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Digital-Research-Source-Code/CPM OPERATING SYSTEMS/CPM 86/CONCURRENT/CCPM-86 3.1 SOURCE/D2/FILE3.BDO
Sepp J Morris 31738079c4 Upload 
Digital Research
2020-11-06 18:50:37 +01:00

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;************ bdos file system part 3 ************
conv_rr: ;convert random record #
;-------
mov al,info_fcb+ranrec ;AL = fcb(ranrec(0))
mov dl,al
and dl,7fh ;record number
rcl al,1 ;cy=lsb of extent#
mov al,info_fcb+ranrec+1 ;AL = fcb(ranrec(1))
mov ch,al
rcl ch,1
and ch,11111b ;CH = extent #
;DL = record #
and al,11110000b
or al,info_fcb+ranrec+2
mov cl,4
rol al,cl
mov cl,ch
mov ch,al ;CH = mod#, CL = ext#
ret
rseek: ;random access seek operation
;-----
; fcb is assumed to address an active fcb
; (modnum has been set to 1100$0000b if previous bad seek)
; entry: CL = true if read operation
; = false if write operation
; exit: Z flag set if successful
push cx ;save r/w flag (indexed on stack)
call conv_rr ;CH = mod #, CL = ext#, DL = record #
cmp byte ptr info_fcb+ranrec+2,3 ;r(3) field must
;be <= 3
mov bl,6 ;zero flag, BL=6
;produce error 6,
jbe $+5 ;seek past physical eod
jmp seekerr ;random record out of range
;otherwise, high byte = 0
mov info_fcb+nxtrec,dl ;record number
; arrive here with CH=mod#, CL=ext#, SI=.fcb, rec stored
; the r/w flag is still stacked. compare fcb values
cmp fx_intrn,fxi99
je rseek3
call chk_inv_fcb
jz rseek3
;check module # first
mov al,ch ;b=seek mod#
;could be overflow at eof,
;producing module# of 90h
;or 10h, so compare all
;but fwf
sub al,info_fcb+modnum
and al,3fh ;same modnum?
jnz ranclose ; no
mov al,info_fcb+extnum
cmp al,cl
jnz $+5
jmp seekok1 ;extents equal
call compext
jnz ranclose
push cx
call get_dir_ext
pop cx
cmp al,cl ;is dir_ext < new extent?
jnb rseek2 ;no
test high_ext,80h ;is open mode unlocked?
jnz rseek2 ;yes
pop dx! push dx ;dl = read/write flag
inc dl ;is this a write fx?
jnz rseek2 ;yes
inc dl ;reset z flag
pop dx ;discard read/write flag
jmp set_lret1 ;lret=1, reading unwritten data
rseek2:
mov info_fcb+extnum,cl ;fcb(ex) = new extent
mov cl,al
call restore_rc
call set_rc
jmps seekok1
ranclose:
push cx ;save seek ext# and mod#
call close ;current extent closed
pop cx ;recall ext# and mod#
mov bl,3 ;cannot close error #3
mov al,lret
inc al
jz seekerr
rseek3:
mov xdcnt,0ffffh ;reset xdcnt for make
if BMPM
mov byte ptr sdcnt+1,0ffh
endif
xchg info_fcb+extnum,cl ;fcb(extnum)=ext#
mov al,info_fcb+modnum
xchg ch,al
push cx ;save CL=extent and CH=module
and ch,40h ;copy file write flag
or al,ch
mov info_fcb+modnum,al ;fcb(modnum)=mod#
call open ;is the file present?
mov al,lret
inc al
jnz seekok ;open successful?
;cannot open file, read mode?
mov bp,sp ;CL = r/w flag (=0ffh if read)
mov cx,2[bp] ;everyone expects this
;item stacked
mov bl,4 ;seek to unwritten extent #4
inc cl ;becomes 00 if read operation
jz badseek ;error if read operation
;write, make new extent
call make
mov bl,5 ;cannot create new extent #5
mov al,lret
inc al
jz badseek ;no dir space
;file make successful
if BMPM
call fix_olist_item
endif
seekok:
pop cx ;discard ext and mod
if BMPM
mov comp_fcb_cks,true
endif
if BCPM
call set_lsn
endif
seekok1:
pop cx ;discard r/w flag
xor al,al
jmp set_lret ;with Z flag set
badseek: ;restore fcb(ext) and fcb(mod)
pop ax ;AL = extent, AH = module
mov info_fcb+extnum,al
mov info_fcb+modnum,ah
seekerr:
pop cx ;discard r/w flag
mov lret,bl ;lret=#
or bl,bl ;Z flag reset
ret
if BMPM
test_disk_fcb:
;-------------
; exit: Z flag reset if file opened in unlock mode and
; access of dir fcb was successful
test high_ext,80h ;was file opened in unlocked mode
jz ret13a ;no
test dont_close,0ffh ;return if dont_close false
jz ret13a
call close1 ;fcb in memory
test_disk_fcb1:
mov bx,offset lret
cmp b[bx],0ffh
jne not_err
pop si ;discard return address
mov al,11 ;unallocated block verify error
mov lock_shell,false ;in case called from check_rec
jmp set_lret ;error - close operation unsuccessful
not_err:
mov b[bx],0 ;lret = 0
mov al,info_fcb+reccnt
mov rcount,al
xor al,al
mov dont_close,al ;dont_close = false
inc al ;successful operation, reset zero flag
ret13a: ret
endif
CHECK_NPRS:
;----------
; DIR_CNT CONTAINS THE NUMBER OF 128 BYTE RECORDS
; TO TRANSFER DIRECTLY. THIS ROUTINE SET DIR_CNT
; WHEN INITIATING A SEQUENCE OF DIRECT PHYSICAL I/O
; OPERATIONS. DIR_CNT IS DECREMENTED EACH TIME CHECK_NPRS
; IS CALLED DURING SUCH A SEQUENCE.
; exit: ~C FLG & ~Z FLG - DIRECT PHYSICAL I/O OPERATION
; ~C FLG & Z FLG - INDIRECT(DEBLOCK) I/O OPERATION
; C FLG - NO PHYSICAL I/O OPERATION
MOV CH,blk_off ;CH = VRECORD & BLKMSK
MOV AL,DIR_CNT
CMP AL,2 ;IS DIR_CNT > 1?
JC CHECK_NPR1 ;NO
DEC AL ;DIR_CNT = DIR_CNT - 1
MOV DIR_CNT,AL ;we are in mid-multi sector i/o
STC
ret ;RETURN WITH C FLAG SET
CHECK_NPR1:
MOV AL,PHYMSK ;CL = PHYMSK
MOV CL,AL
AND AL,CH ;AL = VRECORD & PHYMSK
;ARE WE IN MID-PHYSICAL RECORD?
JZ CHECK_NPR11 ;NO
CHECK_NPR1X:
OR CL,CL ;IS PHYMSK = 0?
JZ CHECK_NPR1Y ;YES
XOR AL,AL ;RETURN WITH Z FLAG SET & C FLAG RESET
RET
CHECK_NPR1Y:
OR AL,1 ;RESET C & Z FLAGS
RET
CHECK_NPR11:
MOV DH,CL
not DH ;DH = ~ PHYMSK
MOV AL,MULT_NUM
CMP AL,2 ;IS MULT_NUM < 2?
JC CHECK_NPR1X ;YES
TEST HIGH_EXT,80H ;WAS FILE OPENED IN UNLOCKED MODE?
JNZ CHECK_NPR1X ;YES
CMP FX_INTRN,FXI40 ;DOES FX = F_WRITEZF?
JE CHECK_NPR1X ;YES
MOV BX,OFFSET VRECORD
MOV AH,[BX] ;AH = VRECORD
ADD AL,ah
CMP AL,80H
JC CHECK_NPR2
MOV AL,80H
CHECK_NPR2: ;AL = MIN(VRECORD + MULT_NUM,80H) = X
PUSH CX ;SAVE VRECORD & BLKMSK, PHYMSK
MOV B[BX],7FH ;VRECORD = 7F
PUSH BX! PUSH AX
MOV BL,AL ;BL = X
MOV AL,BLKMSK
MOV DL,AL
INC DL ;DL = BLKMSK + 1
not AL
AND AH,AL ;AH = VRECORD & ~BLKMSK
TEST RMF,0FFH ;READ FUNCTION?
JZ CHECK_NPR21 ;NO
MOV AL,RCOUNT
AND AL,DH ;AL = RCOUNT & ~PHYMSK
CMP AL,BL ;IS AL < X?
JC CHECK_NPR23 ;YES
CHECK_NPR21:
MOV AL,BL ;AL = MIN(VRECORD + MULT_NUM,80H) = X
CHECK_NPR23:
SUB AL,AH ;AL = AL - VRECORD & ~BLKMSK
CMP AL,DL ;IS AL < BLKMSK + 1?
