Digi 9P 9360/9750 - Manual (Page 39)

3 9
K e r n e l D e v e l o p m e n t
Kernel Development
C H A P T E R 6
Writing kernel modules
What is a kernel module?
Modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They are useful
because they extend the functionality of the kernel without the need to reboot the system.
A typical kernel module is the device driver, which allows the kernel to access hardware connected to the
system. Without modules, you would have to build substantial kernels and add new functionality directly
into the kernel image. Besides having extensive kernels, you would be required to rebuild and reboot the
kernel for every new functionality.
Writing your own kernel modules
Some kernel modules are included as examples. They can be found in the modules/ subdirectory of the
project folder. Each kernel module must be stored in a different folder.
The easiest way to create your own kernel module is to clone one of the existing modules:
Add your source files
Add the sources for your kernel module directly to the new folder you’ve just created, and remove the
original source files of the folder that you cloned.
~/LxNETES3.2$ cd modules
~/LxNETES3.2/modules$ cp -r minimal my_kmodule
~/LxNETES3.2/modules$ cd my_kmodule