Initial support ATAPI CD-ROMs.

Based on Manuel Bouyer's drivers.

10 files changed, 4742 insertions, 1065 deletions

diff --git a/sys/dev/atapi/acd.c b/sys/dev/atapi/acd.c
new file mode 100644
index 00000000000..3b95e279722
--- /dev/null
+++ b/sys/dev/atapi/acd.c
@@ -0,0 +1,1337 @@
+/*	$NetBSD: $	*/
+
+/*
+ * Copyright (c) 1996 Manuel Bouyer.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by Manuel Bouyer.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/buf.h>
+#include <sys/uio.h>
+#include <sys/malloc.h>
+#include <sys/errno.h>
+#include <sys/device.h>
+#include <sys/disklabel.h>
+#include <sys/disk.h>
+#include <sys/cdio.h>
+#include <sys/proc.h>  
+
+#include <dev/atapi/atapilink.h>
+#include <dev/atapi/atapi.h>
+
+#define	CDUNIT(z)			DISKUNIT(z)
+#define	CDPART(z)			DISKPART(z)
+#define	MAKECDDEV(maj, unit, part)	MAKEDISKDEV(maj, unit, part)
+
+#ifdef ACD_DEBUG
+#define ACD_DEBUG_PRINT(args)		printf args
+#else
+#define ACD_DEBUG_PRINT(args)
+#endif
+
+struct acd_softc {
+	struct	device sc_dev;
+	struct	disk sc_dk;
+
+	int flags;
+#define	CDF_LOCKED	0x01
+#define	CDF_WANTED	0x02
+#define	CDF_WLABEL	0x04		/* label is writable */
+#define	CDF_LABELLING	0x08		/* writing label */
+	struct	at_dev_link *ad_link;	/* contains our drive number, etc ... */
+	struct	cd_parms {
+		int	blksize;
+		u_long	disksize;	/* total number sectors */
+	} params;
+	struct	buf buf_queue;
+};
+
+int	acdmatch __P((struct device *, void *, void *));
+void	acdattach __P((struct device *, struct device *, void *));
+
+struct cfattach acd_ca = {
+	sizeof(struct acd_softc), acdmatch, acdattach
+};
+
+struct cfdriver acd_cd = {
+	NULL, "acd", DV_DISK
+};
+
+void	acdgetdisklabel __P((struct acd_softc *));
+int	acd_get_parms __P((struct acd_softc *, int));
+void	acdstrategy __P((struct buf *));
+void	acdstart __P((struct acd_softc *));
+int	acd_pause __P((struct acd_softc *, int));
+void	acdminphys __P((struct buf*));
+u_long	acd_size __P((struct acd_softc*, int));
+int	acddone __P((struct atapi_command_packet *));
+
+struct dkdriver acddkdriver = { acdstrategy };
+
+/*
+ * Called by the low level atapi code to find the right driver
+ * for a drive on the bus.
+ */
+int
+acdmatch(parent, match, aux)
+	struct device *parent;
+	void *match, *aux;
+{
+	struct cfdata *cf = match;
+	struct at_dev_link *sa = aux;
+
+#ifdef ATAPI_DEBUG_PROBE
+	printf("acdmatch: device %d\n",
+	    sa->id.config.device_type & ATAPI_DEVICE_TYPE_MASK);
+#endif
+
+	if ((sa->id.config.device_type & ATAPI_DEVICE_TYPE_MASK) ==
+	    ATAPI_DEVICE_TYPE_CD)
+		return 1;
+	return 0;
+}
+
+/*
+ * The routine called by the low level atapi routine when it discovers
+ * A device suitable for this driver
+ */
+void
+acdattach(parent, self, aux)
+	struct device *parent, *self;
+	void *aux;
+{
+	struct acd_softc *acd = (void *)self;
+	struct at_dev_link *sa = aux;
+	struct mode_sense cmd;
+	struct cappage cap;
+	int print_type = 0;
+	char *mtype;
+
+	printf("\n");
+
+	sa->device_softc = acd;
+	sa->start = acdstart;
+	sa->done = acddone;
+	sa->flags |= ADEV_REMOVABLE;
+	sa->openings = 1;
+	acd->ad_link = sa;
+
+	/*
+	 * Initialize and attach the disk structure.
