cdevio.a86

一个dos操作系统DRDOS的源码

title 'F_DOS Character device I/O'
;    File              : $CDEVIO.A86$
;
;    Description       :
;
;    Original Author   : DIGITAL RESEARCH
;
;    Last Edited By    : $CALDERA$
;
;-----------------------------------------------------------------------;
;    Copyright Work of Caldera, Inc. All Rights Reserved.
;      
;    THIS WORK IS A COPYRIGHT WORK AND CONTAINS CONFIDENTIAL,
;    PROPRIETARY AND TRADE SECRET INFORMATION OF CALDERA, INC.
;    ACCESS TO THIS WORK IS RESTRICTED TO (I) CALDERA, INC. EMPLOYEES
;    WHO HAVE A NEED TO KNOW TO PERFORM TASKS WITHIN THE SCOPE OF
;    THEIR ASSIGNMENTS AND (II) ENTITIES OTHER THAN CALDERA, INC. WHO
;    HAVE ACCEPTED THE CALDERA OPENDOS SOURCE LICENSE OR OTHER CALDERA LICENSE
;    AGREEMENTS. EXCEPT UNDER THE EXPRESS TERMS OF THE CALDERA LICENSE
;    AGREEMENT NO PART OF THIS WORK MAY BE USED, PRACTICED, PERFORMED,
;    COPIED, DISTRIBUTED, REVISED, MODIFIED, TRANSLATED, ABRIDGED,
;    CONDENSED, EXPANDED, COLLECTED, COMPILED, LINKED, RECAST,
;    TRANSFORMED OR ADAPTED WITHOUT THE PRIOR WRITTEN CONSENT OF
;    CALDERA, INC. ANY USE OR EXPLOITATION OF THIS WORK WITHOUT
;    AUTHORIZATION COULD SUBJECT THE PERPETRATOR TO CRIMINAL AND
;    CIVIL LIABILITY.
;-----------------------------------------------------------------------;
;
;    *** Current Edit History ***
;    *** End of Current Edit History ***
;    $Log: $
;    CDEVIO.A86 1.18 94/12/21 11:16:29
;    Changed dev_dup to refuse from duplicating remote devices rather
;    than refuse from duplicating FCBs 
;    Made open_dev return IFN rather than XFN for FCB opens 
;    Made open_dev put the current time/date into DHNDL_TIME/DHNDL_DATE
;    CDEVIO.A86 1.16 94/10/07 09:00:18
;    Added patch 004 as source fix. Changed request header length for character
;    device to 16h. Used RH4_CDEV_LEN instead of RH4_LEN.
;    CDEVIO.A86 1.15 93/12/10 00:09:17
;    Move non-inherited bit to correct place in file handle
;    CDEVIO.A86 1.14 93/11/26 16:17:14
;    Update char_error so ES:SI -> device driver header itself;
;    ENDLOG

	eject ! include i:psp.def
	eject ! include i:modfunc.def
	eject ! include i:fdos.equ
	eject ! include i:mserror.equ
	eject ! include i:doshndl.def
	eject ! include i:driver.equ
	eject ! include rh.equ

BDOS_DATA	dseg

	extrn	fdos_buf:byte		; caveat: in PCMODE data segment
	extrn	fdos_pb:word
	extrn	fdos_ret:word

;
;	Critical Error responses from the default INT 24 handler and
;	the DO_INT24 routine.
;
ERR_IGNORE	equ	0		; Ignore Error
ERR_RETRY	equ	1		; Retry the Operation
ERR_ABORT	equ	2		; Terminate the Process
ERR_FAIL	equ	3		; Fail Function

BDOS_CODE	cseg

	public	open_dev
	public	close_dev
	public	dup_dev
	public	read_dev
	public	write_dev
	public	first_dev
	public	ioc6_dev
	public	ioc7_dev

	extrn	cooked_write:near	; write to cooked console
	extrn	read_line:near		; read edited line
	extrn	break_check:near	; look for CTRL C
	extrn	char_error:near		; generate Int 24

	extrn	current_dsk2al:near	; get default drive in AL
	extrn	device_driver:near
	extrn	alloc_dhndl:near	; find free DHNDL_ structure
	extrn	alloc_xfn:near
	extrn	les_di_dmaptr:near
	extrn	release_handle:near
	extrn	get_xftptr:near
	extrn	timestamp_dhndl:near


;			   Character device functions
;			   ==========================

open_dev:
;--------
;	Entry:	ES:BX -> character device header

;	Note:	We own the MXdisk here, fdos_pb -> parameter data

	push es ! push bx		; save device driver address
	call	alloc_xfn		; DI = XFN
	push	di			; save XFN
	call	alloc_dhndl		; ES:BX -> DHNDL, AX = IFN
	pop	dx			; DX = XFN
	xchg	ax,si			; SI = IFN
	xor	ax,ax
	lea	di,DHNDL_DATRB[bx]	; point at start of area to fill
	mov	cx,DHNDL_UID-DHNDL_DATRB
	rep	stosb
	mov	es:DHNDL_SHARE[bx],ax	; also zap share word	
	pop	es:DHNDL_DEVOFF[bx]
	pop	es:DHNDL_DEVSEG[bx]	; save device driver address

