244 lines
4.4 KiB
ArmAsm
244 lines
4.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* low-level functions for the SWIM floppy controller
|
|
*
|
|
* needs assembly language because is very timing dependent
|
|
* this controller exists only on macintosh 680x0 based
|
|
*
|
|
* Copyright (C) 2004,2008 Laurent Vivier <Laurent@lvivier.info>
|
|
*
|
|
* based on Alastair Bridgewater SWIM analysis, 2001
|
|
* based on netBSD IWM driver (c) 1997, 1998 Hauke Fath.
|
|
*
|
|
* 2004-08-21 (lv) - Initial implementation
|
|
* 2008-11-05 (lv) - add get_swim_mode
|
|
*/
|
|
|
|
.equ write_data, 0x0000
|
|
.equ write_mark, 0x0200
|
|
.equ write_CRC, 0x0400
|
|
.equ write_parameter,0x0600
|
|
.equ write_phase, 0x0800
|
|
.equ write_setup, 0x0a00
|
|
.equ write_mode0, 0x0c00
|
|
.equ write_mode1, 0x0e00
|
|
.equ read_data, 0x1000
|
|
.equ read_mark, 0x1200
|
|
.equ read_error, 0x1400
|
|
.equ read_parameter, 0x1600
|
|
.equ read_phase, 0x1800
|
|
.equ read_setup, 0x1a00
|
|
.equ read_status, 0x1c00
|
|
.equ read_handshake, 0x1e00
|
|
|
|
.equ o_side, 0
|
|
.equ o_track, 1
|
|
.equ o_sector, 2
|
|
.equ o_size, 3
|
|
.equ o_crc0, 4
|
|
.equ o_crc1, 5
|
|
|
|
.equ seek_time, 30000
|
|
.equ max_retry, 40
|
|
.equ sector_size, 512
|
|
|
|
.global swim_read_sector_header
|
|
swim_read_sector_header:
|
|
link %a6, #0
|
|
moveml %d1-%d5/%a0-%a4,%sp@-
|
|
movel %a6@(0x0c), %a4
|
|
bsr mfm_read_addrmark
|
|
moveml %sp@+, %d1-%d5/%a0-%a4
|
|
unlk %a6
|
|
rts
|
|
|
|
sector_address_mark:
|
|
.byte 0xa1, 0xa1, 0xa1, 0xfe
|
|
sector_data_mark:
|
|
.byte 0xa1, 0xa1, 0xa1, 0xfb
|
|
|
|
mfm_read_addrmark:
|
|
movel %a6@(0x08), %a3
|
|
lea %a3@(read_handshake), %a2
|
|
lea %a3@(read_mark), %a3
|
|
moveq #-1, %d0
|
|
movew #seek_time, %d2
|
|
|
|
wait_header_init:
|
|
tstb %a3@(read_error - read_mark)
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
moveb #0x01, %a3@(write_mode1 - read_mark)
|
|
moveb #0x01, %a3@(write_mode0 - read_mark)
|
|
tstb %a3@(read_error - read_mark)
|
|
moveb #0x08, %a3@(write_mode1 - read_mark)
|
|
|
|
lea sector_address_mark, %a0
|
|
moveq #3, %d1
|
|
|
|
wait_addr_mark_byte:
|
|
|
|
tstb %a2@
|
|
dbmi %d2, wait_addr_mark_byte
|
|
bpl header_exit
|
|
|
|
moveb %a3@, %d3
|
|
cmpb %a0@+, %d3
|
|
dbne %d1, wait_addr_mark_byte
|
|
bne wait_header_init
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
amark0: tstb %a2@
|
|
dbmi %d2, amark0
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_track)
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
amark1: tstb %a2@
|
|
dbmi %d2, amark1
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_side)
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
amark2: tstb %a2@
|
|
dbmi %d2, amark2
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_sector)
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
amark3: tstb %a2@
|
|
dbmi %d2, amark3
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_size)
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
crc0: tstb %a2@
|
|
dbmi %d2, crc0
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_crc0)
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
crc1: tstb %a2@
|
|
dbmi %d2, crc1
|
|
bpl signal_nonyb
|
|
|
|
moveb %a3@, %a4@(o_crc1)
|
|
|
|
tstb %a3@(read_error - read_mark)
|
|
|
|
header_exit:
|
|
moveq #0, %d0
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
rts
|
|
signal_nonyb:
|
|
moveq #-1, %d0
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
rts
|
|
|
|
.global swim_read_sector_data
|
|
swim_read_sector_data:
|
|
link %a6, #0
|
|
moveml %d1-%d5/%a0-%a5,%sp@-
|
|
movel %a6@(0x0c), %a4
|
|
bsr mfm_read_data
|
|
moveml %sp@+, %d1-%d5/%a0-%a5
|
|
unlk %a6
|
|
rts
|
|
|
|
mfm_read_data:
|
|
movel %a6@(0x08), %a3
|
|
lea %a3@(read_handshake), %a2
|
|
lea %a3@(read_data), %a5
|
|
lea %a3@(read_mark), %a3
|
|
movew #seek_time, %d2
|
|
|
|
wait_data_init:
|
|
tstb %a3@(read_error - read_mark)
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
moveb #0x01, %a3@(write_mode1 - read_mark)
|
|
moveb #0x01, %a3@(write_mode0 - read_mark)
|
|
tstb %a3@(read_error - read_mark)
|
|
moveb #0x08, %a3@(write_mode1 - read_mark)
|
|
|
|
lea sector_data_mark, %a0
|
|
moveq #3, %d1
|
|
|
|
/* wait data address mark */
|
|
|
|
wait_data_mark_byte:
|
|
|
|
tstb %a2@
|
|
dbmi %d2, wait_data_mark_byte
|
|
bpl data_exit
|
|
|
|
moveb %a3@, %d3
|
|
cmpb %a0@+, %d3
|
|
dbne %d1, wait_data_mark_byte
|
|
bne wait_data_init
|
|
|
|
/* read data */
|
|
|
|
tstb %a3@(read_error - read_mark)
|
|
|
|
movel #sector_size-1, %d4 /* sector size */
|
|
read_new_data:
|
|
movew #max_retry, %d2
|
|
read_data_loop:
|
|
moveb %a2@, %d5
|
|
andb #0xc0, %d5
|
|
dbne %d2, read_data_loop
|
|
beq data_exit
|
|
moveb %a5@, %a4@+
|
|
andb #0x40, %d5
|
|
dbne %d4, read_new_data
|
|
beq exit_loop
|
|
moveb %a5@, %a4@+
|
|
dbra %d4, read_new_data
|
|
exit_loop:
|
|
|
|
/* read CRC */
|
|
|
|
movew #max_retry, %d2
|
|
data_crc0:
|
|
|
|
tstb %a2@
|
|
dbmi %d2, data_crc0
|
|
bpl data_exit
|
|
|
|
moveb %a3@, %d5
|
|
|
|
moveq #max_retry, %d2
|
|
|
|
data_crc1:
|
|
|
|
tstb %a2@
|
|
dbmi %d2, data_crc1
|
|
bpl data_exit
|
|
|
|
moveb %a3@, %d5
|
|
|
|
tstb %a3@(read_error - read_mark)
|
|
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
|
|
/* return number of bytes read */
|
|
|
|
movel #sector_size, %d0
|
|
addw #1, %d4
|
|
subl %d4, %d0
|
|
rts
|
|
data_exit:
|
|
moveb #0x18, %a3@(write_mode0 - read_mark)
|
|
moveq #-1, %d0
|
|
rts
|