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1;
2; system call entry points MSDOS
3;
4
5INCLUDE DOSSEG.ASM
6
7CODE SEGMENT BYTE PUBLIC 'CODE'
8 ASSUME SS:DOSGROUP,CS:DOSGROUP
9
10.xlist
11.xcref
12INCLUDE DOSSYM.ASM
13INCLUDE DEVSYM.ASM
14.cref
15.list
16
17
18 i_need YEAR,WORD
19 i_need DAY,BYTE
20 i_need WeekDay,BYTE
21 i_need TimeBuf,6
22 i_need BCLOCK,DWORD
23 i_need DskErr,BYTE
24 i_need Attrib,BYTE
25 i_need Name1,BYTE
26 i_need Name2,BYTE
27 i_need Name3,BYTE
28 i_need DelAll,BYTE
29 i_need ThisDPB,DWORD
30 i_need CurBuf,DWORD
31 i_need LastEnt,WORD
32 i_need ThisDrv,BYTE
33 i_need DirStart,WORD
34 i_need DevPt,DWORD
35 i_need Creating,BYTE
36 i_need VolID,BYTE
37 i_need FoundDel,BYTE
38
39SUBTTL DATE AND TIME - SYSTEM CALLS 42,43,44,45; S/G DATE,TIME
40PAGE
41 procedure $GET_DATE,NEAR ;System call 42
42ASSUME DS:NOTHING,ES:NOTHING
43
44; Inputs:
45; None
46; Function:
47; Return current date
48; Returns:
49; Date in CX:DX
50
51 PUSH SS
52 POP DS
53ASSUME DS:DOSGROUP
54 invoke READTIME ;Check for rollover to next day
55 MOV AX,[YEAR]
56 MOV BX,WORD PTR [DAY]
57 invoke get_user_stack ;Get pointer to user registers
58ASSUME DS:NOTHING
59 MOV [SI.user_DX],BX ;DH=month, DL=day
60 ADD AX,1980 ;Put bias back
61 MOV [SI.user_CX],AX ;CX=year
62 MOV AL,BYTE PTR [WEEKDAY]
63 RET
64$GET_DATE ENDP
65
66 procedure $SET_DATE,NEAR ;System call 43
67ASSUME DS:NOTHING,ES:NOTHING
68
69; Inputs:
70; CX:DX valid date
71; Function:
72; Set current date
73; Returns:
74; AL = -1 date bad, = 0 OK
75
76 MOV AL,-1 ;Be ready to flag error
77 SUB CX,1980 ;Fix bias in year
78 JC RET24 ;Error if not big enough
79 CMP CX,119 ;Year must be less than 2100
80 JA RET24
81 OR DH,DH
82 JZ RET24
83 OR DL,DL
84 JZ RET24 ;Error if either month or day is 0
85 CMP DH,12 ;Check against max. month
86 JA RET24
87 PUSH SS
88 POP DS
89ASSUME DS:DOSGROUP
90 invoke DODATE
91RET24: RET
92$SET_DATE ENDP
93
94 procedure $GET_TIME,NEAR ;System call 44
95ASSUME DS:NOTHING,ES:NOTHING
96
97; Inputs:
98; None
99; Function:
100; Get current time
101; Returns:
102; Time in CX:DX
103
104 PUSH SS
105 POP DS
106ASSUME DS:DOSGROUP
107 invoke READTIME
108 invoke get_user_stack ;Get pointer to user registers
109 MOV [SI.user_DX],DX
110 MOV [SI.user_CX],CX
111 XOR AL,AL
112RET26: RET
113$GET_TIME ENDP
114
115 procedure $SET_TIME,NEAR ;System call 45
116;Time is in CX:DX in hours, minutes, seconds, 1/100 sec.
