MS-DOS/v2.0/source/FCB.ASM
2018-09-21 17:53:34 -07:00

513 lines
13 KiB
NASM

;
; FCB management routines for MSDOS
;
INCLUDE DOSSEG.ASM
IFNDEF KANJI
KANJI EQU 0 ;FALSE
ENDIF
CODE SEGMENT BYTE PUBLIC 'CODE'
ASSUME SS:DOSGROUP,CS:DOSGROUP
.xlist
.xcref
INCLUDE DOSSYM.ASM
INCLUDE DEVSYM.ASM
.cref
.list
i_need Name1,BYTE
i_need NumIO,BYTE
i_need DevFCB,BYTE
i_need Creating,BYTE
i_need ExtFCB,BYTE
i_need Attrib,BYTE
i_need SpaceFlag,BYTE
i_need Current_Country,WORD
procedure MakeFcb,NEAR
DRVBIT EQU 2
NAMBIT EQU 4
EXTBIT EQU 8
MOV BYTE PTR [SpaceFlag],0
XOR DL,DL ; Flag--not ambiguous file name
TEST AL,DRVBIT ; Use current drive field if default?
JNZ DEFDRV
MOV BYTE PTR ES:[DI],0 ; No - use default drive
DEFDRV:
INC DI
MOV CX,8
TEST AL,NAMBIT ; Use current name fields as defualt?
XCHG AX,BX ; Save bits in BX
MOV AL," "
JZ FILLB ; If not, go fill with blanks
ADD DI,CX
XOR CX,CX ; Don't fill any
FILLB:
REP STOSB
MOV CL,3
TEST BL,EXTBIT ; Use current extension as default
JZ FILLB2
ADD DI,CX
XOR CX,CX
FILLB2:
REP STOSB
XCHG AX,CX ; Put zero in AX
STOSW
STOSW ; Initialize two words after to zero
SUB DI,16 ; Point back at start
TEST BL,1 ; Scan off separators if not zero
JZ SKPSPC
CALL SCANB ; Peel off blanks and tabs
CALL DELIM ; Is it a one-time-only delimiter?
JNZ NOSCAN
INC SI ; Skip over the delimiter
SKPSPC:
CALL SCANB ; Always kill preceding blanks and tabs
NOSCAN:
CALL GETLET
JBE NODRV ; Quit if termination character
CMP BYTE PTR[SI],":" ; Check for potential drive specifier
JNZ NODRV
INC SI ; Skip over colon
SUB AL,"@" ; Convert drive letter to binary drive number
JBE BADDRV ; Valid drive numbers are <= NUMIO
CMP AL,BYTE PTR [NUMIO]
JBE HAVDRV
BADDRV:
MOV DL,-1
HAVDRV:
STOSB ; Put drive specifier in first byte
INC SI
DEC DI ; Counteract next two instructions
NODRV:
DEC SI ; Back up
INC DI ; Skip drive byte
NORMSCAN:
MOV CX,8
CALL GETWORD ; Get 8-letter file name
CMP BYTE PTR [SI],"."
JNZ NODOT
INC SI ; Skip over dot if present
MOV CX,3 ; Get 3-letter extension
CALL MUSTGETWORD
NODOT:
MOV AL,DL
return
NONAM:
ADD DI,CX
DEC SI
return
GETWORD:
CALL GETLET
JBE NONAM ; Exit if invalid character
DEC SI
;
; UGH!!! Horrible bug here that should be fixed at some point:
; If the name we are scanning is longer than CX, we keep on reading!
;
MUSTGETWORD:
CALL GETLET
;
; If spaceFlag is set then we allow spaces in a pathname
;
JB FILLNAM
JNZ MustCheckCX
TEST BYTE PTR [SpaceFlag],0FFh
JZ FILLNAM
CMP AL," "
JNZ FILLNAM
MustCheckCX:
JCXZ MUSTGETWORD
DEC CX
CMP AL,"*" ; Check for ambiguous file specifier
JNZ NOSTAR
MOV AL,"?"
REP STOSB
NOSTAR:
STOSB
IF KANJI
CALL TESTKANJ
JZ NOTDUAL3
JCXZ BNDERR ; Attempt to straddle boundry
MOVSB ; Transfer second byte
DEC CX
JMP SHORT NOTDUAL3
BNDERR:
MOV BYTE PTR ES:[DI-1]," " ; patch up that space
JMP MustGetWord ; go back and scan until delim
NOTDUAL3:
ENDIF
CMP AL,"?"