+	 */
+	acd->sc_dk.dk_driver = &acddkdriver;
+	acd->sc_dk.dk_name = acd->sc_dev.dv_xname;
+	disk_attach(&acd->sc_dk);
+
+	dk_establish(&acd->sc_dk, &acd->sc_dev);   
+
+	(void)atapi_test_unit_ready(sa, A_POLLED | A_SILENT); 
+	delay(1000);
+	(void)atapi_test_unit_ready(sa, A_POLLED | A_SILENT);
+
+	/* To clear media change, etc ...*/
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_MODE_SENSE;
+	cmd.page_code_control = CAP_PAGE;
+	_lto2b(sizeof(cap), cmd.length);
+	if (atapi_exec_cmd(sa, &cmd , sizeof(cmd), &cap, sizeof(cap),
+	    B_READ, A_POLLED) != 0) {
+		printf("%s: can't MODE SENSE: atapi_exec_cmd failed\n",
+		    self->dv_xname);
+		return;
+	}
+
+	/* Determine media type. */
+	switch (cap.medium_type) {
+	case MDT_UNKNOWN:
+		mtype = "medium type unknown";
+		break;
+
+	case MDT_DATA_120:
+		mtype = "120mm data disc";
+		break;
+
+	case MDT_AUDIO_120:
+		mtype = "120mm audio disc";
+		break;
+
+	case MDT_COMB_120:
+		mtype = "120mm data/audio disc";
+		break;
+
+	case MDT_PHOTO_120:
+		mtype = "120mm photo disc";
+		break;
+
+	case MDT_DATA_80:
+		mtype = "80mm data disc";
+		break;
+
+	case MDT_AUDIO_80:
+		mtype = "80mm audio disc";
+		break;
+
+	case MDT_COMB_80:
+		mtype = "80mm data/audio disc";
+		break;
+
+	case MDT_PHOTO_80:
+		mtype = "80mm photo disc";
+		break;
+
+	case MDT_NO_DISC:
+		mtype = "drive empty";
+		break;
+
+	case MDT_DOOR_OPEN:
+		mtype = "door open";
+		break;
+
+	case MDT_FMT_ERROR:
+		mtype = "medium format error";
+		break;
+
+	default:
+		mtype = "unknown type";
+		print_type = 1;
+		break;
+	}
+
+	/*
+	 * Display information about the drive.
+	 */
+	printf("%s: %s", self->dv_xname, mtype);
+	if (print_type)
+		printf(" (type 0x%x)", cap.medium_type);
+	printf("\n");
+}
+
+/*
+ * Wait interruptibly for an exclusive lock.
+ *
+ * XXX
+ * Several drivers do this; it should be abstracted and made MP-safe.
+ */
+int
+acdlock(acd)
+	struct acd_softc *acd;
+{
+	int error;
+
+	while ((acd->flags & CDF_LOCKED) != 0) {
+		acd->flags |= CDF_WANTED;
+		if ((error = tsleep(acd, PRIBIO | PCATCH, "acdlck", 0)) != 0)
+			return error;
+	}
+	acd->flags |= CDF_LOCKED;
+	return 0;
+}
+
+/*
+ * Unlock and wake up any waiters.
+ */
+void
+acdunlock(acd)
+	struct acd_softc *acd;
+{
+
+	acd->flags &= ~CDF_LOCKED;
+	if ((acd->flags & CDF_WANTED) != 0) {
+		acd->flags &= ~CDF_WANTED;
+		wakeup(acd);
+	}
+}
+
+/*
+ * open the device. Make sure the partition info is a up-to-date as can be.
+ */
+int
+acdopen(dev, flag, fmt)
+	dev_t dev;
+	int flag, fmt;
+{
+	struct acd_softc *acd;
+	struct at_dev_link *ad_link;
+	int unit, part;
+	int error;
+
+	ACD_DEBUG_PRINT(("acd: open\n"));
+
+	unit = CDUNIT(dev);
+	if (unit >= acd_cd.cd_ndevs)
+		return ENXIO;
+	acd = acd_cd.cd_devs[unit];
+	if (acd == NULL)
+		return ENXIO;
+
+	ad_link = acd->ad_link;
+
+	if ((error = atapi_test_unit_ready(ad_link,0)) != 0) {
+		if (error != UNIT_ATTENTION)
+			return EIO;
+		if ((ad_link->flags & ADEV_OPEN) != 0)
+			return EIO;
+	}
+
+	if (error = acdlock(acd))
+		return error;
+
+	if (acd->sc_dk.dk_openmask != 0) {
+		/*
+		 * If any partition is open, but the disk has been invalidated,
+		 * disallow further opens.
