;=================================================================================
; sys_ioperm demonstration. 
;
; Enables access to 0x378 (parallel port) and raises/lowers the current. 
; (LED's are a nice way to test this. Connect anode to any of 2-9 pins and cathode 
; to a ground pin (18-25)(1Kom resistor might be necessary).
;
; The LSCR Project. 
;=================================================================================

format ELF

include '../macros.inc'
include '../../include/symbols.inc'
include '../../include/structs.inc'

extrn error_chk

section '.text' executable 

public _start
_start:
	mov	eax, SYS_IOPERM
	mov 	ebx, 0x378
	mov 	ecx, 3
	mov     edx, 1
	int 	0x80
        ccall	error_chk, <"SYS_IOPERM has failed: ">, exit

	mov	dx, 0x378	
	in	al, dx
	xor	al, 11111111b                           ; switch current state
	out	dx, al          

	mov	eax, SYS_IOPERM                         ; this is not actually required, since Linux will disable
	mov	ebx, edx                                ; the range anyway when the process terminates.
	mov	ecx, 3
	xor	edx, edx
	int	0x80
	            
exit:	mov     eax, SYS_EXIT
	xor     ebx, ebx
	int	0x80