That's called a "fork", and it wouldn't be a new kernel at all.
Yes and No.
Yes, it will take a lot of code from the chosen kernel.
No, it wouldn't called a "fork" as it would be different from the design standpoint and it would not be another unix-like kernel, so ..
Adding to that, the Linux kernel is a very much moving target, and you would be hard-pressed to keep up with it in order not to lose compatibility with its driver
.. no need to keep up with its very fast changing drivers code.
The chosen kernel will be only used as "one time snapshot", further development of new kernel will be independent from the development of the chosen kernel.
I would not waste my time creating another unix based operating system and then relying on fanatical "flexibility" or "stability" arguments to prop it up against the 20th century age of properly designed, high usability, people focused computing. I would build a new kernel that is actually usable by human beings.
That's my point, I
would not waste my time creating a new OS entirely from scratch.
I agree with "properly designed, high usability, people focused computing" principles but making it from "proper design" to "working OS" and code it from entirely zero line of code is just not feasible as it would need too much time to do that and as there's so much good code already written by people I can pick up and also to avoid as much as "reinvent-the-wheel" plague.
Linux would probably be easier, because it's so widely used and (I assume) better documented. You may be interested in the Linux From Scratch project.
No, I'm not willing to make GNU/Linux OS. I was just interested looking at the kernel.
In short, the new OS will be
designed from scratch, but not code it from scratch. I need to decide which piece of code written by which people to pick up and to speed up development furthermore maybe i can just use one, the chosen kernel, as my starting point.
The following is the big picture of what I think:
Goal : Open source Desktop OS
Background :
( correct me if i'm wrong ... )
The failure of Linux as desktop OS.
I only mention Linux as it is the most succesful open source operating system used widely as desktop OS.
But I noted two weaknesses of Linux that make Linux would be so hard to become proper desktop OS: X window and its device driver development.
1. X window
IMO it is funny to have a desktop OS (so that the User Interface is its main component) but its UI subsystem decoupled far enough from the kernel (you said modularity?). There is only limited communication between kernel and X. People struggle to make X as efficient as possible. There's noted effort such as KMS, DRI, TTM, GEM to cope with problems created by X itself but I think X itself is the main problem.
There is Wayland project
http://wayland.freedesktop.org/architecture.html with its main goal is to replace X. There is also Mark Shuttleworth announcement for his future plan to replace X with Wayland in his Ubuntu.
2. Device driver development
Stable-API-nonsense at
http://www.kroah.com/log/linux/stable_api_nonsense.html is good from technical standpoint as device driver code tightly integrated into the kernel (modularity?) which make the whole system more robust. But I believe this is the major obstacle to make a new device get its driver ready as soon as the device launched to the market. Yes, the device manufacturer need to join on Linux device driver development in order to make the driver for their new device.
Actually, the question is why not so many good quality device driver for Linux (for new device)?
The Design :
I made a division of operating system environment:
device-drivers, kernel, libraries, utilities, user-libraries, user-applications
Based on dependency between them, let we see what these OS does regarding to the division above :
Linux = device-drivers + kernel
FreeBSD = device-drivers + kernel + libraries + utilities
Windows = kernel + libraries + utilities
Which model is good? It depend on what your goal is. But I must admit that I would choose the windows model as it let the device manufacturer develop their own driver for their device, be it open source or closed source.
( Are GPL'd code could do this, linked to closed source code ? )
Motivation : fun ... right?