Makefile for Linux kernel module?

Question

I was just reading The Linux Kernel Module Programming Guide and and got stuck on character device drivers example.

Makefiles for previous examples were provided, but no

Answer 1

actually driver gets loaded by the macro MODULE_INIT(my_init); here "my_init" can be the user specified function and MUDULE_EXIT(my_cleanup); here my_exit can be the user specified function . those two macros are missing in the above code.

Makefile: the obj-m += chardev.o is to be replaced with obj-m := chardev.o.

I am also a beginner to LLD. If any mistake is there please let me know.

Answer 2

obj-m += chardev.o

Answer 3

Because the function unregister_chrdev() don't return value. This is a helpful link. http://forum.kernelnewbies.org/read.php?17,1114