Wed, 28 September 2016, 22:18
A student writes: > Hello Dr. Patt, > > My name is *****, a student in your Computer Architecture class. Today > when you discussed the Page Directory and you said each entry was PTE (Page > Table Entry), it was not quite correct. Each entry of the Page Directory > should be Page Directory Entry, according to the Intel's manual that I > attached in this email. I am aware that you may not care about naming of > these things but I hope it does not cause confusion to some student. > > -- > Best, > <<name withheld to protect the student who is absolutely correct>> The student is of course absolutely correct, (a) the entry is called a Page Directory Entry, (b) I am far less interested in the actual names of these things and far more interested in you understanding the concepts, and (c) I do not want any student to be unnecessarily confused. Ergo, I am forwarding his correction to all of you, including the figure he sent which is much prettier than the one I drew in class. Incidentally, since I have your attention, do you know why there are 32 bits coming out of CR3 but only 20 bits coming out of the PDE and the PTE? Yale Patt