C'mon Tobsik, show us the real code! Nasm won't get past "mov 5, eax"!!! :)
Try:
global _start
section .text
_start:
mov edx, msg_len ; length
mov ecx, msg ; buffer
mov ebx, 1 ; file descriptor STDOUT
mov eax, 4 ; __NR_write
int 80h
; now exit the application!
mov eax, 1 ; __NR_exit
int 80h
section .data
msg db "Hello, Debian!", 10
msg_len equ $ - msg
Most likely, your segfault is from failing to exit cleanly, although there are other causes... Hang in there, you'll find 'em. :)
Best,
Frank