Linux systems may load some modules at boot time.

A kernel daemon process can also load existing modules into the kernel on demand while the system is running.

The daemon uses this utility:

      modprobe
   

Given a string that is either a module name or a generic identifer, modprobe discovers the location of the compiled module object file.

(Module object files have an extra section that describes the module and the file names end with .ko instead of .o of ordinary object files.

Files:

 Modules loaded at boot time
 /etc/modules   

 Module list and file locations for existing modules to be loaded dynamically
 /lib/modules/[kernel version]/modules.dep