how to compile 

1 Download and install kernel source code (if it is not in the released version);(e.g.: Install it at /opt/linux-2.6.18)
   if it is the first time to install, you need:
       make menuconfig        //kernel configurations (generally use default configurations, exit and save)
       make modules_prepare   //prepare for making modules

2 Modify KERNELDIR=/opt/linux-2.6.18 in Makefile;

3 After make //, produce relevant kernel's drive file---ztemt.ko

4 ./load to load ztemt.ko to linux kernel;  