Dear All,

I like to know the following:

1. How to change Linux Kernel to make it Real Time OS.
2. Does one has to take approval to change the Linux Kernel.
3. If Yes, to whom should one approach for the same.
4. If No, then how can one visualise that it has been made real time OS.

With regards,

Arvind

no need to do these all UNLESS YOU DON'T WANT TO USE TI COMMERCIALLY
(I've listened from sources. Is this really true ?)

Yes, I want to use it for commercial purpose.

Hello, how "real-time" do you need to be?

Perhaps it might be sufficient to use the standard kernel and the RT_PREEMPT patch and high resolution timers? Look on https://rt.wiki.kernel.org/index.php/Main_Page for more information; alternatively have a look into RTAI, on https://www.rtai.org/, or more generally go on http://www.realtimelinuxfoundation.org/

May I give you a piece of advice if you start modifying the vanilla kernel with your own real-time "enhancements". Don't, unless you plan to work with the kernel community. Otherwise your kernel will fall out of sync with the kernel development and after a not so long period of time you'll be trapped in your own proprietary corner.

Cheers,
peter

this commercial use means you want to distribute this like fedora and red-hat and other distros right ??and if you don't wanna distribute it then of course you can modify it.
Linux is meant for that.. !!

I want to use the changed Linux Kernel for more than one location commercially. So kindly advise for the same.

With regards,
Arvind

When you say changing the kernel, I guess you mean more than just writing a kernel module that implements parts of your concept. You really want to modify the kernel?

Well, the kernel is under the GPL, so I recommend to read up on the GPL. In a nutshell, the GPL makes sure that freedom of software is maintained throughout its life cycle (free like in free speech). When you use GPLed software, you are granted the freedom to use it, but also the freedom to modify it such that it suits your needs (open source is the practical requirement to realise this freedom).

If you modify GPLed code such as the Linux kernel, then the result becomes derived work. Following the principles of free software, you'll have to pass on the freedom you were granted to any user of your derived code; you do not want to deprive others from the freedom you were granted, that would be unfair. Consequently you will have to make your code available to whoever you deliver your code to, your customer. For example, like many embedded systems nowadays, modern Samsung TVs run Linux, and the user manual gives instructions to the user how to obtain the source code of the (potentially) modified Linux kernel.

One piece of advice: try to discuss your modifications with the kernel community and try to make it a feature, not a proprietary add-on; otherwise you soon will not be able to keep up with the development speed. If your kernel modifications constitute the core of your business, though, then I am afraid you are in a delicate situation and you will have to rethink your busines case.

Cheers,
peter

See the following links too:
http://www.captain.at/programming/rtai/
http://www.captain.at/xenomai-2.1-installation.php

These information is really nice to share with us for the kernal to real time OS . These module implements the parts of the concept . It is one of the free software which all can like it in different manners .