/*
 * DANG_BEGIN_MODULE
 *
 * drivers/cdrom.c
 *
 * Author: Karsten Rucker (rucker@astro.uni-bonn.de)
 *
 * REMARK
 * See dosemu/doc/README.txt (8. Using CDROMS) for further information
 * /REMARK
 *
 * History:
 *   May 25, 95, Karsten Rucker (rucker@astro.uni-bonn.de)
 *   May 30, 95, Werner Zimmermann (zimmerma@rz.fht-esslingen.de)
 *   - Works with Mitsumi and Aztech/Orchid/Okano/Wearnes CDROM drives
 *   - Minor modifications in comments
 *   Dec 3, 95, lee
 *   - Debugging output changed from *printf()/error() to C_printf()
 *   - Minor editing, no real changes
 *
 * DANG_END_MODULE
 */

#ifdef HAVE_LINUX_CDROM_H
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#ifdef __linux__
#include <linux/cdrom.h>
#endif

#include "emu.h"
#include "dos2linux.h"
#include "utilities.h"

#undef CDROM_DEBUG

static int CdromFd[4] = { -1, -1, -1, -1 };

static int IndexCd = -1;
#define cdrom_fd CdromFd[IndexCd]

static int cdu33a = 0;

/* eject_allowed = 0
 * For Mitsumi and Aztech/Orchid/Okano/Wearnes drives, because eject.com may
 * hang thes system.
 *
 * eject_allowed = 1
 * Allows to eject the cdrom using eject.com.
 */

static int eject_allowed = 1;

/*
 * From mscdex21.doc:
 *
 * The device driver will return a 32-bit value. Bit 0 is the least significant
 * bit. The bits are interpreted as follows (* = dosemu defaults):
 *
 *  Bit 0     0    Door closed
 *            1    Door open
 *  Bit 1     0    Door locked
 *            1    Door unlocked
 *  Bit 2     0    Supports only cooked reading (*)
 *            1    Supports cooked and raw reading
 *  Bit 3     0    Read only (*)
 *            1    Read/write
 *  Bit 4     0    Data read only
 *            1    Data read and plays audio/video tracks (*)
 *  Bit 5     0    No interleaving (*)
 *            1    Supports interleaving
 *  Bit 6     0    Reserved
 *  Bit 7     0    No prefetching (*)
 *            1    Supports prefetching requests
 *  Bit 8     0    No audio channel manipulation
 *            1    Supports audio channel manipulation (*)
 *  Bit 9     0    Supports HSG addressing mode
 *            1    Supports HSG and Red Book addressing modes (*)
 *  "Bit 10-31 0    Reserved (all 0)"
 *  Bit 10    0    Ignore XA directory entries (?)
 *            1    Read XA directory entries (*)(?)
 *  Bit 11    0    Disk present (?)
 *            1    No disk (?)
 *
 */
unsigned int device_status;
struct audio_status {
    unsigned int status;
    unsigned char media_changed;
    unsigned char paused_bit;
    unsigned int last_StartSector, last_EndSector;
    unsigned char outchan0, outchan1, outchan2, outchan3;
    unsigned char volume0, volume1, volume2, volume3;
} audio_status;


#define CALC_PTR(PTR,OFFSET,RESULT_TYPE) ((RESULT_TYPE *)(PTR+OFFSET))


#define MSCD_GETVOLUMESIZE_SIZE    1

#define MSCD_READ_ADRESSING       13
#define MSCD_READ_STARTSECTOR     20
#define MSCD_READ_NUMSECTORS      18

#define MSCD_SEEK_STARTSECTOR     20

#define MSCD_PLAY_ADRESSING       13
#define MSCD_PLAY_STARTSECTOR     14
#define MSCD_PLAY_NUMSECTORS      18

#define MSCD_LOCH_ADRESSING        1
#define MSCD_LOCH_LOCATION         2

#define MSCD_DISKINFO_LTN          1
#define MSCD_DISKINFO_HTN          2
#define MSCD_DISKINFO_LEADOUT      3