117ASSUME DS:NOTHING,ES:NOTHING
118
119; Inputs:
120; CX:DX = Time
121; Function:
122; Set time
123; Returns:
124; AL = -1 time bad, = 0 OK
125
126 MOV AL,-1 ;Flag in case of error
127 CMP CH,24 ;Check hours
128 JAE RET26
129 CMP CL,60 ;Check minutes
130 JAE RET26
131 CMP DH,60 ;Check seconds
132 JAE RET26
133 CMP DL,100 ;Check 1/100's
134 JAE RET26
135 PUSH CX
136 PUSH DX
137 PUSH SS
138 POP DS
139ASSUME DS:DOSGROUP
140 MOV BX,OFFSET DOSGROUP:TIMEBUF
141 MOV CX,6
142 XOR DX,DX
143 MOV AX,DX
144 PUSH BX
145 invoke SETREAD
146ASSUME ES:DOSGROUP
147 PUSH DS
148 LDS SI,[BCLOCK]
149ASSUME DS:NOTHING
150 invoke DEVIOCALL2 ;Get correct day count
151 POP DS
152ASSUME DS:DOSGROUP
153 POP BX
154 invoke SETWRITE
155 POP WORD PTR [TIMEBUF+4]
156 POP WORD PTR [TIMEBUF+2]
157 LDS SI,[BCLOCK]
158ASSUME DS:NOTHING
159 invoke DEVIOCALL2 ;Set the time
160 XOR AL,AL
161 RET
162$SET_TIME ENDP
163
164SUBTTL DISK R/W ROUTINES
165PAGE
166 procedure $FCB_SEQ_READ,NEAR ; System call 20
167ASSUME DS:NOTHING,ES:NOTHING
168
169; Inputs:
170; DS:DX Points to openned FCB
171; Function:
172; Read next record from file to disk transfer address
173; Returns:
174; AL = 1 EOF record is empty
175; AL = 3 EOF record is partial zero filled
176; AL = 2 No room at disk transfer address
177; AL = 0 All OK
178
179 invoke GETREC
180 invoke LOAD
181 JMP SHORT FINSEQ
182
183 entry $FCB_SEQ_WRITE ; System call 21
184ASSUME DS:NOTHING,ES:NOTHING
185
186; Inputs:
187; DS:DX Points to openned FCB
188; Function:
189; Write next record to file from disk transfer address
190; Returns:
191; AL = 1 Disk full
192; AL = 2 No room in disk transfer segment
193; AL = 0 All OK
194
195 invoke GETREC
196 invoke STORE
197FINSEQ:
198 JCXZ SETNREX
199 ADD AX,1
200 ADC DX,0
201 JMP SHORT SETNREX
202
203 entry $FCB_RANDOM_READ ; System call 33
204ASSUME DS:NOTHING,ES:NOTHING
205
206; Inputs:
207; DS:DX Points to openned FCB
208; Function:
209; Read record addressed by random record field from file to
210; disk transfer address
211; Returns:
212; AL = 1 EOF record is empty
213; AL = 3 EOF record is partial zero filled
214; AL = 2 No room at disk transfer address
215; AL = 0 All OK
216
217 invoke GETRRPOS1
218 invoke LOAD
219 JMP SHORT FINRND
220
221 entry $FCB_RANDOM_WRITE ; System call 34
222ASSUME DS:NOTHING,ES:NOTHING
223
224; Inputs:
225; DS:DX Points to openned FCB
226; Function:
227; Write record addressed by random record field to file from
228; disk transfer address
229; Returns:
230; AL = 1 Disk full
231; AL = 2 No room in disk transfer segment
232; AL = 0 All OK
233
234 invoke GETRRPOS1
235 invoke STORE
236 JMP SHORT FINRND
237
238 entry $FCB_RANDOM_READ_BLOCK ; System call 39
239ASSUME DS:NOTHING,ES:NOTHING
240
241; Inputs:
242; DS:DX Points to openned FCB
243; CX = Record count
244; Function:
245; Read CX records starting at random record field from file
246; to disk transfer address
247; Returns:
248; AL = 1 EOF record is empty
249; AL = 3 EOF record is partial zero filled
250; AL = 2 No room at disk transfer address
251; AL = 0 All OK
252; CX = Actual number of records read
253
254 invoke GETRRPOS
255 invoke LOAD
256 JMP SHORT FINBLK
257
258 entry $FCB_RANDOM_WRITE_BLOCK ; System call 40
259ASSUME DS:NOTHING,ES:NOTHING
260
261; Inputs:
262; DS:DX Points to openned FCB
263; CX = Record count
264; Function:
265; Write CX records starting at random record field to file
266; from disk transfer address
