;
; MSCODE.ASM -- MSDOS code
;
INCLUDE DOSSEG.ASM
INCLUDE STDSW.ASM
CODE SEGMENT BYTE PUBLIC 'CODE'
ASSUME CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
.xcref
INCLUDE DOSSYM.ASM
INCLUDE DEVSYM.ASM
.cref
.list
IFNDEF KANJI
KANJI EQU 0 ; FALSE
ENDIF
IFNDEF IBM
IBM EQU 0
ENDIF
IFNDEF HIGHMEM
HIGHMEM EQU 0
ENDIF
i_need USER_SP,WORD
i_need USER_SS,WORD
i_need SAVEDS,WORD
i_need SAVEBX,WORD
i_need INDOS,BYTE
i_need NSP,WORD
i_need NSS,WORD
i_need CURRENTPDB,WORD
i_need AUXSTACK,BYTE
i_need CONSWAP,BYTE
i_need IDLEINT,BYTE
i_need NOSETDIR,BYTE
i_need ERRORMODE,BYTE
i_need IOSTACK,BYTE
i_need WPERR,BYTE
i_need DSKSTACK,BYTE
i_need CNTCFLAG,BYTE
i_need LEAVEADDR,WORD
i_need NULLDEVPT,DWORD
IF NOT IBM
i_need OEM_HANDLER,DWORD
ENDIF
EXTRN DSKSTATCHK:NEAR,GETBP:NEAR,DSKREAD:NEAR,DSKWRITE:NEAR
BREAK <Copyright notice and version>
CODSTRT EQU $
IF NOT IBM
IF NOT KANJI
PUBLIC HEADER
HEADER DB 13,10,"Microsoft MS-DOS version "
DB DOS_MAJOR_VERSION + "0"
DB "."
DB (DOS_MINOR_VERSION / 10) + "0"
DB (DOS_MINOR_VERSION MOD 10) + "0"
IF HIGHMEM
DB "H"
ENDIF
ENDIF
IF KANJI
PUBLIC HEADER
HEADER DB 13,10,82h,"M"+1fh,82h,"i"+20h,82h,"c"+20h,82h,"r"+20h,82h,"o"+20h
DB 82h,"s"+20h,82h,"o"+20h,82h,"f"+20h,82h,"t"+20h
DB 81h,40h,82h,"M"+1fh,82h,"S"+1fh,81h,5dh+1fh
DB 82h,"D"+1fh,82h,"O"+1fh,82h,"S"+1fh,81h,40h
DB 82h,DOS_MAJOR_VERSION+"0"+1fh
DB 81h,25h+1fh
DB 82h,(DOS_MINOR_VERSION / 10)+"0"+1fh
DB 82h,(DOS_MINOR_VERSION MOD 10)+"0"+1fh
DB 94h,0c5h
ENDIF
DB 13,10
DB "Copyright 1981,82,83 Microsoft Corp.",13,10,"$"
ENDIF
BREAK <System call entry points and dispatcher>
ASSUME CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
procedure SYSTEM_CALL,NEAR
entry QUIT ; INT 20H entry point
MOV AH,0
JMP SHORT SAVREGS
entry COMMAND ; Interrupt call entry point (INT 21H)
IF NOT IBM
CMP AH,SET_OEM_HANDLER
JB NOTOEM
JMP $SET_OEM_HANDLER
NOTOEM:
ENDIF
CMP AH,MAXCOM
JBE SAVREGS
BADCALL:
MOV AL,0
entry IRET
IRET
entry CALL_ENTRY ; System call entry point and dispatcher
POP AX ; IP from the long call at 5
POP AX ; Segment from the long call at 5
POP [User_SP] ; IP from the CALL 5
PUSHF ; Start re-ordering the stack
CLI
PUSH AX ; Save segment
PUSH [User_SP] ; Stack now ordered as if INT had been used
CMP CL,MAXCALL ; This entry point doesn't get as many calls
JA BADCALL
MOV AH,CL
SAVREGS:
CALL save_world
MOV [SaveDS],DS
MOV [SaveBX],BX
MOV BX,CS
MOV DS,BX
ASSUME DS:DOSGROUP
INC [INDOS] ; Flag that we're in the DOS
MOV AX,[user_SP]
MOV [NSP],AX
MOV AX,[user_SS]
MOV [NSS],AX
POP AX
PUSH AX
MOV [user_SP],SP
MOV [user_SS],SS
;
; save user stack in his area for later returns (possibly from EXEC)
; Here comes multitasking!!!
;
MOV DS,[CurrentPDB]
MOV WORD PTR DS:[PDB_User_stack],SP
MOV WORD PTR DS:[PDB_User_stack+2],SS
MOV BX,CS ; no holes here.
