[Nasm-devel] Fwd: Debugging programs made with nasm in gdb/ddd.

[Guillermo B. de Q. M. <deb...@gm...>]

Hi, good morning,

I'm new in the mailing list, so, my name is Guillermo. I'm learning to
write assembly code with several books such as Duntemann and Irvine books
too so I'm sorry if I ask quite basic questions.

I've installed an OpenBSD Operating System in a INTEL I7 of 64bit and I'm
trying to debug some applications made by myself with gdb or ddd and built
with nasm (Version 2.11.08). (More information next).

My problem is when I launch gdb or ddd I can't debug the software. With DDD
for example, I can't put breakpoints or I can't go step by step into the
code and I don't know why. With GDB the problem is similar, in this case at
least I can go step by step but I can't see the source code neither the
instructions. Just I can see the addresses of the instructions and I don't
know why  (Next you have the output of a session with GDB).

Of course, the program was built with debugging support. I tried dwarf and
stabs but neither works to me.

Someone can help me? I need debug support because I'm learning to program
software and if I don't have a debugger I won't learn anything but a lot of
theory.

Here I put the contents of the Makefile:
all:
nasm -l main.lst -f elf64 -g -F stabs main.asm
gcc -gstabs -o main main.o

Here, the contents of the assembly program:
default rel

section .data

section .bss

section .text
global main

main:
  nop

    pop rax
    pop rbx
    pop rcx

  mov eax,1 ;
  mov edi,0 ;
    syscall

  nop


Next I put an example of my problem with gdb:

(gdb) start
Breakpoint 2 at 0x17c914700b10
Starting program:
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
Breakpoint 2 at 0x88508100b10
0x0000088508100b10 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb) disassemble
Dump of assembler code for function main:
0x0000088508100b10 <main+0>: nop
0x0000088508100b11 <main+1>: pop    %rax
0x0000088508100b12 <main+2>: pop    %rbx
0x0000088508100b13 <main+3>: pop    %rcx
0x0000088508100b14 <main+4>: mov    $0x1,%eax
0x0000088508100b19 <main+9>: mov    $0x0,%edi
0x0000088508100b1e <main+14>: syscall
0x0000088508100b20 <main+16>: nop
0x0000088508100b21 <main+17>: nop
0x0000088508100b22 <main+18>: nop
0x0000088508100b23 <main+19>: nop
End of assembler dump.
(gdb) stepi
0x0000088508100b11 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)
0x0000088508100b12 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)
0x0000088508100b13 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)
0x0000088508100b14 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)
0x0000088508100b19 in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)
0x0000088508100b1e in main () from
/home/debugbsd/Projects/Assembly_Language/GettingArguments/main
(gdb)

Program exited normally.
(gdb)

Thanks in advance,
Guille