+		 */
+		if ((ad_link->flags & ADEV_MEDIA_LOADED) == 0) {
+			error = EIO;
+			goto bad3;
+		}
+	} else {
+		ad_link->flags |= ADEV_OPEN;
+
+		/* Lock the pack in. */
+		if (error = atapi_prevent(ad_link, PR_PREVENT))
+			goto bad;
+
+		if ((ad_link->flags & ADEV_MEDIA_LOADED) == 0) {
+			ad_link->flags |= ADEV_MEDIA_LOADED;
+
+			/* Load the physical device parameters. */
+			if (acd_get_parms(acd, 0) != 0) {
+				error = ENXIO;
+				goto bad2;
+			}
+
+			/* Fabricate a disk label. */
+			acdgetdisklabel(acd);
+		}
+	}
+
+	part = CDPART(dev);
+
+	/* Check that the partition exists. */
+	if (part != RAW_PART &&
+	    (part >= acd->sc_dk.dk_label->d_npartitions ||
+	     acd->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
+		error = ENXIO;
+		goto bad;
+	}
+
+	/* Insure only one open at a time. */
+	switch (fmt) {
+	case S_IFCHR:
+		acd->sc_dk.dk_copenmask |= (1 << part);
+		break;
+	case S_IFBLK:
+		acd->sc_dk.dk_bopenmask |= (1 << part);
+		break;
+	}
+	acd->sc_dk.dk_openmask =
+	    acd->sc_dk.dk_copenmask | acd->sc_dk.dk_bopenmask;
+
+	ACD_DEBUG_PRINT(("acd: open complete\n"));
+
+	acdunlock(acd);
+	return 0;
+
+bad2:
+	ad_link->flags &= ~ADEV_MEDIA_LOADED;
+
+bad:
+	if (acd->sc_dk.dk_openmask == 0) {
+		atapi_prevent(ad_link, PR_ALLOW);
+		ad_link->flags &= ~ADEV_OPEN;
+	}
+
+bad3:
+	acdunlock(acd);
+	return error;
+}
+
+/*
+ * close the device.. only called if we are the LAST
+ * occurence of an open device
+ */
+int
+acdclose(dev, flag, fmt)
+	dev_t dev;
+	int flag, fmt;
+{
+	struct acd_softc *acd = acd_cd.cd_devs[CDUNIT(dev)];
+	int part = CDPART(dev);
+	int error;
+
+	if ((error = acdlock(acd)) != 0)
+		return error;
+
+	switch (fmt) {
+	case S_IFCHR:
+		acd->sc_dk.dk_copenmask &= ~(1 << part);
+		break;
+	case S_IFBLK:
+		acd->sc_dk.dk_bopenmask &= ~(1 << part);
+		break;
+	}
+	acd->sc_dk.dk_openmask =
+	    acd->sc_dk.dk_copenmask | acd->sc_dk.dk_bopenmask;
+
+	if (acd->sc_dk.dk_openmask == 0) {
+		/* XXXX Must wait for I/O to complete! */
+
+		atapi_prevent(acd->ad_link, PR_ALLOW);
+		acd->ad_link->flags &= ~ADEV_OPEN;
+	}
+
+	acdunlock(acd);
+	return 0;
+}
+
+/*
+ * Actually translate the requested transfer into one the physical driver can
+ * understand.  The transfer is described by a buf and will include only one
+ * physical transfer.
+ */
+void
+acdstrategy(bp)
+	struct buf *bp;
+{
+	struct acd_softc *acd = acd_cd.cd_devs[CDUNIT(bp->b_dev)];
+	int opri;
+
+	ACD_DEBUG_PRINT(("acdstrategy\n"));
+
+	/*
+	 * The transfer must be a whole number of blocks.
