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mame/src/lib/formats/coco_dsk.c

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/*********************************************************************
formats/coco_dsk.c
Tandy Color Computer / Dragon disk images
*********************************************************************/
#include <string.h>
#include <time.h>
#include <assert.h>
#include "formats/coco_dsk.h"
#include "formats/basicdsk.h"
#include "imageutl.h"
#include "coretmpl.h"
/* -----------------------------------------------------------------------
* JVC (Jeff Vavasour CoCo) format
*
* Used by Jeff Vavasour's CoCo Emulators
*
* Documentation taken from Tim Linder's web site:
* http://home.netcom.com/~tlindner/JVC.html
*
* A. Header length
* The header length is determined by the file length modulo 256:
* headerSize = fileLength % 256;
* This means that the header is variable length and the minimum size
* is zero bytes, and the maximum size of 255 bytes.
*
* B. Header
* Here is a description of the header bytes:
* Byte Offset Description Default
* ----------- ----------------- -------
* 0 Sectors per track 18
* 1 Side count 1
* 2 Sector size code 1
* 3 First sector ID 1
* 4 Sector attribute flag 0
*
* If the sector attribute flag is zero then the track count is determined
* by the formula:
*
* (fileLength - headerSize) / (sectorsPerTrack * (128 <<
* sectorSizeCode)) / sideCount
*
* If the sector attribute flag is non zero then the track count is
* determined by the more complex formula:
*
* (fileLength - headerSize) / (sectorsPerTrack * ((128 <<
* sectorSizeCode) + 1) ) / sideCount
*
* If the length of the header is to short to contain the geometry desired,
* then the default values are assumed. If the header length is zero the all
* of the geometry is assumed. When creating disk images it is desirable to
* make the header length as short as possible. The header should only be
* used to deviate from the default values.
*
* The sector data begins immediately after the header. If the header length
* is zero then the sector data is at the beginning file.
*
* C. Sectors per track
* This is the number of sectors per track (ones based). A value of 18
* means there are 18 sectors per track
*
* D. Side Count
* This is the number of sides in the disk image. Values of 1 or 2 are
* acceptable. If there are two sides then the tracks are interleaved.
* The first track in the image file is track zero side 1, the second
* track in the image file is track zero side 2.
*
* E. Sector size
* The is the same value that is stored in the wd179x ID field to
* determine sector size:
*
* 0x00 128 bytes
* 0x01 256 bytes
* 0x02 512 bytes
* 0x03 1024 bytes
*
* Other values are undefined. Every sector in the disk image must be the
* same size.
*
* F. First sector ID
* This determines the first sector ID for each track. Each successive
* sector adds one to the previous ID. If the first sector ID is 1, then
* the second sector has an ID of 2, and the third has an ID of 3.
*
* G. Sector Attribute Flag
* If this byte is non zero, then each sector contains an additional
* byte prepended to the sector data. If the attribute flag is zero then
* there are no extra bytes in front of the sector data.
*
* H. Sector attribute byte
* This byte is put at the beginning of every sector if the header flag
* is turned on. The information this byte contains is the same as the
* status register (of the wd179x) would contain when a 'Read Sector'
* command was issued. The bit fields are defined as:
*
* Bit position:
* ---------------
* 7 6 5 4 3 2 1 0
* | | | | | | | |
* | | | | | | | +--- Not used. Set to zero.
* | | | | | | +----- Not used. Set to zero.
* | | | | | +------- Not used. Set to zero.
* | | | | +--------- Set on CRC error.
* | | | +----------- Set if sector not found.
* | | +------------- Record type: 1 - Deleted Data Mark, 0 - Data Mark.
* | +--------------- Not Used. Set to zero.
* +----------------- Not Used. Set to zero.
