wirehaze git hosting - MS-DOS.git/blob - v2.0/source/SYSINIT.ASM

1 TITLE BIOS SYSTEM INITIALIZATION

3 FALSE EQU 0

4 TRUE EQU NOT FALSE

6 IBMVER EQU FALSE

7 IBM EQU IBMVER

8 IBMJAPVER EQU FALSE ; If TRUE set KANJI true also

9 MSVER EQU TRUE

10 ALTVECT EQU FALSE ; Switch to build ALTVECT version

11 HIGHMEM EQU FALSE

12 KANJI EQU FALSE

14 IF IBMVER OR IBMJAPVER

15 NOEXEC EQU TRUE

16 ELSE

17 NOEXEC EQU FALSE

18 ENDIF

20 ; Set to agree with those in DOST:MSHEAD.ASM, ALTVECT version only

21 MAJOR_VERSION EQU 2

22 MINOR_VERSION EQU 0B ;2.11

24 DOSSIZE EQU 5000H

26 ; Internal DOS data returned by DOSINIT

28 SYSINITVAR STRUC

29 DPBHEAD DD ? ; Pointer to head of DPB-FAT list

30 sft_addr DD ? ; Pointer to first FCB table

31 ; The following address points to the CLOCK device

32 BCLOCK DD ?

33 ; The following address is used by DISKSTATCHK it is always

34 ; points to the console input device header

35 BCON DD ? ; Console device entry points

36 NUMIO DB 0 ; Number of disk tables

37 MAXSEC DW 0 ; Maximum allowed sector size

38 BUFFHEAD DD ? ; Head of buffer queue

39 DEVHEAD DD ?

40 SYSINITVAR ENDS

42 INCLUDE DOSSYM.ASM

43 INCLUDE DEVSYM.ASM

45 IF NOT IBM

46 IF NOT IBMJAPVER

47 EXTRN RE_INIT:FAR

48 ENDIF

49 ENDIF

51 SYSINITSEG SEGMENT PUBLIC 'SYSTEM_INIT'

 ASSUME  CS:SYSINITSEG,DS:NOTHING,ES:NOTHING,SS:NOTHING

         EXTRN   BADOPM:BYTE,CRLFM:BYTE,BADCOM:BYTE

         EXTRN   BADSIZ_PRE:BYTE,BADLD_PRE:BYTE

         EXTRN   BADSIZ_POST:BYTE,BADLD_POST:BYTE

         EXTRN   SYSSIZE:BYTE,BADCOUNTRY:BYTE

60 PUBLIC CURRENT_DOS_LOCATION

61 PUBLIC FINAL_DOS_LOCATION

62 PUBLIC DEVICE_LIST

63 PUBLIC MEMORY_SIZE

64 PUBLIC DEFAULT_DRIVE

65 PUBLIC BUFFERS

66 PUBLIC FILES

67 PUBLIC SYSINIT

69 IF HIGHMEM

70 PUBLIC DPBBUF_SIZ

71 ENDIF

73 SYSINIT:

74 JMP GOINIT

76 DOSINFO LABEL DWORD

77 DW 0000

78 CURRENT_DOS_LOCATION DW 0000

80 MSDOS LABEL DWORD

81 ENTRY_POINT LABEL DWORD

82 DW 0000

83 FINAL_DOS_LOCATION DW 0000

84 DEVICE_LIST DD 00000000

86 IF HIGHMEM

 DPBBUF_SIZ              DW      (4472  + 15) / 16

88 ENDIF

90 MEMORY_SIZE DW 0001

91 DEFAULT_DRIVE DB 00

92 BUFFERS DB 2

93 FILES DB 8

 COMMAND_LINE            DB      2,0,"P" ; Default Command.com Args

                         DB      29 DUP (0)

96 ZERO DB 0

98 IF NOT NOEXEC

 COMEXE  EXEC0 <0,COMMAND_LINE,DEFAULT_DRIVE,ZERO>

100 ENDIF

101

102 COUNT DW 0000

103 CHRPTR DW 0000

104

105 BUFPTR LABEL DWORD ; LEAVE THIS STUFF IN ORDER!

106 MEMLO DW 0

107 PRMBLK LABEL WORD

108 MEMHI DW 0

109 LDOFF DW 0

110 AREA DW 0

111

112 PACKET DB 22

113 DB 0

114 DB 0 ; INITIALIZE CODE

115 DW 0

                         DB      8 DUP (?)

117 UNITCOUNT DB 0

118 BREAK_ADDR DD 0

119 BPB_ADDR DD 0

120

121 GOINIT:

122 CLD

123 XOR SI,SI

124 MOV DI,SI

125

126 IF MSVER

127 MOV CX,[MEMORY_SIZE]

128 CMP CX,1

129 JNZ NOSCAN

         MOV     CX,2048                 ; START SCANNING AT 32K BOUNDARY

131 XOR BX,BX

132

133 MEMSCAN:INC CX

134 JZ SETEND

135 MOV DS,CX

         MOV     AL,[BX]

137 NOT AL

         MOV     [BX],AL

         CMP     AL,[BX]

140 NOT AL

         MOV     [BX],AL

142 JZ MEMSCAN

143 SETEND:

144 MOV [MEMORY_SIZE],CX

145 ENDIF

146

147 IF IBMVER OR IBMJAPVER

148 MOV CX,[MEMORY_SIZE]

149 ENDIF

150

151 NOSCAN:

152 MOV AX,CS

153 MOV DS,AX

154 ASSUME DS:SYSINITSEG

155

156 IF HIGHMEM

         SUB     CX,(DOSSIZE / 16)       ; Leave room for DOS

         SUB     CX,CS:[DPBBUF_SIZ]      ; Allow OEM to tune

159 ENDIF

160

         MOV     AX,OFFSET SYSSIZE + 15

         SHR     AX,1                    ; Divide by 16 for paras

163 SHR AX,1

164 SHR AX,1

165 SHR AX,1

166 SUB CX,AX

167 MOV ES,CX

         MOV     CX,OFFSET SYSSIZE + 1

         SHR     CX,1                    ; Divide by 2 to get words

170 REP MOVSW ; RELOCATE SYSINIT

171

172 ASSUME ES:SYSINITSEG

173

174 PUSH ES

175 MOV AX,OFFSET SYSIN

176 PUSH AX

177

178 AAA PROC FAR

179 RET

180 AAA ENDP

181 ;

