Driver porting: compiling external modules

Posted Nov 9, 2004 0:57 UTC (Tue) by kabbalah (guest, #25930)
Parent article: Driver porting: compiling external modules

hi there
I installed SuSe 9.1 with 2.6.4-52-default kernel and I'm having some problems writing modules for it.
I've read these articles and still can't find the answer....
that's my module

//#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>

//MODULE_LICENSE("Dual BSD/GPL");

static int module_init(void)
{
printk("<1>Hello world 1.\n");
return 0;
}

static void module_exit(void)
{
printk("Goodbye world 1.\n");
}

and that's the makefile

ifneq ($(KERNELRELEASE),)
obj-m:= h.o

else
KDIR:= /lib/modules/$(shell uname -r)/build
PWD:= $(shell pwd)

default:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
endif

When I compile it I get these
h.c:10: error: parse error before "__initcall_void"
h.c:10: error: parse error before "void"
h.c:19: error: parse error before "__exitcall_void"
h.c:19: error: redefinition of `__attribute_used__'
h.c:10: error: `__attribute_used__' previously defined here
h.c:19: error: parse error before "void"
make: *** [h] Error 1

any ideas why this happens ?

to post comments

Driver porting: compiling external modules

Posted Nov 9, 2004 10:16 UTC (Tue) by madhavi_srinivas (guest, #25933) [Link] (2 responses)

Dear Kabbalah,

I am using SuSE 9.1 with 2.6.5-7.71 kernel. I have written small hello.c program here. It was working fine on my x86 machine.

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>

MODULE_LICENSE("GPL");

static int hello_init(void)
{
printk("Hello World!\n");
return 0;
}

static void hello_exit(void)
{
printk("Good bye!\n");
}

module_init(hello_init);
module_exit(hello_exit);

For this the make file is as follows.

KDIR:=/lib/modules/$(shell uname -r)/build

obj-m:=hello.o

default:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
clean:
$(RM) .*.cmd *.o *.ko -r .tmp*

It was working fine under x86 machine with 2.6.5-7.71 kernel version with SuSE Linux.

Regards,
Srinivas G

Driver porting: compiling external modules

Posted Nov 9, 2004 21:25 UTC (Tue) by kabbalah (guest, #25930) [Link] (1 responses)

thank you for your reply, I tried your code but when i compile it I still get plenty of errors:
cc hello.c -o hello
In file included from /usr/include/linux/sched.h:12,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/jiffies.h:16: error: parse error before "jiffies_64"
/usr/include/linux/jiffies.h:20: error: parse error before "get_jiffies_64"
In file included from /usr/include/linux/sched.h:21,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/asm/mmu.h:13: error: field `sem' has incomplete type
In file included from /usr/include/linux/signal.h:4,
from /usr/include/linux/sched.h:25,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/list.h:604:2: warning: #warning "don't include kernel headers in userspace"
In file included from /usr/include/asm/siginfo.h:4,
from /usr/include/linux/signal.h:7,
from /usr/include/linux/sched.h:25,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/asm-generic/siginfo.h:53: error: size of array `_pad' is too large
In file included from /usr/include/linux/sched.h:27,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/fs_struct.h:9: error: parse error before "rwlock_t"
/usr/include/linux/fs_struct.h:13: error: parse error before '}' token
In file included from /usr/include/linux/sched.h:29,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/completion.h:15: error: parse error before "wait_queue_head_t"
/usr/include/linux/completion.h: In function `init_completion':
/usr/include/linux/completion.h:26: error: dereferencing pointer to incomplete type
/usr/include/linux/completion.h:27: error: dereferencing pointer to incomplete type
In file included from /usr/include/linux/sched.h:30,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/pid.h: At top level:
/usr/include/linux/pid.h:18: error: field `task_list' has incomplete type
/usr/include/linux/pid.h:19: error: field `hash_chain' has incomplete type
/usr/include/linux/pid.h:24: error: field `pid_chain' has incomplete type
In file included from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/sched.h:93: error: parse error before "process_counts"
In file included from /usr/include/linux/sched.h:102,
from /usr/include/linux/module.h:9,
from hello.c:2:
/usr/include/linux/timer.h:10: error: field `entry' has incomplete type
hello.c:22: error: parse error before "__attribute_used__"
hello.c:22: warning: initialization makes integer from pointer without a cast
hello.c:22: warning: data definition has no type or storage class
hello.c:23: error: parse error before "__attribute_used__"
hello.c:23: error: redefinition of `__attribute_used__'
hello.c:22: error: `__attribute_used__' previously defined here
hello.c:23: warning: initialization makes integer from pointer without a cast
hello.c:23: warning: data definition has no type or storage class
hello.c:23:25: warning: no newline at end of file
make: *** [hello] Error 1

when i remove the #include <linux/modules.h> directive I get less errors but it still won't compile:
cc hello.c -o hello
hello.c:6: error: parse error before string constant
hello.c:6: warning: data definition has no type or storage class
hello.c:22: error: parse error before "__attribute_used__"
hello.c:22: warning: initialization makes integer from pointer without a cast
hello.c:22: warning: data definition has no type or storage class
hello.c:23: error: parse error before "__attribute_used__"
hello.c:23: error: redefinition of `__attribute_used__'
hello.c:22: error: `__attribute_used__' previously defined here
hello.c:23: warning: initialization makes integer from pointer without a cast
hello.c:23: warning: data definition has no type or storage class
make: *** [hello] Error 1

so that makes me pretty much desperate now :)
I guess I will have to forget about LKMs till the next Linux I install...
anyhow 10x again :)

Driver porting: compiling external modules

Posted Nov 26, 2004 9:44 UTC (Fri) by wuyanmin2 (guest, #26262) [Link]

My kernel version is 2.6.5, I complied a "Hello world" module,it's very simple but the size is more than 100K, however, most of the kernel modules in /lib/modules/ are less than 50K . What's the matter? How can I complie a smaller module??

Thanks

WU Yan-min