FreeDOS/drivers/floppy.asm
2001-04-15 03:21:50 +00:00

318 lines
8.3 KiB
NASM

;
; File:
; floppy.asm
; Description:
; floppy disk driver primitives
;
; Copyright (c) 1995
; Pasquale J. Villani
; All Rights Reserved
;
; This file is part of DOS-C.
;
; DOS-C is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version
; 2, or (at your option) any later version.
;
; DOS-C is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
; the GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public
; License along with DOS-C; see the file COPYING. If not,
; write to the Free Software Foundation, 675 Mass Ave,
; Cambridge, MA 02139, USA.
;
; $Logfile: C:/usr/patv/dos-c/src/drivers/floppy.asv $
;
; $Id$
;
; $Log$
; Revision 1.5 2001/04/15 03:21:50 bartoldeman
; See history.txt for the list of fixes.
;
; Revision 1.4 2001/03/21 02:56:25 bartoldeman
; See history.txt for changes. Bug fixes and HMA support are the main ones.
;
; Revision 1.3 2000/05/25 20:56:19 jimtabor
; Fixed project history
;
; Revision 1.2 2000/05/11 03:56:20 jimtabor
; Clean up and Release
;
; Revision 1.1.1.1 2000/05/06 19:34:53 jhall1
; The FreeDOS Kernel. A DOS kernel that aims to be 100% compatible with
; MS-DOS. Distributed under the GNU GPL.
;
; Revision 1.4 1999/08/10 17:21:08 jprice
; ror4 2011-01 patch
;
; Revision 1.3 1999/04/16 21:29:17 jprice
; ror4 multi-sector IO
;
; Revision 1.2 1999/03/29 17:08:31 jprice
; ror4 changes
;
; Revision 1.1.1.1 1999/03/29 15:40:24 jprice
; New version without IPL.SYS
;
; Revision 1.4 1999/02/14 04:25:16 jprice
; Added functions to check if a floppy disk has been changed.
;
; Revision 1.3 1999/02/08 05:49:47 jprice
; Added Pat's 1937 kernel patches
;
; Revision 1.2 1999/01/22 04:16:39 jprice
; Formating
;
; Revision 1.1.1.1 1999/01/20 05:51:00 jprice
; Imported sources
;
; Rev 1.3 06 Dec 1998 8:43:00 patv
;New floppy support functions.
;
; Rev 1.2 29 Aug 1996 13:07:14 patv
;Bug fixes for v0.91b
;
; Rev 1.1 01 Sep 1995 18:50:34 patv
;Initial GPL release.
;
; Rev 1.0 02 Jul 1995 7:57:02 patv
;Initial revision.
;
%ifndef SYS
%include "..\kernel\segs.inc"
%else
group TGROUP HMA_TEXT _TEXT
segment _TEXT class=CODE
segment HMA_TEXT class=CODE
%endif
segment HMA_TEXT
;
;
; Reset both the diskette and hard disk system
;
; BOOL fl_reset(WORD drive)
;
; returns TRUE if successful
;
global _fl_reset
_fl_reset:
mov bx,sp
mov ah,0 ; BIOS reset disketter & fixed disk
mov dl,[bx+2]
int 13h
jc fl_rst1 ; cy==1 is error
mov ax,1 ; TRUE on success
ret
fl_rst1: xor ax,ax ; FALSE on error
ret
;
;
; Read DASD Type
;
; COUNT fl_readdasd(WORD drive)
;
; returns 0-3 if successful, 0xFF if error
;
; Code Meaning
; 0 The drive is not present
; 1 Drive present, cannot detect disk change
; 2 Drive present, can detect disk change
; 3 Fixed disk
;
global _fl_readdasd
_fl_readdasd:
push bp
mov bp,sp
mov dl,[bp+4] ; get the drive number
mov ah,15h ; read DASD type
int 13h
jc fl_rdasd1 ; cy==1 is error
mov al,ah ; for the return code
xor ah,ah
pop bp ; C exit
ret
fl_rdasd1: mov ah,0 ; BIOS reset disketter & fixed disk
int 13h
mov ax,0FFh ; 0xFF on error
pop bp ; C exit
ret
;
;
; Read disk change line status
;
; COUNT fl_diskchanged(WORD drive)
;
; returns 1 if disk has changed, 0 if not, 0xFF if error
;
global _fl_diskchanged
_fl_diskchanged:
push bp ; C entry
mov bp,sp
mov dl,[bp+4] ; get the drive number
mov ah,16h ; read change status type
int 13h
jc fl_dchanged1 ; cy==1 is error or disk has changed
xor ax,ax ; disk has not changed
pop bp ; C exit
ret
fl_dchanged1: cmp ah,6
jne fl_dc_error
mov ax,1
pop bp ; C exit
ret
fl_dc_error: mov ax,0FFh ; 0xFF on error
pop bp ; C exit
ret
;
; Read the disk system status
;
; COUNT fl_rd_status(WORD drive)
;
; Returns error codes
;
; See Phoenix Bios Book for error code meanings
;
global _fl_rd_status
_fl_rd_status:
push bp ; C entry
mov bp,sp
mov dl,[bp+4] ; get the drive number
mov ah,1 ; read status
int 13h
mov al,ah ; for the return code
xor ah,ah
pop bp ; C exit
ret
;
; Read Sectors
;
; COUNT fl_read(WORD drive, WORD head, WORD track, WORD sector, WORD count, BYTE FAR *buffer);
;
; Reads one or more sectors.
;
; Returns 0 if successful, error code otherwise.
;
;
; Write Sectors
;
; COUNT fl_write(WORD drive, WORD head, WORD track, WORD sector, WORD count, BYTE FAR *buffer);
;
; Writes one or more sectors.
;
; Returns 0 if successful, error code otherwise.
;
global _fl_read
_fl_read:
mov ah,2 ; cmd READ
jmp short fl_common
global _fl_verify
_fl_verify:
mov ah,4 ; cmd verify
jmp short fl_common
global _fl_write
_fl_write:
mov ah,3 ; cmd WRITE
fl_common:
push bp ; C entry
mov bp,sp
mov dl,[bp+4] ; get the drive (if or'ed 80h its
; hard drive.
mov dh,[bp+6] ; get the head number
mov bx,[bp+8] ; cylinder number (lo only if hard)
mov al,1 ; this should be an error code
cmp bx,3ffh ; this code can't write above 3ff=1023
ja fl_error
mov ch,bl ; low 8 bits of cyl number
xor bl,bl ; extract bits 8+9 to cl
shr bx,1
shr bx,1
mov cl,[bp+0Ah] ; sector number
and cl,03fh ; mask to sector field bits 5-0
or cl,bl ; or in bits 7-6
mov al,[bp+0Ch] ; count to read/write
les bx,[bp+0Eh] ; Load 32 bit buffer ptr
int 13h ; write sectors from mem es:bx
mov al,ah
jc fl_wr1 ; error, return error code
xor al,al ; Zero transfer count
fl_wr1:
fl_error:
xor ah,ah ; force into < 255 count
pop bp
ret
global _fl_format
_fl_format:
xor ax,ax
ret
;
;
; Get number of disks
;
; COUNT fl_nrdrives(VOID)
;
; returns AX = number of harddisks
;
global _fl_nrdrives
_fl_nrdrives:
push di ; di reserved by C-code ???
mov ah,8 ; DISK, get drive parameters
mov dl,80h
int 13h
mov ax,0 ; fake 0 drives on error
jc fl_nrd1
mov al,dl
fl_nrd1:
pop di
ret