Just only watch the intro lecture and I can confidently confirm that this course would be fantastic. However, the professor mentioned that this course is only about processor. Anyone know similar courses/books about filesystem, network, RAM, ....?

I think MIT's 6.033 should cover a lot of what you're looking for; it goes deep on the "systems" that build up modern computing.

On OCW: https://ocw.mit.edu/courses/electrical-engineering-and-compu...

As pointed out in the comments, 6.033 is a good overarching course to learn about a lot of computer systems fundamentals. If you want to dig deeper into networks, OS, computer architecture, MIT has plenty of specific courses for those:

http://web.mit.edu/6.829/www/currentsemester/ https://ocw.mit.edu/courses/electrical-engineering-and-compu... https://ocw.mit.edu/courses/electrical-engineering-and-compu...

If you are completely new to this I'll suggest http://pages.cs.wisc.edu/~remzi/OSTEP/