+	 */
+	if ((bp->b_bcount % acd->sc_dk.dk_label->d_secsize) != 0) {
+		bp->b_error = EINVAL;
+		goto bad;
+	}
+	if ((bp->b_flags & (B_READ|B_WRITE)) == B_WRITE) {
+		bp->b_error = EROFS;
+		goto bad;
+	}
+	/*
+	 * If the device has been made invalid, error out
+	 * maybe the media changed
+	 */
+	if ((acd->ad_link->flags & ADEV_MEDIA_LOADED) == 0) {
+		bp->b_error = EIO;
+		goto bad;
+	}
+	/*
+	 * If it's a null transfer, return immediately
+	 */
+	if (bp->b_bcount == 0)
+		goto done;
+
+	/*
+	 * Do bounds checking, adjust transfer. if error, process.
+	 * If end of partition, just return.
+	 */
+	if (CDPART(bp->b_dev) != RAW_PART &&
+	    bounds_check_with_label(bp, acd->sc_dk.dk_label,
+	    (acd->flags & (CDF_WLABEL|CDF_LABELLING)) != 0) <= 0)
+		goto done;
+
+	opri = splbio();
+
+	/*
+	 * Place it in the queue of disk activities for this disk
+	 */
+	disksort(&acd->buf_queue, bp);
+
+	/*
+	 * Tell the device to get going on the transfer if it's
+	 * not doing anything, otherwise just wait for completion
+	 */
+	acdstart(acd);
+
+	splx(opri);
+	return;
+
+bad:
+	bp->b_flags |= B_ERROR;
+done:
+	/*
+	 * Correctly set the buf to indicate a completed xfer
+	 */
+	bp->b_resid = bp->b_bcount;
+	biodone(bp);
+}
+
+/*
+ * acdstart looks to see if there is a buf waiting for the device
+ * and that the device is not already busy. If both are true,
+ * It deques the buf and creates a atapi command to perform the
+ * transfer in the buf. The transfer request will call atapi_done
+ * on completion, which will in turn call this routine again
+ * so that the next queued transfer is performed.
+ * The bufs are queued by the strategy routine (cdstrategy)
+ *
+ * This routine is also called after other non-queued requests
+ * have been made of the atapi driver, to ensure that the queue
+ * continues to be drained.
+ *
+ * must be called at the correct (highish) spl level
+ * cdstart() is called at splbio from cdstrategy and atapi_done
+ */
+void
+acdstart(acd)
+	struct acd_softc *acd;
+{
+	struct at_dev_link *ad_link;
+	struct buf *bp = 0;
+	struct buf *dp;
+	struct read cmd;
+	u_int32_t blkno, nblks;
+	struct partition *p;
+
+	ACD_DEBUG_PRINT(("acd: acdstart\n"));
+
+#ifdef DIAGNOSTIC
+	if (acd == NULL) {
+		printf("acdstart: null acd\n");
+		return;
+	}
+#endif
+		
+	ad_link = acd->ad_link;
+
+#ifdef DIAGNOSTIC
+	if (ad_link == NULL) {
+		printf("acdstart: null ad_link\n");
+		return;
+	}
+#endif
+	/*
+	 * Check if the device has room for another command
+	 */
+	while (ad_link->openings > 0) {
+		/*
+		 * there is excess capacity, but a special waits
+		 * It'll need the adapter as soon as we clear out of the
+		 * way and let it run (user level wait).
+		 */
+		if (ad_link->flags & ADEV_WAITING) {
+#ifdef ATAPI_DEBUG
+			printf("acdstart: waking up\n");
+#endif
+			ad_link->flags &= ~ADEV_WAITING;
+			wakeup((caddr_t)ad_link);
+			return;
+		}
+		
+		/*
+		 * See if there is a buf with work for us to do..
+		 */
+		dp = &acd->buf_queue;
+#ifdef ACD_DEBUG
+		if (dp == NULL) {
+			printf("acdstart: null dp\n");
+			return;
+		}
+#endif
+		if ((bp = dp->b_actf) == NULL)	/* yes, an assign */
+			return;
+
+		ACD_DEBUG_PRINT(("acdstart: a buf\n"));
+
+		dp->b_actf = bp->b_actf;
+
+		/*
+		 * If the device has become invalid, abort all the
+		 * reads and writes until all files have been closed and
+		 * re-opened
+		 */
+		if ((ad_link->flags & ADEV_MEDIA_LOADED) == 0) {
+			bp->b_error = EIO;
+			bp->b_flags |= B_ERROR;
+			biodone(bp);
+			continue;
+		}
+
+		/*
+		 *
+		 * First, translate the block to absolute and put it in terms
+		 * of the logical blocksize of the device.
