86Box/src/cdrom/cdrom_image.cc

/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		CD-ROM image support.
 *
 * Version:	@(#)cdrom_image.cc	1.0.2	2018/10/09
 *
 * Author:	RichardG867,
 *		Miran Grca, <mgrca8@gmail.com>
 *		bit,
 *
 *		Copyright 2015-2018 Richardg867.
 *		Copyright 2015-2018 Miran Grca.
 *		Copyright 2017,2018 bit.
 */
#define __USE_LARGEFILE64
#define _LARGEFILE_SOURCE
#define _LARGEFILE64_SOURCE
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include "../config.h"
#include "../plat.h"
#include "../scsi/scsi_device.h"
#include "cdrom_dosbox.h"
#include "cdrom.h"
#include "cdrom_image.h"
#include "cdrom_null.h"

#define CD_STATUS_EMPTY		0
#define CD_STATUS_DATA_ONLY	1
#define CD_STATUS_PLAYING	2
#define CD_STATUS_PAUSED	3
#define CD_STATUS_STOPPED	4

/* The addresses sent from the guest are absolute, ie. a LBA of 0 corresponds to a MSF of 00:00:00. Otherwise, the counter displayed by the guest is wrong:
   there is a seeming 2 seconds in which audio plays but counter does not move, while a data track before audio jumps to 2 seconds before the actual start
   of the audio while audio still plays. With an absolute conversion, the counter is fine. */
#define MSFtoLBA(m,s,f)		((((m*60)+s)*75)+f)

extern CDROM	image_cdrom;

typedef struct __attribute__((__packed__))
{
    uint8_t user_data[2048],
	    ecc[288];
} m1_data_t;

typedef struct __attribute__((__packed__))
{
    uint8_t sub_header[8],
    user_data[2328];
} m2_data_t;

typedef union __attribute__((__packed__))
{
    m1_data_t m1_data;
    m2_data_t m2_data;
    uint8_t raw_data[2336];
} sector_data_t;

typedef struct __attribute__((__packed__))
{
    uint8_t sync[12];
    uint8_t header[4];
    sector_data_t data;
} sector_raw_data_t;

typedef union __attribute__((__packed__))
{
    sector_raw_data_t sector_data;
    uint8_t raw_data[2352];
} sector_t;

typedef struct __attribute__((__packed__))
{
    sector_t sector;
    uint8_t c2[296];
    uint8_t subchannel_raw[96];
    uint8_t subchannel_q[16];
    uint8_t subchannel_rw[96];
} cdrom_sector_t;

typedef union __attribute__((__packed__))
{
    cdrom_sector_t cdrom_sector;
    uint8_t buffer[2856];
} sector_buffer_t;

sector_buffer_t cdrom_sector_buffer;

int cdrom_sector_size;
uint8_t raw_buffer[2448];
uint8_t extra_buffer[296];

enum
{
    CD_STOPPED = 0,
    CD_PLAYING,
    CD_PAUSED
};


#ifdef ENABLE_CDROM_IMAGE_LOG
int cdrom_image_do_log = ENABLE_CDROM_IMAGE_LOG;
#endif


static CDROM_Interface_Image*	cdimg[CDROM_NUM] = { NULL, NULL, NULL, NULL };
static char			afn[1024];

void	image_close(uint8_t id);


void
cdrom_image_log(const char *format, ...)
{
#ifdef ENABLE_CDROM_IMAGE_LOG
    if (cdrom_image_do_log) {
	va_list ap;
	va_start(ap, format);
	vprintf(format, ap);
	va_end(ap);
	fflush(stdout);
    }
#endif
}


int
image_audio_callback(uint8_t id, int16_t *output, int len)
{
    cdrom_drive_t *dev = &cdrom_drives[id];
    int ret = 1;

    if (!dev->sound_on || (dev->cd_state != CD_PLAYING) || cdrom_image[id].image_is_iso) {
	cdrom_image_log("image_audio_callback(i): Not playing\n", id);
	if (dev->cd_state == CD_PLAYING)
		dev->seek_pos += (len >> 11);
	memset(output, 0, len * 2);
	return 0;
    }
    while (dev->cd_buflen < len) {
	if (dev->seek_pos < dev->cd_end) {
		if (!cdimg[id]->ReadSector((unsigned char*)&dev->cd_buffer[dev->cd_buflen], true,
					   dev->seek_pos)) {
			memset(&dev->cd_buffer[dev->cd_buflen], 0, (BUF_SIZE - dev->cd_buflen) * 2);
			dev->cd_state = CD_STOPPED;
			dev->cd_buflen = len;
			ret = 0;
		} else {
			dev->seek_pos++;
			dev->cd_buflen += (RAW_SECTOR_SIZE / 2);
			ret = 1;
		}
	} else {
		memset(&dev->cd_buffer[dev->cd_buflen], 0, (BUF_SIZE - dev->cd_buflen) * 2);
		dev->cd_state = CD_STOPPED;
		dev->cd_buflen = len;
		ret = 0;
	}
    }