JC CHECK_NPR9 ;YES
PUSH AX ;AL = MAX # OF RECORDS
CALL DMPOSITION ;COMPUTE MAXIMUM DISK POSITION
MOV CH,AL ;CH = MAX DISK POS
MOV AL,DMINX ;AL = CURRENT DISK POS
CMP AL,CH ;IS CURR POS = MAX POS?
MOV DL,AL
JZ CHECK_NPR5 ;YES
MOV CL,AL
PUSH CX ;CL = CURR POS, CH = MAX POS
MOV CH,0
CALL GETDM ;BX = BLOCK NUMBER (CURR POS)
CHECK_NPR4:
PUSH BX
INC CX ;CURR POS = CURR POS + 1
CALL GETDM ;GET NEXT BLOCK(CURR POS)
POP DX
INC DX
CMP BX,DX ;DOES CURR BLK = LAST BLK + 1?
JZ CHECK_NPR4 ;YES
test rmf,0ffh ;write function?
jnz check_npr45 ; no
or bx,bx! jnz check_npr45 ;does curr blk = 0?
cmp dx,maxall ;is last blk + 1 >= max alloc blk
jae check_npr45 ; yes
push cx! push dx
mov cx,dx
call getallocbit
pop bx! pop cx
shr al,1! jnc check_npr4 ;if blk not allocated it will be
check_npr45:
DEC CL ;CL = INDEX OF LAST SEQ BLK
POP DX
MOV AL,DH ;AL = MAX POS
CMP AL,CL ;IS AL < LAST SEQ BLK POS
JC CHECK_NPR5 ;YES
MOV AL,CL
CHECK_NPR5: ;AL = LAST BLK POS
SUB AL,DL ;AL = AL - STARTING POS
MOV CH,AL
INC CH ;CH = # OF CONSECUTIVE BLOCKS
MOV AL,BLKMSK
INC AL ;AL = BLKMSK + 1
MUL CH ;AL = # OF CONSECUTIVE LOGICAL RECS
POP CX ;CL = MAXIMUM # OF RECORDS
XCHG AL,CL
TEST RMF,0FFH ;READ FUNCTION?
JZ CHECK_NPR8 ;NO
CMP AL,CL ;IS MAX < # OF CONS. RECS?
JC CHECK_NPR9 ;YES
CHECK_NPR8:
MOV AL,CL
CHECK_NPR9: ;AL = # OF CONSECUTIVE RECS
POP CX
POP BX
MOV [BX],CH ;RESTORE VRECORD
POP CX
MOV DH,MULT_NUM
SUB AL,CH ;AL = AL - VRECORD & blkmsk
CMP AL,DH ;IS AL < MULT_NUM
JC CHECK_NPR10 ;YES
MOV AL,DH
CHECK_NPR10: ;AL = # OF CONSECUTIVE RECS
not CL
AND AL,CL ;IF DIR_CNT = 0 THEN
JZ RET13B ;RETURN WITH Z FLAG SET, C FLAG RESET
MOV DIR_CNT,AL ;DIR_CNT = AL & ~PHYMSK
TEST RMF,0FFH ;READ FUNCTION?
JZ CHECK_NPR10X ;NO
PUSH AX
CALL flushx ;FLUSH BLOCKING/DEBLOCKING
POP AX ;BUFFERS FOR DRIVE
CHECK_NPR10X:
MOV CL,PHYSHF
SHR AL,CL ;AL = # OF CONSECUTIVE PHYSICAL RECS
mov mult_sec,al ;save multisector count for r/w
OR AL,1 ;RETURN WITH C AND Z FLAGS RESET
RET13B: RET
diskread: ;enter here for sequential and random disk reads
;--------
call tst_inv_fcb ;verify fcb has not been flagged
mov al,true ;as invalid
mov rmf,al ;read mode flag =
;true (open$reel)
;read the next record from
;the current fcb
if BMPM
mov dont_close,al
endif
call getfcb ;sets parameters for the read
disk_read0:
mov al,vrecord
cmp al,rcount ;vrecord-rcount
;skip if rcount > vrecord
jb recordok
if BMPM
; if fcb was opened in unlocked mode, check the directory fcb
; to make sure another process has not allocated a block to
; the fcb since this process opened the fcb
call test_disk_fcb ;jump back to disk_read0 if dont_close
jnz disk_read0 ;true, file opened in unlocked mode,
;and access of dir fcb successful
;dont_close set to false
mov al,vrecord
endif
;not enough records in extent
;record count must be 128
;to continue
cmp al,128 ;vrecord = 128?
jnz diskeof ;skip if vrecord<>128
call openreel ;go to next extent if so
;now check for open ok
cmp lret,0 ;stop at eof
jnz diskeof
recordok: ;fcb addresses a record to read
call index ;error 2 if reading
;unwritten data
;(returns 1 to be compatible
;with 1.4)
;arecord=0000?
if BMPM
jnz recordok1
call test_disk_fcb ;jump back to disk_read0 if dont_close
jnz disk_read0 ;true, file opened in unlocked mode,
;and access of dir fcb successful
endif
jz diskeof
recordok1: ;record has been allocated, read it
if BMPM
call test_lock ;check if record locked by another
endif
call atran ;arecord now a disk address
CALL CHECK_NPRS
JC RECORDOK2
JNZ $+5
JMP READ_DEBLOCK
CALL SETDATA
call seek ;to proper track,sector
call rdbuff ;to dma address
RECORDOK2:
jmp setfcb ;replace parameter
diskeof:
jmp set_lret1 ;lret = 1
;ret
init_wzf: ;F_WRITEZF physical record initialization routine
;--------
MOV AL,PHYMSK
INC AL
XOR AH,AH
PUSH AX ;AX = PHYMSK + 1
xchg al,ah
shr ax,1 ;times 128
mov cx,ax ;CX = # OF BYTES IN PHY RECORD
MOV di,DIR_BCBA
sub di,12
FILL00:
mov di,12[di]
cmp word ptr 12[di],0 ;check if last bcb
JNZ FILL00 ;BX = OLDEST DIRECTORY BCB
MOV b[di],0ffh ;BCB(0) = 0FFH, DISCARD BCB
mov di,10[di]
mov cur_dma,di
mov cur_dma_seg,ds
XOR AL,AL ;ZERO PHYSICAL RECORD BUFFER
REP STOS AL
pop ax
ret
diskwrite: ;enter here for sequential and random disk writes
;---------
mov rmf,false ;read mode flag
;write record to currently
;selected file
call checkwrite ;in case write protected
mov al,info_fcb+modnum
rcl al,1! not al
test xfcb_read_only,al ;read/only error if xfcb_read_only true
mov ah,3 ;xfcb_read_only true if file is
jz $+5 ;password protected in write mode
;and password was not supplied
;when the file was opened.
jmp_set_aret:
jmp set_aret
test high_ext,40h ;read/only error if fcb opened
jnz jmp_set_aret ;in read/only mode
mov bx,offset info_fcb ;bx = .fcb(0)
call ckrofile ;may be a read-only file
call tst_inv_fcb ;test for valid fcb
call update_stamp
call getfcb ;to set local parameters
mov al,vrecord
cmp al,lstrec+1 ;vrecord-128
;skip if vrecord > lstrec
;vrecord = 128, cannot open
;next extent
jb dskwr0
call openreel ;try to open next extent
test lret,true
jz dskwr0
ret
dskwr0:
if BMPM
mov dont_close,true
;if file is opened unlocked,
call test_lock ; verify record is not locked
; by another process
disk_write1:
endif
call index
JZ DISK_WRITE2
mov cl,0 ;marked as normal write
;operation for wrbuff
jmps dskwr1
disk_write2:
if BMPM
call test_disk_fcb ;jump back to disk_write1 if
;dont_close is true, file was opened
;in unlocked mode, and access of
;dir fcb was successful
jnz disk_write1
endif
; not allocated:
; the argument to getblock is the starting
; position for the disk search, and should be
; the last allocated block for this file, or
; the value 0 if no space has been allocated
call dmposition
mov dminx,al ;save for later
xor cx,cx ;may use block zero
or al,al
jz nopblock ;skip if no previous block
;previous block exists at a
mov cl,al
dec cx
call getdm ;previous block # to bx
mov cx,bx ;cx=prev block#
nopblock:
;cx = 0, or previous block #
call getblock ;block # to bx
;arrive with block# or zero
or bx,bx
jnz blockok
;cannot find block to allocate
mov al,2
jmp set_lret ;lret=2
blockok:
if BMPM
mov comp_fcb_cks,true ;must recompute fcb checksum
endif
mov arecord,bx ;bx contains allocated block #
mov dx,bx ;place unallocated block in
call ua_setup ; list for pre read check
;block number in dx preserved
mov bx,offset info_fcb+dskmap ;bx=.fcb(diskmap)
cmp single,0 ;set flags for single byte dm
mov al,dminx ;recall dm index
mov ah,0
jz allocwd ;skip if allocating word
;allocating a byte value
add bx,ax
mov [bx],dl ;single byte alloc
jmps dskwru ;to continue
allocwd:
add bx,ax ;allocate a word value
add bx,ax ;bx=.fcb(dminx*2)
mov [bx],dx ;double wd
inc bx
dskwru: ;disk write to previously unallocated block
mov cl,2 ;marked as unallocated write
dskwr1: ;continue the write operation of no allocation error
;c = 0 if normal write, 2 if to prev unalloc block
mov wflag,cl ;save the write flag
call atran ;arecord set
diskwr10:
cmp fx_intrn,fxi40 ;check random with 0 fill
jnz dskw11
; this is random write with zero fill
cmp wflag,2 ;check for new allocation
jnz dskw11 ;old allocation
; new alloction for random with zero fill
MOV WFLAG,0 ;RESET WRITE FLAG
PUSH arecord ;SAVE ARECORD
call init_wzf
push ax ;AX = phymsk + 1
mov cl,blkmsk ;set high water mark for
call ua_preread ; pre read check
MOV ax,ARECORD1
MOV CL,2 ;SET WRITE FLAG
FILL2:
MOV ARECORD,ax
PUSH CX
call discard_data
CALL SEEK
POP CX
CALL WRBUFF
MOV ax,ARECORD ;ARECORD = ARECORD + PHYMSK + 1
POP bx
PUSH bx
ADD ax,bx
MOV bl,BLKMSK ;END OF BLOCK?