+		 */
+		blkno =
+		    bp->b_blkno / (acd->sc_dk.dk_label->d_secsize / DEV_BSIZE);
+		if (CDPART(bp->b_dev) != RAW_PART) {
+			p =
+			  &acd->sc_dk.dk_label->d_partitions[CDPART(bp->b_dev)];
+			blkno += p->p_offset;
+		}
+		nblks = howmany(bp->b_bcount, acd->sc_dk.dk_label->d_secsize);
+
+		ACD_DEBUG_PRINT(("acdstart: blkno %d nblk %d\n",
+		    blkno, nblks));
+
+		/*
+		 *  Fill out the atapi command
+		 */
+		bzero(&cmd, sizeof(cmd));
+		cmd.operation_code = ATAPI_READ;
+		_lto4b(blkno, cmd.lba);
+		_lto2b(nblks, cmd.length);
+
+		/* Instrumentation. */
+		disk_busy(&acd->sc_dk);
+
+		/*
+		 * Call the routine that chats with the adapter.
+		 * Note: we cannot sleep as we may be an interrupt
+		 */
+		 if (atapi_exec_io(ad_link, &cmd, sizeof(cmd), bp, A_NOSLEEP))
+			printf("%s: not queued", acd->sc_dev.dv_xname);
+	}
+}
+
+int
+acdread(dev, uio)
+	dev_t dev;
+	struct uio *uio;
+{
+
+	return (physio(acdstrategy, NULL, dev, B_READ, acdminphys, uio));
+}
+
+int
+acdwrite(dev, uio)
+	dev_t dev;
+	struct uio *uio;
+{
+
+	return (physio(acdstrategy, NULL, dev, B_WRITE, acdminphys, uio));
+}
+
+/*
+ * Perform special action on behalf of the user.
+ * Knows about the internals of this device
+ */
+int
+acdioctl(dev, cmd, addr, flag, p)
+	dev_t dev;
+	u_long cmd;
+	caddr_t addr;
+	int flag;
+	struct proc *p;
+{
+	struct acd_softc *acd = acd_cd.cd_devs[CDUNIT(dev)];
+	int error;
+
+	/*
+	 * If the device is not valid.. abandon ship
+	 */
+	if ((acd->ad_link->flags & ADEV_MEDIA_LOADED) == 0)
+		return EIO;
+
+	switch (cmd) {
+	case DIOCGDINFO:
+		*(struct disklabel *)addr = *acd->sc_dk.dk_label;
+		return 0;
+
+	case DIOCGPART:
+		((struct partinfo *)addr)->disklab = acd->sc_dk.dk_label;
+		((struct partinfo *)addr)->part =
+		    &acd->sc_dk.dk_label->d_partitions[CDPART(dev)];
+		return 0;
+
+	case DIOCWDINFO:
+	case DIOCSDINFO:
+		if ((flag & FWRITE) == 0)
+			return EBADF;
+
+		if (error = acdlock(acd))
+			return error;
+		acd->flags |= CDF_LABELLING;
+
+		error = setdisklabel(acd->sc_dk.dk_label,
+		    (struct disklabel *)addr, /*acd->sc_dk.dk_openmask : */0,
+		    acd->sc_dk.dk_cpulabel);
+		if (error == 0) {
+			/* XXX ?? */
+		}
+
+		acd->flags &= ~CDF_LABELLING;
+		acdunlock(acd);
+		return error;
+
+	case DIOCWLABEL:
+		return EROFS;
+
+#ifdef notyet
+	case CDIOCPLAYTRACKS:
+		{
+		struct ioc_play_track *args = (struct ioc_play_track *)addr;
+		struct acd_mode_data data;
+		if (error = acd_get_mode(acd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.flags &= ~CD_PA_SOTC;
+		data.page.audio.flags |= CD_PA_IMMED;
+		if (error = acd_set_mode(acd, &data))
+			return error;
+		return acd_play_tracks(acd, args->start_track,
+		    args->start_index, args->end_track, args->end_index);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCPLAYMSF:
+		{
+		struct ioc_play_msf *args
+		= (struct ioc_play_msf *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.flags &= ~CD_PA_SOTC;
+		data.page.audio.flags |= CD_PA_IMMED;
+		if (error = cd_set_mode(cd, &data))
+			return error;
+		return cd_play_msf(cd, args->start_m, args->start_s,
+		    args->start_f, args->end_m, args->end_s, args->end_f);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCPLAYBLOCKS:
+	{
+		struct ioc_play_blocks *args
