Creating a Hello World program in Assembly Language in 5 minutes

This article walks you through the process of building a very simple program in assembly language in 5 minutes. Tutorial programs usually go by the name “Hello World” because that’s all they print out to the screen. Plenty of this information came from: http://www.tutorialspoint.com/assembly_programming/assembly_environment_setup.htm.

Install the tools.

yum install nasm -y

Create a file called “~/hello.asm” and populate it with the following:

section	.text
   global_start   ;must be declared for linker (ld)
	
_start:	          ;tells linker entry point
   mov	edx,len   ;message length
   mov	ecx,msg   ;message to write
   mov	ebx,1     ;file descriptor (stdout)
   mov	eax,4     ;system call number (sys_write)
   int	0x80      ;call kernel
	
   mov	eax,1     ;system call number (sys_exit)
   int	0x80      ;call kernel

section	.data
msg db 'Hello, world!', 0xa  ;string to be printed
len equ $ - msg     ;length of the string

Run the following from the same location as the “hello.asm” file.

nasm -f elf hello.asm

You will now have an additional file:

hello.asm  hello.o

Now run the following:

ld -m elf_i386 -s -o hello hello.o

How you have an additional file called “hello”. You can execute the “hello” program as you would with any other program.

hello  hello.asm  hello.o