Linking C & ASM (Mac OS 10.6)

[DtY]

I'm having trouble linking C and Assembly, I seem to be getting different target processors on both.

The files I'm using:
driver.c

C:

#include <stdio.h> int main(void) {     int ret_status;     ret_status = asm_main();     return ret_status; }

first.asm

Asm:

; first.asm ; Asks for two integers, displays their sum ; ; To create executable: ;   nasm -f elf first.asm ;   gcc -o first first.o driver.c asm_io.o %include "asm_io.inc" ; initialized data goes in the .data segment segment .data prompt1 db "Enter a number: ", 0 prompt2 db "Another: ", 0 outmsg1 db "You entered: ", 0 outmsg2 db " and ", 0 outmsg3 db ", the sum of both is ", 0 ; uninitialized data goes in the .bss segment segment .bss input1 resd 1 input2 resd 1 ; Code is put in the .text segment segment .text     global _asm_main _asm_main: (and the main body, which I can post, if it would help)

asm_io.inc
This is from the book I'm using: http://www.drpaulcarter.com/pcasm/

To compile:

Bash:

nasm -f elf first.asm #Gives no output gcc -arch i386 -o first first.o driver.c asm_io.inc

Gives me:

code:

ld: warning: in first.o, file is not of required architecture ld: warning: in asm_io.inc, file is not of required architecture Undefined symbols:   "_asm_main", referenced from:       _main in ccetlbX9.o ld: symbol(s) not found collect2: ld returned 1 exit status

I'm pretty sure the problem is with the -arch flag, but I tried i386, i486 and i686, but none worked.

[edit] Whoops, have to assemble asm_io.inc
Problem persists though

[DtY]

So apparently, there were two errors in here that I worked out today (1) Mac OS X doesn't use ELFs, it uses macho (2) asm_io.inc is not the actual library, it's just a header.

So now, it links fine, but I get a seg fault when I run it.

Here's the complete first.asm

asm:

; first.asm ; Asks for two integers, displays their sum ; ; To create executable: ;   nasm -f macho first.asm ;   gcc -o first first.o driver.c asm_io.o %include "asm_io.inc" ; initialized data goes in the .data segment segment .data prompt1 db "Enter a number: ", 0 prompt2 db "Another: ", 0 outmsg1 db "You entered: ", 0 outmsg2 db " and ", 0 outmsg3 db ", the sum of both is ", 0 ; uninitialized data goes in the .bss segment segment .bss input1 resd 1 input2 resd 1 ; Code is put in the .text segment segment .text     global _asm_main _asm_main:     ; setup routine     enter 0, 0     pusha     ; print out prompt     mov eax, prompt1     call print_string         call read_int ; read integer     mov [input1], eax ; store into input1     mov eax, prompt2 ; second prompt     call print_string     call read_int     mov [input2], eax     mov eax, [input1] ; eax = *input1     add eax, [input2] ; eax += *input2     mov ebx, eax ; ebx = eax     dump_regs 1     dump_mem 2, outmsg1, 1     ; Output     mov eax, outmsg1     call print_string     mov eax, [input1]     call print_int     mov eax, outmsg2     call print_string     mov eax, [input2]     call print_int     mov eax, outmsg3     call print_string     mov eax, ebx     call print_int     call print_nl     popa     mov eax, 0         leave     ret