_module(void)
{
        printk("<1>Hello world 1.\n");

        return 0;
}

void cleanup_module(void)
{
        printk(KERN_ALERT "Goodbye world 1.\n");
}
[/code]
meanwhile i built a makefile:
[code]
TARGET  := hello-1
WARN    := -W -Wall -Wstrict-prototypes -Wmissing-prototypes
INCLUDE := -isystem /lib/modules/`uname -r`/build/include
CFLAGS  := -O2 -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE}
CC      := gcc

${TARGET}.o: ${TARGET}.c
[/code]
but, when i executed the make command, i have gotten these:
[code]
hello-1.c:5: warning: no previous prototype for `init_module'
hello-1.c:12: warning: no previous prototype for `cleanup_module'
/lib/modules/2.4.20-8/build/include/asm/processor.h: In function
`copy_segments':
/lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
parameter `p'
/lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
parameter `mm'
/lib/modules/2.4.20-8/build/include/asm/processor.h: In function
`release_segments':
/lib/modules/2.4.20-8/build/include/asm/processor.h:457: warning: unused
parameter `mm'
/lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
`prefetch':
/lib/modules/2.4.20-8/build/include/linux/prefetch.h:43: warning: unused
parameter `x'
/lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
`prefetchw':
/lib/modules/2.4.20-8/build/include/linux/prefetch.h:48: warning: unused
parameter `x'
[/code]
what is wrong with it? who would tell me? many thanks!!!

Final wrote:

[]

> WARN    := -W -Wall -Wstrict-prototypes -Wmissing-prototypes

[]

> hello-1.c:5: warning: no previous prototype for `init_module'
> hello-1.c:12: warning: no previous prototype for `cleanup_module'

[]

> what is wrong with it? who would tell me? many thanks!!!

man gcc

       -Wmissing-prototypes (C only)
           Warn if a global function is defined without a previous
prototype
           declaration.  This warning is issued even if the definition
itself
           provides a prototype.  The aim is to detect global functions
that
           fail to be declared in header files.

"Final" <k00kyy@gmail.com> wrote in message 
news:dnt853$333$1@news.yaako.com...
> hi all:
> i followed the <The Linux Kernel Module Programming Guide>, and wrote a
> module hello-1.c:
> [code]
> #include <linux/module.h>
> #include <linux/kernel.h>
>
> int init_module(void)
> {
>        printk("<1>Hello world 1.\n");
>
>        return 0;
> }
>
> void cleanup_module(void)
> {
>        printk(KERN_ALERT "Goodbye world 1.\n");
> }
> [/code]
> meanwhile i built a makefile:
> [code]
> TARGET  := hello-1
> WARN    := -W -Wall -Wstrict-prototypes -Wmissing-prototypes
> INCLUDE := -isystem /lib/modules/`uname -r`/build/include
> CFLAGS  := -O2 -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE}
> CC      := gcc
>
> ${TARGET}.o: ${TARGET}.c
> [/code]
> but, when i executed the make command, i have gotten these:
> [code]
> hello-1.c:5: warning: no previous prototype for `init_module'
> hello-1.c:12: warning: no previous prototype for `cleanup_module'
> /lib/modules/2.4.20-8/build/include/asm/processor.h: In function
> `copy_segments':
> /lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
> parameter `p'
> /lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
> parameter `mm'
> /lib/modules/2.4.20-8/build/include/asm/processor.h: In function
> `release_segments':
> /lib/modules/2.4.20-8/build/include/asm/processor.h:457: warning: unused
> parameter `mm'
> /lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
> `prefetch':
> /lib/modules/2.4.20-8/build/include/linux/prefetch.h:43: warning: unused
> parameter `x'
> /lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
> `prefetchw':
> /lib/modules/2.4.20-8/build/include/linux/prefetch.h:48: warning: unused
> parameter `x'
> [/code]
> what is wrong with it? who would tell me? many thanks!!!
>

Well, your compilation options included "-Wmissing-prototypes", so it 
complains because you did not provide a prototype for those functions.
Try putting the prototypes in at the top of your source file (after 
#includes):
   int init_module(void);
   int init_module(void);

-- 
Fred L. Kleinschmidt
Boeing Associate Technical Fellow
Technical Architect, Software Reuse Project

Maxim Yegorushkin �:
> Final wrote:
> 
> []
> 
> 
>>WARN    := -W -Wall -Wstrict-prototypes -Wmissing-prototypes
> 
> 
> []
> 
> 
>>hello-1.c:5: warning: no previous prototype for `init_module'
>>hello-1.c:12: warning: no previous prototype for `cleanup_module'
> 
> 
> []
> 
> 
>>what is wrong with it? who would tell me? many thanks!!!
> 
> 
> man gcc
> 
>        -Wmissing-prototypes (C only)
>            Warn if a global function is defined without a previous
> prototype
>            declaration.  This warning is issued even if the definition
> itself
>            provides a prototype.  The aim is to detect global functions
> that
>            fail to be declared in header files.
> 
thanks,i modified the source:
////////////////////////////////////////////
#include <linux/module.h>
#include <linux/kernel.h>

int init_module(void);
void cleanup_module(void);

int init_module(void)
{
        printk("<1>Hello world 1.\n");

        return 0;
}

void cleanup_module(void)
{
        printk(KERN_ALERT "Goodbye world 1.\n");
}
///////////////////////////////////////////////////////////////
but some warnings keep on:
//////////////////////////////////////////////////////////////
/lib/modules/2.4.20-8/build/include/asm/processor.h: In function
`copy_segments':
/lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
parameter `p'
/lib/modules/2.4.20-8/build/include/asm/processor.h:456: warning: unused
parameter `mm'
/lib/modules/2.4.20-8/build/include/asm/processor.h: In function
`release_segments':
/lib/modules/2.4.20-8/build/include/asm/processor.h:457: warning: unused
parameter `mm'
/lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
`prefetch':
/lib/modules/2.4.20-8/build/include/linux/prefetch.h:43: warning: unused
parameter `x'
/lib/modules/2.4.20-8/build/include/linux/prefetch.h: In function
`prefetchw':
/lib/modules/2.4.20-8/build/include/linux/prefetch.h:48: warning: unused
parameter `x'
////////////////////////////////////////////////////////////////////////

Final wrote:

[]

> but some warnings keep on:

Study your compiler documentation. -Wall flag turns on -Wunused.

You are not likely to modify linux headers, you only can turn the
warning off or ignore it.