The Flow of Booting an Intel Architecture System

Taking a lot of little steps walking a path is a good analogy for understanding the Intel Architecture boot flow. The bare minimum firmware requirements for making an Intel architecture platform operational and for booting an OS are presented in this article in a particular order. Design- or market segment-based requirements might add, delete, or reorder many of the items presented in this article; however, for the vast majority of system designs, these steps in this order are sufficient for a full or cold boot (that is, from a state where the power is off to the handoff to the operating system). Depending on the architecture of the BIOS, there may be multiple software phases to jump through with different sets of rules, but the sequence for actually touching the hardware is, at least in the early phases, very much the same.