MOV SS,BX
ASSUME SS:DOSGROUP
entry REDISP
MOV SP,OFFSET DOSGROUP:AUXSTACK ; Enough stack for interrupts
STI ; Stack OK now
PUSH CS
POP DS
XOR BH,BH
MOV [CONSWAP],BH
MOV [IDLEINT],1
MOV BYTE PTR [NoSetDir],0 ; set directories on search
MOV BL,AH
SHL BX,1
CLD
OR AH,AH
JZ DSKROUT ; ABORT
CMP AH,12
JBE IOROUT ; Character I/O
CMP AH,GET_CURRENT_PDB ; INT 24 needs GET,SET PDB
JZ IOROUT
CMP AH,SET_CURRENT_PDB
JNZ DSKROUT
IOROUT:
CMP [ERRORMODE],0
JNZ DISPCALL ; Stay on AUXSTACK if INT 24
MOV SP,OFFSET DOSGROUP:IOSTACK
JMP SHORT DISPCALL
DSKROUT:
MOV [ERRORMODE],0 ; Cannot make non 1-12 calls in
MOV [WPERR],-1 ; error mode, so good place to
; make sure flags are reset
MOV SP,OFFSET DOSGROUP:DSKSTACK
TEST [CNTCFLAG],-1
JZ DISPCALL
PUSH AX
invoke DSKSTATCHK
POP AX
DISPCALL:
PUSH [LEAVEADDR]
PUSH CS:[BX+DISPATCH]
MOV BX,[SaveBX]
MOV DS,[SaveDS]
ASSUME DS:NOTHING
return
entry LEAVE
ASSUME SS:NOTHING ; User routines may misbehave
CLI
DEC [INDOS]
MOV SP,[user_SP]
MOV SS,[user_SS]
MOV BP,SP
MOV BYTE PTR [BP.user_AX],AL
MOV AX,[NSP]
MOV [user_SP],AX
MOV AX,[NSS]
MOV [user_SS],AX
CALL restore_world
IRET
SYSTEM_CALL ENDP
;
; restore_world restores all registers ('cept SS:SP, CS:IP, flags) from
; the stack prior to giving the user control
;
ASSUME DS:NOTHING,ES:NOTHING
restore_tmp DW ?
procedure restore_world,NEAR
POP restore_tmp ; POP restore_tmp
POP AX ; PUSH ES
POP BX ; PUSH DS
POP CX ; PUSH BP
POP DX ; PUSH DI
POP SI ; PUSH SI
POP DI ; PUSH DX
POP BP ; PUSH CX
POP DS ; PUSH BX
POP ES ; PUSH AX
world_ret:
PUSH restore_tmp ; PUSH restore_tmp
return
restore_world ENDP
;
; save_world saves complete registers on the stack
;
procedure save_world,NEAR
POP restore_tmp
PUSH ES
PUSH DS
PUSH BP
PUSH DI
PUSH SI
PUSH DX
PUSH CX
PUSH BX
PUSH AX
JMP SHORT world_ret
save_world ENDP
;
; get_user_stack returns the user's stack (and hence registers) in DS:SI
;
procedure get_user_stack,NEAR
LDS SI,DWORD PTR [user_SP]
return
get_user_stack ENDP
; Standard Functions
DISPATCH LABEL WORD
.lall
short_addr $ABORT ; 0 0
.xall
short_addr $STD_CON_INPUT ; 1 1
short_addr $STD_CON_OUTPUT ; 2 2
short_addr $STD_AUX_INPUT ; 3 3
short_addr $STD_AUX_OUTPUT ; 4 4
short_addr $STD_PRINTER_OUTPUT ; 5 5
short_addr $RAW_CON_IO ; 6 6
short_addr $RAW_CON_INPUT ; 7 7
short_addr $STD_CON_INPUT_NO_ECHO ; 8 8
short_addr $STD_CON_STRING_OUTPUT ; 9 9
short_addr $STD_CON_STRING_INPUT ; 10 A
short_addr $STD_CON_INPUT_STATUS ; 11 B
short_addr $STD_CON_INPUT_FLUSH ; 12 C
short_addr $DISK_RESET ; 13 D
short_addr $SET_DEFAULT_DRIVE ; 14 E
short_addr $FCB_OPEN ; 15 F
short_addr $FCB_CLOSE ; 16 10
short_addr $DIR_SEARCH_FIRST ; 17 11
short_addr $DIR_SEARCH_NEXT ; 18 12
short_addr $FCB_DELETE ; 19 13
short_addr $FCB_SEQ_READ ; 20 14
short_addr $FCB_SEQ_WRITE ; 21 15
short_addr $FCB_CREATE ; 22 16
short_addr $FCB_RENAME ; 23 17
short_addr CPMFUNC ; 24 18
short_addr $GET_DEFAULT_DRIVE ; 25 19
short_addr $SET_DMA ; 26 1A
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $SLEAZEFUNC ; 27 1B
short_addr $SLEAZEFUNCDL ; 28 1C
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr CPMFUNC ; 29 1D