*
* ----------------------------------------------------------------------- */
static int coco_jvc_decode_header(floppy_image_legacy *floppy, UINT64 size,
struct basicdsk_geometry *geometry)
{
UINT8 header[256];
UINT8 sector_attribute_flag;
UINT16 physical_bytes_per_sector;
UINT32 header_size, file_size;
struct basicdsk_geometry dummy_geometry;
if (geometry)
memset(geometry, 0, sizeof(*geometry));
else
geometry = &dummy_geometry;
if (size > 0xFFFFFFFF)
return -1;
file_size = (UINT32) size;
/* read the header */
header_size = (UINT32) file_size % 0x100;
floppy_image_read(floppy, header, 0, header_size);
geometry->offset = header_size;
/* byte offset 0 - sectors per track */
geometry->sectors = (header_size > 0) ? header[0] : 18;
if (geometry->sectors <= 0)
return -1;
/* byte offset 1 - side count */
geometry->heads = (header_size > 1) ? header[1] : 1;
if (geometry->heads <= 0)
return -1;
/* byte offset 2 - sector size code */
geometry->sector_length = 128 << ((header_size > 2) ? header[2] : 1);
if (geometry->sector_length <= 0)
return -1;
/* byte offset 3 - first sector ID */
geometry->first_sector_id = (header_size > 3) ? header[3] : 1;
/* byte offset 4 - sector attribute flag */
sector_attribute_flag = (header_size > 4) ? header[4] : 0;
if (sector_attribute_flag != 0)
return -1; /* we do not support sector attribute flags */
physical_bytes_per_sector = geometry->sector_length;
if (sector_attribute_flag)
physical_bytes_per_sector++;
geometry->tracks = (file_size - header_size) / geometry->sectors / geometry->heads / physical_bytes_per_sector;
/* do we have an oddball size? reject this file if not */
if ((file_size - header_size) % physical_bytes_per_sector)
return -1;
/* minimum of 35 tracks; support degenerate JVC files */
if (geometry->tracks < 35)
geometry->tracks = 35;
return 0;
}
static FLOPPY_IDENTIFY(coco_jvc_identify)
{
UINT64 size;
size = floppy_image_size(floppy);
*vote = coco_jvc_decode_header(floppy, size, NULL) ? 0 : 100;
return FLOPPY_ERROR_SUCCESS;
}
static FLOPPY_CONSTRUCT(coco_jvc_construct)
{
struct basicdsk_geometry geometry;
UINT8 header[5];
size_t header_size;
if (params)
{
/* create */
memset(&geometry, 0, sizeof(geometry));
geometry.heads = option_resolution_lookup_int(params, PARAM_HEADS);
geometry.tracks = option_resolution_lookup_int(params, PARAM_TRACKS);
geometry.sectors = option_resolution_lookup_int(params, PARAM_SECTORS);
geometry.first_sector_id = option_resolution_lookup_int(params, PARAM_FIRST_SECTOR_ID);
geometry.sector_length = option_resolution_lookup_int(params, PARAM_SECTOR_LENGTH);
header[0] = (UINT8) geometry.sectors;
header[1] = (UINT8) geometry.heads;
header[2] = (UINT8) compute_log2(geometry.sector_length) - 7;
header[3] = (UINT8) geometry.first_sector_id;
header[4] = 0;
/* now that we have the header computed, figure out the header size */
header_size = 0;
if (header[0] != 18)
header_size = 1;
if (header[1] != 1)
header_size = 2;
if (header[2] != 1)
header_size = 3;
if (header[3] != 1)
header_size = 4;
if (header[4] != 0)
header_size = 5;
geometry.offset = header_size;
floppy_image_write(floppy, header, 0, header_size);
}
else
{
/* load */
if (coco_jvc_decode_header(floppy, floppy_image_size(floppy), &geometry))
return FLOPPY_ERROR_INVALIDIMAGE;
}
return basicdsk_construct(floppy, &geometry);
}
/* -----------------------------------------------------------------------
* OS-9 file format
*
* This file format is largely a hack because there are a large amount of
* disk images that do not have geometry image separate from the disk image
* itself. So we support OS-9 images with are simply basic disks whose
* geometry is determined by the disk image.
*
* OS-9 images identified by an LSN; which are simply blocks of 256 bytes
*
* LSN0
* Byte size use
* $00 3 sectors on disk
* $03 1 track size in sectors
* $04 2 bytes in allocation bit map; typically 1bit/sector so for
* 35 tracks of 18 sectors each that's $4E (single sided disk)
* 40 tracks per side, 18 sectors each = $B4
* $06 2 sectors per bit in allocation map; normally 1
* $08 3 LSN of root directory; normally 2 but depends on size of
* $04 value
* $0B 2 owner's user number; normally 0
* $0D 1 disk attributes; normally $FF
* $0E 2 psuedo random number for identification
* $10 1 disk format; typical is 3
* %00000001 0=single side 1=double side
* %00000010 0=single density (non Coco) 1=double density
* %00000100 0=48tracks/inch 1=96tracks/inch
* $11 2 sectors per track; normal is $12 skip several not needed
* for Format
* $1A 5 date of creation Y:M:D:H:M
* $1F 32 ASCII name of disk, last letter has $80 added to it,
* the full 32 bytes do not need to be used.