    memcpy(output, dev->cd_buffer, len * 2);
    memmove(dev->cd_buffer, &dev->cd_buffer[len], (BUF_SIZE - len) * 2);
    dev->cd_buflen -= len;
    return ret;
}


void
image_audio_stop(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    dev->cd_state = CD_STOPPED;
}


static uint8_t
image_playaudio(uint8_t id, uint32_t pos, uint32_t len, int ismsf)
{
    cdrom_drive_t *dev = &cdrom_drives[id];
    if (!cdimg[id])
	return 0;
    int number;
    unsigned char attr;
    TMSF tmsf;
    int m = 0, s = 0, f = 0;
    cdimg[id]->GetAudioTrackInfo(cdimg[id]->GetTrack(pos), number, tmsf, attr);
    if (attr == DATA_TRACK) {
	cdrom_image_log("Can't play data track\n");
	dev->seek_pos = 0;
	dev->cd_state = CD_STOPPED;
	return 0;
    }
    cdrom_image_log("Play audio - %08X %08X %i\n", pos, len, ismsf);
    if (ismsf == 2) {
	cdimg[id]->GetAudioTrackInfo(pos, number, tmsf, attr);
	pos = MSFtoLBA(tmsf.min, tmsf.sec, tmsf.fr) - 150;
	cdimg[id]->GetAudioTrackInfo(len, number, tmsf, attr);
	len = MSFtoLBA(tmsf.min, tmsf.sec, tmsf.fr) - 150;
    } else if (ismsf == 1) {
	m = (pos >> 16) & 0xff;
	s = (pos >> 8) & 0xff;
	f = pos & 0xff;

	if (pos == 0xffffff) {
		cdrom_image_log("Playing from current position (MSF)\n");
		pos = dev->seek_pos;
	} else
		pos = MSFtoLBA(m, s, f) - 150;

	m = (len >> 16) & 0xff;
	s = (len >> 8) & 0xff;
	f = len & 0xff;
	len = MSFtoLBA(m, s, f) - 150;

	cdrom_image_log("MSF - pos = %08X len = %08X\n", pos, len);
    } else if (ismsf == 0) {
	if (pos == 0xffffffff) {
		cdrom_image_log("Playing from current position\n");
		pos = dev->seek_pos;
	}
	len += pos;
    }

    dev->seek_pos   = pos;
    dev->cd_end   = len;
    dev->cd_state = CD_PLAYING;
    dev->cd_buflen = 0;

    return 1;
}


static void
image_pause(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    if (!cdimg[id] || cdrom_image[id].image_is_iso) return;
    if (dev->cd_state == CD_PLAYING)
	dev->cd_state = CD_PAUSED;
}


static void
image_resume(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    if (!cdimg[id] || cdrom_image[id].image_is_iso)
	return;
    if (dev->cd_state == CD_PAUSED)
	dev->cd_state = CD_PLAYING;
}


static void
image_stop(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    if (!cdimg[id] || cdrom_image[id].image_is_iso)
	return;
    dev->cd_state = CD_STOPPED;
}


static int
image_ready(uint8_t id)
{
    if (!cdimg[id] || (wcslen(cdrom_image[id].image_path) == 0))
	return 0;

    return 1;
}


static int
image_get_last_block(uint8_t id)
{
    int first_track, last_track;
    int number, c;
    unsigned char attr;
    TMSF tmsf;
    uint32_t lb=0;

    if (!cdimg[id])
	return 0;

    cdimg[id]->GetAudioTracks(first_track, last_track, tmsf);

    for (c = 0; c <= last_track; c++) {
	uint32_t address;
	cdimg[id]->GetAudioTrackInfo(c+1, number, tmsf, attr);
	address = MSFtoLBA(tmsf.min, tmsf.sec, tmsf.fr) - 150;	/* Do the - 150 here as well. */
	if (address > lb)
		lb = address;
    }
    return lb;
}


