1. Install
sudo apt-get install nasm
Such nasm installed on the Terminal enter the command:
nasm -version
Output version information on the installation is successful
2. Use
Create a "hello.asm" file:
touch hello.asm
gedit hello.asm
Enter the following assembly code in the file
section .data
hello: db 'Hello world!',10 ; 'Hello world!' plus a linefeed character
helloLen: equ $-hello ; Length of the 'Hello world!' string
; (I'll explain soon)
section .text
global _start
_start:
mov eax,4 ; The system call for write (sys_write)
mov ebx,1 ; File descriptor 1 - standard output
mov ecx,hello ; Put the offset of hello in ecx
mov edx,helloLen ; helloLen is a constant, so we don't need to say
; mov edx,[helloLen] to get it's actual value
int 80h ; Call the kernel
mov eax,1 ; The system call for exit (sys_exit)
mov ebx,0 ; Exit with return code of 0 (no error)
int 80h
Save and exit.
Compile
nasm -f elf64 hello.asm
If you put a 32-bit system elf64
instead elf32
link
ld -s -o hello hello.o
run
./hello
Terminal output "Hello, world!" No problem