#define MSCD_TRACKINFO_TRACKNUM    1
#define MSCD_TRACKINFO_TRACKPOS    2
#define MSCD_TRACKINFO_CTRL        6

#define MSCD_QCHAN_CTRL            1
#define MSCD_QCHAN_TNO             2
#define MSCD_QCHAN_IND             3
#define MSCD_QCHAN_MIN             4
#define MSCD_QCHAN_SEC             5
#define MSCD_QCHAN_FRM             6
#define MSCD_QCHAN_ZERO            7
#define MSCD_QCHAN_AMIN            8
#define MSCD_QCHAN_ASEC            9
#define MSCD_QCHAN_AFRM           10

#define MSCD_AUDSTAT_PAUSED        1
#define MSCD_AUDSTAT_START         3
#define MSCD_AUDSTAT_END           7

#define MSCD_CTRL_VOLUME0          2
#define MSCD_CTRL_VOLUME1          4
#define MSCD_CTRL_VOLUME2          6
#define MSCD_CTRL_VOLUME3          8

#ifdef __linux__
const char *Path_cdrom[] =
    { "/dev/cdrom", "/dev/cdrom2", "/dev/cdrom3", "/dev/cdrom4" };
#endif
#define path_cdrom Path_cdrom[IndexCd]

#ifdef CDROM_DEBUG
static int logging_ioctl(int fd, unsigned int cmd, void *arg)
{
    int rval;
    int err;
    if (debug_level('C') > 5)
	C_printf("CDROM: ioctl %#x\n", cmd);
    rval = ioctl(fd, cmd, arg);
    err = errno;

    if (rval == -1) {
	C_printf("CDROM: err %s\n", strerror(errno));
	errno = err;
    }
    return rval;
}

static void dump_cd_sect(char *tb)
{
    unsigned char buf[128];
    int i, j;
    unsigned char *p, *q, c;

    q = tb;
    for (i = 0; i < 32 && debug_level('C') > 5; i++) {	/* 32x64 */
	p = buf;
	for (j = 0; j < 64; j++) {
	    c = *q++;
	    *p++ = (isprint(c) ? c : '.');
	}
	C_printf("%03x[%s]\n", i * 64, buf);
    }
    q = tb;
    for (i = 0; i < 64 && debug_level('C') > 8; i++) {	/* 64x32 */
	p = buf;
	for (j = 0; j < 4; j++) {
	    p += sprintf(p, ":%02x%02x%02x%02x%02x%02x%02x%02x", q[0],
			 q[1], q[2], q[3], q[4], q[5], q[6], q[7]);
	    q += 8;
	}
	C_printf("%03x%s\n", i * 32, buf);
    }
}


#define ioctl logging_ioctl
#endif

static void cdrom_reset(void)
{
    /* after a disk change a new read access will
       return an error. In order to unlock this condition
       the drive must be reopened.
       Does someone know a better way?                   */
    C_printf("CDROM: cdrom reset\n");
    close(cdrom_fd);
    cdrom_fd = open(path_cdrom, O_RDONLY | O_NONBLOCK);
    if (cdrom_fd >= 0)
	ioctl(cdrom_fd, CDROMRESET, NULL);
}

#define MSCD_AUDCHAN_VOLUME0       2
#define MSCD_AUDCHAN_VOLUME1       4
#define MSCD_AUDCHAN_VOLUME2       6
#define MSCD_AUDCHAN_VOLUME3       8

void cdrom_helper(unsigned char *req_buf, unsigned char *transfer_buf,
		  unsigned int dos_transfer_buf)
{
    unsigned int Sector_plus_150, Sector;
    struct cdrom_msf cdrom_msf;
    struct cdrom_subchnl cdrom_subchnl;
    struct cdrom_tochdr cdrom_tochdr;
    struct cdrom_tocentry cdrom_tocentry;
    struct cdrom_volctrl cdrom_volctrl;
    int n;
//   int err;

    cdrom_subchnl.cdsc_format = CDROM_MSF;