AND bl,al
MOV CL,0
JNZ FILL2 ;NO
POP BX
POP ARECORD ;RESTORE ARECORD
dskw11:
CALL CHECK_NPRS
JC DONT_WRITE
JNZ WRITE
MOV AH,2
CALL DEBLOCK_DTA
jmps write_done
WRITE:
CALL SETDATA
call seek ;to proper file position
call discard_data
mov cl,blk_off ;set high water mark for
call ua_preread ; preread check
MOV CL,WFLAG ;(cl=2 if new block,0 if not)
;set wflag to zero if blk_off
cmp blk_off,0 ;does not specify 1st record of
JZ WRITE0 ;new block
MOV CL,0
WRITE0:
call wrbuff ;written to disk
;inc rec count if rcount <= vrecord
jmps write_done
dont_write:
call discard_data ;discard existing block for phys write
write_done:
mov al,vrecord
mov bx,offset rcount
cmp al,[bx] ;vrecord-rcount
jb dskwr2
;rcount <= vrecord
mov [bx],al
inc b[bx] ;rcount = vrecord+1
if BMPM
;disabling extention of reccnt to block size for unlocked files
test high_ext,00h
jz write1
; for unlocked file
; rcount = vrecord & (~ blkmsk) + blkmsk + 1
mov ch,blkmsk
mov cl,ch
not cl
inc ch
and al,cl
add al,ch
mov [bx],al
write1:
endif
mov wflag,2 ;mark as record count
;incremented
dskwr2:
cmp wflag,2 ;wflag=2 if new block or new record #
jnz noupdate
and info_fcb+modnum,not fwfmsk
if BMPM
test high_ext,80h ;is file open mode unlocked?
jz dskwr2a
mov al,[bx]
mov info_fcb+reccnt,al ;restore fcb(rcount)
cmp mult_cnt,1
jne dskwr2a
call close
call test_disk_fcb1
dskwr2a:
endif
noupdate:
call getmodnum ;set file write flag if reset
and al,40h
jnz dskwr3
or b[bx],40h
and info_fcb+modnum,not fwfmsk ;reset fcb write flag to ensure
;t3' gets reset by the close function
dskwr3:
jmp setfcb ;replace parameters
;ret
compute_rr: ;compute random record position for getfilesize/setrandom
;----------
; entry: BX = offset of fcb
; DX = index into fcb to pick record no. from
; exit: AL,CX = random record number
; BX = offset of fcb
xchg bx,dx
add bx,dx
;dx=.buf(dptr) or .fcb(0),
;bx=.f(nxtrec/reccnt)
mov cl,[bx] ;pick up record no.
xor ch,ch ;cx = 0000 0000 ?rrr rrrr
mov bx,dx
mov ah,extnum[bx]
shr ax,1
and ax,0f80h
add cx,ax ;cx = 000? eeee errrr rrrr
mov al,modnum[bx] ;al = xxmm mmmm
and al,3fh
mov ah,16
mul ah ;ax = 0000 00mm mmmm 0000
add ch,al
;cx = mmmm eeee errr rrrr
mov al,0
adc al,ah ;al = 0000 0?mm
ret19: ret
compare_rr: ;compare dir to fcb random records
;----------
; entry: AL,CX = directory random record #
; exit: C flag set
; BX = .fcb(rndrec)
mov bx,offset info_fcb+ranrec
cmp al,2[bx]! jne ret19
cmp cx,[bx] ;carry if .fcb(ranrec) >
ret ;directory
selectdisk:
;----------
; select the disk drive given in AL, and fill
; the base addresses curtrka - alloca, then fill
; the values of the disk parameter block
; entry: AL = disk to select
; exit: C flag set if no error
push dx
mov cl,al ;current disk# to CL
;lsb of DL = 0 if not yet
mov al,io_seldsk ;logged in
call xiosif ;BX filled by call
pop dx ;BX = 0000 if error,
or bx,bx ;otherwise disk headers
jz ret19 ;rz - carry flag reset
inc bx! inc bx
mov cdrmaxa,bx
inc bx! inc bx
mov drvlbla,bx ;media flag = drv lbl + 1
add bx,4 ;lsn_add = drvlbl + 2
mov si,bx
MOV di,offset dpbaddr ;SI= source for move, DI=dest
mov cx,addlist ;addlist filled
rep movsb ;now fill the disk
mov si,dpbaddr ;parameter block
if PCMODE
lodsw
cmp ax,0FFFFh ! jne cpm_format ;if format is PC-DOS
add dpbaddr,(pclist + 2 - dpblist) ;DPBADDR -> CPM DPB
mov di,offset nfats
mov cx,pclist
rep movsb ;copy extended DPB to local area
test dl,1 ! jnz loggedin ;if disk is not logged in
push ax
call get_fat ;read FAT into hash table area
pop ax
or bx,bx ! jz ret4
loggedin:
mov al,1 ; PC-DOS media format
jmps sel_exit
cpm_format:
mov di,offset sectpt ;DI is destination
stosw
mov cx,dpblist-2
rep movsb ;copy in CP/M DPB
xor al,al ; CP/M media format
sel_exit:
mov media_format,al
else
mov di,offset sectpt ;DI is destination
mov cx,dpblist
rep movsb ;copy in CP/M DPB
endif
;set single/double map mode
mov al,byte ptr maxall+1 ;largest allocation number
or al,al
jz retselect ;if high order of maxall not
mov al,1 ;zero then use double disk map
retselect:
dec al
mov single,al ;true if single disk map mode
stc ;select disk function ok
ret4:
ret
if PCMODE
get_fat:
;-------
; Exit: BX = 0 if no fats could be read
mov ax,fatadd ;AX = phys record offset of first FAT
mov cx,nfats ;get number of FATs for error retries
get_fat1:
push ax ! push cx
xor dx,dx ;convert FAT record offset to
div sectpt ;sectors and tracks for I/O system
mov track,ax
mov sector,dx
mov al,byte ptr nfatrecs
mov mult_sec,al ;multi sector count = # FAT records
mov ax,hash_seg
mov cur_dma_seg,ax ;read FAT into hash table area
mov cur_dma,0
mov al,IO_READ
call rwxiosif ;call I/O system to read FAT
mov bx,1
pop cx ! pop dx
or al,al ! jz get_fat2 ;if an error occured during the read
mov ax,nfatrecs ; try reading the next FAT
add ax,dx
loop get_fat1
xor bx,bx ;could'nt read any of the FAT's
get_fat2:
ret
update_fat:
;----------
mov ax,fatadd ;AX = save physical record offset
; of first FAT
mov cx,nfats ;get number of FATs to update
xor bx,bx
update_fat1:
push ax ! push bx ! push cx
xor dx,dx ;convert FAT record offset to
div sectpt ;sectors and tracks for I/O system
mov track,ax
mov sector,dx
mov al,byte ptr nfatrecs
mov mult_sec,al ;multi sector count = # FAT records
mov ax,hash_seg
mov cur_dma_seg,ax ;write FAT in hash table area
mov cur_dma,0
mov al,IO_WRITE
call rwxiosif ;call I/O system to write FAT
pop cx ! pop bx
or bx,ax ;save error code
pop ax
add ax,nfatrecs ;write the next FAT
loop update_fat1
mov al,bl
mov ah,true
jmp diocomp
endif
disk_select:
;-----------
; entry: AL = disk to select
; exit: Z flag set if drive logged in
mov adrive,al
disk_select1:
mov curdsk,al
mov dx,dlog
call test_vector ;dl = 1 if drive logged in
push dx ;save it for test below, send to seldsk
call selectdisk
pop bx ;recall dlog vector
jnc select0 ;carry set if select ok
dec bl ;is the disk logged in?
