Portable Shellcode

ORG.asm

;Suppose our code will be located at
;Following address in memory
org 0xDEADBEEF

mov eax, Sleep	;Sleep means [0xDEADBEEF+Sleep]
push Time		;Time means [0xDEADBEEF+Time]
call eax

Sleep	dw		0x74c37990
Time	dw		1000

REL.asm

;This shellcode is independent of its origin
bits 32

call Here	;Issue a near call
Here:		;Now EIP will be in stack
pop edi		;Store it to data register (data index)
sub edi,5	;Point edi to base of shellcode

;Load sleep value in eax
mov eax,[edi+Sleep]
;Load value of Time in ebx
mov ebx,[edi+Time]

;Call Sleep
push ebx
call eax

;Data
Sleep	dq		0x74c37990
Time	dq		1000