    IndexCd = (int) ((HI(ax) & 0xC0) >> 6);
    HI(ax) = HI(ax) & 0x3F;

    if (HI(ax) != 1 && cdrom_fd < 0) {
	if (!cdu33a) {
	    LO(ax) = 1;		/* not initialized */
	    return;
	}
	cdrom_fd = open(path_cdrom, O_RDONLY | O_NONBLOCK);

	if (cdrom_fd < 0) {
	    switch (HI(ax)) {
	    case 0x09:		/* media changed request */
		LO(bx) = 1;	/* media changed */
		LO(ax) = 0;
		return;
	    case 0x0A:		/* device status request */
		LWORD(ebx) = audio_status.status | 0x800;	/* no disc */
		LO(ax) = 0;
		return;
	    }
	    LO(ax) = 1;		/* for other requests return with error */
	    return;
	}
    }


    switch (HI(ax)) {
    case 0x01:			/* NOTE: you can't see XA data disks if bit 10 of status
				 * is cleared, MSCDEX will test it and skip XA entries!
				 * Actually the entries skipped must have this pattern:
				 *   xxxx1xxx xxxxxxxx 0x58 0x41
				 * and the mscdex 2.25 code is:
				 *      test    word ptr [bx+1Eh],400h
				 *      jz      [check for XA]
				 *      [return 0 = valid entry]
				 * [check for XA]
				 * ...
				 *      cmp     word ptr es:[bx+6],4158h  'XA'
				 *      jne     [return 0]
				 *      mov     ax,es:[bx+4]
				 *      and     ax,8
				 *      [return ax]
				 */
	audio_status.status = 0x00000710;	/* see function 0x0A below */
	audio_status.paused_bit = 0;
	audio_status.media_changed = 0;
	audio_status.volume0 = 0xFF;
	audio_status.volume1 = 0xFF;
	audio_status.volume2 = 0;
	audio_status.volume3 = 0;
	audio_status.outchan0 = 0;
	audio_status.outchan1 = 1;
	audio_status.outchan2 = 2;
	audio_status.outchan3 = 3;
#if 0
	cdrom_fd = open(path_cdrom, O_RDONLY | O_NONBLOCK);
	err = errno;

	if (cdrom_fd < 0) {
	    C_printf("CDROM: cdrom open (%s) failed: %s\n",
		     path_cdrom, strerror(err));
	    LO(ax) = 0;
	    if ((err == EIO) || (err == ENOMEDIUM)) {
		/* drive which cannot be opened if no
		   disc is inserted!                   */
		cdu33a = 1;
		if (!eject_allowed)
		    LO(ax) = 1;	/* no disk in drive */
	    } else
		LO(ax) = 1;	/* no cdrom drive installed */
	    if (!eject_allowed)
		LO(ax) = 1;	/* no disk in drive */
	} else {
	    LO(ax) = 0;
	    if (!eject_allowed) {
		if (ioctl(cdrom_fd, CDROMREADTOCHDR, &cdrom_tochdr))
		    if (ioctl(cdrom_fd, CDROMREADTOCHDR, &cdrom_tochdr))
			LO(ax) = 1;
	    }
	}
#else
	cdu33a = 1;
	LO(ax) = 0;
#endif
	break;
    case 0x02:			/* read long */
	if (eject_allowed && ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)
	    && errno != ENOTTY) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disc in drive */
		LO(ax) = 1;
		break;
	    } else {		/* disc in drive */
	    }
	}

	if (req_buf == NULL && transfer_buf == NULL) {
	    req_buf = SEG_ADR((unsigned char *), es, di);
	    dos_transfer_buf = SEGOFF2LINEAR(SREG(ds), LWORD(esi));
	}

	if (*CALC_PTR(req_buf, MSCD_READ_ADRESSING, u_char) == 1) {
	    cdrom_msf.cdmsf_min0 =
		*CALC_PTR(req_buf, MSCD_READ_STARTSECTOR + 2, u_char);
	    cdrom_msf.cdmsf_sec0 =
		*CALC_PTR(req_buf, MSCD_READ_STARTSECTOR + 1, u_char);
	    cdrom_msf.cdmsf_frame0 =
		*CALC_PTR(req_buf, MSCD_READ_STARTSECTOR + 0, u_char);
	    Sector =
		cdrom_msf.cdmsf_min0 * 60 * 75 +
		cdrom_msf.cdmsf_sec0 * 75 + cdrom_msf.cdmsf_frame0 - 150;
	} else {
	    Sector = *CALC_PTR(req_buf, MSCD_READ_STARTSECTOR, u_long);
	}

