Difference between revisions of "CSC231 Hello World!"

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(Created page with '--~~~~ ---- =Hello World!= * Assemble, link and run as follows: nasm -f elf -F stabs helloworld.asm ld -melf_i386 -o helloworld helloworld.o ./helloworld <code><pre> ;;;…')
 
 
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--[[User:Thiebaut|D. Thiebaut]] 13:25, 20 September 2010 (UTC)
 
--[[User:Thiebaut|D. Thiebaut]] 13:25, 20 September 2010 (UTC)
 
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=Hello World!=
 
=Hello World!=

Latest revision as of 08:25, 20 September 2010

--D. Thiebaut 13:25, 20 September 2010 (UTC)



Hello World!

  • Assemble, link and run as follows:
nasm -f elf -F  stabs helloworld.asm
ld -melf_i386 -o helloworld helloworld.o
./helloworld


;;; helloword.asm
;;; D. Thiebaut
;;; 9/13/10
;;; A simple "Hello world!" program.  The program simply displays a string
;;; on the screen.
;;;
;;; to assemble and run:
;;;     nasm -f elf -F  stabs helloworld.asm
;;;     ld -melf_i386 -o helloworld helloworld.o
;;;     ./helloworld
;;; -------------------------------------------------------------------
EXIT    equ             1
WRITE   equ             4
STDOUT  equ             1
 
      	;; ------------------------------------------------------------
	;; data areas
	;; ------------------------------------------------------------
 
	section	.data
hello   db	10, "hello world!",10,10,10 ; the string we printing
MSGLEN  equ	$-hello
 
	;; ------------------------------------------------------------
	;; code area
	;; ------------------------------------------------------------
 
	section	.text
	global	_start

	;; print the string hello
_start:	mov	eax, WRITE
	mov	ebx, STDOUT
	mov	ecx, hello
	mov	edx, MSGLEN
	int	0x80		; system call to print to stdout
 
	;; exit()
	mov	eax,EXIT
	mov	ebx,0
	int	0x80		; final system call

Listing File

  • Generate the listing file as follows:
nasm -f elf -F stabs -l helloworld.S helloworld.asm
     1                                  ;;; helloword.asm
     2                                  ;;; D. Thiebaut
     3                                  ;;; 9/13/10
     4                                  ;;; A simple "Hello world!" program.  The program simply displays a string
     5                                  ;;; on the screen.
     6                                  ;;;
     7                                  ;;; to assemble and run:
     8                                  ;;;     nasm -f elf -F  stabs helloworld.asm
     9                                  ;;;     ld -melf_i386 -o helloworld helloworld.o
    10                                  ;;;     ./helloworld
    11                                  ;;; -------------------------------------------------------------------
    12                                  EXIT    equ             1
    13                                  WRITE   equ             4
    14                                  STDOUT  equ             1
    15                                   
    16                                        	;; ------------------------------------------------------------
    17                                  	;; data areas
    18                                  	;; ------------------------------------------------------------
    19                                   
    20                                  	section	.data
    21 00000000 0A68656C6C6F20776F-     hello   db	10, "hello world!",10,10,10 ; the string we printing
    22 00000009 726C64210A0A0A     
    23                                  MSGLEN  equ	$-hello
    24                                   
    25                                  	;; ------------------------------------------------------------
    26                                  	;; code area
    27                                  	;; ------------------------------------------------------------
    28                                   
    29                                  	section	.text
    30                                  	global	_start
    31                                  
    32                                  	;; print the string hello
    33 00000000 B804000000              _start:	mov	eax, WRITE
    34 00000005 BB01000000              	mov	ebx, STDOUT
    35 0000000A B9[00000000]            	mov	ecx, hello
    36 0000000F BA10000000              	mov	edx, MSGLEN
    37 00000014 CD80                    	int	0x80		; system call to print to stdout
    38                                   
    39                                  	;; exit()
    40 00000016 B801000000              	mov	eax,EXIT
    41 0000001B BB00000000              	mov	ebx,0
    42 00000020 CD80                    	int	0x80		; final system call