182 ; MOVE THE DOS TO ITS PROPER LOCATION

183 ;

184 SYSIN:

185

         ASSUME  DS:NOTHING,ES:SYSINITSEG,SS:NOTHING

187

188 MOV AX,[CURRENT_DOS_LOCATION]

189 MOV DS,AX

190 MOV AX,[FINAL_DOS_LOCATION]

191 MOV ES,AX

192

193 ASSUME ES:NOTHING

194

195 XOR SI,SI

196 MOV DI,SI

         MOV     CX,DOSSIZE/2

198 REP MOVSW

199

200 LDS SI,[DEVICE_LIST]

201 MOV DX,[MEMORY_SIZE]

202

203 CLI

204 MOV AX,CS

205 MOV SS,AX

206 MOV SP,OFFSET LOCSTACK

207

208 ASSUME SS:SYSINITSEG

209

210 IF NOT ALTVECT

211 STI ; Leave INTs disabled for ALTVECT

212 ENDIF

213 LOCSTACK LABEL BYTE

214

215 CALL MSDOS

         MOV     WORD PTR [DOSINFO+2],ES ; SAVE POINTER TO DOS INFO

         MOV     WORD PTR [DOSINFO],DI

218

219 IF NOT IBM

220 IF NOT IBMJAPVER

221 CALL RE_INIT ; Re-call the BIOS

222 ENDIF

223 ENDIF

224

225 STI

226 CLD

227

228 IF HIGHMEM

229 PUSH DS

230 MOV BX,DS

231 ADD BX,10H

232 MOV ES,BX

233 PUSH CS

234 POP DS

235 XOR SI,SI

236 MOV DI,SI

         MOV     CX,OFFSET SYSSIZE + 1

         SHR     CX,1                    ; Divide by 2 to get words

239 REP MOVSW

240 POP DS

241 PUSH ES

242 MOV AX,OFFSET SECONDRELOC

243 PUSH AX

244 BBB PROC FAR

245 RET

246 BBB ENDP

247

248 SECONDRELOC:

249 MOV AX,CS

250 CLI

251 MOV SS,AX

252 MOV SP,OFFSET LOCSTACK

253 STI

254 ELSE

255 MOV BX,CS

256 SUB BX,10H

257 MOV ES,BX

258 XOR SI,SI

259 MOV DI,SI

260 MOV CX,80H

261 REP MOVSW

262 MOV AH,SET_CURRENT_PDB

263 INT 21H

264 ENDIF

265

266 PUSH DS

267 PUSH CS

268 POP DS

269 MOV DX,OFFSET INT24 ; SET UP INT 24 HANDLER

         MOV     AX,(SET_INTERRUPT_VECTOR SHL 8) OR 24H

271 INT 21H

272

273 IF ALTVECT

274 MOV DX,OFFSET BOOTMES

275 CALL PRINT ; Print message DOSINIT couldn't

276 ENDIF

277

278 POP DS

279

280 MOV DL,[DEFAULT_DRIVE]

281 OR DL,DL

282 JZ NODRVSET

283 DEC DL ; A = 0

284 MOV AH,SET_DEFAULT_DRIVE

285 INT 21H ; SELECT THE DISK

286 NODRVSET:

287

288 CALL DOCONF ; DO THE CONFIG STUFF

289

290 IF HIGHMEM

291 PUSH DS

         MOV     AX,OFFSET SYSSIZE + 15

293 MOV CL,4

         SHR     AX,CL                   ; Divide by 16 to get para

295 MOV CX,ES

296 SUB CX,AX

297 MOV ES,CX

298 PUSH CS

299 POP DS

300 XOR SI,SI

301 MOV DI,SI

         MOV     CX,OFFSET SYSSIZE + 1

         SHR     CX,1                    ; Divide by 2 to get words

304 REP MOVSW

305 POP DS

306 PUSH ES

307 MOV AX,OFFSET THIRDRELOC

308 PUSH AX

309 CCC PROC FAR

310 RET

311 CCC ENDP

312

313 THIRDRELOC:

314 MOV AX,CS

315 CLI

316 MOV SS,AX

317 MOV SP,OFFSET LOCSTACK

318 STI

319 ENDIF

320

321 IF NOEXEC

         MOV     BP,DS                   ; SAVE COMMAND.COM SEGMENT

323

324 PUSH DS

325 POP ES

326

327 MOV BX,CS

328 SUB BX,10H

329 MOV DS,BX

330 XOR SI,SI

331 MOV DI,SI

332 MOV CX,80H

333 REP MOVSW

334 MOV BX,ES

335 MOV AH,SET_CURRENT_PDB

336 INT 21H

337

         MOV     ES:[PDB_PARENT_PID],ES  ; WE ARE THE ROOT

339 ENDIF

340

341 PUSH CS

342 POP DS

343 ASSUME DS:SYSINITSEG

344 MOV AL,[FILES]

345 CBW

346 MOV CX,AX

         XOR     BX,BX                   ; Close standard input

348 MOV AH,CLOSE

349 INT 21H

350 MOV BX,2

351 RCCLLOOP: ; Close everybody but standard output

352 MOV AH,CLOSE

353 INT 21H

354 INC BX

355 LOOP RCCLLOOP

356

357 MOV DX,OFFSET CONDEV

358 MOV AL,2

359 MOV AH,OPEN ; OPEN CON FOR READ/WRITE

360 STC

361 INT 21H

362 JNC GOAUX

363 CALL BADFIL

364 JMP SHORT GOAUX2

365

366 GOAUX: PUSH AX

         MOV     BX,1                    ; close standard output

368 MOV AH,CLOSE

369 INT 21H

370 POP AX

371

         MOV     BX,AX                   ; New device handle

373 MOV AH,XDUP

374 INT 21H ; Dup to 1, STDOUT

375 MOV AH,XDUP

376 INT 21H ; Dup to 2, STDERR

377

 GOAUX2: MOV     DX,OFFSET AUXDEV

         MOV     AL,2                    ; READ/WRITE ACCESS

380 CALL OPEN_DEV

381

382 MOV DX,OFFSET PRNDEV

         MOV     AL,1                    ; WRITE ONLY

384 CALL OPEN_DEV

385 ;

