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MS-DOS/v2.0/source/XENIX.ASM

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MS-DOS v2.0 Release
1983-08-13 01:53:34 +01:00
;
; xenix file calls 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
TITLE XENIX - IO system to mimic UNIX
NAME XENIX
i_need NoSetDir,BYTE
i_need CURDRV,BYTE
i_need IOCALL,BYTE
i_need IOMED,BYTE
i_need IOSCNT,WORD
i_need IOXAD,DWORD
i_need DIRSTART,WORD
i_need ATTRIB,BYTE
i_need THISFCB,DWORD
i_need AuxStack,BYTE
i_need Creating,BYTE
i_need ThisDRV,BYTE
i_need NAME1,BYTE
i_need LastEnt,WORD
i_need ThisDPB,DWORD
i_need EntLast,WORD
i_need CurrentPDB,WORD
i_need sft_addr,DWORD ; pointer to head of table
i_need CURBUF,DWORD ; pointer to current buffer
i_need DMAADD,DWORD ; pointer to current dma address
BREAK <Local data>
CODE ENDS
DATA SEGMENT BYTE PUBLIC 'DATA'
open_name DW ?
DW ?
open_access DB ?
open_jfn DW ? ; accessed as DD
open_jfn_b DW ? ; accessed as DD with above
open_sfn DW ?
open_sfoff DW ? ; accessed as DD
open_sfn_b DW ? ; accessed as DD with above
open_devid DB ?
Cr_read_only DB ?
rename_source DD ?
rename_dest DD ?
DATA ENDS
CODE SEGMENT BYTE PUBLIC 'CODE'
BREAK <Validate_path - check to see if there are meta characters in path>
;
; Input: DS:DX is an ASCIZ path
; Output: Carry set if meta-characters present or path malformed and
; Zero is set if the only problem is that meta-characters
; are present in the last element of the path
procedure Validate_path,near
ASSUME DS:NOTHING,ES:NOTHING
PUSH AX
PUSH CX
PUSH SI
MOV SI,DX
MOV CX,0FFH ;No path seps yet
MOV AX,[SI] ; Get first two bytes
OR AL,AL
JZ validate_malformed ; NUL path
CMP AH,':'
JNZ validate_loop ; OK so far
CMP BYTE PTR [SI+2],0
JZ validate_malformed ; NUL path (just d:)
validate_loop:
LODSB
validate_loop1:
IF KANJI
invoke TESTKANJ
JZ NOTKANJ6
INC SI
JMP validate_loop
NOTKANJ6:
ENDIF
OR AL,AL
JZ validate_end
CMP AL,"?"
JZ validate_error
CMP AL,"*"
JZ validate_error
invoke PathChrCmp
JNZ validate_loop
JCXZ validate_malformed ;If path sep, cannot have meta yet
LODSB ;Look ahead one char
OR AL,AL
JZ validate_checktslsh ;Trailing path sep
invoke PathChrCmp
JNZ validate_loop1 ;Double path sep?
validate_malformed:
INC CX
OR CX,CX ;Reset zero
JMP SHORT validate_set_carry
validate_error:
XOR CX,CX ;Flag metas found
JMP validate_loop
validate_checktslsh:
;A bizarre case, "/" is OK, "d:/" is OK, anything else is an error
SUB SI,DX
CMP SI,2
JZ validate_end ;Two chars, the '/' and the NUL
CMP SI,4
JNZ validate_malformed ;Four chars, "D:/<NUL>"
MOV SI,DX
CMP BYTE PTR [SI+1],':'
JNZ validate_malformed ;Second char must be a ':'
validate_end:
OR CX,CX ;Clears carry
JNZ validate_ok ;No metas found, leave carry clear
validate_set_carry:
STC
validate_ok:
POP SI
POP CX
POP AX
return
validate_path ENDP
BREAK <Access_path - determine if file found>
;
; Input: DS:DX point to a path
; Output: Carry reset - outputs of GetPath
; carry set - AL has error code
;
procedure Access_path,NEAR
ASSUME DS:NOTHING,ES:NOTHING
CALL Validate_path
JC access_no_path
MOV SI,DX
invoke GetPath
retnc
MOV AL,error_file_not_found
OR CL,CL
JNZ access_ret
access_no_path:
MOV AL,error_path_not_found
access_ret:
STC
return
access_path ENDP
BREAK <Find_free_jfn - return a free jfn in users PDB>
;
; system file table data
;
;
; The system file table is two linear tables. The first table is the
; DOS initialization table containing a default number of FCBs. The
; first word in the table is a link to the second table, which
; SYSINIT sets up, the second word is the number of FCBs in the table.
