Question

I recently started reading Programing From The Ground Up (PDF), but I’ve run into an issue in the first program. The program is very simple:

.section .data
.section .text

.globl _start

_start:
    movl    $1, %eax
    movl    $0, %ebx
    int     $0x80

But in compiling and running I get the error Illegal Instruction: 4. I did edit the program so that it would compile properly (removed the two .sections and changed _start to _main) so that may have affected it.

I am using the x86_64 instruction set (Intel processor).

Answer 1

If you are using x86-64, you need to change the ABI slightly, see this. For a very nice summary of the differences, see this post.