*
* Allocation bit map, fill with zeros and set bits from low to high as
* sectors are used. So, for a fresh disk sectors LSN0,LSN1,LSN2, and LSN3
* will be in use so the first byte will be $FF $C0 and all others
* in the map are $00
*
* Root directory LSN2
* Byte size use
* $00 1 attributes will be $BF
* $01 2 owners ID will be $0000
* $03 5 date last modified will be creation date Y:M:D:H:M
* $08 1 link count; set to $02
* $09 4 file size in bytes, set to $40
* $0D 3 date created Y:M:D
* $10 3 block LSN set to current sector number+1 ie $03 in this case
* $13 2 size in sectors of directory block, set to $07
* All other bytes in sector set to $00
* LSN3 first sector of directory with names
* Fill sector with all $00 and then set listed bytes
* $00 2 value $2EAE which is .. with last byte+$80
* $1F 1 value $02 LSN for start of this directory as there is
* none higher in tree
* $20 1 value $AE which is . with $80 added
* $3F 1 value $02 LSN for start of this directory
* ----------------------------------------------------------------------- */
static floperr_t coco_os9_readheader(floppy_image_legacy *floppy, struct basicdsk_geometry *geometry)
{
UINT8 header[0x20];
int total_sectors;
floppy_image_read(floppy, header, 0, sizeof(header));
total_sectors = (header[0x00] << 16) | (header[0x01] << 8) | header[0x02];
memset(geometry, 0, sizeof(*geometry));
geometry->first_sector_id = 1;
geometry->sector_length = 256;
geometry->sectors = (header[0x11] << 8) + header[0x12];
geometry->heads = (header[0x10] & 0x01) ? 2 : 1;
if (!geometry->sectors)
return FLOPPY_ERROR_INVALIDIMAGE;
geometry->tracks = total_sectors / geometry->sectors / geometry->heads;
if (total_sectors != geometry->tracks * geometry->sectors * geometry->heads)
return FLOPPY_ERROR_INVALIDIMAGE;
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_os9_post_format(floppy_image_legacy *floppy, option_resolution *params)
{
UINT8 header[0x0400];
floperr_t err;
time_t t;
struct tm *ltime;
int heads, tracks, sectors, total_sectors;
heads = option_resolution_lookup_int(params, PARAM_HEADS);
tracks = option_resolution_lookup_int(params, PARAM_TRACKS);
sectors = option_resolution_lookup_int(params, PARAM_SECTORS);
total_sectors = heads * tracks * sectors;
/* write the initial header */
time(&t);
ltime = localtime(&t);
memset(&header, 0, sizeof(header));
header[0x0000] = (UINT8) (total_sectors >> 16);
header[0x0001] = (UINT8) (total_sectors >> 8);
header[0x0002] = (UINT8) (total_sectors >> 0);
header[0x0003] = (UINT8) sectors;
header[0x0004] = (UINT8) (((total_sectors + 7) / 8) >> 8);
header[0x0005] = (UINT8) (((total_sectors + 7) / 8) >> 0);
header[0x0006] = 0x00;
header[0x0007] = 0x01;
header[0x0008] = 0x00;
header[0x0009] = 0x00;
header[0x000a] = 0x02;
header[0x000b] = 0x00;
header[0x000c] = 0x00;
header[0x000d] = 0xff;
header[0x000e] = floppy_random_byte(floppy);
header[0x000f] = floppy_random_byte(floppy);
header[0x0010] = (heads == 2) ? 3 : 2;
header[0x0011] = (UINT8) (sectors >> 8);
header[0x0012] = (UINT8) (sectors >> 0);
header[0x001A] = (UINT8) ltime->tm_year;
header[0x001B] = (UINT8) ltime->tm_mon + 1;
header[0x001C] = (UINT8) ltime->tm_mday;
header[0x001D] = (UINT8) ltime->tm_hour;
header[0x001E] = (UINT8) ltime->tm_min;
header[0x001F] = 0xA0;
header[0x0100] = 0xFF;
header[0x0101] = 0xC0;
header[0x0200] = 0xBF;
header[0x0201] = 0x00;
header[0x0202] = 0x00;
header[0x0203] = (UINT8) ltime->tm_year;
header[0x0204] = (UINT8) ltime->tm_mon + 1;
header[0x0205] = (UINT8) ltime->tm_mday;
header[0x0206] = (UINT8) ltime->tm_hour;
header[0x0207] = (UINT8) ltime->tm_min;
header[0x0208] = 0x02;
header[0x0209] = 0x00;
header[0x020A] = 0x00;
header[0x020B] = 0x00;
header[0x020C] = 0x40;
header[0x020D] = (UINT8) (ltime->tm_year % 100);
header[0x020E] = (UINT8) ltime->tm_mon;
header[0x020F] = (UINT8) ltime->tm_mday;
header[0x0210] = 0x00;
header[0x0211] = 0x00;
header[0x0212] = 0x03;
header[0x0213] = 0x00;
header[0x0214] = 0x07;
header[0x0300] = 0x2E;
header[0x0301] = 0xAE;
header[0x031F] = 0x02;
header[0x0320] = 0xAE;
header[0x033F] = 0x02;
if (total_sectors % 8)
header[0x0100 + (total_sectors / 8)] = 0xFF >> (total_sectors % 8);
err = floppy_write_sector(floppy, 0, 0, 1, 0, &header[0x0000], 256, 0);
if (err)
return err;
err = floppy_write_sector(floppy, 0, 0, 2, 0, &header[0x0100], 256, 0);
if (err)
return err;
err = floppy_write_sector(floppy, 0, 0, 3, 0, &header[0x0200], 256, 0);
if (err)
return err;