;
;
; find_free_jfn
; input: none
; output: JNC <found>
; ES:DI is pointer to free JFN
; JC <no free jfns>
; ES,DI indeterminate
;
procedure Find_free_jfn,NEAR
ASSUME DS:NOTHING,ES:NOTHING
PUSH AX
PUSH CX
MOV AL,0FFh
MOV ES,[CurrentPDB]
MOV DI,PDB_JFN_Table
MOV CX,FilPerProc
REPNE SCASB
STC
JNZ Find_jfn_ret
DEC DI
CLC
Find_jfn_ret:
POP CX
POP AX
return
Find_free_jfn ENDP
BREAK <find_free_sfn - return a free sfn and sf pointer>
;
; find_free_sfn
; input: none
; output: JNC <found>
; ES:DI is free sf entry
; SI is sfn
; JC <not found>
; ES,DI,SI indeterminate
;
; sft_addr --> (link) count (fcbs)
; links = -1 means end of list
;
procedure Find_free_sfn,NEAR
ASSUME DS:NOTHING,ES:NOTHING
PUSH BX
PUSH CX
LES BX,sft_addr ; head of chain of tables
XOR SI,SI ; count of sfn
; ES:BX points to table... search through table
Find_sfn_in_table:
CMP BX,-1 ; end of chain
JZ Find_no_free_sfns
MOV DI,sft_table ; offset to sf entry
MOV CX,ES:[BX].sft_count ; count of fcbs in table
Find_sfn:
CMP ES:BYTE PTR [BX+DI].sf_ref_count,0h
JZ Find_got_sfn ; ref count is 0 -> free entry
ADD DI,SIZE sf_entry ; look to next entry
INC SI ; bump sfn
LOOP Find_sfn
LES BX,ES:[BX].sft_link ; link to next
JMP SHORT Find_sfn_in_table ; look for more
Find_no_free_sfns:
STC
JMP SHORT find_ret
Find_got_sfn:
ADD DI,BX
CLC
Find_ret:
POP CX
POP BX
RET
Find_free_sfn ENDP
BREAK <$Open - open a file handle>
;
; Assembler usage:
; LDS DX, Name
; MOV AH, Open
; MOV AL, access
; INT int_command
;
; ACCESS Function
; ------ --------
; open_for_read file is opened for reading
; open_for_write file is opened for writing
; open_for_both file is opened for both reading and writing.
;
; Error returns:
; AX = error_invalid_access
; = error_file_not_found
; = error_access_denied
; = error_too_many_open_files
;
procedure $Open,NEAR
ASSUME DS:NOTHING,ES:NOTHING
MOV [Cr_read_only],0
Open_create:
CMP AL,open_for_both ; validate access
JBE OPEN_get_jfn
error error_invalid_access
OPEN_get_jfn:
MOV [open_name+2],DS
context DS
MOV open_name,DX
MOV open_access,AL
invoke Find_free_jfn ; scan through user's area
; ES:DI is the jfn entry
JNC OPEN_get_sfn
OPEN_too_many:
error error_too_many_open_files
OPEN_get_sfn:
MOV OPEN_jfn_b,ES
MOV OPEN_jfn,DI
invoke Find_free_sfn ; get a free sft entry
; ES:DI is the SFT entry that's free, SI is the sfn
JC OPEN_too_many
OPEN_file:
MOV OPEN_sfn,SI
MOV OPEN_sfoff,DI
MOV OPEN_sfn_b,ES
;
; open the file
;
PUSH DS
LDS DX,DWORD PTR [open_name]
ASSUME DS:NOTHING
CALL access_path
POP DS
ASSUME DS:DOSGROUP
JNC open_check_access ; carry set -> error
transfer SYS_RET_ERR
open_check_access:
MOV ES,WORD PTR [CURBUF+2] ; get buffer location
MOV open_devid,AH
TEST AH,080h
JNZ open_set_FCB_dev ;is a device
MOV AL,ES:[BX].dir_attr
TEST AL,attr_directory ; can't open directories
JZ open_try_volid
open_bad_access:
error error_access_denied
open_try_volid:
TEST AL,attr_volume_id ; can't open volume ids
JNZ open_bad_access
TEST AL,attr_read_only ; check write on read only
JZ open_set_FCB
CMP [Cr_read_only],0
JNZ open_set_FCB ; ok if creating read only file
CMP open_access, open_for_read
JNZ open_bad_access ; writing on a read only file
JMP SHORT open_set_FCB
open_set_FCB_dev:
PUSH SS
POP ES ;Device opens are DOSGROUP relative
open_set_FCB:
MOV CX,11 ; copy name into FCB...