	C_printf("CDROM: reading sector %#x (fmt %d)\n", Sector,
		 *CALC_PTR(req_buf, MSCD_READ_ADRESSING, u_char));
	if ((off_t) - 1 ==
	    lseek(cdrom_fd, Sector * CD_FRAMESIZE, SEEK_SET)) {
	    HI(ax) = (errno == EINVAL ? 0x08 : 0x0F);
	    C_printf("CDROM: lseek failed: %s\n", strerror(errno));
	    LO(ax) = 1;
	} else {
	    n = *CALC_PTR(req_buf, MSCD_READ_NUMSECTORS,
			  u_short) * CD_FRAMESIZE;
	    if (transfer_buf == NULL) {
		n = dos_read(cdrom_fd, dos_transfer_buf, n);
	    } else {
		n = unix_read(cdrom_fd, transfer_buf, n);
	    }
	    if (n < 0) {
		/* cd must be in drive, reset drive and try again */
		cdrom_reset();
		if ((off_t) - 1 ==
		    lseek(cdrom_fd, Sector * CD_FRAMESIZE, SEEK_SET)) {
		    HI(ax) = (errno == EINVAL ? 0x08 : 0x0F);
		    C_printf("CDROM: lseek failed: %s\n", strerror(errno));
		    LO(ax) = 1;
		} else {
		    n = *CALC_PTR(req_buf, MSCD_READ_NUMSECTORS,
				  u_short) * CD_FRAMESIZE;
		    if (transfer_buf == NULL)
			n = dos_read(cdrom_fd, dos_transfer_buf, n);
		    else
			n = unix_read(cdrom_fd, transfer_buf, n);
		    if (n < 0) {
			HI(ax) = (errno == EFAULT ? 0x0A : 0x0F);
			C_printf
			    ("CDROM: sector read (to %p, len %#x) failed: %s\n",
			     transfer_buf, *CALC_PTR(req_buf,
						     MSCD_READ_NUMSECTORS,
						     u_short) *
			     CD_FRAMESIZE, strerror(errno));
			LO(ax) = 1;
		    } else
			LO(ax) = 0;
		}
	    }
	    if (n !=
		*CALC_PTR(req_buf, MSCD_READ_NUMSECTORS,
			  u_short) * CD_FRAMESIZE) {
		C_printf("CDROM: sector read len %#x got %#x\n",
			 *CALC_PTR(req_buf, MSCD_READ_NUMSECTORS,
				   u_short) * CD_FRAMESIZE, n);
		LO(ax) = 1;
		HI(ax) = 0x0F;
	    } else {
#ifdef CDROM_DEBUG
		dump_cd_sect(transfer_buf);
#endif
		LO(ax) = 0;
	    }
	}
	break;
    case 0x03:			/* seek */
	req_buf = SEG_ADR((unsigned char *), es, di);
	if ((off_t) - 1 ==
	    lseek(cdrom_fd,
		  *CALC_PTR(req_buf, MSCD_SEEK_STARTSECTOR,
			    u_long) * CD_FRAMESIZE, SEEK_SET)) {
	    C_printf("CDROM: lseek failed: %s\n", strerror(errno));
	    LO(ax) = 1;
	}
	break;
    case 0x04:			/* play */
	req_buf = SEG_ADR((unsigned char *), es, di);
	if (*CALC_PTR(req_buf, MSCD_PLAY_ADRESSING, u_char) == 1) {
	    cdrom_msf.cdmsf_min0 =
		*CALC_PTR(req_buf, MSCD_PLAY_STARTSECTOR + 2, u_char);
	    cdrom_msf.cdmsf_sec0 =
		*CALC_PTR(req_buf, MSCD_PLAY_STARTSECTOR + 1, u_char);
	    cdrom_msf.cdmsf_frame0 =
		*CALC_PTR(req_buf, MSCD_PLAY_STARTSECTOR + 0, u_char);
	    Sector_plus_150 =
		cdrom_msf.cdmsf_min0 * 60 * 75 +
		cdrom_msf.cdmsf_sec0 * 75 + cdrom_msf.cdmsf_frame0;
	    audio_status.last_StartSector = Sector_plus_150;
	} else {
	    Sector_plus_150 =
		*CALC_PTR(req_buf, MSCD_PLAY_STARTSECTOR, u_long) + 150;
	    cdrom_msf.cdmsf_min0 = (Sector_plus_150 / (60 * 75));
	    cdrom_msf.cdmsf_sec0 = (Sector_plus_150 % (60 * 75)) / 75;
	    cdrom_msf.cdmsf_frame0 = (Sector_plus_150 % (60 * 75)) % 75;
	    audio_status.last_StartSector = Sector_plus_150;
	}
	Sector_plus_150 +=
	    *CALC_PTR(req_buf, MSCD_PLAY_NUMSECTORS, u_long);
	cdrom_msf.cdmsf_min1 = (Sector_plus_150 / (60 * 75));
	cdrom_msf.cdmsf_sec1 = (Sector_plus_150 % (60 * 75)) / 75;
	cdrom_msf.cdmsf_frame1 = (Sector_plus_150 % (60 * 75)) % 75;