+		= (struct ioc_play_blocks *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.flags &= ~CD_PA_SOTC;
+		data.page.audio.flags |= CD_PA_IMMED;
+		if (error = cd_set_mode(cd, &data))
+			return error;
+		return cd_play(cd, args->blk, args->len);
+	}
+#endif
+
+#ifdef notyet 
+	case CDIOCREADSUBCHANNEL:
+	{
+		struct ioc_read_subchannel *args
+		= (struct ioc_read_subchannel *)addr;
+		struct cd_sub_channel_info data;
+		int len = args->data_len;
+		if (len > sizeof(data) ||
+		    len < sizeof(struct cd_sub_channel_header))
+			return EINVAL;
+		if (error = cd_read_subchannel(cd, args->address_format,
+		    args->data_format, args->track, &data, len))
+			return error;
+		len = min(len, ((data.header.data_len[0] << 8) +
+		    data.header.data_len[1] +
+		    sizeof(struct cd_sub_channel_header)));
+		return copyout(&data, args->data, len);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOREADTOCHEADER:
+	{
+		struct ioc_toc_header th;
+		if (error = cd_read_toc(cd, 0, 0, &th, sizeof(th)))
+			return error;
+		th.len = ntohs(th.len);
+		bcopy(&th, addr, sizeof(th));
+		return 0;
+	}
+#endif
+
+#ifdef notyet
+	case CDIOREADTOCENTRYS:
+	{
+		struct cd_toc {
+			struct ioc_toc_header header;
+			struct cd_toc_entry entries[65];
+		} data;
+		struct ioc_read_toc_entry *te =
+		(struct ioc_read_toc_entry *)addr;
+		struct ioc_toc_header *th;
+		int len = te->data_len;
+		th = &data.header;
+
+		if (len > sizeof(data.entries) ||
+		    len < sizeof(struct cd_toc_entry))
+			return EINVAL;
+		if (error = cd_read_toc(cd, te->address_format,
+		    te->starting_track, (struct cd_toc_entry *)&data,
+		    len + sizeof(struct ioc_toc_header)))
+			return error;
+		len = min(len, ntohs(th->len) - (sizeof(th->starting_track) +
+		    sizeof(th->ending_track)));
+		return copyout(data.entries, te->data, len);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETPATCH:
+	{
+		struct ioc_patch *arg = (struct ioc_patch *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = arg->patch[0];
+		data.page.audio.port[RIGHT_PORT].channels = arg->patch[1];
+		data.page.audio.port[2].channels = arg->patch[2];
+		data.page.audio.port[3].channels = arg->patch[3];
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCGETVOL:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		arg->vol[LEFT_PORT] = data.page.audio.port[LEFT_PORT].volume;
+		arg->vol[RIGHT_PORT] = data.page.audio.port[RIGHT_PORT].volume;
+		arg->vol[2] = data.page.audio.port[2].volume;
+		arg->vol[3] = data.page.audio.port[3].volume;
+		return 0;
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETVOL:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = CHANNEL_0;
+		data.page.audio.port[LEFT_PORT].volume = arg->vol[LEFT_PORT];
+		data.page.audio.port[RIGHT_PORT].channels = CHANNEL_1;
+		data.page.audio.port[RIGHT_PORT].volume = arg->vol[RIGHT_PORT];
+		data.page.audio.port[2].volume = arg->vol[2];
+		data.page.audio.port[3].volume = arg->vol[3];
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETMONO:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels =
+		    LEFT_CHANNEL | RIGHT_CHANNEL | 4 | 8;
+		data.page.audio.port[RIGHT_PORT].channels =
+		    LEFT_CHANNEL | RIGHT_CHANNEL;
+		data.page.audio.port[2].channels = 0;
