Re: problems compiling kernel module

["Fernando Barsoba" <fbarsoba@hotmail.com>]

Thanks a lot for your makefile. It worked nicely. I wasn't sure if the 
question was too basic for this mailing list.

Thanks also for Arjan's reference to 
http://fxr.watson.org/fxr/source/Documentation/kbuild/makefiles.txt?v=linux-2.6.9

I am new in kernel programming...

tnx,
Fernando

>From: Erik Mouw <erik@harddisk-recovery.com>
>To: Fernando Barsoba <fbarsoba@hotmail.com>
>CC: linux-kernel@vger.kernel.org
>Subject: Re: problems compiling kernel module
>Date: Wed, 19 Apr 2006 16:24:42 +0200
>
>On Wed, Apr 19, 2006 at 09:44:08AM -0400, Fernando Barsoba wrote:
> > I am really stuck with this thing.. For couple of days i have been
> > trying to compile a kernel module. I have been following the info in
> > http://www.faqs.org/docs/kernel/x204.html. But no success... i
> > recompiled the latest kernel version, and i think i trying to compile
> > the module against the source code for that kernel.. however, strange
> > errors appear.
>
>That way just doesn't work. Use kbuild instead of brewing your own
>Makefiles. See http://lwn.net/Articles/21823/ .
>
> > And here are the files:
> >
> > Code:
> >
> > /* hello-1.c - The simplest kernel module.
> > */ #include <linux/module.h> /* Needed by all modules
>
>Not necessary, IIRC.
>
> > */ #include <linux/kernel.h> /* Needed for KERN_ALERT */
>
>OK...
>
> > int init_module(void) {
> > printk("<1>Hello world 1.\n"); // A non 0 return means init_module
>
>... so why don't you use KERN_ALERT instead of <1>?
>
>Make that printk(KERN_ALERT "Hello, world!\n");
>
> > failed; module can't be loaded.
> > return 0;
> > }
> >
> > void cleanup_module(void) {
> > printk(KERN_ALERT "Goodbye world 1.\n");
> > }
> >
> >
> > 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: ${TARGET}.c
> > .PHONY: clean
> > clean: rm -rf {TARGET}.o
>
>You want something like:
>
>ifneq ($(KERNELRELEASE),)
>obj-m	:= hello.o
>else
>KDIR	:= /lib/modules/$(shell uname -r)/build
>PWD		:= $(shell pwd)
>
>default:
>	$(MAKE) -C $(KDIR) M=$(PWD) modules
>endif
>
>
>Erik
>
>--
>+-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 --
>| Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands
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