;; Cross platform executable, 07/2005
;; Milani Giacomo <giacomo.milani@core-dumped.info>
;; 
;; $ nasm -felf crossplatexe.asm -o test.o
;; $ ld test.o -o testcpe.com
;;
;; (warning on entry point), now find _start symbol
;; end relink it, like elf entry (example:)
;;
;; $ nm test3.com | grep _start
;; 080490c8 A __bss_start
;; 0804809b t _start
;;
;; $ ld test.o -o test3.com -e 0x0804809b
;;
;; Now test it:
;;
;; (Linux:)
;; $ ./test3.com
;; Hello, World!
;; $     
;;
;; (DosEmu:)
;; C:\BIN>test3
;; Hello, World!
;; C:\BIN>
;;
;;
;; How works:
;; Output file is ELF/COM executable,
;; It works like elf on *nix, and like .com on windows
;; Elf hdr makes on dos nothing important (only you must
;; be careful that assembled entry point address make's nothing
;; distruptable). If you have problem with entry point, you can
;; add extra nop on start of file.
;; Check the executable with debug.exe ;)
;;
;; The address of "hello world!" was computed by ld on ELF 
;; (ld fix relocation). 
;; On COM is absolute:
;; add edx,0100h (COM is mapped at address 100h, cause PSP)
;; add edx,00b8h (b8 is offset of string in file)
;;

nop
nop
nop
nop
dos:
	xor dx,dx
	add edx,0100h
	add edx,00b8h
	mov ah,9
	int 21h
	mov ah,4Ch
	int 21h

_start:
	mov ecx,$msg
	mov eax,4
	mov ebx,1
	mov edx,15
	int 80h
	mov eax,1
	int 80h

msg:
	db 'Hello, World!',0Dh,0Ah,'$'