JNZ MUSTGETWORD
OR DL,1 ; Flag ambiguous file name
JMP MUSTGETWORD
FILLNAM:
MOV AL," "
REP STOSB
DEC SI
return
SCANB:
LODSB
CALL SPCHK
JZ SCANB
DEC SI
return
MakeFCB ENDP
;
; NameTrans is used by FindPath to scan off an element
; of a path. We must allow spaces in pathnames
; Inputs: SS - DOSGROUP
; DS:SI name
; Outputs: DS:SI advanced over spot
; ES:DI point to after Name1
; registers modified: AX, BX, CX, DX
procedure NameTrans,near
MOV BYTE PTR [SpaceFlag],1
PUSH SS
POP ES
MOV DI,OFFSET DOSGROUP:NAME1
PUSH DI
MOV AL,' '
MOV CX,11
REP STOSB
XOR AL,AL
MOV DL,AL
STOSB
POP DI
CMP BYTE PTR [SI],'.'
IF KANJI
JZ FOOBAR
CALL NORMSCAN
CMP [NAME1],0E5H
retnz
MOV [NAME1],5
return
FOOBAR:
ELSE
JNZ NORMSCAN
ENDIF
MOVSB
LODSB
CALL PATHCHRCMP
JZ GOTDOTNAME
OR AL,AL
JZ GOTDOTNAME
CMP AL,'.'
JNZ BADDOTS
STOSB
LODSB
CALL PATHCHRCMP
JZ GOTDOTNAME
OR AL,AL
JZ GOTDOTNAME
DEC SI
BADDOTS:
DEC SI
GOTDOTNAME:
DEC SI
XOR AL,AL
return
nametrans ENDP
SUBTTL BUILDFCB -- MAKE A BLANK FCB FOR A DEVICE
PAGE
procedure BuildFCB,near
ASSUME DS:DOSGROUP,ES:DOSGROUP
; Function:
; Build a blank FCB for I/O to a device
; Outputs:
; Same as GETNAME
MOV AX," "
MOV DI,OFFSET DOSGROUP:DEVFCB+8 ; Point to extent field
STOSW
STOSB ; Blank out extent field
XOR AX,AX
MOV CX,10
REP STOSW ; Fill FCB with zeros
STOSB
invoke DATE16
MOV DI,OFFSET DOSGROUP:DEVFCB+22
XCHG AX,DX
STOSW
XCHG AX,DX
STOSW
XCHG AX,BX ; But device number in AH
MOV BX,OFFSET DOSGROUP:DEVFCB
MOV SI,DI
XOR AL,AL ; Set zero, clear carry
return
BuildFCB ENDP
SUBTTL MOVENAME, LODNAME -- EXAMINE FCB AND SETUP
PAGE
procedure FCB_move,NEAR
entry MOVNAMENOSET
MOV DI,1
JMP SHORT MOVSTART
entry MOVNAME
ASSUME DS:NOTHING,ES:NOTHING
; Inputs:
; DS, DX point to FCB or extended FCB
; Outputs:
; DS:DX point to normal FCB
; DS:SI point after end of NAME/EXT in FCB
; ES = DOSGROUP
; If file name OK:
; [NAME1] has name in upper case
; All registers destroyed
; Carry set if bad file name or drive
XOR DI,DI
MOVSTART:
MOV WORD PTR [CREATING],0E500H ; Not creating, not DEL *.*
MOV SI,DX
LODSB
MOV [EXTFCB],AL ; Set flag if extended FCB in use
XOR AH,AH ; Set default attributes
CMP AL,-1 ; Is it an extended FCB?
JNZ HAVATTRB
ADD DX,7 ; Adjust to point to normal FCB
ADD SI,6
MOV AH,[SI-1] ; Attribute byte
LODSB ; Get drive select byte
HAVATTRB:
invoke GETTHISDRV
retc
PUSH DS
PUSH DX
PUSH SI
PUSH AX
;
; DS:DX is pointer to good FCB
; DS:SI is same
;
; Move the file into Name1 and UCASE it
;
PUSH DI
context ES
MOV DI,OFFSET DOSGROUP:NAME1
CALL LodName
POP DI
JC DrvNoSet
;
; are we setting current dir info?