	audio_status.last_EndSector = Sector_plus_150;
	audio_status.paused_bit = 0;
	if (ioctl(cdrom_fd, CDROMPLAYMSF, &cdrom_msf)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMPLAYMSF, &cdrom_msf)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	LO(ax) = 0;
	break;
    case 0x05:			/* pause (stop) audio */
	LO(ax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl) == 0) {
	    if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY) {
		audio_status.last_StartSector =
		    cdrom_subchnl.cdsc_absaddr.msf.minute * 60 * 75
		    + cdrom_subchnl.cdsc_absaddr.msf.second * 75
		    + cdrom_subchnl.cdsc_absaddr.msf.frame;
		ioctl(cdrom_fd, CDROMPAUSE, NULL);
		audio_status.paused_bit = 1;
	    } else {
		audio_status.last_StartSector = 0;
		audio_status.last_EndSector = 0;
		audio_status.paused_bit = 0;
	    }
	} else {
	    audio_status.last_StartSector = 0;
	    audio_status.last_EndSector = 0;
	    audio_status.paused_bit = 0;
	    audio_status.media_changed = 1;
	}
	break;
    case 0x06:			/* resume audio */
	LO(ax) = 0;
	if (audio_status.paused_bit) {
	    if (ioctl(cdrom_fd, CDROMRESUME, NULL) == 0) {
		audio_status.paused_bit = 0;
		HI(ax) = 1;
	    }
	} else
	    LO(ax) = 1;
	break;
    case 0x07:			/* location of head */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;