err = floppy_write_sector(floppy, 0, 0, 4, 0, &header[0x0300], 256, 0);
if (err)
return err;
return FLOPPY_ERROR_SUCCESS;
}
static FLOPPY_IDENTIFY(coco_os9_identify)
{
struct basicdsk_geometry geometry;
*vote = coco_os9_readheader(floppy, &geometry) ? 0 : 100;
return FLOPPY_ERROR_SUCCESS;
}
static FLOPPY_CONSTRUCT(coco_os9_construct)
{
floperr_t err;
struct basicdsk_geometry geometry;
if (params)
{
/* create */
memset(&geometry, 0, sizeof(geometry));
geometry.heads = option_resolution_lookup_int(params, PARAM_HEADS);
geometry.tracks = option_resolution_lookup_int(params, PARAM_TRACKS);
geometry.sectors = option_resolution_lookup_int(params, PARAM_SECTORS);
geometry.first_sector_id = option_resolution_lookup_int(params, PARAM_FIRST_SECTOR_ID);
geometry.sector_length = option_resolution_lookup_int(params, PARAM_SECTOR_LENGTH);
}
else
{
/* open */
err = coco_os9_readheader(floppy, &geometry);
if (err)
return err;
}
/* actually construct the image */
err = basicdsk_construct(floppy, &geometry);
floppy_callbacks(floppy)->post_format = coco_os9_post_format;
return err;
}
/* -----------------------------------------------------------------------
* VDK file format
*
* Used by Paul Burgin's PC-Dragon emulator
*
* Offset Bytes Field Description
* ------ ----- ------------ -----------
* 0 1 magic1 Signature byte 1 ('d')
* 1 1 magic2 Signature byte 2 ('k')
* 2 2 header_len Total header length (little endian)
* 4 1 ver_actual Version of the VDK format (0x10)
* 5 1 ver_compat Backwards compatibility version (0x10)
* 6 1 source_id Identify of the file source
* 7 1 source_ver Version of the file source
* 8 1 tracks Number of tracks
* 9 1 sides Number of sides (1-2)
* 10 1 flags Various flags
* bit 0: Write protect
* bit 1: A Lock
* bit 2: F Lock
* bit 3: Disk set
* 11 1 compression Compression flags (bits 0-2) and name length
* ----------------------------------------------------------------------- */
static int coco_vdk_decode_header(floppy_image_legacy *floppy, struct basicdsk_geometry *geometry)
{
UINT8 header[12];
UINT8 heads, tracks, sectors;
UINT16 sector_length, offset;
UINT64 size;
size = floppy_image_size(floppy);
floppy_image_read(floppy, header, 0, sizeof(header));
if (header[0] != 'd')
return -1;
if (header[1] != 'k')
return -1;
if (header[5] != 0x10)
return -1;
if (header[11] & 0x07)
return -1;
heads = header[9];
tracks = header[8];
sectors = 18;
sector_length = 0x100;
offset = header[3] * 0x100 + header[2];
if (size != ((UINT32) heads * tracks * sectors * sector_length + offset))
return -1;
if (geometry)
{
memset(geometry, 0, sizeof(*geometry));
geometry->heads = heads;
geometry->tracks = tracks;
geometry->sectors = sectors;
geometry->first_sector_id = 1;
geometry->sector_length = sector_length;
geometry->offset = offset;
}
return 0;
}
static FLOPPY_IDENTIFY(coco_vdk_identify)
{
*vote = coco_vdk_decode_header(floppy, NULL) ? 0 : 100;
return FLOPPY_ERROR_SUCCESS;
}
static FLOPPY_CONSTRUCT(coco_vdk_construct)
{
struct basicdsk_geometry geometry;
UINT8 header[12];
if (params)
{
/* create */
memset(&geometry, 0, sizeof(geometry));
geometry.heads = option_resolution_lookup_int(params, PARAM_HEADS);
geometry.tracks = option_resolution_lookup_int(params, PARAM_TRACKS);
geometry.sectors = 18;
geometry.first_sector_id = 1;
geometry.sector_length = 256;
geometry.offset = sizeof(header);
memset(&header, 0, sizeof(header));
header[0] = 'd';
header[1] = 'k';
header[2] = (UINT8) (sizeof(header) >> 0);
header[3] = (UINT8) (sizeof(header) >> 8);
header[4] = 0x10;
header[5] = 0x10;
header[8] = (UINT8) geometry.tracks;
header[9] = (UINT8) geometry.heads;
floppy_image_write(floppy, header, 0, sizeof(header));
}
else
{
/* load */
if (coco_vdk_decode_header(floppy, &geometry))
return FLOPPY_ERROR_INVALIDIMAGE;
}
return basicdsk_construct(floppy, &geometry);
}
/* -----------------------------------------------------------------------
* DMK file format
*
* David M. Keil's disk image format is aptly called an 'on disk' image
* format. This means that whatever written to the disk is enocded into
* the image file. IDAMS, sector headers, traling CRCs, and intra sector
* spacing. *
*
* HEADER DESCRIPTION:
*
* Offset Bytes Field Description
* ------ ----- ------------ -----------
* 0 1 write_prot 0xff = Writed Protected, 0x00 = R/W
* 1 1 tracks Number of tracks
* 2 2 track_length Bytes per track (little endian)
* 4 1 disk_options Miscellaneous flags
* bit 0-3: Unused
* bit 4: 1=single sided 0=dbl
* bit 5: Unused
* bit 6: Single density?