static int
image_medium_changed(uint8_t id)
{
    /* There is no way to change the medium within an already mounted image. */
    return 0;
}


static uint8_t
image_getcurrentsubchannel(uint8_t id, uint8_t *b, int msf)
{
    cdrom_drive_t *dev = &cdrom_drives[id];
    uint8_t ret;
    int pos = 0;
    uint32_t cdpos;
    TMSF relPos, absPos;
    unsigned char attr, track, index;

    cdpos = dev->seek_pos;

    if (!cdimg[id])
	return 0;

    cdimg[id]->GetAudioSub(cdpos, attr, track, index, relPos, absPos);

    if (cdrom_image[id].image_is_iso)
	ret = 0x15;
    else {
	if (dev->cd_state == CD_PLAYING)
		ret = 0x11;
	else if (dev->cd_state == CD_PAUSED)
		ret = 0x12;
	else
		ret = 0x13;
    }

    b[pos++] = attr;
    b[pos++] = track;
    b[pos++] = index;

    if (msf) {
	b[pos + 3] = (uint8_t) absPos.fr;
	b[pos + 2] = (uint8_t) absPos.sec;
	b[pos + 1] = (uint8_t) absPos.min;
	b[pos]     = 0;
	pos += 4;
	b[pos + 3] = (uint8_t) relPos.fr;
	b[pos + 2] = (uint8_t) relPos.sec;
	b[pos + 1] = (uint8_t) relPos.min;
	b[pos]     = 0;
	pos += 4;
    } else {
	uint32_t dat = MSFtoLBA(absPos.min, absPos.sec, absPos.fr) - 150;
	b[pos++] = (dat >> 24) & 0xff;
	b[pos++] = (dat >> 16) & 0xff;
	b[pos++] = (dat >> 8) & 0xff;
	b[pos++] = dat & 0xff;
	dat = MSFtoLBA(relPos.min, relPos.sec, relPos.fr);
	b[pos++] = (dat >> 24) & 0xff;
	b[pos++] = (dat >> 16) & 0xff;
	b[pos++] = (dat >> 8) & 0xff;
	b[pos++] = dat & 0xff;
    }

    return ret;
}


static int
image_is_track_audio(uint8_t id, uint32_t pos, int ismsf)
{
    int m, s, f;
    unsigned char attr;
    TMSF tmsf;
    int number;

    if (!cdimg[id] || cdrom_image[id].image_is_iso)
	return 0;

    if (ismsf) {
	m = (pos >> 16) & 0xff;
	s = (pos >> 8) & 0xff;
	f = pos & 0xff;
	pos = MSFtoLBA(m, s, f) - 150;
    }

    /* GetTrack requires LBA. */
    cdimg[id]->GetAudioTrackInfo(cdimg[id]->GetTrack(pos), number, tmsf, attr);

    return attr == AUDIO_TRACK;
}


static int
is_legal(int id, int cdrom_sector_type, int cdrom_sector_flags, int audio, int mode2)
{
    if (!(cdrom_sector_flags & 0x70)) {		/* 0x00/0x08/0x80/0x88 are illegal modes */
	cdrom_image_log("CD-ROM %i: [Any Mode] 0x00/0x08/0x80/0x88 are illegal modes\n", id);
	return 0;
    }

    if ((cdrom_sector_type != 1) && !audio) {
	if (!(cdrom_sector_flags & 0x70)) {		/* 0x00/0x08/0x80/0x88 are illegal modes */
		cdrom_image_log("CD-ROM %i: [Any Data Mode] 0x00/0x08/0x80/0x88 are illegal modes\n", id);
		return 0;
	}

	if ((cdrom_sector_flags & 0x06) == 0x06) {
		cdrom_image_log("CD-ROM %i: [Any Data Mode] Invalid error flags\n", id);
		return 0;
	}

	if (((cdrom_sector_flags & 0x700) == 0x300) || ((cdrom_sector_flags & 0x700) > 0x400)) {
		cdrom_image_log("CD-ROM %i: [Any Data Mode] Invalid subchannel data flags (%02X)\n", id, cdrom_sector_flags & 0x700);
		return 0;
	}

	if ((cdrom_sector_flags & 0x18) == 0x08) {		/* EDC/ECC without user data is an illegal mode */
		cdrom_image_log("CD-ROM %i: [Any Data Mode] EDC/ECC without user data is an illegal mode\n", id);
		return 0;
	}