PUSH SI ; ES:BX is source, must change
MOV SI,BX ; ES:SI is source
MOV DI,open_sfoff ; ??:DI is dest
PUSH DS
PUSH ES
MOV ES,open_sfn_b ; ES:DI is dest
POP DS ; DS:SI is source
ASSUME DS:NOTHING
;
; need to save attribute for the close operation
;
MOV AH,DS:[BX.dir_attr] ; save attribute for close
MOV ES:[DI.sf_attr],AH
ADD DI,sf_fcb+1 ; point to name
IF KANJI
MOVSB
CMP BYTE PTR ES:[DI-1],5
JNZ NOTKTRAN
MOV BYTE PTR ES:[DI-1],0E5H
NOTKTRAN:
DEC CX
ENDIF
REP MOVSB ; move in parsed name
POP DS
ASSUME DS:DOSGROUP
POP SI
LES DI,DWORD PTR [open_sfoff]
ADD DI,sf_fcb ; offset on fcb in sf entry
MOV AH,open_devid
invoke DOOPEN ; let open code fill in blanks
context DS
LES DI,DWORD PTR [open_sfoff]
INC ES:[DI].sf_ref_count ; reference this FCB
MOV AL,open_access ; stash the access
MOV ES:BYTE PTR [DI].sf_mode,AL
XOR AX,AX
MOV ES:WORD PTR [DI.sf_FCB.fcb_RR],AX ; beginning of file
MOV ES:WORD PTR [DI.sf_FCB.fcb_RR+2],AX
INC AX
MOV ES:WORD PTR [DI.sf_FCB.fcb_RECSIZ],AX ; byte io only
LES DI,DWORD PTR [open_jfn]
MOV AX,open_sfn
MOV ES:BYTE PTR [DI],AL ; stash sfn in PDB
SUB DI,PDB_jfn_table ; get jfn for user
MOV AX,DI
transfer SYS_RET_OK
$Open ENDP
BREAK <$UNLINK - delete a file entry>
;
; Assembler usage:
; LDS DX, name
; MOV AH, Unlink
; INT 21h
;
; Error returns:
; AX = error_file_not_found
; = error_access_denied
;
procedure $UNLINK,NEAR
ASSUME DS:NOTHING,ES:NOTHING
CALL access_path
JNC unlink_check_attr
transfer SYS_RET_ERR
unlink_check_attr:
JZ unlink_dir
LDS DI,DWORD PTR [CURBUF] ; get directory entry
TEST DS:[BX.dir_attr],attr_read_only
JZ unlink_doit
unlink_dir:
error error_access_denied
unlink_doit:
MOV BYTE PTR DS:[BX.dir_name],0E5h ; delete dir entry
MOV BYTE PTR DS:[DI.BUFDIRTY],1 ; dirty the buffer
LODSW
MOV BX,AX
AND BX,0FFFh
context DS
JZ unlink_flush
invoke RELEASE
unlink_flush:
MOV AL,BYTE PTR ES:[BP.DPB_drive]
invoke FLUSHBUF
transfer SYS_RET_OK
$UNLINK ENDP
BREAK <$CREAT - creat a new file and open him for input>
;
; Assembler usage:
; LDS DX, name
; MOV AH, Creat
; MOV CX, access
; INT 21h
; ; AX now has the handle
;
; Error returns:
; AX = error_access_denied
; = error_path_not_found
; = error_too_many_open_files
;
procedure $CREAT,NEAR
ASSUME DS:NOTHING,ES:NOTHING
CALL Validate_path
JNC unlink_do_make
error error_path_not_found
unlink_do_make:
PUSH DX
PUSH DS
context DS
MOV WORD PTR [CREATING],0E5FFh
MOV WORD PTR [ThisFCB+2],SS
MOV WORD PTR [ThisFCB],OFFSET DOSGROUP:AUXSTACK-40
MOV SI,DX
MOV AL,CL