267; If CX = 0 File is set to length determined from random record field
268; Returns:
269; AL = 1 Disk full
270; AL = 2 No room in disk transfer segment
271; AL = 0 All OK
272; CX = Actual number of records written
273
274 invoke GETRRPOS
275 invoke STORE
276FINBLK:
277 invoke get_user_stack
278 MOV [SI.user_CX],CX
279 entry FINNOSAV
280 JCXZ FINRND
281 ADD AX,1
282 ADC DX,0
283FINRND:
284 MOV WORD PTR ES:[DI.fcb_RR],AX
285 MOV ES:[DI.fcb_RR+2],DL
286 OR DH,DH
287 JZ SETNREX
288 MOV ES:[DI.fcb_RR+3],DH ; Save 4 byte of RECPOS only if significant
289SETNREX:
290 MOV CX,AX
291 AND AL,7FH
292 MOV ES:[DI.fcb_NR],AL
293 AND CL,80H
294 SHL CX,1
295 RCL DX,1
296 MOV AL,CH
297 MOV AH,DL
298 MOV ES:[DI.fcb_EXTENT],AX
299 MOV AL,BYTE PTR [DSKERR]
300RET4:
301 RET
302$FCB_SEQ_READ ENDP
303
304SUBTTL $FCB_DELETE -- SYSTEM CALL 19
305PAGE
306 procedure $FCB_DELETE,NEAR ; System call 19
307ASSUME DS:NOTHING,ES:NOTHING
308
309; Inputs:
310; DS:DX point to unopened FCB
311; Function:
312; Delete all matching entries
313; Returns:
314; AL = -1 if no entries matched, otherwise 0
315
316 invoke MOVNAME
317ASSUME ES:DOSGROUP
318 MOV AL,-1
319 MOV BYTE PTR [FoundDel],AL
320 JC RET4
321 MOV AL,BYTE PTR [ATTRIB]
322 AND AL,attr_hidden+attr_system+attr_directory+attr_volume_id+attr_read_only
323 ; Look only at hidden bits
324 CMP AL,attr_hidden+attr_system+attr_directory+attr_volume_id+attr_read_only
325 ; All must be set
326 JNZ NOTALL
327 MOV CX,11
328 MOV AL,"?"
329 MOV DI,OFFSET DOSGROUP:NAME1
330 REPE SCASB ; See if name is *.*
331 JNZ NOTALL
332 MOV BYTE PTR [DELALL],0 ; DEL *.* - flag deleting all
333NOTALL:
334 invoke FINDNAME
335ASSUME DS:DOSGROUP
336 MOV AL,-1
337 JC RET4
338 OR AH,AH ; Check if device name
339 JS RET4 ; Can't delete I/O devices
340DELFILE:
341 LES BP,[THISDPB]
342 MOV AH,BYTE PTR [DELALL]
343 PUSH DS
344 LDS DI,[CURBUF]
345ASSUME DS:NOTHING
346 TEST [Attrib],attr_read_only ; are we deleting RO files too?
347 JNZ DoDelete ; yes
348 TEST DS:[BX.dir_attr],attr_read_only
349 JZ DoDelete ; not read only
350 POP DS
351 JMP SHORT DelNxt
352DoDelete:
353 MOV BYTE PTR [FoundDel],0
354 MOV [DI.BUFDIRTY],1
355 MOV BYTE PTR [BX],AH
356 MOV BX,[SI]
357 POP DS
358ASSUME DS:DOSGROUP
359 OR BX,BX
360 JZ DELNXT
361 CMP BX,ES:[BP.dpb_max_cluster]
362 JA DELNXT
363 invoke RELEASE
364DELNXT:
365 invoke GETENTRY ; Registers need to be reset
366 invoke NEXTENT
367 JNC DELFILE
368 CALL FLUSHRET1
369 MOV AL,BYTE PTR [FoundDel]
370 RET
371
372$FCB_DELETE ENDP
373
374SUBTTL $FCB_RENAME -- SYSTEM CALL 23; RENAME FILES
375PAGE
376ERRETJ: JMP ERRET
377
378 procedure $FCB_RENAME,NEAR ; System call 23
379ASSUME DS:NOTHING,ES:NOTHING
380
381; Inputs:
382; DS:DX point to a modified FCB (DS:DX+11H points to destination
383; name)
384; Function:
385; Rename all matching entries to indicated name
386; Returns:
387; AL = -1 if no entries matched, otherwise 0
388
389 invoke MOVNAME
390ASSUME ES:DOSGROUP
391 JC ERRETJ
392 ADD SI,5
393 MOV DI,OFFSET DOSGROUP:NAME2
394 invoke LODNAME
395 JC ERRETJ ; Report error if second name invalid
396 invoke FINDNAME
397ASSUME DS:DOSGROUP
398 JC ERRETJ
399 OR AH,AH ; Check if I/O device name
400 JS ERRETJ ; If so, can't rename it
401 MOV SI,OFFSET DOSGROUP:NAME1
402 MOV DI,OFFSET DOSGROUP:NAME3
403 MOV CX,13
404 REP MOVSB ; Copy name to search for --include attribute byte
405RENFIL:
406 MOV DI,OFFSET DOSGROUP:NAME1
407 MOV SI,OFFSET DOSGROUP:NAME2
408 MOV CX,11
409NEWNAM:
410 LODSB
411 CMP AL,"?"
412 JNZ NOCHG
413 PUSH DS
414 MOV DS,WORD PTR [CURBUF+2]
415 MOV AL,[BX]
416 POP DS
417NOCHG:
418 STOSB
419 INC BX
420 LOOP NEWNAM
421 INC DI
422 MOV BYTE PTR [DI],attr_all ;Sets ATTRIB
423 ; Stop duplicates with any attributes
424 invoke DEVNAME ; Check if giving it a device name
425 JNC RENERR
426 XOR AX,AX
427 PUSH [LASTENT]
428 invoke FINDENTRY ; See if new name already exists
429 POP AX
430 JNC RENERR ; Error if found
431 LES BP,[THISDPB]
432 invoke GETENT ; Re-read matching entry
433 MOV DI,BX ; Leave BX,DX until call to NEXTENT
434 MOV ES,WORD PTR [CURBUF+2]
435 MOV SI,OFFSET DOSGROUP:NAME1
436 MOV CX,11
437 REP MOVSB ; Replace old name with new one
438 MOV DI,WORD PTR [CURBUF]
439 MOV ES:[DI.BUFDIRTY],1 ; Directory changed
440 PUSH SS
441 POP ES
442 MOV SI,OFFSET DOSGROUP:NAME3
443 MOV DI,OFFSET DOSGROUP:NAME1
444 MOV CX,13 ; Include attribute byte
445 REP MOVSB ; Copy name back into search buffer
446 invoke NEXTENT
447 JNC RENFIL
448 JMP FLUSHRET1
449
450RENERR:
451 CALL FLUSHRET1
452ERRET:
453 MOV AL,-1
454 RET
455$FCB_RENAME ENDP
456
457SUBTTL $FCB_OPEN -- SYSTEM CALL 15; OPEN A FILE
458PAGE
459 procedure $FCB_OPEN,NEAR ; System call 15
460ASSUME DS:NOTHING,ES:NOTHING
461
462; Inputs:
463; DS:DX point to an unopened FCB
464; Function:
465; Open indicated file and fill in FCB
466; Returns:
467; AL = -1 if no entries matched, otherwise 0
468; FOR INTERNAL USE
469; [CURBUF+2]:SI and [CURBUF+2]:BX Preserved
470
471 invoke GETFILE
472ASSUME DS:DOSGROUP,ES:NOTHING
473
474 entry DOOPEN
475
476; Enter here to perform $FCB_OPEN on file already found
477; in directory. AH=device ID number, DS=CS, BX points to directory
478; entry in [CURBUF], SI points to First Cluster field, and
479; ES:DI point to the FCB to be opened. This entry point
480; is used by $FCB_CREATE.