386 ; SET UP THE PARAMETERS FOR COMMAND

387 ;

388 GOSET:

         MOV     SI,OFFSET COMMAND_LINE+1

390

391 IF NOEXEC

392 MOV DI,81H

393 ELSE

394 PUSH DS

395 POP ES

396 MOV DI,SI

397 ENDIF

398

399 MOV CL,-1

400 COMTRANLP: ; FIND LENGTH OF COMMAND LINE

401 INC CL

402 LODSB

403 STOSB ; COPY COMMAND LINE IN

404 OR AL,AL

405 JNZ COMTRANLP

406 DEC DI

407 MOV AL,0DH

408 STOSB

409

410 IF NOEXEC

         MOV     ES:[80H],CL

412 MOV AL,[DEFAULT_DRIVE]

         MOV     ES:[5CH],AL

414 ELSE

         MOV     [COMMAND_LINE],CL       ; Count

416 ENDIF

417

418 PUSH CS

419 POP ES

420

421 ASSUME ES:SYSINITSEG

422

423 MOV DX,OFFSET COMMND ; NOW POINTING TO FILE DESCRIPTION

424

425 IF NOEXEC

         MOV     ES,BP                   ; SET LOAD ADDRESS

427 MOV BX,100H

428 CALL LDFIL ; READ IN COMMAND

429 JC COMERR

430 MOV DS,BP

431 CLI

432 MOV DX,80H

433 MOV SS,BP

434 MOV SP,DX

435 STI

436

         XOR     AX,AX                   ; PUSH A WORD OF ZEROS

438 PUSH AX

439 MOV AH,SET_DMA ; SET DISK TRANFER ADDRESS

440 INT 21H

441 PUSH BP ; SET HIGH PART OF JUMP ADDRESS

442 MOV AX,100H

443 PUSH AX ; SET LOW PART OF JUMP ADDRESS

444 CCC PROC FAR

445 RET ; CRANK UP COMMAND!

446 CCC ENDP

447

448 ELSE

449 MOV BX,OFFSET COMEXE

         MOV     WORD PTR [BX.EXEC0_COM_LINE+2],CS

         MOV     WORD PTR [BX.EXEC0_5C_FCB+2],CS

         MOV     WORD PTR [BX.EXEC0_6C_FCB+2],CS

453

454 XOR AX,AX

455 MOV AH,EXEC

456 STC ; IN CASE OF INT 24

457 INT 21H ; GO START UP COMMAND

458 ENDIF

459

460 COMERR:

461 MOV DX,OFFSET BADCOM ; WANT TO PRINT COMMAND ERROR

462 CALL BADFIL

463 STALL: JMP STALL

464

465 DOCONF:

466 PUSH CS

467 POP DS

468

469 ASSUME DS:SYSINITSEG

470

471 MOV BX,0FFFFH

472 MOV AH,ALLOC

473 INT 21H ; FIRST TIME FAILS

474 MOV AH,ALLOC

475 INT 21H ; SECOND TIME GETS IT

476 MOV [AREA],AX

477

478 IF HIGHMEM

479 ADD AX,BX

480 ENDIF

481

482 MOV [MEMHI],AX

483

         MOV     AX,(CHAR_OPER SHL 8)    ; GET SWITCH CHARACTER

485 INT 21H

         MOV     [COMMAND_LINE+1],DL

487

488 MOV DX,OFFSET CONFIG ; NOW POINTING TO FILE DESCRIPTION

         MOV     AX,OPEN SHL 8           ; OPEN FILE "CONFIG.SYS"

490 STC ; IN CASE OF INT 24

491 INT 21H ; FUNCTION REQUEST

492 JC ENDFILE

493 JMP NOPROB ; PROBLEM WITH OPEN

494

495 ENDFILE:

496 PUSH CS

497 POP DS

498 CALL ROUND

499 MOV AL,[FILES]

500 SUB AL,5

501 JBE DOBUFF

502 CBW

503

504 IF HIGHMEM

505 PUSH AX

506 MOV BL,SIZE SF_ENTRY

507 MUL BL

         ADD     AX,15+6

509 MOV CL,4

510 SHR AX,CL

511 SUB [MEMHI],AX

512 POP AX

513 ENDIF

514

515 MOV BX,[MEMLO]

516 MOV DX,[MEMHI]

         LDS     DI,[DOSINFO]            ; GET POINTER TO DOS DATA

         LDS     DI,[DI+SFT_ADDR]        ; DS:BP POINTS TO SFT

         MOV     WORD PTR [DI+SFT_LINK],BX

         MOV     WORD PTR [DI+SFT_LINK+2],DX ; SET POINTER TO NEW SFT

521 PUSH CS

522 POP DS

         LES     DI,DWORD PTR [MEMLO]    ; POINT TO NEW SFT

         MOV     WORD PTR ES:[DI+SFT_LINK],-1

         MOV     ES:[DI+SFT_COUNT],AX

526 MOV BL,SIZE SF_ENTRY

527 MUL BL ; AX = NUMBER OF BYTES TO CLEAR

528 MOV CX,AX

529

530 IF HIGHMEM

531 MOV AX,6

532 ELSE

         ADD     [MEMLO],AX              ; ALLOCATE MEMORY

534 MOV AX,6

         ADD     [MEMLO],AX              ; REMEMBER THE HEADER TOO

536 ENDIF

537

538 ADD DI,AX

539 XOR AX,AX

540 REP STOSB ; CLEAN OUT THE STUFF

541

542 DOBUFF: CALL ROUND

543

544 DEC [BUFFERS]

545 JZ BUF1

546

547 PUSH DS

548 LES DI,BUFPTR

549 LDS BX,DOSINFO

550

551 IF HIGHMEM

         MOV     AX,[BX.MAXSEC]