	if (((cdrom_sector_flags & 0xf0) == 0x90) || ((cdrom_sector_flags & 0xf0) == 0xc0)) {		/* 0x90/0x98/0xC0/0xC8 are illegal modes */
		cdrom_image_log("CD-ROM %i: [Any Data Mode] 0x90/0x98/0xC0/0xC8 are illegal modes\n", id);
		return 0;
	}

	if (((cdrom_sector_type > 3) && (cdrom_sector_type != 8)) || (mode2 && (mode2 & 0x03))) {
		if ((cdrom_sector_flags & 0xf0) == 0x30) {		/* 0x30/0x38 are illegal modes */
			cdrom_image_log("CD-ROM %i: [Any XA Mode 2] 0x30/0x38 are illegal modes\n", id);
			return 0;
		}
		if (((cdrom_sector_flags & 0xf0) == 0xb0) || ((cdrom_sector_flags & 0xf0) == 0xd0)) {	/* 0xBx and 0xDx are illegal modes */
			cdrom_image_log("CD-ROM %i: [Any XA Mode 2] 0xBx and 0xDx are illegal modes\n", id);
			return 0;
		}
	}
    }

    return 1;
}


static void
read_sector_to_buffer(uint8_t id, uint8_t *raw_buffer, uint32_t msf, uint32_t lba, int mode2, int len)
{
    uint8_t *bb = raw_buffer;

    cdimg[id]->ReadSector(raw_buffer + 16, false, lba);

    /* Sync bytes */
    bb[0] = 0;
    memset(bb + 1, 0xff, 10);
    bb[11] = 0;
    bb += 12;

    /* Sector header */
    bb[0] = (msf >> 16) & 0xff;
    bb[1] = (msf >> 8) & 0xff;
    bb[2] = msf & 0xff;

    bb[3] = 1; /* mode 1 data */
    bb += mode2 ? 12 : 4;
    bb += len;
    if (mode2 && ((mode2 & 0x03) == 1))
	memset(bb, 0, 280);
    else if (!mode2)
	memset(bb, 0, 288);
}


static void
read_audio(int id, uint32_t lba, uint8_t *b)
{
    if (cdimg[id]->GetSectorSize(lba) == 2352)
	cdimg[id]->ReadSector(raw_buffer, true, lba);
    else
	cdimg[id]->ReadSectorSub(raw_buffer, lba);

    memcpy(b, raw_buffer, 2352);
    cdrom_sector_size = 2352;
}


static void
read_mode1(int id, int cdrom_sector_flags, uint32_t lba, uint32_t msf, int mode2, uint8_t *b)
{
    if ((cdrom_image[id].image_is_iso) || (cdimg[id]->GetSectorSize(lba) == 2048))
	read_sector_to_buffer(id, raw_buffer, msf, lba, mode2, 2048);
    else if (cdimg[id]->GetSectorSize(lba) == 2352)
	cdimg[id]->ReadSector(raw_buffer, true, lba);
    else
	cdimg[id]->ReadSectorSub(raw_buffer, lba);

    cdrom_sector_size = 0;

    if (cdrom_sector_flags & 0x80) {	/* Sync */
	cdrom_image_log("CD-ROM %i: [Mode 1] Sync\n", id);
	memcpy(b, raw_buffer, 12);
	cdrom_sector_size += 12;
	b += 12;
    }

    if (cdrom_sector_flags & 0x20) {	/* Header */
	cdrom_image_log("CD-ROM %i: [Mode 1] Header\n", id);
	memcpy(b, raw_buffer + 12, 4);
	cdrom_sector_size += 4;
	b += 4;
    }

    if (cdrom_sector_flags & 0x40) {	/* Sub-header */
	if (!(cdrom_sector_flags & 0x10)) {		/* No user data */
		cdrom_image_log("CD-ROM %i: [Mode 1] Sub-header\n", id);
		memcpy(b, raw_buffer + 16, 8);
		cdrom_sector_size += 8;
		b += 8;
	}
    }

    if (cdrom_sector_flags & 0x10) {	/* User data */
	cdrom_image_log("CD-ROM %i: [Mode 1] User data\n", id);
	memcpy(b, raw_buffer + 16, 2048);
	cdrom_sector_size += 2048;
	b += 2048;
    }

    if (cdrom_sector_flags & 0x08) {	/* EDC/ECC */
	cdrom_image_log("CD-ROM %i: [Mode 1] EDC/ECC\n", id);
	memcpy(b, raw_buffer + 2064, 288);
	cdrom_sector_size += 288;
	b += 288;
    }
}