ret
tmp_select:
;----------
; entry: DL = drive to select (0-f)
mov seldsk,dl
curselect:
;---------
mov al,seldsk
cmp al,curdsk
jne select ;don't select if seldsk = curdsk
inc al! jz select0
ret19a: ret
SELECT: ;select disk in info_fcb for subsequent input or output ops
;------
cmp al,16 ! jb sel0
select0:
jmp selerror
sel0:
call disk_select
jz ret19a ;rz
;return if bit is set
if PCMODE
cmp media_format,0
jne sel_pc
call initialize ;disk not logged in,
jmps sel1
sel_pc:
call initialize_pc
sel1: ;set bit and initialize
else
call initialize ;disk not logged in,
endif
mov bx,offset dlog
call setcdisk ;dlog=set$cdisk(dlog)
cmp chksiz,8000h
je select2 ;drive is permanent
mov bx,offset rlog
call setcdisk ;rlog=setcdisk(rlog)
select2:
ret
reselectx:
;---------
xor al,al
mov high_ext,al
mov xfcb_read_only,al
jmps reselect1
reselect:
;--------
mov cx,807fh ;ch = 80h, cl = 7fh
mov bx,offset info_fcb+f7
mov al,[bx] ;if fcb(7) & 80h
and al,ch ;then xfcb_read_only = 80h
mov xfcb_read_only,al ;else xfcb_read_only = 00h
and [bx],cl ;fcb(7) = fcb(7) & 7fh
inc bx
mov al,[bx]
and al,cl ;fcb(8) = fcb(8) & 7fh
cmp al,[bx]
mov [bx],al ;if fcb(8) & 80h
mov al,60h ;then high_ext = 60h
jnz reselect0
mov al,4[bx] ;else high_ext = fcb(12) & e0h
and al,0e0h
reselect0:
mov high_ext,al
call clr_ext
reselect1: ;check current fcb to see if reselection necessary
mov resel,true ;mark possible reselect
mov al,info_fcb ;drive select code
mov fcbdsk,al ;save drive
and al,00011111b ;non zero is auto drive select
dec al ;drive code normalized to
;0...30, or 255
cmp al,0ffh
jz noselect ;auto select function,
mov seldsk,al ;save seldsk
noselect:
call curselect
;set user code
mov al,usrcode ;0...31
mov info_fcb,al
noselect0:
CALL TST_LOG_FXS ;IS FX = 15,17,22,23,30?
JNZ noselect1
mov rd_dir_flag,0f0h ; yes - must read directory to
noselect1:
call check_media ;chk media change on current disk
;jmps check_all_media ;chk media change on other disks
check_all_media:
;---------------
; This routine checks all logged-in drives for
; a set DPH media flag and pending buffers. It reads
; the directory for these drives to verify the media
; has not changed. If the media has changed the drive
; gets reset (but not relogged-in).
xor al,al
xchg media_flag,al ;reset SCB media flag
test al,al ;was SCB media flag set
jz ret20 ; no
mov bx,dlog ;test logged-in drives only
mov al,16
chk_am1:
dec al
shl bx,1! jnc chk_am5 ;is drive logged-in
push ax! push bx ; yes
call disk_select ;get DPH
mov bx,dat_bcba
mov bx,[bx]
chk_am2:
or bx,bx! jz chk_am4 ;end of bcb list?
test byte ptr 4[bx],0ffh ; no - is buffer pending
jnz chk_am3 ; yes
mov bx,12[bx] ;get next bcb
jmps chk_am2
chk_am3:
call check_media ;write pending, chk media change
chk_am4:
pop bx! pop ax
chk_am5:
or al,al! jnz chk_am1
jmp curselect
check_media: ;chk media if DPH media flag set
;-----------
mov bx,drvlbla
xor al,al
xchg 1[bx],al ;RESET MEDIA FLAG
or al,al ;was media flag set
JZ RET20 ;NO
;DISCARD DIRECTORY BUFFERS
CALL discard_dir ;READ DIRECTORY TO TEST FOR MEDIA
CALL SETENDDIR ;CHANGE
push dcnt ;save dcnt incase media hasnt changed
check_media1:
MOV CL,FALSE
CALL RDIR
xor al,al ;reset relog flag
xchg relog,al
test al,al ;HAS CHECKSUM ERROR BEEN DETECTED?
jz check_media2 ; no
cmp fx_intrn,fxi48 ;is func# = flush buffer
jz check_media3 ; yes
mov al,adrive ;is flush to another drive ?
cmp al,seldsk
jnz check_media3 ; yes
pop dcnt ;restore dcnt
call drv_relog
jmp chk_exit_fxs
check_media2:
CALL COMPCDR ;HAS DIR HIGH WATER MARK BEEN REACHED
jc check_media1 ; no
check_media3:
pop dcnt ;restore dcnt media has not changed
ret20: ret
copy_dma_in_8:
;-------------
mov cl,8
copy_dma_in: ;copy (cl) bytes from user's
;-----------
; entry: CL = number of bytes to copy
mov si,dma_ofst ;dma to common_dma
mov di,offset common_dma
push ds
mov ds,dma_seg
xor ch,ch
rep movs al,al
pop ds
ret
get_dir_mode:
;------------
; exit: AL = directory label data byte
mov bx,drvlbla ;return dir lbl data byte in al
mov al,[bx]
ret
get_xfcb: ;get xfcb (search mode)
;--------
; exit: Z flag set if no xfcb exists
; BX = .xfcb(pwmode)
; DX = .xfcb(0)
; AL = pwmode + 1
mov bx,offset info_fcb
mov al,[bx]
push ax
or b[bx],10h ;fcb(0) = fcb(0) | 10h
call search_ext ;returns with zero flag set if
pop ax ; xfcb not found
mov info_fcb,al ;restore fcb(0)
mov lret,0 ;zero lret
jnz get_xfcb1
ret ;xfcb not found - al = 0, zflag set
get_xfcb1:
call get_dptra ;get directory pointer
mov dx,bx ;DX = .directory_xfcb(0)
add bx,extnum
mov al,[bx]
and al,0e0h
or al,1 ;al = xfcb(extnum) & 0e0h + 1
ret ;xfcb found, zero flag reset
init_xfcb:
;---------
call setcdr ;may have extended the directory
mov cx,1014h ;ch = 16, cl = 20
init_xfcb0: ;ch = fcb(0) logical or mask
;cl = zero count
push cx
call get_dptra ;does not use cx
mov si,offset info_fcb ;xfcb(0) = fcb(0) | ch
lodsb
or al,ch
mov [bx],al
inc bx
mov cl,11
mov dx,si
call move ;xfcb(1..11) = fcb(1..11)
mov dx,si ;dx = .fcb(12)
mov bx,di ;bx = .xfcb(12)
pop cx ;cl contains # of remaining bytes
sub ch,ch ;of xfcb to zero
xor al,al ;move sets di to addr of next char
rep stos al
ret
chk_pw_error:
;------------
mov byte ptr xdcnt+1,0 ;disable special searches
mov si,offset info_fcb
mov di,offset save_fcb ;save info_fcb
mov cx,16
rep movsb
call get_dptra
mov si,bx! inc si
mov di,offset info_fcb+1 ;info_fcb = dir_xfcb
mov cx,11
rep movsb
xor al,al! stos al ;fcb(extnum) = 0
inc di!stos al ;fcb(modnum) = 0
lods al ;save password mode
mov pw_mode,al
call search_name ;does fcb(ext=0,mod=0) exist
jz chk_pwe2 ; no
call get_dtba8 ;does sfcb exist
or al,al! jnz chk_pwe1 ; no
mov si,offset pw_mode
mov ch,[si] ;CH = xfcb.pwmode
mov al,[bx] ;AL = sfcb.pwmode
mov [si],al ;pw_mode = sfcb.pwmode
or al,al! jz chk_pwe2 ;is sfcb password mode nonzero
xor al,ch! and al,0e0h ; yes
jz chk_pwe1 ;do password modes match
call get_xfcb ; no - update xfcb
jz chk_pwe1 ;error - no xfcb
mov al,pw_mode
mov [bx],al ;xfcb.pwmode = sfcb.pwmode
call nowrite
jnz chk_pwe1
call wrdir
chk_pwe1:
call chk_pwe3
mov al,fx_intrn ;is func# = open or make?