short_addr CPMFUNC ; 30 1E
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $GET_DEFAULT_DPB ; 31 1F
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr CPMFUNC ; 32 20
short_addr $FCB_RANDOM_READ ; 33 21
short_addr $FCB_RANDOM_WRITE ; 34 22
short_addr $GET_FCB_FILE_LENGTH ; 35 23
short_addr $GET_FCB_POSITION ; 36 24
MAXCALL = ($-DISPATCH)/2 - 1
; Extended Functions
short_addr $SET_INTERRUPT_VECTOR ; 37 25
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $CREATE_PROCESS_DATA_BLOCK ; 38 26
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr $FCB_RANDOM_READ_BLOCK ; 39 27
short_addr $FCB_RANDOM_WRITE_BLOCK ; 40 28
short_addr $PARSE_FILE_DESCRIPTOR ; 41 29
short_addr $GET_DATE ; 42 2A
short_addr $SET_DATE ; 43 2B
short_addr $GET_TIME ; 44 2C
short_addr $SET_TIME ; 45 2D
short_addr $SET_VERIFY_ON_WRITE ; 46 2E
; Extended functionality group
short_addr $GET_DMA ; 47 2F
short_addr $GET_VERSION ; 48 30
short_addr $Keep_Process ; 49 31
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $GET_DPB ; 50 32
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr $SET_CTRL_C_TRAPPING ; 51 33
short_addr $GET_INDOS_FLAG ; 52 34
short_addr $GET_INTERRUPT_VECTOR ; 53 35
short_addr $GET_DRIVE_FREESPACE ; 54 36
short_addr $CHAR_OPER ; 55 37
short_addr $INTERNATIONAL ; 56 38
; XENIX CALLS
; Directory Group
short_addr $MKDIR ; 57 39
short_addr $RMDIR ; 58 3A
short_addr $CHDIR ; 59 3B
; File Group
short_addr $CREAT ; 60 3C
short_addr $OPEN ; 61 3D
short_addr $CLOSE ; 62 3E
short_addr $READ ; 63 3F
short_addr $WRITE ; 64 40
short_addr $UNLINK ; 65 41
short_addr $LSEEK ; 66 42
short_addr $CHMOD ; 67 43
short_addr $IOCTL ; 68 44
short_addr $DUP ; 69 45
short_addr $DUP2 ; 70 46
short_addr $CURRENT_DIR ; 71 47
; Memory Group
short_addr $ALLOC ; 72 48
short_addr $DEALLOC ; 73 49
short_addr $SETBLOCK ; 74 4A
; Process Group
short_addr $EXEC ; 75 4B
short_addr $EXIT ; 76 4C
short_addr $WAIT ; 77 4D
short_addr $FIND_FIRST ; 78 4E
; Special Group
short_addr $FIND_NEXT ; 79 4F
; SPECIAL SYSTEM GROUP
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $SET_CURRENT_PDB ; 80 50
short_addr $GET_CURRENT_PDB ; 81 51
short_addr $GET_IN_VARS ; 82 52
short_addr $SETDPB ; 83 53
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr $GET_VERIFY_ON_WRITE ; 84 54
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
; C A V E A T P R O G R A M M E R ;
; ;
short_addr $DUP_PDB ; 85 55
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
short_addr $RENAME ; 86 56
short_addr $FILE_TIMES ; 87 57
short_addr $AllocOper ; 88 58
MAXCOM = ($-DISPATCH)/2 - 1
CPMFUNC:
XOR AL,AL
return
IF NOT IBM
BREAK <Set_OEM_Handler -- Set OEM sys call address and handle OEM Calls>
$SET_OEM_HANDLER:
ASSUME DS:NOTHING,ES:NOTHING
; Inputs:
; User registers, User Stack, INTS disabled
; If CALL F8, DS:DX is new handler address
; Function:
; Process OEM INT 21 extensions
; Outputs:
; Jumps to OEM_HANDLER if appropriate
JNE DO_OEM_FUNC ; If above F8 try to jump to handler
MOV WORD PTR [OEM_HANDLER],DX ; Set Handler
MOV WORD PTR [OEM_HANDLER+2],DS