static void
read_mode2_non_xa(int id, int cdrom_sector_flags, uint32_t lba, uint32_t msf, int mode2, uint8_t *b)
{
    if ((cdrom_image[id].image_is_iso) || (cdimg[id]->GetSectorSize(lba) == 2336))
	read_sector_to_buffer(id, raw_buffer, msf, lba, mode2, 2336);
    else if (cdimg[id]->GetSectorSize(lba) == 2352)
	cdimg[id]->ReadSector(raw_buffer, true, lba);
    else
	cdimg[id]->ReadSectorSub(raw_buffer, lba);

    cdrom_sector_size = 0;

    if (cdrom_sector_flags & 0x80) {	/* Sync */
	cdrom_image_log("CD-ROM %i: [Mode 2 Formless] Sync\n", id);
	memcpy(b, raw_buffer, 12);
	cdrom_sector_size += 12;
	b += 12;
    }

    if (cdrom_sector_flags & 0x20) {	/* Header */
	cdrom_image_log("CD-ROM %i: [Mode 2 Formless] Header\n", id);
	memcpy(b, raw_buffer + 12, 4);
	cdrom_sector_size += 4;
	b += 4;
    }

    /* Mode 1 sector, expected type is 1 type. */
    if (cdrom_sector_flags & 0x40) {	/* Sub-header */
	cdrom_image_log("CD-ROM %i: [Mode 2 Formless] Sub-header\n", id);
	memcpy(b, raw_buffer + 16, 8);
	cdrom_sector_size += 8;
	b += 8;
    }

    if (cdrom_sector_flags & 0x10) {	/* User data */
	cdrom_image_log("CD-ROM %i: [Mode 2 Formless] User data\n", id);
	memcpy(b, raw_buffer + 24, 2336);
	cdrom_sector_size += 2336;
	b += 2336;
    }
}


static void
read_mode2_xa_form1(int id, int cdrom_sector_flags, uint32_t lba, uint32_t msf, int mode2, uint8_t *b)
{
    if ((cdrom_image[id].image_is_iso) || (cdimg[id]->GetSectorSize(lba) == 2048))
	read_sector_to_buffer(id, raw_buffer, msf, lba, mode2, 2048);
    else if (cdimg[id]->GetSectorSize(lba) == 2352)
	cdimg[id]->ReadSector(raw_buffer, true, lba);
    else
	cdimg[id]->ReadSectorSub(raw_buffer, lba);

    cdrom_sector_size = 0;

    if (cdrom_sector_flags & 0x80) {	/* Sync */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] Sync\n", id);
	memcpy(b, raw_buffer, 12);
	cdrom_sector_size += 12;
	b += 12;
    }

    if (cdrom_sector_flags & 0x20) {	/* Header */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] Header\n", id);
	memcpy(b, raw_buffer + 12, 4);
	cdrom_sector_size += 4;
	b += 4;
    }

    if (cdrom_sector_flags & 0x40) {	/* Sub-header */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] Sub-header\n", id);
	memcpy(b, raw_buffer + 16, 8);
	cdrom_sector_size += 8;
	b += 8;
    }

    if (cdrom_sector_flags & 0x10) {	/* User data */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] User data\n", id);
	memcpy(b, raw_buffer + 24, 2048);
	cdrom_sector_size += 2048;
	b += 2048;
    }

    if (cdrom_sector_flags & 0x08) {	/* EDC/ECC */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] EDC/ECC\n", id);
	memcpy(b, raw_buffer + 2072, 280);
	cdrom_sector_size += 280;
	b += 280;
    }
}


static void
read_mode2_xa_form2(int id, int cdrom_sector_flags, uint32_t lba, uint32_t msf, int mode2, uint8_t *b)
{
    if ((cdrom_image[id].image_is_iso) || (cdimg[id]->GetSectorSize(lba) == 2324))
	read_sector_to_buffer(id, raw_buffer, msf, lba, mode2, 2324);
    else if (cdimg[id]->GetSectorSize(lba) == 2352)
	cdimg[id]->ReadSector(raw_buffer, true, lba);
    else
	cdimg[id]->ReadSectorSub(raw_buffer, lba);

    cdrom_sector_size = 0;

    if (cdrom_sector_flags & 0x80) {	/* Sync */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 2] Sync\n", id);
	memcpy(b, raw_buffer, 12);
	cdrom_sector_size += 12;
	b += 12;
    }