cmp al,fxi15! je ret20a
cmp al,fxi22! je ret20a
pw_error: ; no
mov ah,7 ;password error
jmp set_aret
chk_pwe2:
mov pw_mode,0
call nowrite ;delete unused xfcb
jnz chk_pwe3
call get_xfcb ;get xfcb
jz chk_pwe3 ; it should have been there
or info_fcb,10h
call delete11 ;delete xfcb
chk_pwe3:
mov si,offset save_fcb
mov di,offset info_fcb ;restore info_fcb
mov cx,16
rep movsb
ret20a: ret
chk_password:
;------------
call get_dir_mode ;al = dir lbl data byte
and al,80h
jz ret20a ;bit 0 on => passwords active
call get_xfcb ;al = xfcb password mode | 01h
jz ret20a ;zero set if no xfcb found
cmp_pw: ;compare passwords
;------
; entry: BX = .xfcb(12)
; exit: Z flag set if password is valid
inc bx
mov ch,[bx] ;fcb(13) = xfcb checksum
or ch,ch
jnz cmp_pw2 ;jump if xfcb(13) ~= 0
mov si,bx ;save bx
add si,3 ;because xfcb checksum is zero
;test for null password
mov cl,9 ;null passwords are all blanks and/or
cmp_pw1: ;zeros that sum to zero
lodsb ;any password matches a null password
dec cl
jz ret20a ;password is all blanks and/or zeros
or al,al
jz cmp_pw1
cmp al,20h
jz cmp_pw1 ;password contains a value other
;than blank or zero
cmp_pw2: ;bx = .xfcb(13)
lea si,10[bx]
lea dx,3[bx] ;dx = .xfcb(16)
mov bx,offset common_dma
mov cl,8
std ;lods decrements si
cmp_pw3:
lods al
xor al,ch ;exclusive or password byte with cks
cmp al,[bx]
jnz cmp_pw4 ;password mismatch
inc bx
dec cl
jnz cmp_pw3
cld
ret ;password matches
cmp_pw4:
cld
mov bx,offset df_password ;compare xfcb password to default pw
mov cl,8 ;bx = .default pw, dx = .xfcb password
jmp compare
chk_xfcb_password:
;-----------------
; exit: BX = .xfcb(12)
call get_xfcb1 ;access xfcb in directory buffer
;al = (xfcb(ext) & e0h) | 1
chk_xfcb_password1:
push bx ;bx = .xfcb(ex)
call cmp_pw ;check password
pop bx
ret ;return with bx = .xfcb(ex)
set_pw: ;set password in xfcb
;------
; entry: BX = .xfcb(12)
; SI = .password in common dma area
mov cx,8 ;ch = 0, cl = 8
lea di,11[bx] ;di = .xfcb(23)
set_pw0:
sub ah,ah ;zero null password flag
set_pw1:
lodsb
mov [di],al ;copy password char to xfcb
or al,al ;is password char zero?
jz set_pw2 ;yes
cmp al,20h ;is password char blank?
je set_pw2 ;yes
inc ah ;password is not null
set_pw2:
add ch,al ;add password char to xfcb chksum
dec di
dec cl
jnz set_pw1
or ah,ch ;if (ah | ch) = 0 then password is null
jnz set_pw3
mov [bx],ah ;xfcb(ex) = 0, zero password mode
set_pw3:
inc di
mov cl,8
set_pw4:
xor [di],ch ;encrypt password chars in xfcb
inc di
dec cl
jnz set_pw4
mov 1[bx],ch ;bx + 1 = .xfcb(13)
ret ;ch = xfcb pasword checksum
get_dtba8: ;get password mode address
;---------
mov ch,8
GET_DTBA: ;GET STAMP ADDRESS IN SFCB
;--------
; entry: CH = offset into sfcb
; exit: BX = address of offset into sfcb
MOV AL,3 ;RET WITH AL ~= 0 IF STAMP CANNOT
mov ah,byte ptr dcnt ;BE MADE
and ah,dskmsk
CMP AL,AH ;IS LRET = 3? (SFCB POSITION)
JZ RET21A ;YES
mov bx,buffa
add bx,96
MOV AL,[BX]
SUB AL,21H ;DOES DIR FCB(3) BEGIN WITH 21H?
JNZ RET21A ;NO
MOV AL,ah
MOV CL,10
MUL CL ;AL = LRET*10
INC AL ; + 1
ADD AL,CH ; + CH
ADD BX,AX ;RETURN WITH BX = STAMP ADDR
xor al,al
RET21A:
RET
QDIRFCB1:
;--------
; exit: Z flag reset if fcb is first dir fcb of file
; CL = preserved
mov bx,offset info_fcb+extnum ;IS FCB IN 1ST DIR FCB OF FILE?
MOV AL,[BX]
mov ah,extmsk
not ah
and al,ah
and al,01fh
JNZ RET21A ;NO
TEST BYTE PTR 2[BX],3FH ;IS FCB(MOD) = 0?
RET ;Z FLAG RESET IF NOT
QSTAMP:
;------
; exit: Z flag reset if stamp is requested
CALL QDIRFCB1 ;IS FCB IN 1ST DIR FCB OF FILE?
JNZ RET21A ;NO
QSTAMP1:
call get_dir_mode ;ARE REQUIRED DIR LBL OPTIONS SET?
and al,cl! jz $+5 ; NO
JMP NOWRITE ; yes - VERIFY DISK NOT READ/ONLY
inc al ;return z flag reset
ret
stamp1:
;------
MOV CH,0
jmps stamp3
stamp2:
;------
MOV CH,4
stamp3:
;------
; entry: CH = stamp offset
CALL GET_DTBA ;GET STAMP ADDRESS
OR AL,AL
JNZ ret21a ;NON-ZERO - CAN'T STAMP
STAMP4:
mov dx,offset tod
stamp45:
MOV CL,4
PUSH BX! PUSH DX
CALL COMPARE ;COMPARE EXISTING STAMP TO NEW STAMP
POP DX! POP BX
jz ret21a ;EQUAL - SKIP CALL TO WRDIR
MOV CL,4
call move
jmp wrdir
STAMP5: ;DIR LBL STAMP ENTRY
;------
; entry: CX = stamp offset
CALL GET_DPTRA
ADD BX,CX
MOV AX,OFFSET FUNCRET
PUSH AX
jmps STAMP4
update_stamp:
;------------
mov cl,20h ;is update stamp requested
call qstamp1 ; on drive
jnz ret21a ; no
test info_fcb+modnum,40h ;has file been written to since
jnz ret21a ; it was opened
mov ah,info_fcb+extnum ; yes - search for first
mov al,info_fcb+modnum ; dir fcb
push ax ;save extnum and modnum
call search_1_name
jz $+5 ;perform update stamp
call stamp2 ; if 1st dir fcb found
mov lret,0
pop ax ;restore extnum and modnum
mov info_fcb+extnum,ah
mov info_fcb+modnum,al
ret
if BMPM
pack_sdcnt: ;packed_dcnt = sdcnt
;----------
mov ax,sdcnt
mov word ptr packed_dcnt,ax
mov byte ptr packed_dcnt+2,0
ret
;
; olist element:
; +------+------+------+------+------+------+
; 00h | LINK | ATTS | DCNT |
; +------+------+------+------+------+------+
; 06h | PDADDR | OPNCNT |
; +------+------+------+------+
;
; link = 0 -> end of list
;
; atts - 8x - open in locked mode
; 4x - open in unlocked mode
; 2x - open in read/only mode
; 1x - PC media function 116 update stamp flag
; xN - drive code (0-f)
;
; dcnt = packed sdcnt+sdblk
; pdaddr = process descriptor addr
; opncnt = # of open calls - # of close calls
; olist item freed by close when opncnt = 0
;
; llist element:
; +------+------+------+------+------+------+
; 00h | LINK | DRV | RECORD |
; +------+------+------+------+------+------+
; 06h | CNT | .OLISTITEM |
; +------+------+------+------+
;
; link = 0 -> end of list
;
; drive - 0x - Prevent Other Reads + Writes
; 8x - Prevent All Writes - allow reads if PAW locked
; xN - drive code (0-f)
;
; record = starting record number of locked records
; count = # of locked records starting at record
; .olist_item = address of file's olist item
;
search_olist:
;------------
mov bx,offset open_root! jmps search_listo
search_llist:
;------------
mov bx,offset lock_root! jmps search_listo
searchn_list:
;------------
mov bx,cur_pos
search_listo:
;------------
mov prv_pos,bx
;search_olist, search_llist, searchn_list conventions
;
; entry: CH = 0 -> return next item
; CH = 1 -> search for matching drive
; CH = 3 -> search for matching dcnt
; CH = 5 -> search for matching dcnt + pdaddr
;
; exit: Z flag set if found and
; prv_pos -> previous list element
; cur_pos -> found list element
; BX = cur_pos
; else prv_pos -> list element to insert after
;
; olist and llist are maintained in drive order
;
srch_list1:
mov bx,[bx]
or bx,bx! jnz srch_list2 ;if (end of list)
or al,1 ; return( NZ )
ret
srch_list2:
or ch,ch! je srch_list5
mov cl,2[bx]! and cl,0fh
mov si,offset curdsk
lods al
cmp al,cl! jne srch_list4 ;do drive # match?
cmp ch,1! je srch_list5 ; is search for matching drive only?