IRET ; Quick return, Have altered no registers
DO_OEM_FUNC:
CMP WORD PTR [OEM_HANDLER],-1
JNZ OEM_JMP
JMP BADCALL ; Handler not initialized
OEM_JMP:
JMP [OEM_HANDLER]
ENDIF
ASSUME SS:DOSGROUP
;
; $Set_current_PDB takes BX and sets it to be the current process
; *** THIS FUNCTION CALL IS SUBJECT TO CHANGE!!! ***
;
procedure $SET_CURRENT_PDB,NEAR
ASSUME DS:NOTHING,SS:NOTHING
MOV [CurrentPDB],BX
return
$SET_CURRENT_PDB ENDP
;
; $get_current_PDB returns in BX the current process
; *** THIS FUNCTION CALL IS SUBJECT TO CHANGE!!! ***
;
procedure $GET_CURRENT_PDB,NEAR
ASSUME DS:NOTHING,SS:NOTHING
invoke get_user_stack
PUSH [CurrentPDB]
POP [SI.user_BX]
return
$GET_CURRENT_PDB ENDP
; ;
; C A V E A T P R O G R A M M E R ;
;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
BREAK <NullDev -- Driver for null device>
procedure SNULDEV,FAR
ASSUME DS:NOTHING,ES:NOTHING,SS:NOTHING
MOV WORD PTR [NULLDEVPT],BX
MOV WORD PTR [NULLDEVPT+2],ES
return
SNULDEV ENDP
procedure INULDEV,FAR
PUSH ES
PUSH BX
LES BX,[NULLDEVPT]
OR ES:[BX.REQSTAT],STDON ; Set done bit
POP BX
POP ES
return
INULDEV ENDP
BREAK <AbsDRD, AbsDWRT -- INT int_disk_read, int_disk_write handlers>>
IF IBM
ERRIN: ; Codes returned by BIOS
DB 2 ; NO RESPONSE
DB 6 ; SEEK FAILURE
DB 12 ; GENERAL ERROR
DB 4 ; BAD CRC
DB 8 ; SECTOR NOT FOUND
DB 0 ; WRITE ATTEMPT ON WRITE-PROTECT DISK
ERROUT: ; DISK ERRORS RETURNED FROM INT 25 and 26
DB 80H ; NO RESPONSE
DB 40H ; Seek failure
DB 2 ; Address Mark not found
DB 8 ; DMA OVERRUN
DB 4 ; SECTOR NOT FOUND
DB 3 ; WRITE ATTEMPT TO WRITE-PROTECT DISK
NUMERR EQU $-ERROUT
ENDIF
procedure ABSDRD,FAR
ASSUME DS:NOTHING,ES:NOTHING,SS:NOTHING
CLI
MOV [user_SS],SS
MOV [user_SP],SP
PUSH CS
POP SS
ASSUME SS:DOSGROUP
MOV SP,OFFSET DOSGROUP:DSKSTACK
INC BYTE PTR [INDOS]
STI
CLD
PUSH ES
PUSH DS
PUSH SS
POP DS
ASSUME DS:DOSGROUP
invoke GETBP
POP DS
ASSUME DS:NOTHING
JC ILEAVE
invoke DSKREAD
TLEAVE:
JZ ILEAVE
IF IBM
; Translate the error code to ancient 1.1 codes
PUSH ES
PUSH CS
POP ES
XOR AH,AH ; Nul error code
MOV CX,NUMERR ; Number of possible error conditions
MOV DI,OFFSET DOSGROUP:ERRIN ; Point to error conditions
REPNE SCASB
JNZ LEAVECODE ; Not found
MOV AH,ES:[DI+NUMERR-1] ; Get translation
LEAVECODE:
POP ES
ENDIF
STC
ILEAVE:
POP ES
CLI
DEC BYTE PTR [INDOS]
MOV SP,[user_SP]
MOV SS,[user_SS]
ASSUME SS:NOTHING
STI
return
ABSDRD ENDP
procedure ABSDWRT,FAR
ASSUME DS:NOTHING,ES:NOTHING,SS:NOTHING
CLI
MOV [user_SS],SS
MOV [user_SP],SP
PUSH CS
POP SS
ASSUME SS:DOSGROUP
MOV SP,OFFSET DOSGROUP:DSKSTACK
INC BYTE PTR [INDOS]
STI
CLD
PUSH ES
PUSH DS
PUSH SS
POP DS
ASSUME DS:DOSGROUP
invoke GETBP
POP DS
ASSUME DS:NOTHING
JC ILEAVE
invoke DSKWRITE
JMP TLEAVE
ABSDWRT ENDP
procedure SYS_RETURN,NEAR
ASSUME DS:NOTHING,ES:NOTHING
entry SYS_RET_OK
call get_user_stack
PUSH [SI.user_F]
POPF
CLC
JMP SHORT DO_RET
entry SYS_RET_ERR
XOR AH,AH ; hack to allow for smaller error rets
call get_user_stack
PUSH [SI.user_F]
POPF
STC
DO_RET:
MOV [SI.user_AX],AX ; Really only sets AH
PUSHF
POP [SI.user_F] ; dump on his flags
return
SYS_RETURN ENDP
do_ext
CODE ENDS
END