AND CL,attr_read_only
MOV [Cr_read_only],CL
POP DS
PUSH DS
ASSUME DS:NOTHING
invoke MakeNode
POP DS
POP DX
OR AL,AL
JZ creat_open
CMP AL,3
JZ creat_open
creat_no_access:
error error_access_denied
creat_open:
MOV AL,open_for_both
JMP Open_create
$CREAT ENDP
BREAK <$DUP - duplicate a jfn>
;
; Assembler usage:
; MOV BX, fh
; MOV AH, Dup
; INT int_command
; AX has the returned handle
; Errors:
; AX = dup_invalid_handle
; = dup_too_many_open_files
procedure $DUP,NEAR
ASSUME DS:NOTHING,ES:NOTHING
context DS
invoke Find_free_jfn
JC dup_no_free_handles
dup_force:
PUSH ES
PUSH DI
invoke Get_sf_from_jfn
POP SI
POP DS
JC dup_bad_handle
; ES:DI is pointer to sf entry
; DS:DI is pointer to jfn
INC ES:[DI].sf_ref_count ; another jfn reference...
MOV AL,[BX].PDB_JFN_table ; get old sfn
MOV [SI],AL ; store in new place
SUB SI,PDB_JFN_table ; get jfn
MOV AX,SI
transfer SYS_RET_OK
dup_no_free_handles:
error error_too_many_open_files
dup_bad_handle:
error error_invalid_handle
$DUP ENDP
BREAK <$DUP2 - force a dup on a particular jfn>
;
; Assembler usage:
; MOV BX, fh
; MOV CX, newfh
; MOV AH, Dup2
; INT int_command
; Error returns:
; AX = error_invalid_handle
;
procedure $DUP2,NEAR
ASSUME DS:NOTHING,ES:NOTHING
XCHG BX,CX ; BX < destination jfn
PUSH BX
PUSH CX
invoke $CLOSE ; close BX
context DS
POP CX
POP BX
invoke Get_jfn_pointer
XCHG BX,CX
JNC dup_force
lseek_bad_handle:
error error_invalid_handle
$DUP2 ENDP
BREAK <$CHMOD - change file attributes>
;
; Assembler usage:
; LDS DX, name
; MOV CX, attributes
; INT 21h
; Error returns:
; AX = error_path_not_found
; AX = error_access_denied
;
procedure $CHMOD,NEAR
ASSUME DS:NOTHING,ES:NOTHING
CMP AL,1
JBE chmod_save
error error_invalid_function
chmod_save:
JB chmod_try_file
MOV BX,CX
AND BX,NOT attr_changeable
JZ chmod_try_file
chmod_bad:
error error_access_denied
chmod_bye:
transfer SYS_RET_ERR
chmod_try_file:
PUSH CX
PUSH AX
CALL access_path
POP DX
POP CX
JC chmod_bye
LES DI,[CURBUF]
context DS
OR DL,DL
JZ chmod_fetch
AND BYTE PTR ES:[BX].dir_attr,NOT attr_changeable
OR BYTE PTR ES:[BX].dir_attr,CL
MOV ES:[DI.BUFDIRTY],1
MOV AL,-1
invoke FlushBuf
transfer SYS_RET_OK
chmod_fetch:
XOR CX,CX
MOV CL,BYTE PTR ES:[BX].dir_attr
invoke Get_user_stack
MOV [SI.user_CX],CX
transfer SYS_RET_OK
$chmod ENDP
BREAK <$CURRENT_DIR - dump the current directory into user space>
;
; Assembler usage:
; LDS SI,area
; MOV DL,drive
; INT 21h
; ; DS:SI is a pointer to 64 byte area that contains drive
; ; current directory.
