.TITLE	VRW$VM - MAP VM BUFFER (READ/WRITE)
	.SBTTL	VRW$VM - TITLE PAGE
	.PSECT	VMX$$$,RO,I
	.IDENT	/V01.01/
	.ENABL	LC
;
; ************************************************************************
;                                                                        *
; THIS PROGRAM IS PROVIDED ON AN "AS IS" BASIS ONLY.  DIGITAL  EQUIPMENT *
; COMPUTER USER'S SOCIETY,  DIGITAL EQUIPMENT CORPORATION, MONSANTO, AND *
; THE AUTHOR DISCLAIM  ALL WARRANTIES ON THE PROGRAM,  INCLUDING WITHOUT *
; LIMITATION, ALL IMPLIED WARRANTIES OF MERCHANTABLITY AND FITNESS.      *
;									 *
; FULL PERMISSION AND CONSENT IS HEREBY GIVEN TO DECUS  AND TO THE DECUS *
; SPECIAL INTEREST  GROUPS  TO  REPRODUCE,  DISTRIBUTE,  AND PUBLISH AND *
; PERMIT  OTHERS  TO  REPRODUCE  IN  WHOLE  OR  IN PART, IN ANY FORM AND *
; WITHOUT RESTRICTION, THIS PROGRAM AND ANY INFORMATION RELATING TO IT.  *
;									 *
; ************************************************************************
;
; MAP VM BUFFER (READ/WRITE)
;
; VERSION:	V01.01
;
; AUTHOR:	R.W. STAMERJOHN	MAPC	03-NOV-81
;
; MODIFICATION HISTORY:
;
;	V01.01	RWS	03-NOV-81	INITIAL VERSION
;

	.SBTTL	VRW$VM - DECLARATIONS
	.DSABL	GBL
	.DSABL	CRF
;
; MACRO LIBRARY CALLS:
;
	.MCALL	CALLR			;Call subroutine and return
;
; GLOBAL DECLARATIONS:
;
	.GLOBL	VRW$VM			;Module entry
;
; GLOBAL REFERENCES:
;
;	VM subroutines.
;
	.GLOBL	MRK$VI			;Mark VM buffer written
	.GLOBL	S16$VI			;Check size value
	.GLOBL	VIR$VI			;Map address to user

	.ENABL	CRF

	.SBTTL	VRW$VM * MAP VM BUFFER (READ/WRITE)
;
;+
; This routine maps the specified virtual address to the specified
; user-space address. The mapping is for read/write access.
;
; INPUT:
;
;	Call by:	JSR	PC,VRW$VM
;
;				R0,R1	= Virtual address
;				R3	= Size to map (bytes)
;				R4	= User space address
;
; OUTPUT:
;
;	Maps the VM address to the specified user-space address.
;
; REGISTERS:
;
;	Uses:	R0-R5	Saves:	R0-R4	Stack:	1 words
;-
VRW$VM::				;Ref label
	CALL	S16$VI			;Check size is within range
	CALL	VIR$VI			;Map the virtual address to user
	CALLR	MRK$VI			;Mark virtual address written

	.END