* bit 6: Ignore density flags?
* 5 7 reserved Reserved for future use
* 12 4 real_disk_code If this is 0x12345678 (little endian)
* then access a real disk drive
* (unsupported)
*
* Each track begins with a track TOC, consisting of 64 little endian 16-bit
* integers. Each integer has the following format:
* bit 0-13: Offset from beginning of track to 'FE' byte of IDAM
* Note these are always sorted from first to last. All empty
* entries are 0x00
* bit 14: Undefined (reserved)
* bit 15: Sector double density (0=SD 1=DD)
* ----------------------------------------------------------------------- */
struct dmk_tag
{
int heads;
int tracks;
UINT32 track_size;
};
#define DMK_HEADER_LEN 16
#define DMK_TOC_LEN 64
#define DMK_IDAM_LENGTH 7
#define DMK_DATA_GAP 80
#define DMK_LEAD_IN 32
#define DMK_EXTRA_TRACK_LENGTH 156
#define dmk_idam_type(x) (x)[0]
#define dmk_idam_track(x) (x)[1]
#define dmk_idam_side(x) (x)[2]
#define dmk_idam_sector(x) (x)[3]
#define dmk_idam_sectorlength(x) (x)[4]
#define dmk_idam_crc(x) (((x)[5] << 8) + (x)[6])
#define dmk_idam_set_crc(x, crc) (x)[5] = ((crc) >> 8); (x)[6] = ((crc) >> 0);
static struct dmk_tag *get_dmk_tag(floppy_image_legacy *floppy)
{
return (dmk_tag *)floppy_tag(floppy);
}
static floperr_t coco_dmk_get_offset(floppy_image_legacy *floppy, int head, int track, UINT64 *offset)
{
struct dmk_tag *tag = get_dmk_tag(floppy);
if ((head < 0) || (head >= tag->heads) || (track < 0) || (track >= tag->tracks))
return FLOPPY_ERROR_SEEKERROR;
*offset = track;
*offset *= tag->heads;
*offset += head;
*offset *= tag->track_size;
*offset += DMK_HEADER_LEN;
return FLOPPY_ERROR_SUCCESS;
}
static UINT32 coco_dmk_min_track_size(int sectors, int sector_length)
{
int sector_physical_length;
sector_physical_length = 8 + 3 + DMK_IDAM_LENGTH + 22 + 12 + 3 + 1 + sector_length + 2 + 24;
return DMK_TOC_LEN * 2 + DMK_LEAD_IN + (sectors * sector_physical_length);
}
static floperr_t coco_dmk_read_track(floppy_image_legacy *floppy, int head, int track, UINT64 offset, void *buffer, size_t buflen)
{
floperr_t err;
UINT64 track_offset;
err = coco_dmk_get_offset(floppy, head, track, &track_offset);
if (err)
return err;
floppy_image_read(floppy, buffer, offset + track_offset, buflen);
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_dmk_write_track(floppy_image_legacy *floppy, int head, int track, UINT64 offset, const void *buffer, size_t buflen)
{
floperr_t err;
UINT64 track_offset;
err = coco_dmk_get_offset(floppy, head, track, &track_offset);
if (err)
return err;
floppy_image_write(floppy, buffer, offset + track_offset, buflen);
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_dmk_get_track_data_offset(floppy_image_legacy *floppy, int head, int track, UINT64 *offset)
{
*offset = DMK_TOC_LEN + 1;
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_dmk_format_track(floppy_image_legacy *floppy, int head, int track, option_resolution *params)
{
int sectors;
int sector_length;
int interleave;
int first_sector_id;
floperr_t err;
int physical_sector;
int logical_sector;
int track_position;
UINT16 idam_offset;
UINT16 crc;
UINT8 *track_data;
void *track_data_v;
UINT32 max_track_size;
dynamic_array<int> sector_map;
sectors = option_resolution_lookup_int(params, PARAM_SECTORS);
sector_length = option_resolution_lookup_int(params, PARAM_SECTOR_LENGTH);
interleave = option_resolution_lookup_int(params, PARAM_INTERLEAVE);
first_sector_id = option_resolution_lookup_int(params, PARAM_FIRST_SECTOR_ID);
max_track_size = get_dmk_tag(floppy)->track_size;
if (sectors > DMK_TOC_LEN)
{
err = FLOPPY_ERROR_INTERNAL;
goto done;
}
if (max_track_size < coco_dmk_min_track_size(sectors, sector_length))
{
err = FLOPPY_ERROR_NOSPACE;
goto done;
}
err = floppy_load_track(floppy, head, track, TRUE, &track_data_v, NULL);
if (err)
goto done;
track_data = (UINT8 *) track_data_v;
/* set up sector map */
sector_map.resize_and_clear(sectors, 0xFF);
physical_sector = 0;
for (logical_sector = 0; logical_sector < sectors; logical_sector++)
{
while(sector_map[physical_sector] >= 0)