         ADD     AX,BUFINSIZ + 15

554 MOV CL,4

555 SHR AX,CL

         SUB     CS:[MEMHI],AX

         MOV     ES,CS:[MEMHI]

558 ENDIF

559

         MOV     AX,WORD PTR [BX.BUFFHEAD]

         MOV     WORD PTR ES:[DI.NEXTBUF],AX

         MOV     AX,WORD PTR [BX.BUFFHEAD+2]

         MOV     WORD PTR ES:[DI.NEXTBUF+2],AX

564

         MOV     WORD PTR [BX.BUFFHEAD],DI

         MOV     WORD PTR [BX.BUFFHEAD+2],ES

567

         MOV     WORD PTR ES:[DI.BUFDRV],00FFH   ; NEW BUFFER FREE

         MOV     BX,[BX.MAXSEC]

570 POP DS

571

572 IF NOT HIGHMEM

573 ADD BX,BUFINSIZ

574 ADD [MEMLO],BX

575 ENDIF

576

577 JMP DOBUFF

578

579 BUF1: CALL ROUND

580 MOV BX,[MEMHI]

581 MOV AX,[AREA]

         MOV     ES,AX                   ; CALC WHAT WE NEEDED

583 SUB BX,AX

584

585 IF HIGHMEM

586 DEC BX ; Arena

587 PUSH BX

588 ENDIF

589

590 MOV AH,SETBLOCK

591 INT 21H ; GIVE THE REST BACK

592

593 IF NOT HIGHMEM

594 PUSH ES

595 MOV AX,ES

596 DEC AX

597 MOV ES,AX

         MOV     ES:[arena_owner],8      ; Set impossible owner

599 POP ES

600 ENDIF

601

602 IF HIGHMEM

603 MOV BX,0FFFFH

604 MOV AH,ALLOC

605 INT 21H

606 MOV AH,ALLOC

607 INT 21H

608

609 PUSH ES

610 DEC AX

611 MOV ES,AX

         MOV     ES:[arena_owner],8      ; Set impossible owner

613 POP ES

614

615 IF NOT NOEXEC

616 MOV ES,[AREA]

617 MOV AH,DEALLOC

618 INT 21H

619 ENDIF

620

621 POP BX

622 MOV AX,[AREA]

623 MOV DS,AX

624 ADD AX,BX

625 MOV ES,AX

626 ELSE

627 IF NOEXEC

         MOV     BX,0FFFFH               ; ALLOCATE THE REST OF MEM FOR COMMAND

629 MOV AH,ALLOC

630 INT 21H

631 MOV AH,ALLOC

632 INT 21H

633 MOV DS,AX

634 ENDIF

635 ENDIF

636

637 RET

638

 BADOP:  MOV     DX,OFFSET BADOPM        ; WANT TO PRINT COMMAND ERROR

640 CALL PRINT

641 JMP COFF

642

643 NOPROB: ; GET FILE SIZE (NOTE < 64K!!)

644 MOV BX,AX

645 XOR CX,CX

646 XOR DX,DX

         MOV     AX,(LSEEK SHL 8) OR 2

648 INT 21H

649 MOV [COUNT],AX

650 XOR DX,DX

         MOV     AX,LSEEK SHL 8          ; Reset pointer to beginning of file

652 INT 21H

653 MOV DX,CS

654

655 IF HIGHMEM

         MOV     AX,OFFSET SYSSIZE + 15

657 MOV CL,4

658 SHR AX,CL

659 ADD DX,AX

660 ELSE

661 MOV AX,[COUNT]

662 ADD AX,15

663 MOV CL,4

         SHR     AX,CL                   ; NUMBER OF SEGMENTS

665 SUB DX,AX

666 SUB DX,11H ; ROOM FOR HEADER

667 ENDIF

668

669 MOV DS,DX

670 MOV ES,DX

 ASSUME  DS:NOTHING,ES:NOTHING

672 XOR DX,DX

673 MOV CX,[COUNT]

674 MOV AH,READ

675 STC ; IN CASE OF INT 24

676 INT 21H ; Function request

677 PUSHF

678 PUSH CS

679 POP DS

680 ASSUME DS:SYSINITSEG

681 PUSH AX

682 MOV AH,CLOSE

683 INT 21H

684 POP AX

685 POPF

686 JC CONFERR ; IF NOT WE'VE GOT A PROBLEM

687 CMP CX,AX

688 JZ GETCOM ; COULDN'T READ THE FILE

689 CONFERR:

690 MOV DX,OFFSET CONFIG ; WANT TO PRINT CONFIG ERROR

691 CALL BADFIL

692 ENDFILV:JMP ENDFILE

693

694 GETCOM:

695 CALL ORGANIZE ; ORGANIZE THE FILE

696 CALL GETCHR

697

698 CONFLP: JC ENDFILV

699 MOV AH,AL

700 CALL GETCHR

701

         CMP     AH,'B'                  ; BUFFER COMMAND?

