Great review materials about the x86 architecture: http://duartes.org/gustavo/blog/post/cpu-rings-privilege-and-protection http://duartes.org/gustavo/blog/post/anatomy-of-a-program-in-memory http://duartes.org/gustavo/blog/post/how-the-kernel-manages-your-memory (you may skip past the VMA explanations straight to the explanations of PTEs; we will examine VMAs and other abstractions that make a "process" later, in great detail).