    if (cdrom_sector_flags & 0x20) {	/* Header */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 2] Header\n", id);
	memcpy(b, raw_buffer + 12, 4);
	cdrom_sector_size += 4;
	b += 4;
    }

    if (cdrom_sector_flags & 0x40) {	/* Sub-header */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 2] Sub-header\n", id);
	memcpy(b, raw_buffer + 16, 8);
	cdrom_sector_size += 8;
	b += 8;
    }

    if (cdrom_sector_flags & 0x10) {	/* User data */
	cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 2] User data\n", id);
	memcpy(b, raw_buffer + 24, 2328);
	cdrom_sector_size += 2328;
	b += 2328;
    }
}


static int
image_readsector_raw(uint8_t id, uint8_t *buffer, int sector, int ismsf, int cdrom_sector_type,
		     int cdrom_sector_flags, int *len)
{
    uint8_t *b, *temp_b;
    uint32_t msf, lba;
    int audio, mode2;
    int m, s, f;

    if (!cdimg[id])
	return 0;

    if (!cdrom_drives[id].host_drive)
	return 0;

    b = temp_b = buffer;

    *len = 0;

    if (ismsf) {
	m = (sector >> 16) & 0xff;
	s = (sector >> 8) & 0xff;
	f = sector & 0xff;
	lba = MSFtoLBA(m, s, f) - 150;
	msf = sector;
    } else {
	lba = sector;
	msf = cdrom_lba_to_msf_accurate(sector);
    }

    if (cdrom_image[id].image_is_iso) {
	audio = 0;
	mode2 = cdimg[id]->IsMode2(lba) ? 1 : 0;
    } else {
	audio = image_is_track_audio(id, sector, ismsf);
	mode2 = cdimg[id]->IsMode2(lba) ? 1 : 0;
    }
    mode2 <<= 2;
    mode2 |= cdimg[id]->GetMode2Form(lba);

    memset(raw_buffer, 0, 2448);
    memset(extra_buffer, 0, 296);

    if (!(cdrom_sector_flags & 0xf0)) {		/* 0x00 and 0x08 are illegal modes */
	cdrom_image_log("CD-ROM %i: [Mode 1] 0x00 and 0x08 are illegal modes\n", id);
	return 0;
    }

    if (!is_legal(id, cdrom_sector_type, cdrom_sector_flags, audio, mode2))
	return 0;

    if ((cdrom_sector_type == 3) || ((cdrom_sector_type > 4) && (cdrom_sector_type != 8))) {
	if (cdrom_sector_type == 3)
		cdrom_image_log("CD-ROM %i: Attempting to read a Yellowbook Mode 2 data sector from an image\n", id);
	if (cdrom_sector_type > 4)
		cdrom_image_log("CD-ROM %i: Attempting to read a XA Mode 2 Form 2 data sector from an image\n", id);
	return 0;
    } else if (cdrom_sector_type == 1) {
	if (!audio || cdrom_image[id].image_is_iso) {
		cdrom_image_log("CD-ROM %i: [Audio] Attempting to read an audio sector from a data image\n", id);
		return 0;
	}

	read_audio(id, lba, temp_b);
    } else if (cdrom_sector_type == 2) {
	if (audio || mode2) {
		cdrom_image_log("CD-ROM %i: [Mode 1] Attempting to read a sector of another type\n", id);
		return 0;
	}

	read_mode1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
    } else if (cdrom_sector_type == 3) {
	if (audio || !mode2 || (mode2 & 0x03)) {
		cdrom_image_log("CD-ROM %i: [Mode 2 Formless] Attempting to read a sector of another type\n", id);
		return 0;
	}

	read_mode2_non_xa(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
    } else if (cdrom_sector_type == 4) {
	if (audio || !mode2 || ((mode2 & 0x03) != 1)) {
		cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 1] Attempting to read a sector of another type\n", id);
		return 0;
	}

	read_mode2_xa_form1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
    } else if (cdrom_sector_type == 5) {
	if (audio || !mode2 || ((mode2 & 0x03) != 2)) {
		cdrom_image_log("CD-ROM %i: [XA Mode 2 Form 2] Attempting to read a sector of another type\n", id);
		return 0;
	}

	read_mode2_xa_form2(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
    } else if (cdrom_sector_type == 8) {
	if (audio) {
		cdrom_image_log("CD-ROM %i: [Any Data] Attempting to read a data sector from an audio track\n", id);
		return 0;
	}

