[plug] Problems building kernel with Mandrake 7.2

[Phil Steege]

I recently purchased mandrake 7.2 and installed it.
Everything looks fine until I tried going to /usr/src/linux and do a make 
config, this is what I got.

[pes at localhost pes]$ cd /usr/src/linux

[pes at localhost linux]$ make config
make: *** No rule to make target `config'.  Stop.

[pes at localhost linux]$ make menuconfig
make: *** No rule to make target `menuconfig'.  Stop.

[pes at localhost linux]$ make xconfig
make: *** No rule to make target `xconfig'.  Stop.

Is this because the GPL version I purchased did not come with the source 
files ?

What do I need to download to be able to build kernels?