Compiling an unconfigured module

Quakeboy02 · 12-25-2006, 08:08 PM

I'm trying to debug a module in Debian, or at least learn something trying. Is there a way to make the module without adding it to the config for the source tree? Running "make M=whatever" doesn't seem to pick it up unless it's configged. What am I missing, or is it normal practice to run an "a" and a "b" directory to do this as protection against brain-fade? I have no real aspirations of actually getting this working and uploading it. I have working fallbacks in grub.

AwesomeMachine · 12-27-2006, 09:08 AM

gcc -c module.c

Quakeboy02 · 12-27-2006, 12:49 PM

"gcc -c module.c"

Thanks for the try, but I get about 7 bazillion warnings and errors when I try that. The subdir makefile is heavily dependent on info from the topdir one, I think.

studioj · 12-30-2006, 01:29 AM

try putting the code you are working on in a seperate directory and making a makefile there like this

Code:

obj-m = foo.o
KVERSION = $(shell uname -r)
all:
     make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
clean:
     make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean

then just make and your module shoud show up foo.ko

AwesomeMachine · 01-02-2007, 04:55 PM

Quote:

Originally Posted by Quakeboy02

"gcc -c module.c"

Thanks for the try, but I get about 7 bazillion warnings and errors when I try that. The subdir makefile is heavily dependent on info from the topdir one, I think.

Gcc spews more cryptic messages than you can imagine. It is pretty typical for gcc to warn of all kinds of things, even though the compile worked. It is possible you are missing a prototype header in /usr/include. In this case you can put the module in the kernel tree, according to the README file, and after you compile it run:
depmod

Quakeboy02 · 01-02-2007, 05:03 PM

"In this case you can put the module in the kernel tree, according to the README file, and after you compile it run:"

This is what I was trying to avoid: putting the module in the kernel tree. Thanks anyway, guys. It's simple enough to just have a "clean" version of the kernel that I normally boot from, and another version with the module I'm messing with configured in. It's not like a few megabytes costs anything anymore.