Problem in compiling a char device driver formerly for kernel 2.4 on kernel 2.6

payretep · 09-16-2007, 11:02 PM

Hi all, this is my first post here on LinuxQuestions and I really hope that you guys will be able to help me. I'm very new on Linux and I hope you all can understand the newbie question that I'm posting. (After all this is the newbie section

)

Here goes: I'm compiling a char device driver for Linux. It was formerly for kernel version 2.4.20-8 on Redhat and it was compiling working properly on that version. The problem comes when I am required to upgrade the kernel version from 2.4.20-8 to 2.6.18.

Fundamentally, I understand that there are major differences when using different kernel versions. However, as I am very new to the Linux environment and the error messages during compilation has nothing to do with device related errors, more of environment mismatch types, I am quite stuck.

I hope that the following error message that I paste can make some sense and provide some clues to you guys as to what I should do.

=====================================================================

/usr/src/linux/include/asm/rwsem.h: In function ‘__down_read’:
/usr/src/linux/include/asm/rwsem.h:106: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/rwsem.h: In function ‘__down_write’:
/usr/src/linux/include/asm/rwsem.h:158: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/rwsem.h: In function ‘__up_read’:
/usr/src/linux/include/asm/rwsem.h:195: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/rwsem.h:189: warning: unused variable ‘tmp’
/usr/src/linux/include/asm/rwsem.h: In function ‘__up_write’:
/usr/src/linux/include/asm/rwsem.h:221: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/rwsem.h: In function ‘__downgrade_write’:
/usr/src/linux/include/asm/rwsem.h:246: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
In file included from /usr/src/linux/include/linux/sched.h:20,
from /usr/src/linux/include/linux/module.h:10,
from client3.c:229:
/usr/src/linux/include/asm/semaphore.h: In function ‘down’:
/usr/src/linux/include/asm/semaphore.h:105: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/semaphore.h: In function ‘down_interruptible’:
/usr/src/linux/include/asm/semaphore.h:130: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/semaphore.h: In function ‘down_trylock’:
/usr/src/linux/include/asm/semaphore.h:155: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
/usr/src/linux/include/asm/semaphore.h: In function ‘up’:
/usr/src/linux/include/asm/semaphore.h:179: error: expected ‘:’ or ‘)’ before ‘KBUILD_BASENAME’
In file included from /usr/src/linux/include/asm/smp.h:18,

=======================================================================
I have tried to look this up on the internet, but I got nothing useful as of now. Any help here will be appreciated. Thanks in advance. =)

jiml8 · 09-17-2007, 03:58 PM

Assuming that your kernel is properly installed, then you are using the wrong makefile.

The makefile to compile a kernel driver for 2.6 must look exactly like this:

Code:

obj-m := mydrivermodule.o
KDIR    := /lib/modules/$(shell uname -r)/build
PWD    := $(shell pwd)

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

Mikhail_16 · 09-17-2007, 05:21 PM

True dat ^^.

Although i think you're missing the obvious point where the OP is trying to compile a 2.4 module for a 2.6 kernel. I think you should try to find out a module version for your spefic kernel version, as there are some major differences between 2.4 and 2.6 modules. Try searching for an updated version as a start. See if you can find some documentation on what needs to be configured or installed for the module to compile successfully too.

2.4.20 to 2.6.18 is a HUGE jump in kernel terms. Are you sure that your device isn't supported by 2.6 already?

jiml8 · 09-17-2007, 07:41 PM

It is indeed a huge jump, but backward compatibility has been (mostly) maintained. A driver written for 2.4 will *probably* work for 2.6. Might be locking issues and might not be as efficient as desired, but will probably work.

In any case, his particular problem is associated with incorrect makefile.

payretep · 09-18-2007, 08:58 AM

Hey guys, thanks for the response. Like you guys said, the makefile structure of kernel 2.6 is totally different from that of kernel 2.4. Therefore, the makefile for the kernel 2.4 compliant device driver cannot be used. Looks like I will need to rewrite the makefile from scratch and follow the kbuild structure. -_-;

Thanks again for the response, I appreciate it. =)

jiml8 · 09-18-2007, 09:58 AM

no, you don't rewrite the makefile from scratch. You use the exact format I provided.

payretep · 09-24-2007, 05:43 AM

Hi all again,

I have successfully used the makefile that was provided to me by jiml8 and its compiling fine now. However, I'm getting loads of warning. 2 of the most common ones are that some XXXX_API is COMMON symbol and YYYY_API is undefined. These warnings occur during the linking stage, and they did not appear during compiling in a kernel 2.4 environment. Can anybody help me with it.

And one "tiny" problem is that when I try to install the generated *.ko module, I will get a "-l invalid module format". Any idea what am I doing wrong here?

Thanks for your help in advance. Cheers!