;SI = offset packed_dcnt
mov cl,ch
push cx
xor al,al
xchg al,5[bx] ;save f1' env switch
;set dcnt+2 to zero
xor ch,ch ;do items match?
lea di,3[bx] ;DI = offset item.dcnt
repe cmps al,al
mov 5[bx],al ;restore f1' env switch
pop cx
jz srch_list5
srch_list3:
mov prv_pos,bx ; no - check next item
jmps srch_list1
srch_list4:
jae srch_list3 ;no need to continue if curdsk < drv
srch_list5:
mov cur_pos,bx
ret
delete_item:
;-----------
; entry: BX = item to be deleted
pushf! cli
mov si,[bx]
mov di,prv_pos
mov cur_pos,di ;prv_pos.link = delete_item.link
mov [di],si
mov si,free_root
mov free_root,bx ;delete_item.link = previous free_root
mov [bx],si
popf
mov cl,2[bx]! and cl,0fh ;get drive of deleted entry
mov bx,offset open_root
chk_open1:
mov bx,[bx] ;do any open files
or bx,bx! jz chk_open2 ; exist on drive
mov al,2[bx]! and al,0fh
cmp al,cl
jne chk_open1
ret
chk_open2:
mov bx,offset open_vector ; no - zero drive bit
jmps remove_drive1 ; in open file vector
;ret
remove_drive:
;------------
mov cl,curdsk
remove_drive1: ;reset bit in vector at bx
;-------------
; entry: BX = address of vector
; CL = bit in vector to reset
mov ax,1! shl ax,cl
not ax! and [bx],ax
ret
remove_locks:
;------------
; entry: BX = offset of olist_item
; exit: BX = preserved
test byte ptr 2[bx],40h! jz retl25
push prv_pos
push bx
mov ax,offset lock_root
mov cur_pos,ax
remove_lock1:
mov ch,0
call searchn_list
jnz remove_lock2
pop dx! push dx
cmp 8[bx],dx
jnz remove_lock1
call delete_item
jmps remove_lock1
remove_lock2:
;
; **3.1M** Record locking patch
;
; remove item from list
;
pop ax ;AX = .olist
push ax
mov bx,offset name_root ;BX = .name_root
dl0:
;for(;;)
; {
mov si,[bx] ; SI = BX-> link 1st item
cmp 2[si],ax ; if (2[si] == .olist)
jnz dl1 ; {
mov di,[si] ; DI = SI->link 2nd item
mov ax,[di] ; link
mov [bx],ax ; BX->link = DI-> link new name_root
mov ax,free_root
mov [di],ax ; DI-> = free_root old free root
mov free_root,si ; free_root = SI new free root
jmps dl2
;
dl1:
mov bx,[si] ; BX-> next item
jmps dl0 ; }
dl2:
;
; **3.1M** End of record locking patch
;
pop bx! pop prv_pos
retl25:
ret
compare_pds:
;-----------
; exit: Z flag set if proccess descriptors match
mov ax,pdaddr
cmp 6[bx],ax
ret
tst_olist:
;---------
mov chk_olist_flag,false
jmps chk_olist0
chk_olist:
;---------
mov chk_olist_flag,true
chk_olist0:
mov ax,dcnt
mov sdcnt,ax
call pack_sdcnt! mov ch,3
call search_olist! jnz retl25
; if in compatibility mode f1', r/o mode is the default open mode
; otherwise default is locked mode. branch to openx06 if the open
; mode is not the default mode.
call get_cmp_mode
rol al,1! mov al,2[bx]
jnb chk_olist01
rol al,1! rol al,1
chk_olist01:
rol al,1! jnb chk_olist05
call compare_pds
jnz chk_olist05
; verify another process does not have the file open when
; the default open mode is r/o as a result of compatibility
; attribute f1' = 1.
call get_cmp_mode
rol al,1! jnb chk_olist02
mov ch,3! call searchn_list
jz chk_olist05
mov ch,3! call search_olist
chk_olist02:
test chk_olist_flag,true! jz retl1
; check to see if the lock list item is extended and if the interface
; attribute requesting that the lock item continue to be extended is
; set. if so, control is returned to the routine calling chk$olist and
; the lock item is retained. otherwise, the lock item is deleted and
; pd_cnt is incremented unless an extended lock was placed on the file.
cmp byte ptr 9[bx],0ffh
jne chk_olist07
test attributes,080h
js retl1
jmp delete_item
chk_olist05:
jmp openx06
chk_olist07:
call delete_item
inc_pdcnt:
;---------
mov al,pd_cnt
and al,0f0h
chk_olist1:
add al,16! jz chk_olist1
mov pd_cnt,al
retl1: ret
pr_term:
;-------
mov ax,offset open_root
mov cur_pos,ax
pr_term1:
mov ch,0
call searchn_list
jnz pr_term2
mov ax,pdaddr
cmp 6[bx],ax
jnz pr_term1
call remove_locks
call delete_item
jmps pr_term1
pr_term2:
call flush0
retl2: ret
flush_files:
;-----------
mov al,true
xchg flushed,al
test al,al! jnz retl2
flush_file0:
mov ax,offset open_root
mov cur_pos,ax
flush_file1:
mov ch,1
call searchn_list! jnz retl2
call remove_locks
call delete_item
jmps flush_file1
free_files:
;----------
; free_mode = 1 - remove curdsk files for process
; 0 - remove all files for process
mov ax,offset open_root
mov cur_pos,ax
free_files1:
mov ch,free_mode
call searchn_list
jnz retl2
mov ax,pdaddr
cmp 6[bx],ax
jnz free_files1
cmp word ptr 3[bx],0ffffh! jnz free_files2
cmp byte ptr 5[bx],0ffh! jz free_files3
free_files2:
mov incr_pdcnt,true
free_files3:
call remove_locks
call delete_item
jmps free_files1
create_item:
;-----------
; exit: BX = offset of new item if successful
; Z flag set if no free items
mov bx,free_root
or bx,bx! je retl2
mov cur_pos,bx ;free_root = free_root.link
mov si,[bx]! mov free_root,si
mov si,prv_pos! mov di,[si] ;create_item.link = prv_pos.link
mov [bx],di ;prv_pos.link = .create_item
mov [si],bx
ret
create_olist_item:
;-----------------
mov ch,1! call search_olist
call create_item
create_olist_item1:
mov al,curdsk
or al,attributes
mov 2[bx],al ; set drive and attributes
mov si,offset packed_dcnt
lea di,3[bx]
mov cx,5
rep movsb ;copy dcnt and pd_addr
xor ax,ax! stosw ;open_cnt = 0;
mov cl,curdsk
inc ax! shl ax,cl ;set curdsk bit in
or open_vector,ax ; open file vector
ret
create_llist_item:
;-----------------
; exit: BX = llist item address
; DI = offset l_item.rec
mov ch,1! call search_llist