481 JC ERRET
482 PUSH SI
483 PUSH AX ; Save I/O driver number
484 XOR AL,AL
485 OR AH,AH
486 JS OPENDEV
487 MOV AL,[THISDRV]
488 MOV DS,WORD PTR [CURBUF+2]
489ASSUME DS:NOTHING
490 INC AX
491OPENDEV:
492 STOSB
493 XOR AX,AX
494IF ZEROEXT
495 ADD DI,11
496 STOSW ; Zero low byte of extent field if ZERPEXT only
497ELSE
498 ADD DI,12 ; Point to high half of CURRENT BLOCK field
499 STOSB ; Set it to zero (CP/M programs set low byte)
500ENDIF
501 MOV AL,128 ; Default record size
502 STOSW ; Set record size
503 LODSW ; Get starting cluster
504 MOV DX,AX ; Save it for the moment
505 MOVSW ; Transfer size to FCB
506 MOVSW
507 MOV AX,[SI-8] ; Get date
508 STOSW ; Save date in FCB
509 MOV AX,[SI-10] ; Get time
510 STOSW ; Save it in FCB
511 POP AX ; Restore I/O driver number
512 POP SI
513 MOV AL,AH
514 OR AL,40H ; Not dirty
515 STOSB
516 JS SAVDEVPT ; If device, go save pointer to it
517 MOV AX,DX ; Restore starting cluster
518 STOSW ; first cluster
519 PUSH AX ; save cluster
520 XOR AX,AX
521 STOSW ; clus pos
522 POP AX ; last cluster
523 STOSB
524 MOV AL,AH
525 MOV AH,BYTE PTR [DIRSTART]
526 PUSH CX
527 MOV CL,4
528 SHL AH,CL
529 OR AL,AH
530 STOSB
531 MOV AX,[DIRSTART]
532 MOV CL,4
533 SHL AX,CL
534 POP CX
535 MOV AL,AH
536 STOSB
537OPEN_RET:
538 XOR AX,AX
539 RET
540
541SAVDEVPT:
542ASSUME DS:DOSGROUP
543 LDS AX,[DEVPT]
544ASSUME DS:NOTHING
545 STOSW
546 MOV ES:[DI],DS
547 JMP SHORT OPEN_RET
548$FCB_OPEN ENDP
549
550SUBTTL $FCB_CLOSE -- SYSTEM CALL 16; CLOSE FILE
551PAGE
552 procedure $FCB_CLOSE,NEAR ; System call 16
553ASSUME DS:NOTHING,ES:NOTHING
554
555; Inputs:
556; DS:DX point to an opened FCB
557; Function:
558; Close the indicated file
559; Returns:
560; AL = -1 if disk has been changed, otherwise 0
561
562 MOV DI,DX
563 CMP BYTE PTR [DI],-1 ; Check for extended FCB
564 JNZ NORMFCB3
565 ADD DI,7
566NORMFCB3:
567 TEST [DI.fcb_DEVID],devid_file_clean+devid_device
568 ; Allow only dirty files
569 JNZ OKRET1 ; can't close I/O device or not written
570 invoke MOVNAMENOSET
571 JC BADCLOSE ; Bad file name
572 entry FCB_CLOSE_INNER
573 PUSH DX
574 PUSH DS
575 MOV SI,DX
576 MOV BX,[SI.fcb_LSTCLUS+1]
577 MOV CL,4
578 SHR BX,CL
579 PUSH BX
580 PUSH SS
581 POP DS
582ASSUME DS:DOSGROUP
583 invoke FATREAD
584 POP BX
585 invoke SETDIRSRCH
586 invoke FINDENTRY
587 POP ES
588 POP DI
589 JC BADCLOSE
590 LDS BX,[CURBUF]
591ASSUME DS:NOTHING
592
593 ; note that SI points to dir_first...
594
595 OR BYTE PTR [SI-dir_first+dir_attr],attr_archive
596 MOV CX,ES:[DI.fcb_FIRCLUS]
597 MOV [SI-dir_first+dir_first],CX
598 MOV DX,ES:WORD PTR [DI.fcb_FILSIZ]
599 MOV [SI-dir_first+dir_size_l],DX
600 MOV DX,ES:WORD PTR [DI.fcb_FILSIZ+2]
601 MOV [SI-dir_first+dir_size_h],DX
602 MOV DX,ES:[DI.fcb_FDATE]
603 MOV [SI-dir_first+dir_date],DX
604 MOV DX,ES:[DI.fcb_FTIME]
605 MOV [SI-dir_first+dir_time],DX
606 MOV [BX.BUFDIRTY],1
607 PUSH SS
608 POP DS
609ASSUME DS:DOSGROUP
610FLUSHRET1:
611 LES BP,[THISDPB]
612 MOV AL,ES:[BP.dpb_drive]
613 invoke FLUSHBUF
614OKRET1:
615 XOR AL,AL
616 RET
617
618BADCLOSE:
619 MOV AL,-1
620 RET
621$FCB_CLOSE ENDP
622
623SUBTTL $FCB_CREATE -- SYSTEM CALL 22; MAKE AND OPEN A NEW FILE
624PAGE
625 procedure $FCB_CREATE,NEAR ; System call 22
626ASSUME DS:NOTHING,ES:NOTHING
627
628; Inputs:
629; DS:DX point to an unopened FCB
630; Function:
631; If file does not exist, create it and open it
632; If file exists, free up its contents and open the file
633; Returns:
634; AL = -1 if file cannot be created, otherwise 0
635
636 invoke MOVNAME
637ASSUME ES:DOSGROUP
638 JC ERRET3
639 MOV DI,OFFSET DOSGROUP:NAME1
640 MOV CX,11
641 MOV AL,"?"
642 REPNE SCASB
643 JZ ERRET3
644 MOV BYTE PTR [CREATING],-1
645 PUSH DX
646 PUSH DS
647 invoke FINDNAME
648ASSUME DS:DOSGROUP
649NWENTY:
650 LES BP,[THISDPB]
651ASSUME ES:NOTHING
652 JNC EXISTENT
653 invoke BUILDDIR
654 JC ERRPOP
655 invoke GETENT ; Point at that free entry
656 JMP SHORT FREESPOT
657ERRPOP:
658 POP DS
659 POP DX
660ASSUME DS:NOTHING
661ERRET3:
662 JMP SHORT BADCLOSE
663
664 entry NEWENTRY
665 POP DX ; Return address
666 POP ES ; ES
667 POP CX ; DI
668 PUSH DX
669 PUSH CX
670 PUSH ES
671 JMP NWENTY
672
673EXISTENT:
674ASSUME DS:DOSGROUP
675 JNZ ERRPOP ; Error if attributes don't match
676 OR AH,AH ; Check if file is I/O device
677 JS OPENJMP ; If so, no action
678 PUSH DS
679 LDS DI,[CURBUF]
680ASSUME DS:NOTHING
681 MOV CX,[SI] ; Get pointer to clusters
682 MOV SI,[DI.BUFSECNO]
683 POP DS
684ASSUME DS:DOSGROUP
685 JCXZ FREESPOT
686 CMP CX,ES:[BP.dpb_max_cluster]
687 JA FREESPOT
688 SUB BX,DI
689 PUSH BX
690 PUSH SI ; Save sector number
691 MOV BX,CX
692 invoke RELEASE ; Free any data already allocated
693 POP DX
694 XOR AL,AL
695 invoke GETBUFFR
696 POP BX
697 ADD BX,WORD PTR [CURBUF]
698FREESPOT:
699 TEST BYTE PTR [ATTRIB],attr_volume_id
700 JZ NOTVOLID
701 CMP BYTE PTR [VOLID],0
702 JNZ ERRPOP ; Can't create a second volume ID
703NOTVOLID:
704 MOV ES,WORD PTR [CURBUF+2]
705 MOV DI,BX
706 MOV SI,OFFSET DOSGROUP:NAME1
707 MOV CX,5
708 MOVSB
709 REP MOVSW
710 MOV AL,[ATTRIB]
711 STOSB
712 MOV CL,5
713 XOR AX,AX
714 REP STOSW
715 invoke DATE16
716 XCHG AX,DX
717 STOSW
718 XCHG AX,DX
719 STOSW
720 XOR AX,AX
721 PUSH DI
722 STOSW
723 STOSW
724 STOSW
725 MOV SI,WORD PTR [CURBUF]
726 MOV ES:[SI.BUFDIRTY],1
727 LES BP,[THISDPB]
728 MOV AL,ES:[BP.dpb_drive]
729 PUSH AX
730 PUSH BX
731 invoke FLUSHBUF
732 POP BX
733 POP AX
734 POP SI
735 MOV AH,AL ; Get I/O driver number back
736OPENJMP:
737 CLC ; Clear carry so OPEN won't fail
738 POP ES
739 POP DI
740ASSUME ES:NOTHING
741 JMP DOOPEN
742$FCB_CREATE ENDP
743
744do_ext
745
746CODE ENDS
747 END
748
749 \ No newline at end of file
HIC SVNT DRACONES