{
physical_sector++;
physical_sector %= sectors;
}
sector_map[physical_sector] = logical_sector + first_sector_id;
physical_sector += interleave + 1;
physical_sector %= sectors;
}
/* set up track table of contents */
physical_sector = 0;
track_position = DMK_TOC_LEN * 2 + DMK_LEAD_IN;
while(physical_sector < DMK_TOC_LEN)
{
if (physical_sector >= sectors)
{
/* no more sectors */
idam_offset = 0;
}
else
{
/* this is a sector */
logical_sector = sector_map[physical_sector];
/* write the sector */
memset(&track_data[track_position], 0x00, 8);
track_position += 8;
memset(&track_data[track_position], 0xA1, 3);
track_position += 3;
idam_offset = track_position | 0x8000;
dmk_idam_type( &track_data[track_position]) = 0xFE;
dmk_idam_track( &track_data[track_position]) = track;
dmk_idam_side( &track_data[track_position]) = head;
dmk_idam_sector( &track_data[track_position]) = logical_sector;
dmk_idam_sectorlength( &track_data[track_position]) = compute_log2(sector_length / 128);
crc = ccitt_crc16(0xcdb4, &track_data[track_position], DMK_IDAM_LENGTH - 2);
dmk_idam_set_crc( &track_data[track_position], crc);
track_position += DMK_IDAM_LENGTH;
memset(&track_data[track_position], 0x4E, 22);
track_position += 22;
memset(&track_data[track_position], 0x00, 12);
track_position += 12;
memset(&track_data[track_position], 0xA1, 3);
track_position += 3;
/* write sector body */
track_data[track_position] = 0xFB;
memset(&track_data[track_position + 1], floppy_get_filler(floppy), sector_length);
crc = ccitt_crc16(0xcdb4, &track_data[track_position], sector_length + 1);
track_data[track_position + sector_length + 1] = (UINT8) (crc >> 8);
track_data[track_position + sector_length + 2] = (UINT8) (crc >> 0);
track_position += sector_length + 3;
/* write sector footer */
memset(&track_data[track_position], 0x4E, 24);
track_position += 24;
}
/* write the TOC entry */
track_data[physical_sector * 2 + 0] = (UINT8) (idam_offset >> 0);
track_data[physical_sector * 2 + 1] = (UINT8) (idam_offset >> 8);
physical_sector++;
}
/* write track lead in */
memset(&track_data[physical_sector * 2], 0x4e, DMK_LEAD_IN);
/* write track footer */
assert(max_track_size >= (UINT32)track_position);
memset(&track_data[track_position], 0x4e, max_track_size - track_position);
done:
return err;
}
static int coco_dmk_get_heads_per_disk(floppy_image_legacy *floppy)
{
return get_dmk_tag(floppy)->heads;
}
static int coco_dmk_get_tracks_per_disk(floppy_image_legacy *floppy)
{
return get_dmk_tag(floppy)->tracks;
}
static UINT32 coco_dmk_get_track_size(floppy_image_legacy *floppy, int head, int track)
{
return get_dmk_tag(floppy)->track_size;
}
static floperr_t coco_dmk_seek_sector_in_track(floppy_image_legacy *floppy, int head, int track, int sector, int sector_is_index, int dirtify, UINT8 **sector_data, UINT32 *sector_length)
{
struct dmk_tag *tag = get_dmk_tag(floppy);
floperr_t err;
UINT32 idam_offset = 0;
UINT16 calculated_crc;
size_t i;
size_t offs;
int state;
UINT8 *track_data;
void *track_data_v;
size_t track_length;
size_t sec_len;
err = floppy_load_track(floppy, head, track, dirtify, &track_data_v, &track_length);
if (err)
return err;
track_data = (UINT8 *) track_data_v;
/* search for matching IDAM */
for (i = 0; i < DMK_TOC_LEN; i++)
{
idam_offset = track_data[i * 2 + 1];
idam_offset <<= 8;
idam_offset |= track_data[i * 2 + 0];
idam_offset &= 0x3FFF;
if (idam_offset == 0)
{
/* we've reached the end of the road */
i = DMK_TOC_LEN;
break;
}
if ((idam_offset + DMK_IDAM_LENGTH) >= tag->track_size)
continue;
calculated_crc = ccitt_crc16(0xCDB4, &track_data[idam_offset], DMK_IDAM_LENGTH - 2);
if (calculated_crc == dmk_idam_crc(&track_data[idam_offset]))
{
if (sector_is_index)
{
/* the sector is indexed; decrement the index and go */
if (sector-- == 0)
break;
}
else
{
/* check IDAM integrity and check for matching sector */
if (sector == dmk_idam_sector(&track_data[idam_offset])
/* && (track == dmk_idam_track(&track_data[idam_offset])) */
/* && (head == dmk_idam_side(&track_data[idam_offset])) */
