[XFree86] xfree86 4.7.0 compilation from sources fails on drm

[Eran Maman]

I am trying to build xfree86 from sources on Centos 5 kernel 2.6.18 and I
get this:

In file included from xf86drm.c:39:
../../../../../../../programs/Xserver/hw/xfree86/os-support/shared/drm/kernel/drm.h:45:26:
error: linux/config.h: No such file or directory

Any ideas?