How to build the kernel in the new L4T 28.1 ?

Hi, Everyone!
I have downloaded new version 28.1 of L4T and there is a question.
When I have extracted kernel source files from ‘kernel_src.tbz2’ file in the top source archive file(source_release.tbz2), I was surprised a little. At there, there were several strange folders. The directory, ‘kernel/kernel-4.4’, must be kernel source directory but what the hell are the others ?
For example, ‘hardware/’, 'kernel/display/’, kernel/nvgpu/’, 'kernel/nvhost/’ and ‘kernel/nvmap/*’.
In other words, how are the others used to build correct kernel image ?

hello DNA01,

there are different folders to isolate several drivers.
and you’ll find the device tree source code under “hardware/*”

please download the L4T R28.1 Documentation via Embedded Download Center,
you should be able to found more details in the Kernel Customization chapter.
thanks

Hi JerryChang:
why not put these drivers in kernel-4.4 folder?
Now there are other code folders besides with kernel source directory, then more difficult work to do for source code management ,like git.

thanks!