User`s guide

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Chapter 7
7. Debugging Machine Language Code
This chapter explains how to debug machine language code by:
• “Examining and Changing Register Values”
• “Examining Memory and Disassembling Code”
• “Setting Machine-Level Breakpoints”
• “Continuing Execution After a Machine-Level Breakpoint”
• “Tracing Execution at the Machine Level”
• “Writing Conditional Commands at the Machine Level”
• “Stepping Through Machine Code”
Examining and Changing Register Values
Using dbx, you can examine and change the hardware registers during
execution of your program. Table 7-1 lists the machine form of the register
names and the alternate software names as defined in the include file
regdef.h.
Table 7-1 Hardware Registers and Aliases
Register Software Name Description
$r0 $zero Always 0
$r1 $at Reserved for assembler
$r2... $r3 $v0... $v1 Expression evaluations, function return
values, static links
$r4... $r7 $a0... $a3 Arguments