CS 2734 Computer Organization II
Laboratory 4

This laboratory explores the use of the debugger with assembly language programs. You will meet in 3.02.04SB for both laboratory 3a (9/11/96) and laboratory 3b (9/16/96). During both sessions, 10 workstations will be reserved for checkoff only. Do not log into these workstations unless you are ready to be checked off or everyone who is ready to be checked off has been checked off. You must log off of these workstations after being checked off so that others can have a chance. In the last 15 minutes of laboratory 3a, Mr. Castaneda will give a demonstration of the debugger for those who are having difficulty.

You are expected to have gone through the laboratory prior to lab day

Preliminaries:

• Create a new subdirectory under your cs2734 directory called debugger and copy
  simple.m
  ctest.c
  Makefile
  macro_defs.h
  Note: These files can be found in ~cs3733s/cs2734/debugger or downloaded directly from the web.
• Use make to compile the function with the -g option.
• Get a printout of simple.m using prtext.
• Enter the debugger by typing:
  gdb simple
  

• Set breakpoints at g and at mylabel (b).
  
• Start running the program (r). Put in input values 3, 4, and 5.
  
• When you reach the g breakpoint, set the display to show each instruction as it is executing (display/i $pc).
  
• Single set through the code from g to mylabel without stepping through .div (ni).
  
• When you reach the breakpoint mylabel, show the values of the relevant registers (p). Look at the code to determine what the relevant registers are.
  
• After the mylabel breakpoint continue execution (c) and show the program gives the correct answer.