I found a few articles on this Google search page.
From what I read I found that the imx updates the platform code and device tree source accordingly.
Here is a cross reference of arch, arm and mxc
Supporting multi-platform ARM kernels
Red Hat has been around longer than ten years.
The earliest date I found was 1994.
And also; depending on how you look at these things, Red Hat has long been a billion dollar company.
Linus Benedict Torvalds is a Finnish American software engineer and hacker, who was the principal force behind the development of the Linux kernel.
The history of UNIX® dates back to 1969.And here is that article that supports that.
A Quick History of UNIX
As the 1990s opened, AT&T's source code licensing had created a flourishing market for hundreds of UNIX variants by different manufacturers. AT&T sold its UNIX business to Novell in 1993.
If your able to and you have time just studying the basic Linux structure will help you to catch on to other ideas and how things work.
Research what you can and you'll be amazed at what you'll find.
I found some good information for you and I hope it helps.