703 JNZ TRYC

704 CALL GETNUM

705 JZ COFF

706 CMP AX,100

707 JAE badop

708 MOV [BUFFERS],AL

709 JMP SHORT COFF

710

 TRYC:   CMP     AH,'C'

712 JZ GOTC

713 JMP TRYD

714 GOTC:

         CMP     AL,'O'                  ; FIRST LETTER OF "ON"

716 JNZ COFF

717 CALL GETCHR

718 JC ENDFILV

         CMP     AL,'N'                  ; SECOND LETTER OF "ON"

720 JNZ COFF

721 MOV AH,SET_CTRL_C_TRAPPING ; TURN ON CONTROL-C CHECK

722 MOV AL,1

723 MOV DL,AL

724 INT 21H

725

726 COFF: PUSH CS

727 POP DS

728 CALL NEWLINE

729 JMP CONFLP

730

 TRYD:   CMP     AH,'D'

732 JZ GOTD

733 JMP TRYF

 GOTD:   MOV     BX,CS

735 MOV DS,BX

736

         MOV     WORD PTR [BPB_ADDR],SI

         MOV     WORD PTR [BPB_ADDR+2],ES

739

740 CALL ROUND

741

742 IF HIGHMEM

743 PUSH DS

744 PUSH ES

745 POP DS

746 MOV DX,SI

         MOV     AX,OPEN SHL 8

748 STC ; In case INT 24H

749 INT 21H

750 POP DS

751 JC BADBRK

752 MOV BX,AX

753 XOR DX,DX

754 MOV CX,DX

         MOV     AX,(LSEEK SHL 8) OR 2

756 INT 21H

757 PUSH AX

758 MOV AH,CLOSE

759 INT 21H

760 POP AX ; DX:AX is size of file

761 ADD AX,15

762 ADC DX,0

763 MOV CL,4

764 SHR AX,CL

765 MOV CL,12

766 SHL DX,CL

         OR      AX,DX                   ; AX is size in PARA

768 MOV CX,[MEMHI]

769 SUB [MEMHI],AX

770 JNC SIZEOK

         MOV     [MEMHI],CX              ; Not enough memory

772 JMP SHORT BADBRK

773 SIZEOK:

774 MOV BX,CS

775 ENDIF

776

777 XOR AX,AX

         MOV     WORD PTR [ENTRY_POINT],AX

779 MOV AX,[MEMHI]

         MOV     WORD PTR [ENTRY_POINT+2],AX ; SET ENTRY POINT

781

782

783 IF NOT NOEXEC

         MOV     [LDOFF],AX              ; SET LOAD OFFSET

785 ENDIF

786

787 PUSH ES

788 POP DS

         MOV     DX,SI                   ; DS:DX POINTS TO FILE NAME

790

791 IF NOEXEC

         LES     BX,DWORD PTR CS:[MEMLO]

793 CALL LDFIL ; LOAD IN THE DEVICE DRIVER

794 ELSE

795 MOV ES,BX

796 MOV BX,OFFSET PRMBLK ; ES:BX POINTS TO PARAMETERS

797 MOV AL,3

798 MOV AH,EXEC

799 STC ; IN CASE OF INT 24

800 INT 21H ; LOAD IN THE DEVICE DRIVER

801 ENDIF

802

803 PUSH DS

804 POP ES ; ES:SI BACK TO CONFIG.SYS

805 PUSH CS

806 POP DS ; DS BACK TO SYSINIT

807 JNC GOODLD

808 BADBRK: CALL BADLOAD

809 JMP COFF

810

 GOODLD: PUSH    ES                      ; INITIALIZE THE DEVICE

812 PUSH SI

813

814 PUSH CS

815 POP ES

816 MOV BX,SDEVSTRAT

817 CALL CALLDEV

818 MOV BX,SDEVINT

819 CALL CALLDEV

820

821 PUSH CS

822 POP DS

823

824 IF NOT HIGHMEM

         MOV     AX,WORD PTR [BREAK_ADDR+2]  ; REMOVE THE INIT CODE

826 CMP AX,[MEMORY_SIZE]

827 JB BREAKOK

828 POP SI

829 POP ES

830 JMP BADBRK

831 BREAKOK:

832

833 MOV [MEMHI],AX

         MOV     AX,WORD PTR [BREAK_ADDR]; REMOVE THE INIT CODE

835 MOV [MEMLO],AX

836 ENDIF

837

         LDS     DX,[ENTRY_POINT]        ; SET DS:DX TO HEADER

839 MOV SI,DX

840 ADD SI,SDEVATT ; DS:SI POINTS TO ATTRIBUTES

         LES     DI,CS:[DOSINFO]         ; ES:DI POINT TO DOS INFO

         MOV     AX,DS:[SI]              ; GET ATTRIBUTES

843 TEST AX,DEVTYP ; TEST IF BLOCK DEV

844 JZ ISBLOCK

845

846 TEST AX,ISCIN ; IS IT A CONSOLE IN?

847 JZ TRYCLK

         MOV     WORD PTR ES:[DI.BCON],DX

         MOV     WORD PTR ES:[DI.BCON+2],DS

850

 TRYCLK: TEST    AX,ISCLOCK              ; IS IT A CLOCK DEVICE?

852 JZ GOLINK

         MOV     WORD PTR ES:[DI+BCLOCK],DX

         MOV     WORD PTR ES:[DI+BCLOCK+2],DS

855 GOLINK: JMP LINKIT

856

857 ISBLOCK:

         MOV     AL,CS:[UNITCOUNT]       ; IF NO UNITS FOUND....

859 OR AL,AL

860 JNZ PERDRV

861

862 IF NOT HIGHMEM

         MOV     CS:[MEMLO],0            ; ...ERASE THE DEVICE

864 ENDIF

865

866 MOV AX,-1

867 JMP ENDDEV

868

869 PERDRV:

870 CBW

871 MOV CX,AX

872 MOV DH,AH

         MOV     DL,ES:[DI.NUMIO]        ; GET NUMBER OF DEVICES

         ADD     ES:[DI.NUMIO],AL        ; UPDATE THE AMOUNT

875

         LDS     BX,CS:[BPB_ADDR]        ; POINT TO BPB ARRAY

877 PERUNIT:

         LES     BP,CS:[DOSINFO]

         LES     BP,DWORD PTR ES:[BP.DPBHEAD]; GET FIRST DPB

880

 SCANDPB:CMP     WORD PTR ES:[BP.DPB_NEXT_DPB],-1

882 JZ FOUNDPB

         LES     BP,ES:[BP.DPB_NEXT_DPB]

884 JMP SCANDPB

885 FOUNDPB:

         MOV     AX,CS:[MEMLO]

         MOV     WORD PTR ES:[BP.DPB_NEXT_DPB],AX

888

889 IF HIGHMEM

         MOV     AX,(DPBSIZ + 15) / 16

         SUB     CS:[MEMHI],AX

892 ENDIF

893

         MOV     AX,CS:[MEMHI]

