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page 80,132
title CP/DOS DosQFsInfo mapper
buffer segment word public 'buffer'
clsdr40 dw ?
avlcls40 dw ?
secalc40 dw ?
bytsec40 dw ?
buffer ends
dosxxx segment byte public 'dos'
assume cs:dosxxx,ds:nothing,es:nothing,ss:nothing
;
; ************************************************************************* *
; *
; * MODULE: DosQFsInfo
; *
; * FILE NAME: DOS040.ASM
; *
; * FUNCTION: This module will return the information for a file
; * system device.
; *
; * CALLING SEQUENCE:
; *
; * PUSH WORD DriveNumber ; Drive Number
; * PUSH OTHER FSInfoLevel ; File system info required
; * PUSH@ OTHER FSInfoBuf ; File system info buffer
; * PUSH WORD FSInfoBufSize ; file system info buffer size
; * Call DosQFsInfo
; *
; *
; * RETURN SEQUENCE:
; *
; * IF ERROR (AX not = 0)
; *
; * AX = Error Code:
; *
; * o Invalid parameter
; *
; *
; * MODULES CALLED: DOS int 21H function 19H
; * DOS int 25H
; *
; *
; *************************************************************************
public DosQFsInfo
.sall
.xlist
include macros.inc
include error.inc
.list
str struc
old_bp dw ?
return dd ?
FSIBS40 dw ? ; info buffer size
FSIB40 dd ? ; info buffer
ILL40 dw ? ; info level
DRNUM40 dw ? ; driver number
str ends
DosQFsInfo proc far
Enter Dosqfsinfo ; push registers
mov dx,[bp].drnum40 ; load drive number
mov ah,036h
int 21h ; get disk space
cmp ax,0ffffh ; check if valid drive number
jne valdr40 ; jump if drive is ok
mov ax,error_invalid_parameter ; esle set error code
jmp erret40 ; error return
valdr40:;
push ax
mov ax,buffer ; set the data segment and save
push ax ; space information in the data area
pop ds
assume ds:buffer
mov avlcls40,bx ; save available cluster
mov clsdr40,dx ; save clusters per drive
mov bytsec40,cx ; save bytes per sector
pop ax ;
mov secalc40,ax ; save sectors per allocation unit
mov ax,[bp].ill40 ; get info level
cmp al,01 ; valid level ??
je getinfo40 ; jump if valid
mov ax,error_invalid_parameter ; else invalid parameter
jmp erret40 ; error return
getinfo40:;
mov ax,[bp].fsibs40 ; get info buffer size address
cmp ax,18 ; check if valid
jge bufok40 ; jump if valid
mov ax,error_buffer_overflow ; move buffer not big enough
jmp erret40 ; error return
bufok40:;
les di,[bp].fsib40 ; get FSI buffer pointer
sub ax,ax ; return
mov es:[di],ax ; null
mov es:[di]+2,ax ; File system ID
add di,4 ; set pointer to number of sectors in alloc
sub ax,ax ;
mov es:[di]+2,ax ; set high order # of sectors in alloc to 0
mov ax,secalc40 ;
mov es:[di],ax ; store low order # of sectors in alloc
add di,4 ; set pointer to number of allocation units
mov ax,clsdr40 ; load low order number
mov es:[di],ax ; of alloc units
sub ax,ax ;
mov es:[di]+2,ax ; set high order # of alloc units to 0
mov ax,avlcls40 ; load low order number
mov es:[di]+4,ax ; of avail alloc units
sub ax,ax ;
mov es:[di]+6,ax ; set high order # of avail alloc to 0
mov ax,bytsec40 ; get number
mov es:[di]+8,ax ; of bytes per sector
sub ax,ax ; set good return code
erret40:;
mexit ; pop registers
ret size str - 6 ; return
DosQFsInfo endp
dosxxx ends
end
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