; Error returns:
; AX = error_invalid_drive
;
procedure $CURRENT_DIR,NEAR
ASSUME DS:NOTHING,ES:NOTHING
PUSH DS
PUSH BX
PUSH SI
invoke $get_DPB
;
; ES:BP points to DPB. DS:SI points to user stack, unless error
;
CMP AL,0FFh
JNZ current_copy
POP AX ; Clean Stack
POP AX
POP AX
error error_invalid_drive
current_copy:
POP DI ; where to move to
POP [SI.user_BX] ; restore old BX
POP BX
MOV [SI.user_DS],BX ; and restore old DS
;
; ES:BP is pointer to DPB. BX:DI is pointer to destination
;
CMP ES:[BP.dpb_current_dir],-1
JNZ current_ok
PUSH BX
PUSH DI
MOV [ATTRIB],attr_all
invoke GETCURRDIR
POP DI
POP BX
current_ok:
MOV SI,BP ; ES:SI is source
PUSH ES
POP DS ; DS:SI is source
MOV ES,BX ; ES:DI is destination
CMP [SI.dpb_current_dir],0
JNZ current_move
MOV BYTE PTR [SI.dpb_dir_text],0
current_move:
ADD SI,dpb_dir_text
MOV CX,DIRSTRLEN
current_loop:
LODSB
STOSB
OR AL,AL
LOOPNZ current_loop
transfer SYS_RET_OK
$CURRENT_DIR ENDP
BREAK <$RENAME - move directory entries around>
;
; Assembler usage:
; LDS DX, source
; LES DI, dest
; MOV AH, Rename
; INT 21h
;
; Error returns:
; AX = error_file_not_found
; = error_not_same_device
; = error_access_denied
procedure $RENAME,near
MOV WORD PTR [rename_source],DX
MOV WORD PTR [rename_source+2],DS
MOV WORD PTR [rename_dest],DI
MOV WORD PTR [rename_dest+2],ES
CALL Access_path
JNC rename_check_dir
transfer SYS_RET_ERR
rename_check_dir:
JZ rename_no_access
MOV DS,WORD PTR [CurBuf+2]
PUSH [BX.dir_date]
PUSH [BX.dir_first]
PUSH [BX.dir_size_h]
PUSH [BX.dir_size_l]
PUSH [BX.dir_time]
PUSH WORD PTR [BX.dir_attr]
PUSH WORD PTR [ThisDrv]
LDS SI,[rename_dest]
invoke GetPath
POP AX
JC rename_check_drives
rename_bad_access:
ADD SP,12
rename_no_access:
error error_access_denied
rename_check_drives:
CMP AL,[ThisDrv]
JZ rename_create
ADD SP,12
error error_not_same_device
rename_create:
LDS SI,[rename_dest]
POP AX
PUSH AX
MOV WORD PTR [Creating],0E5FFh
MOV WORD PTR [ThisFCB+2],SS
MOV WORD PTR [ThisFCB],OFFSET DOSGROUP:AUXStack-40
invoke MakeNode
JC rename_bad_access
LDS SI,[CurBuf]
POP AX
MOV [BX.dir_attr],AL
POP [BX.dir_time]
POP [BX.dir_size_l]
POP [BX.dir_size_h]
POP [BX.dir_first]
POP [BX.dir_date]
MOV [SI.BUFDIRTY],1
LDS SI,[rename_source]
invoke GetPath
LDS SI,[CurBuf]
MOV BYTE PTR [BX],0E5h
MOV [SI.BUFDIRTY],1
context DS
MOV AL,0FFh
invoke FlushBuf
transfer SYS_RET_OK
$RENAME ENDP
BREAK <$FIND_FIRST - find first matching xenix filename>
;
; Assembler usage:
; MOV AH, FindFirst
; LDS DX, name
; MOV CX, attr
; INT 21h
; ; DMA address has datablock
;
; Error Returns:
; AX = error_file_not_found