	req_buf = SEG_ADR((unsigned char *), ds, si);
	if (*CALC_PTR(req_buf, MSCD_LOCH_ADRESSING, u_char) == 0) {
	    *CALC_PTR(req_buf, MSCD_LOCH_LOCATION, u_long)
		= cdrom_subchnl.cdsc_absaddr.msf.minute * 60 * 75
		+ cdrom_subchnl.cdsc_absaddr.msf.second * 75
		+ cdrom_subchnl.cdsc_absaddr.msf.frame - 150;
	} else {		/* red book adressing */
	    *CALC_PTR(req_buf, MSCD_LOCH_LOCATION + 3, u_char) = 0;
	    *CALC_PTR(req_buf, MSCD_LOCH_LOCATION + 2, u_char) =
		cdrom_subchnl.cdsc_absaddr.msf.minute;
	    *CALC_PTR(req_buf, MSCD_LOCH_LOCATION + 1, u_char) =
		cdrom_subchnl.cdsc_absaddr.msf.second;
	    *CALC_PTR(req_buf, MSCD_LOCH_LOCATION + 0, u_char) =
		cdrom_subchnl.cdsc_absaddr.msf.frame;
	}
	break;
    case 0x08:			/* return sectorsize */
	LO(ax) = 0;
	LWORD(ebx) = CD_FRAMESIZE;
	break;
    case 0x09:			/* media changed */
	/* this function will be called from MSCDEX before
	   each new disk access !                         */
	HI(ax) = 0;
	LO(ax) = 0;
	LO(bx) = 0;
	C_printf("CDROM: media changed?  %#x\n",
		 audio_status.media_changed);
	errno = 0;
	if (eject_allowed) {
	    if ((audio_status.media_changed) ||
		ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		if (errno == EIO)
		    cdrom_reset();
		audio_status.media_changed = 0;
		LO(bx) = 1;	/* media has been changed */
		C_printf("CDROM: media changed?  yes\n");
		ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl);
		if (!ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl))
		    cdrom_reset();	/* disc in drive */
	    } else /* media has not changed, check audio status */
	    if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
		HI(ax) = 1;	/* audio playing in progress */
	}
	break;
    case 0x0A:			/* device status */
	HI(ax) = 0;
	LO(ax) = 0;
	if (eject_allowed) {
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {	/* no disk in drive */
		    LWORD(ebx) = audio_status.status | 0x800;
		    C_printf("CDROM: subch failed: %s\n", strerror(errno));
		    break;
		} else
		    cdrom_reset();
	    }
	}
	/* disk in drive */
	LWORD(ebx) = audio_status.status;
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;
	break;
    case 0x0B:			/* drive reset */
	LO(ax) = 0;
	break;
    case 0x0C:			/* lock/unlock door */
	cdrom_reset();
	if (LO(bx) == 1)
	    audio_status.status &= 0xFFFFFFFD;
	else
	    audio_status.status |= 0x2;
	LO(ax) = 0;
	break;
    case 0x0D:			/* eject */
	LO(ax) = 0;
	if ((eject_allowed) && (audio_status.status & 0x02)) {	/* drive unlocked ? */
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMEJECT)) {
		LO(ax) = errno;
	    }
	}
	break;
    case 0x0E:			/* close tray */
	LO(ax) = 0;
	if ((eject_allowed) && (audio_status.status & 0x02)) {	/* drive unlocked ? */
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMCLOSETRAY)) {
		LO(ax) = errno;
	    }
	}
	break;
    case 0x0F:			/* audio channel control */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;

	req_buf = SEG_ADR((unsigned char *), ds, si);
	cdrom_volctrl.channel0 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME0, u_char);
	cdrom_volctrl.channel1 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME1, u_char);
	cdrom_volctrl.channel2 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME2, u_char);
	cdrom_volctrl.channel3 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME3, u_char);
	audio_status.volume0 = cdrom_volctrl.channel0;
	audio_status.volume1 = cdrom_volctrl.channel1;
	audio_status.volume2 = cdrom_volctrl.channel2;
	audio_status.volume3 = cdrom_volctrl.channel3;
	audio_status.outchan0 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME0 - 1, u_char);
	audio_status.outchan1 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME1 - 1, u_char);
	audio_status.outchan2 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME2 - 1, u_char);
	audio_status.outchan3 =
	    *CALC_PTR(req_buf, MSCD_CTRL_VOLUME3 - 1, u_char);
	ioctl(cdrom_fd, CDROMVOLCTRL, &cdrom_volctrl);
	break;
    case 0x10:			/* audio disk info */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMREADTOCHDR, &cdrom_tochdr)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMREADTOCHDR, &cdrom_tochdr)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}