         MOV     WORD PTR ES:[BP.DPB_NEXT_DPB+2],AX

         LES     BP,DWORD PTR CS:[MEMLO]

897

898 IF NOT HIGHMEM

         ADD     WORD PTR CS:[MEMLO],DPBSIZ

900 ENDIF

901

         MOV     WORD PTR ES:[BP.DPB_NEXT_DPB],-1

         MOV     ES:[BP.DPB_FIRST_ACCESS],-1

904

         MOV     SI,[BX]                 ; DS:SI POINTS TO BPB

906 INC BX

907 INC BX ; POINT TO NEXT GUY

         MOV     WORD PTR ES:[BP.DPB_DRIVE],DX

909 MOV AH,SETDPB ; HIDDEN SYSTEM CALL

910 INT 21H

         MOV     AX,ES:[BP.DPB_SECTOR_SIZE]

912 PUSH ES

         LES     DI,CS:[DOSINFO]         ; ES:DI POINT TO DOS INFO

         CMP     AX,ES:[DI.MAXSEC]

915 POP ES

916 JBE NOTMAX

917 POP SI

918 POP ES

919 MOV DX,OFFSET BADSIZ_PRE

920 MOV BX,OFFSET BADSIZ_POST

921 CALL PRNERR

922 JMP COFF

923

924 NOTMAX: PUSH DS

925 PUSH DX

         LDS     DX,CS:[ENTRY_POINT]

         MOV     WORD PTR ES:[BP.DPB_DRIVER_ADDR],DX

         MOV     WORD PTR ES:[BP.DPB_DRIVER_ADDR+2],DS

929 POP DX

930 POP DS

931 INC DX

932 INC DH

933 LOOP PERUNIT

934

935 LINKIT:

         LES     DI,CS:[DOSINFO]         ; ES:DI = DOS TABLE

         MOV     CX,WORD PTR ES:[DI.DEVHEAD] ; DX:CX = HEAD OF LIST

         MOV     DX,WORD PTR ES:[DI.DEVHEAD+2]

939

         LDS     SI,CS:[ENTRY_POINT]     ; DS:SI = DEVICE LOCATION

         MOV     WORD PTR ES:[DI.DEVHEAD],SI ; SET HEAD OF LIST IN DOS

         MOV     WORD PTR ES:[DI.DEVHEAD+2],DS

         MOV     AX,DS:[SI]              ; GET POINTER TO NEXT DEVICE

         MOV     WORD PTR CS:[ENTRY_POINT],AX; AND SAVE IT

945

         MOV     WORD PTR DS:[SI],CX     ; LINK IN THE DRIVER

         MOV     WORD PTR DS:[SI+2],DX

948 ENDDEV:

949 POP SI

950 POP ES

951 INC AX ; AX = FFFF?

952 JZ COFFV

953 JMP GOODLD ; OTHERWISE PRETEND WE LOADED IT IN

954 COFFV: JMP COFF

955

956 TRYQ:

957 CMP AH,'Q'

958 JNZ TRYW

959 CALL GETNUM

960 JZ COFFV

961 OR AH,AH

962 JNZ COFFV

963 MOV AH,INTERNATIONAL ; AL is country code

         MOV     DX,-1                   ; Set country

965 INT 21H

966 JNC COFFV

967 MOV DX,OFFSET BADCOUNTRY

968 CALL PRINT

969 JMP COFFV

970

971 TRYF:

972 CMP AH,'F'

973 JNZ TRYQ

974 CALL GETNUM

975 JZ COFFV

976 CMP AX,100

977 JAE TryX

978 MOV [FILES],AL

979 JMP COFFV

980 TRYW:

981 CMP AH,'W'

982 JNZ TRYA

983 MOV DL,AL

         MOV     AX,(CHAR_OPER SHL 8) OR 1   ; SET SWITCH CHARACTER

         MOV     [COMMAND_LINE+1],DL

986 INT 21H

987 JMP COFF

988

989 TRYA:

990 CMP AH,'A'

991 JNZ TRYS

         CMP     AL,'F'                  ; FIRST LETTER OF "FALSE"

993 JNZ COFFJ

         MOV     AX,(CHAR_OPER SHL 8) OR 3   ; TURN ON "/DEV" PREFIX

995 XOR DL,DL

996 INT 21H

997 COFFJ: JMP COFF

998

999 TRYS:

1000 CMP AH,'S'

1001 JNZ TRYX

         MOV     [COMMAND_LINE+1],0

         MOV     DI,OFFSET COMMND + 1

         MOV     [DI-1],AL

1005 STORESHELL:

1006 CALL GETCHR

1007 OR AL,AL

1008 JZ GETSHPARMS

1009 CMP AL," "

1010 JB ENDSH

         MOV     [DI],AL

1012 INC DI

1013 JMP STORESHELL

1014

1015 ENDSH:

         MOV     BYTE PTR [DI],0

1017 CALL GETCHR

1018 CMP AL,10

1019 JNZ CONV

1020 CALL GETCHR

1021 CONV: JMP CONFLP

1022

1023 TRYX:

1024 JMP BADOP

1025

1026 GETSHPARMS:

         MOV     BYTE PTR [DI],0

         MOV     DI,OFFSET COMMAND_LINE+1

1029 PARMLOOP:

1030 CALL GETCHR

1031 CMP AL," "

1032 JB ENDSH

         MOV     [DI],AL

1034 INC DI

1035 JMP PARMLOOP

1036

 GETCHR: MOV     CX,COUNT

1038 JCXZ NOCHAR

1039 MOV SI,CHRPTR

         MOV     AL,ES:[SI]

