Hello there I have quite similar background.
(10 years experience, in backend and native android development). Most of the comments already contain good advice. Systems Engineering takes time. I followed long route. I initially took some course in digital logic, and computer architecture and than later took following OS courses.
Somebody mentioned Intel manuals in the comment (those are really helpful)
These courses helped alot. I would suggest to take some firmware and device driver development course as well. My conclusion is that, these are tough skills and the learning process can be accelerated if you can find some entry level position in a small company which do this kind of work.