)
break;
}
}
}
if (i >= DMK_TOC_LEN)
return FLOPPY_ERROR_SEEKERROR;
/* we found a matching sector ID */
state = 0;
offs = idam_offset + DMK_IDAM_LENGTH;
/* find pattern 0xA1A1FB; this represents the start of a data sector */
for (i = 0; i < DMK_DATA_GAP; i++)
{
/* overflowing the track? */
if ((i + offs) >= tag->track_size)
return FLOPPY_ERROR_SEEKERROR;
if (track_data[offs + i] == 0xA1)
state++;
else if ((track_data[offs + i] == 0xFB) && state)
break;
else
state = 0;
}
if (i >= DMK_DATA_GAP)
return FLOPPY_ERROR_SEEKERROR;
offs += i + 1;
sec_len = 128 << dmk_idam_sectorlength(&track_data[idam_offset]);
if ((offs + sec_len) > track_length)
return FLOPPY_ERROR_INVALIDIMAGE;
if (sector_data)
*sector_data = track_data + offs;
if (sector_length)
*sector_length = sec_len;
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_dmk_get_sector_length(floppy_image_legacy *floppy, int head, int track, int sector, UINT32 *sector_length)
{
return coco_dmk_seek_sector_in_track(floppy, head, track, sector, FALSE, FALSE, NULL, sector_length);
}
static floperr_t coco_dmk_get_indexed_sector_info(floppy_image_legacy *floppy, int head, int track, int sector_index, int *cylinder, int *side, int *sector, UINT32 *sector_length, unsigned long *flags)
{
floperr_t err;
UINT32 idam_offset;
const UINT8 *track_data;
void *track_data_v;
if (sector_index*2 >= DMK_TOC_LEN)
return FLOPPY_ERROR_SEEKERROR;
err = floppy_load_track(floppy, head, track, FALSE, &track_data_v, NULL);
if (err)
return err;
track_data = (UINT8 *) track_data_v;
idam_offset = track_data[sector_index * 2 + 1];
idam_offset <<= 8;
idam_offset |= track_data[sector_index * 2 + 0];
idam_offset &= 0x3FFF;
if (idam_offset == 0)
return FLOPPY_ERROR_SEEKERROR;
if (cylinder)
*cylinder = dmk_idam_track(&track_data[idam_offset]);
if (side)
*side = dmk_idam_side(&track_data[idam_offset]);
if (sector)
*sector = dmk_idam_sector(&track_data[idam_offset]);
if (sector_length)
*sector_length = 128 << dmk_idam_sectorlength(&track_data[idam_offset]);
if (flags)
/* TODO: read DAM or DDAM and determine flags */
*flags = 0;
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t internal_coco_dmk_read_sector(floppy_image_legacy *floppy, int head, int track, int sector, int sector_is_index, void *buffer, size_t buflen)
{
floperr_t err;
UINT32 sector_length;
UINT16 crc_on_disk;
UINT16 calculated_crc;
UINT8 *sector_data;
err = coco_dmk_seek_sector_in_track(floppy, head, track, sector, sector_is_index, FALSE, &sector_data, &sector_length);
if (err)
return err;
crc_on_disk = sector_data[sector_length + 0];
crc_on_disk <<= 8;
crc_on_disk += sector_data[sector_length + 1];
calculated_crc = ccitt_crc16(0xE295, sector_data, sector_length);
if (calculated_crc != crc_on_disk)
return FLOPPY_ERROR_INVALIDIMAGE;
memcpy(buffer, sector_data, MIN(sector_length, buflen));
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t internal_coco_dmk_write_sector(floppy_image_legacy *floppy, int head, int track, int sector, int sector_is_index, const void *buffer, size_t buflen, int ddam)
{
floperr_t err;
UINT32 sector_length;
UINT8 *sector_data;
UINT16 crc;
err = coco_dmk_seek_sector_in_track(floppy, head, track, sector, sector_is_index, TRUE, &sector_data, &sector_length);
if (err)
return err;
if (buflen > sector_length)
return FLOPPY_ERROR_INTERNAL;
memcpy(sector_data, buffer, buflen);
crc = ccitt_crc16(0xE295, sector_data, sector_length);
sector_data[sector_length + 0] = crc >> 8;
sector_data[sector_length + 1] = crc >> 0;
return FLOPPY_ERROR_SUCCESS;
}
static floperr_t coco_dmk_read_sector(floppy_image_legacy *floppy, int head, int track, int sector, void *buffer, size_t buflen)
{
return internal_coco_dmk_read_sector(floppy, head, track, sector, FALSE, buffer, buflen);
}
static floperr_t coco_dmk_write_sector(floppy_image_legacy *floppy, int head, int track, int sector, const void *buffer, size_t buflen, int ddam)
{
return internal_coco_dmk_write_sector(floppy, head, track, sector, FALSE, buffer, buflen, ddam);
}