1041 DEC COUNT

1042 INC CHRPTR

1043 CLC

1044 RET

1045 NOCHAR: STC

1046 RET

1047

1048 ORGANIZE:

1049 MOV CX,[COUNT]

1050 JCXZ NOCHAR

1051 CALL MAPCASE

1052 XOR SI,SI

1053 MOV DI,SI

1054

1055 ORG1: CALL GET ; SKIP LEADING CONTROL CHARACTERS

1056 CMP AL,' '

1057 JB ORG1

1058

1059 PUSH CX

1060 PUSH SI

1061 PUSH DI

1062 MOV BP,SI

1063 DEC BP

1064 MOV SI,OFFSET COMTAB ; Prepare to search command table

1065 MOV CH,0

1066 FINDCOM:

1067 MOV DI,BP

         MOV     CL,[SI]

1069 INC SI

1070 JCXZ NOCOM

1071 REPE CMPSB

1072 LAHF

         ADD     SI,CX                   ; Bump to next position without affecting flags

1074 SAHF

1075 LODSB ; Get indicator letter

1076 JNZ FINDCOM

1077 POP DI

1078 POP SI

1079 POP CX

1080 JMP SHORT GOTCOM

1081

1082 NOCOM:

1083 POP DI

1084 POP SI

1085 POP CX

1086 MOV AL,'Z'

1087 GOTCOM: STOSB ; SAVE INDICATOR CHAR IN BUFFER

1088

1089 ORG2: CALL GET2 ; SKIP NAME UNTIL DELIMETER

1090 CALL DELIM ;

1091 JNZ ORG2

1092

1093 CALL GET ; GET CHARS TO RIGHT OF EQUALS SIGN

1094 STOSB

1095

1096 ORG4: CALL GET2

1097 STOSB

1098 CMP AL,' '

1099 JA ORG4

1100 CMP AL,10

1101 JZ ORG1

1102

         MOV     BYTE PTR ES:[DI-1],0

1104 ORG5: CALL GET2

1105 STOSB

1106 CMP AL,10

1107 JNZ ORG5

1108 JMP ORG1

1109

1110 GET2:

1111 JCXZ NOGET

         MOV     AL,ES:[SI]

1113 INC SI

1114 DEC CX

1115 RET

1116

1117 GET: JCXZ NOGET

         MOV     AL,ES:[SI]

1119 INC SI

1120 DEC CX

1121 CALL DELIM

1122 JZ GET

1123 GRET: RET

1124

1125

 DELIM:  CMP     AL,' '

1127 JZ GRET

1128 CMP AL,9

1129 JZ GRET

1130 CMP AL,'='

1131 JZ GRET

1132 CMP AL,','

1133 JZ GRET

1134 CMP AL,';'

1135 RET

1136

1137

1138 NOGET: POP CX

1139 MOV COUNT,DI

1140 XOR SI,SI

1141 MOV CHRPTR,SI

1142 RET

1143 ;

1144 ; NEWLINE RETURNS WITH FIRST CHARACTER OF NEXT LINE

1145 ;

1146 NEWLINE:CALL GETCHR ; SKIP NON-CONTROL CHARACTERS

1147 JC NONEW

         CMP     AL,10                   ; LOOK FOR LINE FEED

1149 JNZ NEWLINE

1150 CALL GETCHR

1151 NONEW: RET

1152

1153 MAPCASE:

1154 PUSH CX

1155 PUSH SI

1156 PUSH DS

1157 PUSH ES

1158 POP DS

1159 XOR SI,SI

1160 CONVLOOP:

1161 LODSB

1162

1163 IF KANJI

1164 CALL TESTKANJ

1165 JZ NORMCONV

1166 INC SI ; Skip next char

1167 DEC CX

1168 JCXZ CONVDONE ; Just ignore 1/2 kanji error

1169 ; Fall through, know AL is not in 'a'-'z' range

1170 NORMCONV:

1171 ENDIF

1172

1173 CMP AL,'a'

1174 JB NOCONV

1175 CMP AL,'z'

1176 JA NOCONV

1177 SUB AL,20H

         MOV     [SI-1],AL

1179 NOCONV:

1180 LOOP CONVLOOP

1181 CONVDONE:

1182 POP DS

1183 POP SI

1184 POP CX

1185 RET

1186

1187 IF KANJI

1188 TESTKANJ:

1189 CMP AL,81H

1190 JB NOTLEAD

1191 CMP AL,9FH

1192 JBE ISLEAD

1193 CMP AL,0E0H

1194 JB NOTLEAD

1195 CMP AL,0FCH

1196 JBE ISLEAD

1197 NOTLEAD:

1198 PUSH AX

         XOR     AX,AX                   ; Set zero

1200 POP AX

1201 RET

1202

1203 ISLEAD:

1204 PUSH AX

         XOR     AX,AX                   ; Set zero

1206 INC AX ; Reset zero

1207 POP AX

1208 RET

1209 ENDIF

1210

1211 ASSUME DS:NOTHING

1212

 ROUND:  MOV     AX,[MEMLO]

1214

1215 IF NOT HIGHMEM

1216 ADD AX,15

1217 ENDIF

1218

1219 SHR AX,1

1220 SHR AX,1

1221 SHR AX,1

1222 SHR AX,1

1223 ADD [MEMHI],AX

1224 XOR AX,AX

1225 MOV [MEMLO],AX

1226 RET

1227

 CALLDEV:MOV     DS,WORD PTR CS:[ENTRY_POINT+2]

         ADD     BX,WORD PTR CS:[ENTRY_POINT]; Do a little relocation

         MOV     AX,DS:[BX]

         PUSH    WORD PTR CS:[ENTRY_POINT]

         MOV     WORD PTR CS:[ENTRY_POINT],AX

1233 MOV BX,OFFSET PACKET

1234 CALL [ENTRY_POINT]

         POP     WORD PTR CS:[ENTRY_POINT]

1236 RET

1237

 BADNUM: POP     AX                      ; POP RETURN ADDRESS

1239 JMP BADOP

1240

1241 ToDigit:

1242 SUB AL,'0'

1243 JB NotDig

1244 CMP AL,9

1245 JA NotDig

1246 CLC

1247 RET

1248 NotDig: STC

1249 RET

1250

 GETNUM: XOR     BX,BX                   ; running count is zero

1252 B2: CALL ToDigit ; do we have a digit

1253 JC BadNum ; no, bomb

         XCHG    AX,BX                   ; put total in AX

1255 PUSH BX ; save digit

         MOV     BX,10                   ; base of arithmetic

1257 MUL BX ; shift by one decimal digit

1258 POP BX ; get back digit

         ADD     AL,BL                   ; get total

         ADC     AH,0                    ; make that 16 bits

1261 JC BADNUM ; too big a number

         XCHG    AX,BX                   ; stash total

1263 CALL GETCHR ; GET NEXT DIGIT

1264 JC B1 ; no more characters

         OR      AL,AL                   ; end of line separator?