call create_item
lea di,3[bx]
mov ax,file_id
mov 8[bx],ax
ret
count_opens:
;-----------
mov open_cnt,0
mov ax,offset open_root
mov cur_pos,ax
count_open1:
mov ch,0! call searchn_list
jnz count_open2
mov ax,pdaddr
cmp 6[bx],ax
jnz count_open1
inc open_cnt! jmps count_open1
count_open2:
mov al,open_cnt
sub al,open_max
retl3:
ret
check_free0:
check_free: ;check for required # of entries in free list
;----------
; entry: DL = required # of free entries
mov bx,offset free_root
xor dh,dh ;for (free_entries = 0;
check_free1:
mov bx,[bx]
or bx,bx! jz check_free2 ; (next_free_item ~= end_of_flist) &&
inc dh ; (free_entries < required_#);
cmp dh,dl! jb check_free1 ; free_entries++);
retl4:
ret
check_free2:
pop bx ;remove return address
mov al,14 ;(end_of_flist) return(error -
jmp set_lret ; no room in sys lock list);
move_arecord: ;packed_dcnt = arecord
;------------
mov dx,offset arecord
mov bx,offset packed_dcnt
mov cl,3! jmp move
chk_rec:
;-------
; exit: Z flag reset if unwritten data
call index
jz chk_rec1 ;error - unwritten data
mov al,vrecord
cmp al,rcount
jnb chk_rec1
xor al,al
ret
chk_rec1:
or al,1
ret
check_rec:
;---------
mov lock_sp,sp
mov lock_shell,true
if PCMODE
cmp media_format,0
je $+5
jmp pc_chkrec
endif
mov cl,true ;assume read operation for rseek
call rseek
mov lock_shell,false
call getfcb
test lret,0ffh
jnz retl6
; verify that the block has not been allocated by another
; process before returning error code 1 (reading unwritten data)
call chk_rec
jz retl6
mov dont_close,true
mov lock_shell,true
call test_disk_fcb
mov lock_shell,false
jz lock_err1 ;error - unwritten data
call chk_rec
jnz lock_err1
lock_err:
;--------
retl6:
ret
lock_err1:
jmp set_lret1
cmp_recs: ;compare l_item.rec(+l_item.cnt) and rand_rec(+mult_cnt)
;--------
; entry: SI = l_item.rec (1st record #) offset
; DI = rand_rec (2nd record #) offset
; CL = 00h - no counts added
; = 01h - add mult_cnt to rand_rec
; = 02h - add l_item.cnt to l_item.rec
; exit: Z,C flags set
; SI,DI = preserved
mov bl,[si]! mov ax,1[si] ;AX,BL = l_item.rec
mov bh,[di]! mov dx,1[di] ;DX,BH = rand_rec
test cl,02h! jz cmp_rec1
add bl,3[si]
adc ax,0 ;AX,BL = l_item.rec + l_item.cnt
cmp_rec1:
test cl,01h! jz cmp_rec2
add bh,mult_cnt
adc dx,0 ;DX,BH = rand_rec + mult_cnt
cmp_rec2:
cmp ax,dx! jne cmp_rec3
cmp bl,bh
cmp_rec3:
ret
srch_llist: ;search lock list for matching item
;----------
; exit: AL = 0ffh - end of llist
; = 0feh - incompatable lock type
; = 001h - complete overlap
; = 002h - subset overlap
; = 004h - pre partial overlap
; = 008h - post partial overlap
; BX = cur_pos if AL ~= 0ffh
; DI = o_item.pdaddr if AL ~= 0ffh
mov ch,1! call searchn_list ;search for matching drive
jz srch_l1 ;while(not_end_of_llist) and
mov al,0ffh
ret
srch_l1:
mov di,file_id ; if (file_id.dcnt == o_item.dcnt);
mov cx,3
mov si,8[bx] ; SI = o_item
add si,cx! add di,cx
repe cmpsb
jne srch_llist
lea si,3[bx] ; SI = l_item.rec
mov di,offset info_fcb+ranrec
;check for no overlap
mov cl,01h! call cmp_recs ;if (l_item.rec >=
jae srch_llist ; rand_rec + mult_cnt) or
mov cl,02h! call cmp_recs ; (l_item.rec + cnt <= rand_rec)
jbe srch_llist ; no_olap - search for next l_item
;check for complete overlap
mov cl,00h! call cmp_recs ;else if (l_item.rec >= rand_rec)
jnae srch_l3
mov cl,03h! call cmp_recs ; if (l_item.rec + cnt <=
jnbe srch_l2a ; rand_rec + mult_cnt)
mov al,01h ; srch_ret = complete_olap;
jmps srch_l4
srch_l2a: ; else ;(l_item.rec + cnt >
mov al,04h ; rand_rec + mult_cnt)
jmps srch_l4 ; srch_ret = pre_part_olap;
srch_l3:
;check for subset overlap
mov cl,03h ;else ;(l_item.rec < rand_rec)
call cmp_recs ; if (l_item.rec + cnt >
jna srch_l3a ; rand_rec + mult_cnt)
mov al,02h ; srch_ret = subset_olap;
jmps srch_l4
srch_l3a: ; else ;(l_item.rec + cnt <=
; rand_rec + mult_cnt)
mov al,08h ; srch_ret = post_part_olap;
srch_l4:
;check for incompatable lock type
mov bx,cur_pos ;BX = l_item;
mov si,8[bx] ;SI = o_item;
mov di,6[si] ;DI = o_item.pd_addr
cmp pdaddr,di ;if (o_item.pd_addr == pd_addr)
je srch_l7 ; return(srch_ret);
test attributes,80h
jz srch_l6 ;if (l_item.attrib ~= paw_lock) or
test byte ptr 2[bx],80h
jnz srch_l7 ; (request_type ~= paw_lock)
srch_l6:
mov al,0feh ; return(incompatable_lock_type);
srch_l7:
ret
;
;
; **3.1M** Patch for record locking
;
chk_name:
mov al,6[si] ;
cmp al,curdsk ;does SI ->drive = curdsk ?
jnz cn2a ;no
; cmp media_format,0 ;PC media ?
; jz cn2 ;no
; mov ax,4[si] ;is file in same directory - .chdblk
; mov bx,hdsaddr ;
; or bx,bx
; jz cn1
; mov bx,6[bx]
;cn1:
; cmp ax,bx
; jnz cn2a ;no
;cn2:
lea di,7[si] ;do first 3 chars pf name match
mov bx,offset info_fcb+1
mov cx,3
call namecmp ;
jnz cn2a ;no
mov cx,8
mov dx,si ;does rest of name match
mov si,[si] ; SI -> item2
lea di,2[si] ; DI -> olist item
call namecmp
jnz cn3 ;no
;
;name has matched
;
mov bx,dx ; BX -> item1
mov ax,2[bx] ; AX = file_id = .olist
mov file_id,ax ; set file id
mov es,uda_save
mov u_nameitem,bx ;save name item addr in UDA
push ds
pop es
ret
;
cn2a:
mov si,[si] ; SI -> item2
cn3:
mov si,[si] ;SI now points to next file is and name
ret
;
cn4:
mov bx,dx
ret
;
namecmp:
mov al,[di]
xor al,[bx]
inc bx
inc di
and al,7fh
loopz namecmp
ret
;
; **3.1M** End of patch for record locking
;
test_lock: ;check llist for records with an incompatable lock type
;---------
test high_ext,80h ;was file opened in unlocked mode?
