Re: Query regarding assembly level debugging support

[Peter Barada <peter at the-baradas dot com>]

>     The linked out file is loaded without errors on GDB. When we run
>the respective out file on GDB, the control of debugger moves to label
>main in the assembly code ( Breakpoint 1, 0xa00200ec in main ()). When I
>try to move to next instruction using "nexti", the control moves to next
>address (Displaying: 0xa00200f0 in main ()). This continues till the
>last address is reached. Only the address increments within the assembly
>file are displayed and not the actual assembly source.
>
>      When I try to single step using "step", the message prompted is
>"Single stepping until exit from function main, which has no line number
>information". Whereas if I disassemble one of the addresses give above,
>entire assembly code which I am trying to debug is displayed.
>
>      Does this mean that GDB does not support debugging of the assembly
>code?

Peope have been using GDB to debug assembler code for years.  A
couple of tricks:

1) Use stepi/nexti commands to step or next one *instruction* as
   opposed to source line
2) Use the 'disp/i $pc' to have GDB display the assembler instruction
   that will be executed next.
3) Use 'i reg' to dump the registers, or 'p $reg' where 'reg' is the
   register name.

-- 
Peter Barada
peter@the-baradas.com