;
OR DI,DI
JNZ DrvNoSet ; do not set dir info
;
; check for device name first, eliminating drive hits on devices
;
context DS
invoke DEVNAME
JNC DrvNoSet ; we have a device
;
; make sure that everything is current
;
invoke FATREAD
ASSUME DS:NOTHING,ES:NOTHING
MOV BYTE PTR [ATTRIB],attr_directory+attr_hidden+attr_system
invoke GETCURRDIR
DrvNoSet:
POP AX
MOV BYTE PTR [ATTRIB],AH
POP SI
POP DX
POP DS
context ES
MOV DI,OFFSET DOSGROUP:NAME1
entry LODNAME
; Inputs: DS:SI point to an FCB
; ES:DI point to an FCB
; Outputs: DS:SI point to after FCB
; ES:DI point to after FCB
; FCB from DS:SI copied and ucased to ES:DI
; Carry set if there was an error.
; Destroys AX,CX
CMP BYTE PTR [SI]," " ; Don't allow blank as first letter
STC ; In case of error
retz
IF KANJI
MOV CX,8
CMP BYTE PTR [SI],0E5H
JNZ MOVCHK
INC SI
MOV AL,5
STOSB
MOVSB
MOV CX,6
MOVCHK:
CALL GETLET
JB RET6
JNZ STOLET ; Is it a delimiter?
CMP AL," " ; This is the only delimiter allowed
STC ; In case of error
JNZ RET6
STOLET:
STOSB
CALL TESTKANJ
JZ MOVLP ;No
LODSB ;Get second byte
DEC CX
JZ BOUNDERR ;Attempt to cross boundry
STOSB
MOVLP:
LOOP MOVCHK
MOV CX,3
MOVCHK2:
CALL GETLET
JB RET6
JNZ STOLET2 ; Is it a delimiter?
CMP AL," " ; This is the only delimiter allowed
STC ; In case of error
retnz
STOLET2:
STOSB
CALL TESTKANJ
JZ MOVLP2 ;No
LODSB ;Get second byte
DEC CX
JNZ DOSTORE
BOUNDERR: ;Attempt to cross boundry
STC
return
DOSTORE:
STOSB
MOVLP2:
LOOP MOVCHK2
ELSE
MOV CX,11
MOVCHK:
CALL GETLET
JB RET6
JNZ STOLET ; Is it a delimiter?
CMP AL," " ; This is the only delimiter allowed
STC ; In case of error
retnz
STOLET:
STOSB
LOOP MOVCHK
ENDIF
CLC ; Got through whole name - no error
RET6: return
FCB_Move ENDP
SUBTTL GETLET, DELIM -- CHECK CHARACTERS AND CONVERT
PAGE
procedure GetLet,NEAR
; Get a byte from [SI], convert it to upper case, and compare for delimiter.
; ZF set if a delimiter, CY set if a control character (other than TAB).
LODSB
CMP AL,"a"
JB CHK1
CMP AL,"z"
JA CHK1
SUB AL,20H ; Convert to upper case
CHK1:
PUSH SI
MOV SI,[Current_Country]
ADD SI,Map_call
PUSH CS ; CS for long return
CALL WORD PTR CS:[SI]
POP SI
entry CHK
CMP AL,"."
retz
CMP AL,'"'
retz
CALL PATHCHRCMP
retz
CMP AL,"["
retz
CMP AL,"]"
retz
DELIM:
CMP AL,":" ; Allow ":" as separator in IBM version
retz
CMP AL,"<"
retz
CMP AL,"|"
retz
CMP AL,">"
retz
CMP AL,"+"
retz
CMP AL,"="
retz
CMP AL,";"
retz
CMP AL,","
retz
SPCHK:
CMP AL,9 ; Filter out tabs too
retz
; WARNING! " " MUST be the last compare
CMP AL," "
return
GetLet ENDP
procedure PATHCHRCMP,NEAR
CMP AL,'/'
retz
CMP AL,'\'
return
PathChrCMP ENDP
IF KANJI
procedure TESTKANJ,NEAR
CMP AL,81H
JB NOTLEAD
CMP AL,9FH
JBE ISLEAD
CMP AL,0E0H
JB NOTLEAD
CMP AL,0FCH
JBE ISLEAD
NOTLEAD:
PUSH AX
XOR AX,AX ;Set zero
POP AX
return
ISLEAD:
PUSH AX
XOR AX,AX ;Set zero
INC AX ;Reset zero
POP AX
return
TESTKANJ ENDP
ENDIF
do_ext
CODE ENDS
END