Assembly code malfunction

Question

I am learning how to go through assembly and I am running into a weird problem. I am getting a message stating,

collect2: error: ld returned 1 exit status

and before I get this message though I am getting a string of errors like this.

_start': Name.asm:(.text+0x0): multiple definition of_start' /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 11

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 1 has invalid symbol index 12

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 2 has invalid symbol index 2

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 3 has invalid symbol index 2

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 4 has invalid symbol index 11

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 5 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 6 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 7 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 8 has invalid symbol index 12

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 9 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 10 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 11 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 12 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 13 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 14 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 15 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 16 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 17 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 18 has invalid symbol index 13

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 19 has invalid symbol index 21

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_line): relocation 0 has invalid symbol index 2

/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o:/build/buildd/eglibc-2.19/csu/../sysdeps/x86_64/start.S:118: first defined here /usr/bin/ld: i386 architecture of input file Name.o' is incompatible with i386:x86-64 output /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o: In function_start': (.text+0x20): undefined reference to `main' collect2: error: ld returned 1 exit status

multiple definition of `_start'

I am at a complete loss. I'll post my code below, I am hoping it is just one small error.

section .data                           ;Data segment
    userMsg db 'Please enter your name : ' ;Ask the user to enter a number
    lenUserMsg equ $-userMsg             ;The length of the message
    dispMsg db 'Hi my name is'
    lenDispMsg equ $-dispMsg            

 section .bss           ;Uninitialized data
    num resb 5

section .text          ;Code Segment
global _start

_start:                ;User prompt
    mov eax, 4
    mov ebx, 1
    mov ecx, userMsg
    mov edx, lenUserMsg
    int 80h


    ;Output the message 'Your name is '
    mov eax, 4
    mov ebx, 1
    mov ecx, dispMsg
    mov edx, lenDispMsg
    int 80h  

    ;Output the name entered
    mov eax, 4
    mov ebx, 1
    mov ecx, num
    mov edx, 5
    int 80h  

    ; Exit code
    mov eax, 1
    mov ebx, 0
    int 80h

You realize that there are other architures than x86, right? Also, Ubuntu has nothing to do with this. Please tag your question accordingly. — Jonathon Reinhart
You forgot to show how you assemble and link. Anyway, the issue is that you link with libc and you try to create a 64 bit program from 32 bit object. Use ld -melf_i386 or gcc -m32 -nostdlib. — Jester

cryptostudent cryptostudent · Accepted Answer · 2016-02-21T23:16:53

I'm not on linux at the moment but can assemble file no problem with nasm

nasm -felf32 hello.asm -ohello.obj

Try: gcc -m32 hello.obj

Assembly code malfunction

1 Answers