; = error_no_more_files
;
procedure $FIND_FIRST,near
ASSUME DS:NOTHING,ES:NOTHING
CALL Validate_path
JNC find_get
JZ find_get
error error_file_not_found
find_get:
MOV SI,DX
PUSH CX
INC BYTE PTR [NoSetDir] ; if we find a dir, don't change to it
MOV WORD PTR [Creating],0E500h
CALL GetPath
POP CX
MOV [Attrib],CL
find_check:
JNC find_check_attr
find_no_more:
error error_no_more_files
find_check_attr:
MOV DS,WORD PTR [CURBUF+2]
MOV CH,[BX.dir_attr]
invoke MatchAttributes
JZ found_it
PUSH [LastEnt]
MOV BX,[DirStart]
JMP find_it_next
found_it:
LES DI,[DMAADD]
MOV AL,[Attrib]
STOSB ; find_buf 0 = attribute in search
MOV AL,[ThisDrv]
STOSB ; find_buf 1 = drive
MOV CX,11
PUSH BX
MOV SI,OFFSET DOSGROUP:NAME1; find_buf 2 = formatted name
PUSH DS
PUSH SS
POP DS
IF KANJI
MOVSB
CMP BYTE PTR ES:[DI-1],5
JNZ NOTKANJB
MOV BYTE PTR ES:[DI-1],0E5H
NOTKANJB:
DEC CX
ENDIF
REP MOVSB
POP DS
MOV AX,[LastEnt]
STOSW ; find_buf 13 = LastEnt
MOV AX,WORD PTR [ThisDPB]
STOSW ; find_buf 15 = ThisDPB
MOV AX,WORD PTR [ThisDPB+2]
STOSW
MOV AX,[DirStart]
STOSW ; find_buf 19 = DirStart
MOV AL,[BX].dir_attr
STOSB ; find_buf 21 = attribute found
MOV AX,[BX].dir_time
STOSW ; find_buf 22 = time
MOV AX,[BX].dir_date
STOSW ; find_buf 24 = date
MOV AX,[BX].dir_size_l
STOSW ; find_buf 26 = low(size)
MOV AX,[BX].dir_size_h
STOSW ; find_buf 28 = high(size)
POP SI
MOV CX,8 ; find_buf 30 = packed name
find_loop_name:
LODSB
STOSB
CMP AL," "
LOOPNZ find_loop_name
JNZ find_check_dot
DEC DI
find_check_dot:
ADD SI,CX
CMP BYTE PTR [SI]," "
JZ find_done
MOV AL,"."
STOSB
MOV CX,3
find_loop_ext:
LODSB
STOSB
CMP AL," "
LOOPNZ find_loop_ext
JNZ find_done
DEC DI
find_done:
XOR AL,AL
STOSB
transfer SYS_RET_OK
$FIND_FIRST ENDP
BREAK <$FIND_NEXT - scan for match in directory>
;
; Assembler usage:
; ; dma points at area returned by find_first
; MOV AH, findnext
; INT 21h
; ; next entry is at dma
;
; Error Returns:
; AX = error_no_more_files
;
procedure $FIND_NEXT,near
ASSUME DS:NOTHING,ES:NOTHING
LDS SI,[DMAADD]
MOV DX,SI
INC DX
PUSH SI
invoke MOVNAMENOSET
POP SI
JNC find_load
findnext_no_more:
error error_no_more_files
find_load:
MOV AX,[SI.find_buf_LastEnt]
LES BP,[SI.find_buf_ThisDPB]
OR AX,AX
JS findnext_no_more
MOV BX,[SI.find_buf_DirStart]
MOV DL,[SI.find_buf_sattr]
MOV [Attrib],DL
PUSH AX
MOV WORD PTR [ThisDPB],BP
MOV WORD PTR [ThisDPB+2],ES
find_it_next:
invoke SetDirSrch
ASSUME DS:DOSGROUP
POP AX
MOV [ENTLAST],-1
invoke GetEnt
invoke NextEnt
JMP find_check
$find_next ENDP
do_ext
CODE ENDS
END
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