static floperr_t coco_dmk_read_indexed_sector(floppy_image_legacy *floppy, int head, int track, int sector, void *buffer, size_t buflen)
{
return internal_coco_dmk_read_sector(floppy, head, track, sector, TRUE, buffer, buflen);
}
static floperr_t coco_dmk_write_indexed_sector(floppy_image_legacy *floppy, int head, int track, int sector, const void *buffer, size_t buflen, int ddam)
{
return internal_coco_dmk_write_sector(floppy, head, track, sector, TRUE, buffer, buflen, ddam);
}
static void coco_dmk_interpret_header(floppy_image_legacy *floppy, int *heads, int *tracks, int *track_size)
{
UINT8 header[DMK_HEADER_LEN];
floppy_image_read(floppy, header, 0, DMK_HEADER_LEN);
if (tracks)
*tracks = header[1];
if (heads)
*heads = (header[4] & 0x10) ? 1 : 2;
if (track_size)
*track_size = ((int) header[3]) * 0x100 + header[2];
}
FLOPPY_CONSTRUCT(coco_dmk_construct)
{
struct FloppyCallbacks *callbacks;
struct dmk_tag *tag;
UINT8 header[DMK_HEADER_LEN];
int heads, tracks, track_size, sectors, sector_length;
if (params)
{
heads = option_resolution_lookup_int(params, PARAM_HEADS);
tracks = option_resolution_lookup_int(params, PARAM_TRACKS);
sectors = option_resolution_lookup_int(params, PARAM_SECTORS);
sector_length = option_resolution_lookup_int(params, PARAM_SECTOR_LENGTH);
track_size = coco_dmk_min_track_size(sectors, sector_length) + DMK_EXTRA_TRACK_LENGTH;
memset(header, 0, sizeof(header));
header[1] = tracks;
header[2] = track_size >> 0;
header[3] = track_size >> 8;
header[4] = (heads == 2) ? 0x00 : 0x10;
floppy_image_write(floppy, header, 0, sizeof(header));
}
else
{
coco_dmk_interpret_header(floppy, &heads, &tracks, &track_size);
}
tag = (dmk_tag *)floppy_create_tag(floppy, sizeof(struct dmk_tag));
if (!tag)
return FLOPPY_ERROR_OUTOFMEMORY;
tag->heads = heads;
tag->track_size = track_size;
tag->tracks = tracks;
callbacks = floppy_callbacks(floppy);
callbacks->read_track = coco_dmk_read_track;
callbacks->write_track = coco_dmk_write_track;
callbacks->get_track_data_offset = coco_dmk_get_track_data_offset;
callbacks->format_track = coco_dmk_format_track;
callbacks->get_heads_per_disk = coco_dmk_get_heads_per_disk;
callbacks->get_tracks_per_disk = coco_dmk_get_tracks_per_disk;
callbacks->get_track_size = coco_dmk_get_track_size;
callbacks->get_sector_length = coco_dmk_get_sector_length;
callbacks->get_indexed_sector_info = coco_dmk_get_indexed_sector_info;
callbacks->read_sector = coco_dmk_read_sector;
callbacks->write_sector = coco_dmk_write_sector;
callbacks->read_indexed_sector = coco_dmk_read_indexed_sector;
callbacks->write_indexed_sector = coco_dmk_write_indexed_sector;
return FLOPPY_ERROR_SUCCESS;
}
FLOPPY_IDENTIFY(coco_dmk_identify)
{
int heads, tracks, track_size;
UINT64 size, expected_size;
size = floppy_image_size(floppy);
coco_dmk_interpret_header(floppy, &heads, &tracks, &track_size);
expected_size = DMK_HEADER_LEN + (heads * tracks * track_size);
*vote = (size == expected_size) ? 100 : 0;
return FLOPPY_ERROR_SUCCESS;
}
/* ----------------------------------------------------------------------- */
LEGACY_FLOPPY_OPTIONS_START( coco )
LEGACY_FLOPPY_OPTION( coco_jvc, "dsk", "CoCo JVC disk image", coco_jvc_identify, coco_jvc_construct, NULL,
HEADS([1]-2)
TRACKS([35]-255)
SECTORS(1-[18]-255)
SECTOR_LENGTH(128/[256]/512/1024)
FIRST_SECTOR_ID(0-[1]))
LEGACY_FLOPPY_OPTION( coco_os9, "os9", "CoCo OS-9 disk image", coco_os9_identify, coco_os9_construct, NULL,
HEADS([1]-2)
TRACKS([35]-255)
SECTORS(1-[18]-255)
SECTOR_LENGTH([256])
FIRST_SECTOR_ID([1]))
LEGACY_FLOPPY_OPTION( coco_vdk, "vdk", "CoCo VDK disk image", coco_vdk_identify, coco_vdk_construct, NULL,
HEADS([1]-2)
TRACKS([35]-255)
SECTORS([18])
SECTOR_LENGTH([256])
FIRST_SECTOR_ID([1]))
LEGACY_FLOPPY_OPTION( coco_dmk, "dsk,dmk", "CoCo DMK disk image", coco_dmk_identify, coco_dmk_construct, NULL,
HEADS([1]-2)
TRACKS([35]-255)
SECTORS(1-[18])
SECTOR_LENGTH(128/[256]/512/1024/2048/4096/8192)
INTERLEAVE(0-[6]-17)
FIRST_SECTOR_ID(0-[1]))
LEGACY_FLOPPY_OPTIONS_END
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