This page links to some useful, and hopefully interesting, information
on topics we've discussed in class. I hope you have fun digging!
This information is provided for your enjoyment!
Please do not feel you have to read it, unless you're specifically told
If you'd like help understanding or installing any of the information or
software on this page, please ask us!
x86 Instruction Set - PC
Emulators - Hardware Links
Operating systems need to use special machine support to enforce
protection and to interface with hardware devices. These support
mechanisms differ from machine architecture to machine architecture, of
course; you wouldn't expect PC binary code to run without change on a
Macintosh! To keep things real, we'll present real examples from the Intel
PC architecture from time to time. Although many people look down on
Intel's instruction set, it has several important advantages: PCs are
common and cheap; you've almost certainly used one before; you will use PCs
in the labs; and good PC emulators are available, so if you like you can
fool around with toy operating systems without rebooting your computer!
So you want to learn x86 assembly language? Here are some tutorials to
get you started.
- PC Assembly
Language, Paul A. Carter, November 2003. 188pp.
(PDF copy, printed 2
pages per sheet)
- A clear description of x86 assembly language and assembly language in
general, including some stuff you hopefully know already. You might
prefer to read this on line, rather than print it out. Warning:
This book uses "Intel" assembly syntax, in which instructions are written
instr dst, src"; we will use "AT&T" assembly syntax, in
which they are written "
instr src, dst".
Guide to Inline Assembly, Brennan "Bas" Underwood.
- A short and sweet description of how to use inline assembly
instructions with GCC. Includes a description of the "AT&T" assembly
syntax used by GCC.
These reference manuals will help you understand the precise semantics
of any instruction we've discussed in class.
- Intel 80386 Programmer's
Reference Manual (PDF
- This concise 1986 reference manual describes the features of the 386,
which is the first serious x86 architecture from Intel -- it's the first
one that supports page-table memory protection, for example. (We'll
discuss page tables in more detail in Week 5.)
Intel Architecture Software Developer's Manuals
- The current Intel architecture manuals are much longer, and describe
features of the 486, Pentium, Pentium Pro, and so forth, as well as the
386. These manuals are slightly better written than the 1986 manual, but
they are much longer and harder to navigate. There are four volumes:
- Volume 1, Basic
- The basics: how procedures are called, the register set, and so forth.
- Volume 2A, Instruction Set
Instruction Set Reference N-Z
- The effect of every instruction, listed alphabetically by instruction.
- Volume 3, System Programming
- Most OS-specific programming will require a dip into this manual, which
specifies how to use all the special features of the architecture -- memory
management, interrupts, system calls, and so forth.
These programs let you run operating systems in a virtual sandbox,
allowing you to experiment without screwing up your real hardware.
- A fast emulator (not quite as mature as Bochs, but 50x faster is a big
deal). Can run x86 and PowerPC operating systems, among others. Windows
and Mac OS X binaries are available.
- A slow, but stable PC emulator. Windows binaries are available.
This page has links to a bunch of
information on common PC hardware, including disks and the console.