Getting Started Programming MIPS Assembly

• "But I Don't Understand how to ..."
  • Neither did I, but this is doable.
  • Start early. You will be in a primitive environment. Things might not work as you want them to.
  • Learn how to use the tools while you can.
    • Add break points.
    • Learn how to set break points
    • Find memory locations
    • Learn how to print things out.
    • Figure out how to print out debugging information.
  • You should get help when you need it.
• Why program in assembly?
  • I am not a devotee to assembly language.
  • In fact, I was one of the people who argued to eliminate the class.
  • It does provide some insight for programmers.
  • It is required for compiler, operating systems and other programmers.
  • But it is NOT portable.
  • And it is sometimes hard to do.
  • And it is very very cryptic.
    • This is one case were documentation is very important.
    • I can see 1 comment for each line of code to be too sparse.
    • Use three levels of comments.
      1. Block comments before routines to say what the routine does.
      2. Comments at each C/C++ line of code, give that code
      3. Comments on each assembly line of code. What is it doing.
  • All that aside, we program in assembly because we NEED to know how it works for this class.
• Why MIPS?
  • Wouldn't Intel assembly be better?
    • Well, No!
    • MIPS assembly fits on one page (MIPS Reference Data in the front of the book)
    • It is a semi-modern assembly language.
    • And we need it for the chip we will be studying.
  • But I can't get a job programming MIPS
    • Why would you want to?
    • And if you do, you can easily learn whatever language you need.
    • And why would you want to?
• Why spim/xspim?
  • It is the one I use.
  • It is compiled on all of my machines.
  • It is supported by the book.
  • And I get to set the standard.
  • But I like ...
    • Go ahead, use whatever you want.
    • But it must run on my machine, simulator, ...
• System Issues
  • On my 64 bit machines, I had to modify the Configure script. here is a copy of my modified script.
• Naming Conventions.
  • To get the color highlighting I liked, I had to add mips.vim to my vi syntax files.
  • I had to modify the filetype.vim to use these colors
  • This means I need a unique extension for my mips assembly code.
  • I call my files .mips, but .s or .asm will do.
• Creating Files
  • Use your favorite editor.
  • Indentation is very useful.
  • label:<tab>op-code<tab>op1,<space>op2
• Starting xspim
• Running xspim
• A quick tour of program 1.