I am trying to compile an asm program on a linux server. I am new to writing asm programs, but I follow my school's tutorial and do everything they say but it has no success.
Here is my hello.asm file.
SECTION .data
msg: db "Hello World",10
len: equ $-msg
SECTION .text
global main
main:
mov edx,len
mov ecx,msg
mov ebx,1
mov eax,4
int 0x80
mov ebx,0
mov eax,1
int 0x80
I compile this file using the command line nasm -f elf hello.asm which works completely fine and generates an object file. The problem is, when I try ld hello.o, it says that it cannot read symbols in the file and the file is in the wrong format.
Can anyone help me and tell me how I can compile a .asm file so it can run?
I've had a similar problem today, as a result of mixed 32-bit and 64-bit libraries (which is why I happen to have come upon your question). ld will complain if you try to link libraries of different types. On a 64-bit system, ld defaults to 64-bit.
To specify the type you should be able to specify ld -m elf_i386 for 32-bit, or gcc -m32. (Or gcc -m32 -static -nostdlib for a static binary).
If your asm source code is portable to 64-bit, you could assemble as 64-bit with nasm -f elf64. But it can assemble but fault at runtime from truncating a pointer, or have system calls return errors instead of working because the int 0x80 ABI is purely 32-bit.