	if (mode2 && ((mode2 & 0x03) == 1))
		read_mode2_xa_form1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
	else if (!mode2)
		read_mode1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
	else {
		cdrom_image_log("CD-ROM %i: [Any Data] Attempting to read a data sector whose cooked size is not 2048 bytes\n", id);
		return 0;
	}
    } else {
	if (mode2) {
		if ((mode2 & 0x03) == 0x01)
			read_mode2_xa_form1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
		else if ((mode2 & 0x03) == 0x02)
			read_mode2_xa_form2(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
		else
			read_mode2_non_xa(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
	} else {
		if (audio)
			read_audio(id, lba, temp_b);
		else
			read_mode1(id, cdrom_sector_flags, lba, msf, mode2, temp_b);
	}
    }

    if ((cdrom_sector_flags & 0x06) == 0x02) {
	/* Add error flags. */
	cdrom_image_log("CD-ROM %i: Error flags\n", id);
	memcpy(b + cdrom_sector_size, extra_buffer, 294);
	cdrom_sector_size += 294;
    } else if ((cdrom_sector_flags & 0x06) == 0x04) {
	/* Add error flags. */
	cdrom_image_log("CD-ROM %i: Full error flags\n", id);
	memcpy(b + cdrom_sector_size, extra_buffer, 296);
	cdrom_sector_size += 296;
    }

    if ((cdrom_sector_flags & 0x700) == 0x100) {
	cdrom_image_log("CD-ROM %i: Raw subchannel data\n", id);
	memcpy(b + cdrom_sector_size, raw_buffer + 2352, 96);
	cdrom_sector_size += 96;
    } else if ((cdrom_sector_flags & 0x700) == 0x200) {
	cdrom_image_log("CD-ROM %i: Q subchannel data\n", id);
	memcpy(b + cdrom_sector_size, raw_buffer + 2352, 16);
	cdrom_sector_size += 16;
    } else if ((cdrom_sector_flags & 0x700) == 0x400) {
	cdrom_image_log("CD-ROM %i: R/W subchannel data\n", id);
	memcpy(b + cdrom_sector_size, raw_buffer + 2352, 96);
	cdrom_sector_size += 96;
    }

    *len = cdrom_sector_size;

    return 1;
}


static uint32_t
image_size(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    return dev->cdrom_capacity;
}


static int
image_readtoc(uint8_t id, unsigned char *b, unsigned char starttrack, int msf, int maxlen, int single)
{
    int number, len = 4;
    int c, d, first_track, last_track;
    uint32_t temp;
    unsigned char attr;
    TMSF tmsf;

    if (!cdimg[id])
	return 0;

    cdimg[id]->GetAudioTracks(first_track, last_track, tmsf);

    b[2] = first_track;
    b[3] = last_track;

    d = 0;
    for (c = 0; c <= last_track; c++) {
	cdimg[id]->GetAudioTrackInfo(c+1, number, tmsf, attr);
	if (number >= starttrack) {
		d=c;
		break;
	}
    }

    if (starttrack != 0xAA) {
	cdimg[id]->GetAudioTrackInfo(c+1, number, tmsf, attr);
	b[2] = number;
    }

    for (c = d; c <= last_track; c++) {
	cdimg[id]->GetAudioTrackInfo(c+1, number, tmsf, attr);

	b[len++] = 0; /* reserved */
	b[len++] = attr;
	b[len++] = number; /* track number */
	b[len++] = 0; /* reserved */

	if (msf) {
		b[len++] = 0;
		b[len++] = tmsf.min;
		b[len++] = tmsf.sec;
		b[len++] = tmsf.fr;
	} else {
		temp = MSFtoLBA(tmsf.min, tmsf.sec, tmsf.fr) - 150;
		b[len++] = temp >> 24;
		b[len++] = temp >> 16;
		b[len++] = temp >> 8;
		b[len++] = temp;
	}

	if (single)
		break;
    }

    b[0] = (uint8_t)(((len-2) >> 8) & 0xff);
    b[1] = (uint8_t)((len-2) & 0xff);

    return len;
}


static int
image_readtoc_session(uint8_t id, unsigned char *b, int msf, int maxlen)
{
    int number, len = 4;
    TMSF tmsf;
    unsigned char attr;
    uint32_t temp;

    if (!cdimg[id])
	return 0;

    cdimg[id]->GetAudioTrackInfo(1, number, tmsf, attr);