jz retl7 ; no
;
; **3.1*** Record locking patch
;
cmp file_id,0 ;is file_id zero
jnz gf3 ;no
mov es,uda_save
mov si,u_nameitem ;is UDA nameitem addr zero
; mov es,ds
push ds
pop es
or si,si ;no
jz gf0
call chk_name ;does it match FCB
jz gf3 ;yes
gf0:
mov si,name_root ;no search name list
gf1:
or si,si
jnz gf2
pop bx
mov al,0bh
jmp set_lret
gf2:
call chk_name
jz gf3
jmps gf1
gf3:
;
; **3.1M** End of record locking patch
;
cmp fx_intrn,fxi22
jnb rand_op
call func36 ;set random record #
rand_op:
mov ax,offset lock_root
mov cur_pos,ax
test_lock1:
push word ptr mult_cnt
mov mult_cnt,1
call srch_llist ;while(not_end_of_llist);
pop word ptr mult_cnt
cmp al,0ffh! jne test_lock2
retl7:
ret ; return(no errors)
test_lock2:
cmp al,0feh ; if (incompatable_lock_type)
je test_lock3 ; return(error)
test rmf,true
jnz test_lock1 ; if (write) and
mov bx,cur_pos
test byte ptr 2[bx],80h ; (l_item.attrib == paw_lock)
jz test_lock1
test_lock3:
pop bx ; remove return address
mov al,8 ; return(error -
jmp set_lret ; locked by an other proccess);
lock: ;record lock or unlock
;----
mov cl,2
call copy_dma_in
call get_atts ;get & clear atts f5' - f8'
call check_fcb
test high_ext,80h ;if (open mode ~= unlocked)
jz retl7 ; yes - return ok
mov bx,word ptr common_dma
mov ax,pdaddr
cmp 6[bx],ax! jz lock01 ;if (olist.pd_addr ~= pdaddr)
mov al,13! jmp set_lret ; yes - invalid file id
lock01:
mov file_id,bx
test lock_unlock,true ;if (~lock_unlock)
jnz lock01a
test attributes,80h ; if (attributes && 80h)
jz lock01a
jmp remove_locks ; remove all locks
lock01a:
mov al,info_fcb+ranrec ;if (fcb(ranrec) > 3ffffh)
mov bx,word ptr info_fcb+ranrec+1
cmp bh,4 ; return with lret = 6
jae lock01b
mov ah,mult_cnt
dec ah
add al,ah ;if fcb(ranrec)+mult_cnt > 3ffffh
adc bx,0 ; return with lret = 6
cmp bh,4
jb lock01c
lock01b:
mov lret,6 ;error - random record #
ret ; out of range
lock01c:
;mov olap_type,0 ;olap_type = no_olap;
; check llist for records with an incompatable lock type
mov ax,offset lock_root
mov cur_pos,ax
lock02a:
call srch_llist ;while(not_end_of_llist);
cmp al,0ffh! je lock04a
cmp al,0feh! jne lock03a ; if (incompatable_lock_type)
test lock_unlock,true ; yes - if (lock)
jz lock02a
mov al,8! jmp set_lret ; yes - return(error -
; locked by an other proccess);
lock03a: ; else
cmp pdaddr,di ; if (o_item.pdaddr == pdaddr)
jne lock02a
or olap_type,al ; olap_type |= llist_ret;
jmps lock02a
lock04a:
;determine number of lock entries required by overlap type
mov bx,offset required_table ;CS over ride on table in const area
mov al,olap_type
xlat required_table ;AL = required_table[olap_type];
test lock_unlock,true
jnz lock05a ;if (unlock) &&
or al,al! jz lock05a ; (required_# ~= 0)
dec al ; required_#--;
lock05a:
;check if max entries / proccess will be exceeded
mov dx,file_id
mov cur_pos,offset lock_root
xor ah,ah ;lock_cnt = 0;
count_lock1:
mov ch,0
push ax! push dx
call searchn_list ;get next llist item
pop dx! pop ax
jnz count_lock2 ;while(not_end_of_llist)
cmp 8[bx],dx
jnz count_lock1 ; if (l_item.olist == file_id)
inc ah ; lock_cnt++;
jmps count_lock1
count_lock2:
mov dl,al ;DL = required #, for check_free
add al,ah! jb lock02 ;if (lock_max <
cmp lock_max,al! jae lock05 ; (lock_cnt + required_#))
lock02:
mov al,12! jmp set_lret ; return(error - lock limit exceeded);
lock05:
;check for required # of entries in free list
;
; 3.1M patch for deleting lock list item after all items used
;
;
; call check_free
;
;check for record in file if required
test lock_unlock,true
jz lock4 ;if (lock) &&
;
call check_free ;check for items only if locking
;
; end of 3.1M patch
;
test attributes,40h ; (lock_type == rec_required_in_file)
jnz lock4
mov ah,mult_cnt
lock2: ;for (i = 0; i < mult_cnt; i++);
push ax
call check_rec ; check_for_record(rand_rec + i);
pop ax
test lret,0ffh ; if (record_not_in_file)
jz $+5
jmp reset_rr ; return(error - unwritten data);
dec ah! jz lock4
call incr_rr! jmps lock2
lock4:
call reset_rr
;remove over lapping records from lock list
test olap_type,00Fh ;if (olap_type ~= no_olap)
jnz $+5
jmp lock08a
mov ax,offset lock_root
mov cur_pos,ax
lock06a:
call srch_llist
cmp al,0ffh! jne $+5 ; while(not_end_of_llist);
jmp lock08a
cmp pdaddr,di ; if (o_item.pdaddr == pdaddr)
jne lock06a
test al,01h ; if (llist_ret && complete_olap)
jz lock07a
call delete_item ; delete(cur_item);
jmps lock06a
lock07a: ; else
test al,04h ; if (llist_ret && pre_part_olap)
jz lock07b
mov ch,3[bx] ; l_item.cnt = (l_item.rec+cnt) -
add ch,6[bx] ; (rand_rec+mult_cnt);
mov cl,info_fcb+ranrec ; CH = low(l_item.rec + l_item.cnt);
mov ax,word ptr info_fcb+ranrec+1
add cl,mult_cnt
adc ax,0 ; AX,CL = rand_rec + mult_cnt
sub ch,cl
mov 6[bx],ch ; store l_item.cnt
mov 3[bx],cl ; l_item.rec = rand_rec + mult_cnt;
mov 4[bx],ax ; store l_item.rec
jmps lock06a
lock07b: ; else
test al,08h ; if (llist_ret && post_part_olap)
jz lock07c
mov cl,info_fcb+ranrec ; l_item.cnt = rand_rec-l_item.rec;
sub cl,3[bx] ; CL = low(rand_rec - l_item.rec);
mov 6[bx],cl ; store l_item.cnt
jmps lock06a
lock07c: ; else ;(llist_ret && subset_olap)
push bx ; save current item address
call create_llist_item ; create new llist item
pop si
mov al,2[si]! mov 2[bx],al ; set attributes and drive
mov cl,info_fcb+ranrec ; rec = (rand_rec + mult_cnt)
mov ax,word ptr info_fcb+ranrec+1
add cl,mult_cnt
adc ax,0 ; AX,CL = rand_rec + mult_cnt
mov 3[bx],cl
mov 4[bx],ax ; store new l_item.rec
mov ch,3[si]! add ch,6[si] ; cnt = (l_item + cnt) -
sub ch,cl ; (rand_rec+mult_cnt)
mov 6[bx],ch ; store new l_item.cnt
mov cl,info_fcb+ranrec ; l_item.cnt = rand_rec -
sub cl,3[si] ; l_item.rec;
mov 6[si],cl ; store l_item.cnt
jmp lock06a
lock08a: ; end of while
test lock_unlock,true ;if (lock)
jz lock09a
call create_llist_item ; create(rand_rec,mult_cnt);
mov al,curdsk
or al,attributes
mov 2[bx],al ; set drive and attributes
mov si,offset info_fcb+ranrec
mov cx,3
rep movsb ; copy record #
mov al,mult_cnt
mov 6[bx],al ; l_item.cnt = mult_cnt;
lock09a:
ret
fix_olist_item:
;--------------
mov ax,xdcnt
cmp ax,sdcnt ; is xdcnt < sdcnt?
jae retl8 ; no
;yes - update olist entries
call swap
mov ax,xdcnt
mov sdcnt,ax
mov ax,offset open_root
mov cur_pos,ax
;find file's olist entries & change dcnt values
fix_ol1:
call swap
call pack_sdcnt
call swap
mov ch,3
call searchn_list! jnz retl8
; update olist item with new dcnt value
push bx! call pack_sdcnt! pop bx
add bx,3
mov dx,offset packed_dcnt
mov cl,3
call move
jmps fix_ol1
diskreset:
;---------
; exit: Z flag reset if TLOG has been setup
xor ax,ax
mov ntlog,ax
mov set_ro_flag,al
mov bx,info
intrnl_disk_reset:
cmp open_root,0
jz retl8
mov al,curdsk! push ax
mov ch,0
dskrst1:
shr bx,1! jb dskrst3
dskrst2:
inc ch
cmp bx,0! jnz dskrst1
pop ax! mov curdsk,al
mov bx,ntlog
or tlog,bx
inc al
retl8:
ret
dskrst3:
push cx! push bx
mov curdsk,ch! mov cl,ch
mov dx,tlog
call test_vector1! push dx
mov dx,rlog
call test_vector1! push dx
mov dx,rodsk
call test_vector1! pop bx
or bl,set_ro_flag
or bl,dl! pop dx
or bl,dl! mov check_disk,bl
mov bx,offset open_root
mov cur_pos,bx
dskrst4:
mov ch,1
call searchn_list! jnz dskrst6
test check_disk,true
jz dskrst5
push bx
call compare_pds! jz dskrst45
pop dx
xor al,al! jmps dskrst6
dskrst45:
mov bx,offset ntlog
call setcdisk
pop bx! jmps dskrst4
dskrst5:
mov bx,offset info
call remove_drive
or al,1
dskrst6:
pop bx! pop cx
jz $+5
jmp dskrst2
; error - olist item exists for another process
; on a removeable or read/only drive to be reset
; or any kind of drive if function is write protect disk
pop ax! mov curdsk,al
cmp error_mode,0ffh
je dskrst7
mov err_drv,ch
mov bx,dx! mov ax,6[bx]
mov err_pd_addr,ax
mov err_type,0ffh
dskrst7:
pop bx! mov aret,0ffffh
ret
endif
if BCPM
chk_reset:
;---------
; exit: AX = accumulated vector of drives to not be reset
xor ax,ax
push es
mov es,tlr
chk_rst0:
cmp p_status,ps_term ;if process environment status
je chk_rst1 ; is <> terminated
or ax,p_alc_vec ; OR in processes alloc block vector
chk_rst1:
mov cx,p_thread ;CX = next process environment address
mov es,cx
or cx,cx! jnz chk_rst0 ;check next process if not zero
pop es
ret
chk_drv:
;-------
; exit: Z flag set if file is being written on CURDSK
call chk_reset
not ax! mov dx,ax
jmp test_vector
endif
;********** end bdos file system part 3 **********

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