.title	map	map a file into memory

	$secdef


	.psect	$$rwdata rd, wrt, noexe, rel, pic, con, noshr, long

	.align	long
fab:
	$fab	fac=<GET,PUT>, shr=<GET,PUT,UPI>, fop=<UFO>


	.align	long
inadr:
	.long	1, 1			; map file into p0 space

	.psect	$$code	rd, nowrt, exe, rel, pic, con, shr, long

	.entry	-
map_file, ^m<r2, r3>
;+
;	status = map_file ( file-name.descr, start-addr, end-addr,
;			    section-name.descr )
;
;	"status" is TRUE if operation was successful
;	"start-addr" and "end-addr" are LONGWORD integers
;
;	Maps the specified file onto the end of virtual memory
;-
	moval	fab, r3
	movq	@4(ap), r0		; r0 = length, r1 = address
	movb	r0, fab$b_fns(r3)	; set file name size
	movl	r1, fab$l_fna(r3)	; set file name address
	$open	fab=(r3)
	blbc	r0, 100$		; br if error

	subl2	#8, sp			; make room for retadr
	movl	sp, r2			; save address of retadr

	$crmpsc_s inadr=inadr, retadr=(r2), -
 		flags=#sec$m_sysgbl!sec$m_gbl!sec$m_wrt!sec$m_expreg, -
		chan=fab$l_stv(r3), -
		gsdnam=@16(ap)
     	blbc	r0, 100$		; br if error
                     
	movl	(r2), @8(ap)		; return start address
	movl	4(r2), @12(ap)		; return end address
100$:
	ret				; with error in r0

	.end