1266 JNZ B2 ; no, try as a valid character

1267 INC COUNT ; one more character to scan

1268 DEC CHRPTR ; back up over separator

 B1:     MOV     AX,BX                   ; get proper count

1270 OR AX,AX

1271 RET

1272 ;

1273 ; ES:SI POINTS TO FILE NAME (NUL TERMINATED)

1274 ; DS:DX POINTS TO STRING TO OUTPUT IN FRONT OF NAME ($ TERM)

1275 ;

1276 BADFIL:

1277 PUSH CS

1278 POP ES

1279 MOV SI,DX

1280 BADLOAD:

1281 MOV DX,OFFSET BADLD_PRE ; WANT TO PRINT CONFIG ERROR

1282 MOV BX,OFFSET BADLD_POST

1283 PRNERR:

1284 PUSH CS

1285 POP DS

1286 MOV AH,STD_CON_STRING_OUTPUT

1287 INT 21H

 PRN1:   MOV     DL,ES:[SI]

1289 OR DL,DL

1290 JZ PRN2

1291 MOV AH,STD_CON_OUTPUT

1292 INT 21H

1293 INC SI

1294 JMP PRN1

 PRN2:   MOV     DX,BX

 PRINT:  MOV     AH,STD_CON_STRING_OUTPUT

1297 INT 21H

1298 RET

1299 ;

1300 ; LOAD FILE CALLED [DS:DX] AT MEMORY LOCATION ES:BX

1301 ;

1302 LDFIL:

1303 PUSH AX

1304 PUSH BX

1305 PUSH CX

1306 PUSH DX

1307 PUSH SI

1308 PUSH DS

1309 PUSH BX

1310

         XOR     AX,AX                   ; OPEN THE FILE

1312 MOV AH,OPEN

1313 STC ; IN CASE OF INT 24

1314 INT 21H

1315 POP DX ; Trans addr is DS:DX

1316 JC LDRET

1317

1318 PUSH ES ; READ THE FILE IN

1319 POP DS

         MOV     BX,AX                   ; Handle in BX

1321 MOV CX,0FF00H

1322 MOV AH,READ

1323 STC ; IN CASE OF INT 24

1324 INT 21H

1325 JC LDRET

         MOV     SI,DX                   ; CHECK FOR EXE FILE

         CMP     WORD PTR [SI],"ZM"

1328 JNZ LDCLS

1329 LDERR: STC

1330 JMP SHORT LDRET

1331

 LDCLS:  MOV     AH,CLOSE                ; CLOSE THE FILE

1333 STC

1334 INT 21H

1335

1336 LDRET: POP DS

1337 POP SI

1338 POP DX

1339 POP CX

1340 POP BX

1341 POP AX

1342 RET

1343 ;

1344 ; OPEN DEVICE POINTED TO BY DX, AL HAS ACCESS CODE

1345 ; IF UNABLE TO OPEN DO A DEVICE OPEN NULL DEVICE INSTEAD

1346 ;

1347 OPEN_DEV:

1348 CALL OPEN_FILE

1349 JNC OPEN_DEV3

1350 OPEN_DEV1:

1351 MOV DX,OFFSET NULDEV

1352 CALL OPEN_FILE

1353 OPEN_DEV2:

1354 RET

1355 OPEN_DEV3:

         XOR     AX,AX                   ; GET DEVICE INFO

1357 MOV AH,IOCTL

1358 INT 21H

1359 TEST DL,10000000B

1360 JNZ OPEN_DEV2

1361 MOV AH,CLOSE

1362 INT 21H

1363 JMP OPEN_DEV1

1364

1365 OPEN_FILE:

1366 MOV AH,OPEN

1367 STC

1368 INT 21H

1369 RET

1370

 INT24:  ADD     SP,6                    ; RESTORE MACHINE STATE

1372 POP AX

1373 POP BX

1374 POP CX

1375 POP DX

1376 POP SI

1377 POP DI

1378 POP BP

1379 POP DS

1380 POP ES

1381 PUSH AX

1382 MOV AH,GET_DEFAULT_DRIVE ; INITIALIZE DOS

1383 INT 21H

1384 POP AX

1385 IRET ; BACK TO USER

1386

1387 IF ALTVECT

1388 BOOTMES DB 13

1389 TEN: DB 10

1390 DB "MS-DOS version "

1391 DB MAJOR_VERSION + "0"

1392 DB "."

         DB      (MINOR_VERSION / 10) + "0"

         DB      (MINOR_VERSION MOD 10) + "0"

1395 DB 13,10

         DB      "Copyright 1981,82 Microsoft Corp.",13,10,"$"

1397 ENDIF

1398

1399 NULDEV DB "\DEV\NUL",0

1400 CONDEV DB "\DEV\CON",0

1401 AUXDEV DB "\DEV\AUX",0

1402 PRNDEV DB "\DEV\PRN",0

1403

1404 CONFIG DB "\CONFIG.SYS",0

1405

1406 COMMND DB "\COMMAND.COM",0

1407

1408 COMTAB LABEL BYTE

         DB      7,"BUFFERS",'B'

         DB      5,"BREAK",'C'

         DB      5,"SHELL",'S'

         DB      6,"DEVICE",'D'

         DB      5,"FILES",'F'

         DB      8,"SWITCHAR",'W'

         DB      8,"AVAILDEV",'A'

         DB      7,"COUNTRY",'Q'

1417 DB 0

1418

1419

1420 SYSINITSEG ENDS

1421 END

1422