	req_buf = SEG_ADR((unsigned char *), ds, si);
	*CALC_PTR(req_buf, MSCD_DISKINFO_LTN, u_char) =
	    cdrom_tochdr.cdth_trk0;
	*CALC_PTR(req_buf, MSCD_DISKINFO_HTN, u_char) =
	    cdrom_tochdr.cdth_trk1;
	cdrom_tocentry.cdte_track = CDROM_LEADOUT;
	cdrom_tocentry.cdte_format = CDROM_MSF;
	if (ioctl(cdrom_fd, CDROMREADTOCENTRY, &cdrom_tocentry)) {
	    C_printf
		("Fatal cdrom error(audio disk info); read toc header succeeded but following read entry didn't\n");
	    LO(ax) = 1;
	    break;
	}
#ifdef __linux__
	*CALC_PTR(req_buf, MSCD_DISKINFO_LEADOUT + 3, u_char) = 0;
	*CALC_PTR(req_buf, MSCD_DISKINFO_LEADOUT + 2, u_char) =
	    cdrom_tocentry.cdte_addr.msf.minute;
	*CALC_PTR(req_buf, MSCD_DISKINFO_LEADOUT + 1, u_char) =
	    cdrom_tocentry.cdte_addr.msf.second;
	*CALC_PTR(req_buf, MSCD_DISKINFO_LEADOUT + 0, u_char) =
	    cdrom_tocentry.cdte_addr.msf.frame;
#endif
	break;
    case 0x11:			/* track info */
	req_buf = SEG_ADR((unsigned char *), ds, si);
	cdrom_tocentry.cdte_track =
	    *CALC_PTR(req_buf, MSCD_TRACKINFO_TRACKNUM, u_char);
	cdrom_tocentry.cdte_format = CDROM_MSF;
	C_printf("CDROM: track info, track %d\n",
		 cdrom_tocentry.cdte_track);
	if (ioctl(cdrom_fd, CDROMREADTOCENTRY, &cdrom_tocentry)) {
	    /* XXX MSCDEX reads beyond the end of existing tracks.  Sigh. */
	    if (errno != EINVAL)
		audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMREADTOCENTRY, &cdrom_tocentry)) {
		if (errno == EIO) {
		    audio_status.media_changed = 1;
		    /* no disk in drive */
		}
		LO(ax) = 1;
		break;
	    }
	}
#ifdef __linux__
	*CALC_PTR(req_buf, MSCD_TRACKINFO_TRACKPOS + 3, u_char) = 0;
	*CALC_PTR(req_buf, MSCD_TRACKINFO_TRACKPOS + 2, u_char) =
	    cdrom_tocentry.cdte_addr.msf.minute;
	*CALC_PTR(req_buf, MSCD_TRACKINFO_TRACKPOS + 1, u_char) =
	    cdrom_tocentry.cdte_addr.msf.second;
	*CALC_PTR(req_buf, MSCD_TRACKINFO_TRACKPOS + 0, u_char) =
	    cdrom_tocentry.cdte_addr.msf.frame;
#endif
	*CALC_PTR(req_buf, MSCD_TRACKINFO_CTRL, u_char) =
	    cdrom_tocentry.cdte_ctrl << 4 | 0x20;
	LO(ax) = 0;
	break;
    case 0x12:			/* volume size */
	cdrom_tocentry.cdte_track = CDROM_LEADOUT;
	cdrom_tocentry.cdte_format = CDROM_MSF;
	if (ioctl(cdrom_fd, CDROMREADTOCENTRY, &cdrom_tocentry)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMREADTOCENTRY, &cdrom_tocentry)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	req_buf = SEG_ADR((unsigned char *), ds, si);
#ifdef __linux__
	*CALC_PTR(req_buf, MSCD_GETVOLUMESIZE_SIZE, int) =
	    cdrom_tocentry.cdte_addr.msf.minute * 60 * 75 +
	    cdrom_tocentry.cdte_addr.msf.second * 60 +
	    cdrom_tocentry.cdte_addr.msf.frame;
#endif
	LO(ax) = 0;
	break;
    case 0x13:			/* q channel */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;

