The article jumps over so many steps and leaves out so many mechanics that I had to stop reading, because it just opened more and more questions without closing any. For example, right at the beginning:
> Right after reset the CPU jumps to a special address called the reset vector at 0xFFFFFFF0. Think of it as a permanent bookmark that says “start here.” There is room for almost nothing at that address, so manufacturers put a short jump there that passes control to the firmware on your motherboard.
What does that even mean? It jumps there means that it executed whatever is at that address, but it failed to explain how the instruction at that location is even put there in the first place.
Reading a little more I truly am confused for who this was even written. It seems you need a lot of prior knowledge to understand what the author talks about and then it also makes me wonder what additional information this article conveys if you already can fill in the gaps.