	push si ! push dx		; save IFN/XFN

	mov	es:DHNDL_COUNT[bx],1
	push	ds
	mov	ax,fdos_pb+6		; AX = open mode
	mov	cx,DHAT_DEV+DHAT_CLEAN+DHAT_TIMEOK
	lds	si,es:DHNDL_DEVPTR[bx]	; DS:SI -> device driver
	or	cl,ds:byte ptr DH_ATTRIB[si]
					; get attrib from device driver
	test	al,DHM_LOCAL		; is it private ?
	 jz	open_dev10
	and	al,not DHM_LOCAL	; clear inherit bit
	or	ch,DHAT_LOCAL/256	; rememmber it's local
open_dev10:
	mov	es:DHNDL_MODE[bx],ax
	mov	es:DHNDL_WATTR[bx],cx
	lea	si,DH_NAME[si]		; copy the device name
	lea	di,DHNDL_NAME[bx]	;  from the device header
	mov	cx,8/WORD
	rep	movsw
	mov	al,' '
	mov	cl,3			; space the file extension
	rep	stosb
	pop	ds
	
	pop dx ! pop ax			; AX = IFN, DX = XFN

	push	es
	call	get_xftptr		; ES:DI -> PSP_XFTPTR for current_psp
	 jc	open_dev20		; no PSP, skip updating XFN
	add	di,dx			; ES:DI -> entry in PSP
	stosb				; update entry in PSP
	xchg	ax,dx
open_dev20:
	pop	es

	mov	fdos_ret,ax		; save XFN (IFN for FCB open) to return
	call	timestamp_dhndl
	or	es:DHNDL_ATTR[bx],DHAT_READY
;	jmp	open_dup_dev

open_dup_dev:
;------------
; On Entry:
;	ES:BX = DHNDL_
; On Exit:
;	None
;
	mov	al,CMD_DEVICE_OPEN
;	jmp	open_close_dev		; call device open routine

open_close_dev:
;--------------
; entry:	ES:BX = DHNDL_
;		AL = cmd_type (CMD_DEVICE_OPEN/CMD_DEVICE_CLOSE)
;
	push ds ! push es
	push bx ! push si
	lds	si,es:DHNDL_DEVPTR[bx]	; DS:SI -> device driver
	test	ds:DH_ATTRIB[si],DA_REMOVE
	 jz	ocdev1			 ; does the device support OPEN/CLOSE/RM
	sub	sp,RH13_LEN-2*word	; make space on stack for RH_
	push	ax			; RH_CMD = AL
	mov	ax,RH13_LEN
	push	ax			; RH_LEN = RH13_LEN
	push ss ! pop es
	mov	bx,sp			; ES:BX -> RH_
	call	device_driver		; call the device driver
	add	sp,RH13_LEN		; recover stack space
ocdev1:
	pop si ! pop bx
	pop es ! pop ds
	ret

dup_dev:
;-------
; On Entry:
;	ES:BX -> DHNDL_
; On Exit:
;	None
;	AX trashed
;
	mov	ax,es:DHNDL_WATTR[bx]
	test	al,DHAT_DEV
	 jz	dup_dev10		; skip if disk file
	test	ax,DHAT_REMOTE		; or remote
	 jz	open_dup_dev
dup_dev10:
	ret


close_dev:	; close character device handle
;---------
;	entry:	FDOS_PB+2 = user file handle
;		ES:BX = file handle
;	NOTE:	This is called with the MXdisk owned

	mov	al,CMD_DEVICE_CLOSE
	call	open_close_dev		; call device close routine
	call	release_handle		; release the XFN
	dec	es:DHNDL_COUNT[bx]	; one less XFN refers to this IFN
	ret


write_dev:	; write to character device handle
;---------
;	entry:	ES:BX -> DHNDL_ structure
;

	mov	cl,CMD_OUTPUT		; OUTPUT driver function
	or	es:DHNDL_ATTR[bx],DHAT_READY
	mov	al,es:DHNDL_ATTR[bx]	; get file info
	and	al,DHAT_BIN+DHAT_NUL+DHAT_CIN+DHAT_COT
	cmp	al,DHAT_CIN+DHAT_COT	; is it cooked console?
	 jne	inst_io			; no, device driver i/o
	mov	si,2[bp]		; SI -> parameter block
	mov	cx,ds:8[si]		; CX = string length
	 jcxz	write_dev20		; exit if nothing to write
	les	di,ds:4[si]		; ES:DI -> string to print
	mov	al,'Z'-40h		; we have to stop at ^Z
	repne	scasb			; scan for ^Z character
	 jne	write_dev10		; skip if ^Z not found
	inc	cx			; include ^Z in count of chars to skip
	sub	ds:8[si],cx		; subtract from total count
write_dev10:
	mov	bx,ds:2[si]		; BX = handle number
	mov	cx,ds:8[si]		; CX = string length
	mov	si,ds:4[si]		; ES:SI -> string to print
	call	cooked_write		; write w/ tab expansion & ^C checking
write_dev20:
	sub	bx,bx			; no errors
	ret				; return the result



read_dev:	; read to character device handle
;--------
;	entry:	ES:BX -> DHNDL_ structure

	mov	al,es:DHNDL_ATTR[bx]	; get the file info
	mov	ah,al			; save ioctl info
	and	al,DHAT_BIN+DHAT_CIN+DHAT_COT
	cmp	al,DHAT_CIN+DHAT_COT	; is it cooked console?
	 jne	rddev1			; skip if binary or not console
	jmp	read_con		; read from console handle