    if (number == 0)
	number = 1;

    b[2] = b[3] = 1;
    b[len++] = 0; /* reserved */
    b[len++] = attr;
    b[len++] = number; /* track number */
    b[len++] = 0; /* reserved */
    if (msf) {
	b[len++] = 0;
	b[len++] = tmsf.min;
	b[len++] = tmsf.sec;
	b[len++] = tmsf.fr;
    } else {
	temp = MSFtoLBA(tmsf.min, tmsf.sec, tmsf.fr) - 150;	/* Do the - 150. */
	b[len++] = temp >> 24;
	b[len++] = temp >> 16;
	b[len++] = temp >> 8;
	b[len++] = temp;
    }

    if (maxlen < len)
	return maxlen;

    return len;
}


static int
image_readtoc_raw(uint8_t id, unsigned char *b, int maxlen)
{
    int track, len = 4;
    int first_track, last_track;
    int number;
    unsigned char attr;
    TMSF tmsf;

    if (!cdimg[id])
	return 0;

    cdimg[id]->GetAudioTracks(first_track, last_track, tmsf);

    b[2] = first_track;
    b[3] = last_track;

    for (track = first_track; track <= last_track; track++) {
	cdimg[id]->GetAudioTrackInfo(track, number, tmsf, attr);

	b[len++] = track;
	b[len++]= attr;
	b[len++]=0;
	b[len++]=0;
	b[len++]=0;
	b[len++]=0;
	b[len++]=0;
	b[len++]=0;
	b[len++] = tmsf.min;
	b[len++] = tmsf.sec;
	b[len++] = tmsf.fr;
    }

    return len;
}


static int
image_status(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    if (!cdimg[id])
	return CD_STATUS_EMPTY;

    if (cdrom_image[id].image_is_iso)
	return CD_STATUS_DATA_ONLY;

    if (cdimg[id]->HasAudioTracks()) {
	switch(dev->cd_state) {
		case CD_PLAYING:
			return CD_STATUS_PLAYING;
		case CD_PAUSED:
			return CD_STATUS_PAUSED;
		case CD_STOPPED:
		default:
			return CD_STATUS_STOPPED;
	}
    }

    return CD_STATUS_DATA_ONLY;
}


void
image_reset(UNUSED(uint8_t id))
{
    return;
}


void
image_close(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    dev->cd_state = CD_STOPPED;
    if (cdimg[id]) {
	delete cdimg[id];
	cdimg[id] = NULL;
    }
}


int
image_open(uint8_t id, wchar_t *fn)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    wcscpy(cdrom_image[id].image_path, fn);

    if (! wcscasecmp(plat_get_extension(fn), L"ISO"))
	cdrom_image[id].image_is_iso = 1;
    else
	cdrom_image[id].image_is_iso = 0;

    cdimg[id] = new CDROM_Interface_Image();
    memset(afn, 0, sizeof(afn));
    wcstombs(afn, fn, sizeof(afn));
    if (!cdimg[id]->SetDevice(afn, false)) {
	image_close(id);
	cdrom_set_null_handler(id);
	cdrom_image_log("[f] image_open(): cdrom_drives[%i].handler = %08X\n", id, cdrom_drives[id].handler);
	return 1;
    }
    dev->cd_state = CD_STOPPED;
    dev->seek_pos = 0;
    dev->cd_buflen = 0;
    dev->cdrom_capacity = image_get_last_block(id) + 1;
    cdrom_drives[id].handler = &image_cdrom;

    return 0;
}


static void
image_exit(uint8_t id)
{
    cdrom_drive_t *dev = &cdrom_drives[id];

    dev->handler_inited = 0;
}


/* TODO: Check for what data type a mixed CD is. */
static int image_media_type_id(uint8_t id)
{
    if (image_size(id) > 405000)
	return 65;		/* DVD. */
    else {
	if (cdrom_image[id].image_is_iso)
		return 1;	/* Data CD. */
	else
		return 3;	/* Mixed mode CD. */
    }
}


CDROM image_cdrom = 
{
    image_ready,
    image_medium_changed,
    image_media_type_id,
    image_audio_callback,
    image_audio_stop,
    image_readtoc,
    image_readtoc_session,
    image_readtoc_raw,
    image_getcurrentsubchannel,
    image_readsector_raw,
    image_playaudio,
    image_pause,
    image_resume,
    image_size,
    image_status,
    image_stop,
    image_exit
};