Make && Make Install : please set KERNELPATH

[g0bl1n]

I'm trying to:

make
make install

in the mad-wifi directory.

I get this as soon as i type: make

/bin/sh: line 0: cd: /lib/modules/2.6.39.4/build: No such file or directory
Makefile.inc:66: *** /lib/modules/2.6.39.4/build is missing, please set KERNELPATH. Stop.


I've installed linux-headers and linux-source
It looks like they've been installed into: /usr/src/
I've also tried reinstalling the packages.

The command: uname -r returns:
2.6.39.4


Does anybody have any idea on how i can get make && make install working??


UPDATE: Solved With:

root@bt:~# prepare-kernel-sources
root@bt:~# cd /usr/src/linux
root@bt:~# cp -rf include/generated/* include/linux/