To compile a Linux Kernel Module, you need:
1) The module source, in its own directory (you need R/W access to it!)
2) The source of the kernel for which you want to compile the module (read
   only access to it should be enough). NOTE: you do not really need the
   whole kernel source... Some makefiles and scripts (the KBuild system) and
   the kernel headers should be enough. Look at the kern-headers-xeno.tar.bz2
   package

The module can be easily compiled by typing
	make -C <path to the kernel source> M=<path to your module's source>

So, to compile the test module:
cd /tmp
tar xvzf module_test.tgz
cd module_test
make -C /lib/modules/`uname -r`/build M=/tmp/module_test

Some .ko files will be created... You can insert them in the kernel by
using the "insmod" command. But to do so, you need the root power, which
you generally don't have. So, the only way to experiencing with kernel
modules is to use an emulator. Let's use Qemu, and let's emulate an ARM
system.

- First of all, you need the cross-compiler for ARM:
cd /tmp
tar xvzf cross.tgz
export PATH=$PATH:/tmp/Cross/gcc-4.1.0-glibc-2.3.2/arm-unknown-linux-gnu/bin

- Then, you need the kernel source, configured for ARM, for compiling the
  modules
tar xvjf kern-headers-xeno.tar.bz2
  (this package only contains the needed part of the kernel source, plus
  some patches for Xenomai... But it is ok for our experiments)

- If you did not uncompress the example modules yet, do it now:
tar xvzf module_test.tgz

- And now, finally compile the module!!!
cd module_test
make -C /tmp/l-head M=/tmp/module_test ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnu-

- To test the module, you now need to boot an ARM kernel... The
  binaries-xeno.tar.bz2 package from
  binaries-xeno.tar.bz2

contains the binary of the kernel
  corresponding to the sources from kern-headers-xeno.tar.bz2.
  To boot it, you need an initramfs... To build a proper initramfs
  from busybox, you can use the mkfs-1.tgz scripts from
  www.disi.unitn.it/~abeni/RTOS/mkfs-1.tgz

tar xvzf mkfs-1.tgz
cd initramfs-scripts
./mkfs.sh

  Now copy your test modules in the FS, and re-run the "cpio step":
cp /tmp/module_test/*.ko /tmp/rootfs
cd /tmp/rootfs
find . | cpio -o -H newc | gzip > ../newfs.img
cd ..

- Finally, you can boot your emulated system:
qemu-system-arm -kernel Xeno/zImage -initrd newfs.img
  if you want the "console version", use:
qemu-system-arm -kernel Xeno/zImage -initrd newfs.img -nographic -append "console=ttyAMA0"

- When the system is up, login as root and try
cd /
insmod test_mod.ko n_elem=10
rmmod test_mod


If you have problems with one of the previous steps, send me an email.