Re: Question about jumps

I think a person learns best by playing with existing programs. Here
is a little 'template' or 'starter kit' that you can build on. Just
keep adding macros and subroutines to extend the functionality.

; nasm -f elf -l stk.lst -Xvc -O8 -o stk.o stk.asm
; ld -s -o stk stk.o

; define some system constants

_sys_exit equ 1
_sys_write equ 4
_sys_stdout equ 2

; define some system macros

%macro sys_exit 1
mov eax, _sys_exit
mov ebx, %1
int 0x80
%endmacro

%macro writestr 2+

[section .data]

%%str: db %2
%%endstr:

__SECT__

mov ecx, %%str
mov edx, %%endstr-%%str
mov ebx, %1
mov eax, _sys_write
int 0x80

%endmacro

global _start

section .data

hw db 'Hello, World!', 10
hwlen equ $-hw

section .text

_start:
mov edx, hwlen
mov ecx, hw
mov ebx, _sys_stdout
mov eax, _sys_write
int 0x80

writestr _sys_stdout, 'Goodbye, World!', 10

sys_exit 0


Nathan.

.

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