	req_buf = SEG_ADR((unsigned char *), ds, si);
	*CALC_PTR(req_buf, MSCD_QCHAN_CTRL, u_char) =
	    (cdrom_subchnl.cdsc_adr << 4) + (cdrom_subchnl.cdsc_ctrl);
	*CALC_PTR(req_buf, MSCD_QCHAN_TNO, u_char) =
	    cdrom_subchnl.cdsc_trk;
	*CALC_PTR(req_buf, MSCD_QCHAN_IND, u_char) =
	    cdrom_subchnl.cdsc_ind;
#ifdef __linux__
	*CALC_PTR(req_buf, MSCD_QCHAN_MIN, u_char) =
	    cdrom_subchnl.cdsc_reladdr.msf.minute;
	*CALC_PTR(req_buf, MSCD_QCHAN_SEC, u_char) =
	    cdrom_subchnl.cdsc_reladdr.msf.second;
	*CALC_PTR(req_buf, MSCD_QCHAN_FRM, u_char) =
	    cdrom_subchnl.cdsc_reladdr.msf.frame;
#endif
	*CALC_PTR(req_buf, MSCD_QCHAN_ZERO, u_char) = 0;
	*CALC_PTR(req_buf, MSCD_QCHAN_AMIN, u_char) =
	    cdrom_subchnl.cdsc_absaddr.msf.minute;
	*CALC_PTR(req_buf, MSCD_QCHAN_ASEC, u_char) =
	    cdrom_subchnl.cdsc_absaddr.msf.second;
	*CALC_PTR(req_buf, MSCD_QCHAN_AFRM, u_char) =
	    cdrom_subchnl.cdsc_absaddr.msf.frame;
	break;
    case 0x14:			/* audio status */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;

	req_buf = SEG_ADR((unsigned char *), ds, si);
	*CALC_PTR(req_buf, MSCD_AUDSTAT_PAUSED, u_short) =
	    audio_status.paused_bit;
	*CALC_PTR(req_buf, MSCD_AUDSTAT_START, u_long) =
	    audio_status.last_StartSector;
	*CALC_PTR(req_buf, MSCD_AUDSTAT_END, u_long) =
	    audio_status.last_EndSector;
	break;
    case 0x15:			/* get audio channel information */
	LWORD(eax) = 0;
	if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
	    audio_status.media_changed = 1;
	    if (ioctl(cdrom_fd, CDROMSUBCHNL, &cdrom_subchnl)) {
		/* no disk in drive */
		LO(ax) = 1;
		break;
	    }
	}
	if (cdrom_subchnl.cdsc_audiostatus == CDROM_AUDIO_PLAY)
	    HI(ax) = 1;

	req_buf = SEG_ADR((unsigned char *), ds, si);
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME0, u_char) =
	    audio_status.volume0;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME1, u_char) =
	    audio_status.volume1;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME2, u_char) =
	    audio_status.volume2;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME3, u_char) =
	    audio_status.volume3;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME0 - 1, u_char) =
	    audio_status.outchan0;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME1 - 1, u_char) =
	    audio_status.outchan1;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME2 - 1, u_char) =
	    audio_status.outchan2;
	*CALC_PTR(req_buf, MSCD_AUDCHAN_VOLUME3 - 1, u_char) =
	    audio_status.outchan3;
	break;
    default:
	C_printf("CDROM: unknown request %#x!\n", HI(ax));
    }

#ifdef CDROM_DEBUG
    if (debug_level('C') > 5) {
	C_printf("CDROM: req_buf ");
	req_buf = SEG_ADR((char *), es, di);
	for (n = 0; n < 22; ++n)
	    C_printf("%02x", req_buf[n]);
	C_printf("\n");
    }
#endif
    C_printf("Leave cdrom request with return status %#x\n", LWORD(eax));
    return;
}

void cdrom_done(void)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(CdromFd); i++) {
        if (CdromFd[i] != -1) {
            /* unfortunately playing doesn't stop by just close() */
            ioctl(CdromFd[i], CDROMPAUSE, NULL);
            close(CdromFd[i]);
        }
    }
}

#else

void cdrom_helper(unsigned char *req_buf, unsigned char *transfer_buf,
                  unsigned int dos_transfer_buf)
{
}

void cdrom_done(void)
{
}

#endif