+		data.page.audio.port[3].channels = 0;
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETSTEREO:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = LEFT_CHANNEL;
+		data.page.audio.port[RIGHT_PORT].channels = RIGHT_CHANNEL;
+		data.page.audio.port[2].channels = 0;
+		data.page.audio.port[3].channels = 0;
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETMUTE:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = 0;
+		data.page.audio.port[RIGHT_PORT].channels = 0;
+		data.page.audio.port[2].channels = 0;
+		data.page.audio.port[3].channels = 0;
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETLEFT:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = LEFT_CHANNEL;
+		data.page.audio.port[RIGHT_PORT].channels = LEFT_CHANNEL;
+		data.page.audio.port[2].channels = 0;
+		data.page.audio.port[3].channels = 0;
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+#ifdef notyet
+	case CDIOCSETRIGHT:
+	{
+		struct ioc_vol *arg = (struct ioc_vol *)addr;
+		struct cd_mode_data data;
+		if (error = cd_get_mode(cd, &data, AUDIO_PAGE))
+			return error;
+		data.page.audio.port[LEFT_PORT].channels = RIGHT_CHANNEL;
+		data.page.audio.port[RIGHT_PORT].channels = RIGHT_CHANNEL;
+		data.page.audio.port[2].channels = 0;
+		data.page.audio.port[3].channels = 0;
+		return cd_set_mode(cd, &data);
+	}
+#endif
+
+	case CDIOCRESUME:
+		return acd_pause(acd, PA_RESUME);
+
+	case CDIOCPAUSE:
+		return acd_pause(acd, PA_PAUSE);
+
+	case CDIOCSTART:
+		return atapi_start_stop(acd->ad_link, SSS_START, 0);
+
+	case CDIOCSTOP:
+		return atapi_start_stop(acd->ad_link, SSS_STOP, 0);
+
+	case CDIOCEJECT:
+	case DIOCEJECT:
+		return atapi_start_stop(acd->ad_link, SSS_STOP|SSS_LOEJ, 0);
+
+	case CDIOCALLOW:
+		return atapi_prevent(acd->ad_link, PR_ALLOW);
+
+	case CDIOCPREVENT:
+		return atapi_prevent(acd->ad_link, PR_PREVENT);
+
+	case DIOCLOCK:
+		return atapi_prevent(acd->ad_link,
+		    (*(int *)addr) ? PR_PREVENT : PR_ALLOW);
+	case CDIOCRESET:
+		return acd_reset(acd);
+
+	default:
+		return ENOTTY;
+	}
+
+#ifdef DIAGNOSTIC
+	panic("cdioctl: impossible");
+#endif
+}
+
+/*
+ * Load the label information on the named device
+ * Actually fabricate a disklabel
+ *
+ * EVENTUALLY take information about different
+ * data tracks from the TOC and put it in the disklabel
+ */
+void
+acdgetdisklabel(acd)
+	struct acd_softc *acd;
+{
+	struct disklabel *lp = acd->sc_dk.dk_label;
+
+	bzero(lp, sizeof(struct disklabel));
+	bzero(acd->sc_dk.dk_cpulabel, sizeof(struct cpu_disklabel));
+
+#if 0	/* XXX */
+	lp->d_secsize = acd->params.blksize;
+#endif
+	lp->d_secsize = 2048;
+	lp->d_ntracks = 1;
+	lp->d_nsectors = 100;
+	lp->d_ncylinders = (acd->params.disksize / 100) + 1;
+	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
+
+	strncpy(lp->d_typename, "ATAPI CD-ROM", 16);
+	lp->d_type = DTYPE_SCSI;	/* XXX */
+	strncpy(lp->d_packname, "fictitious", 16);
+	lp->d_secperunit = acd->params.disksize;
+	lp->d_rpm = 300;
+	lp->d_interleave = 1;
+	lp->d_flags = D_REMOVABLE;
+
+	lp->d_partitions[0].p_offset = 0;
+	lp->d_partitions[0].p_size =
+	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
+	lp->d_partitions[0].p_fstype = FS_ISO9660;
+	lp->d_partitions[RAW_PART].p_offset = 0;
+	lp->d_partitions[RAW_PART].p_size =
+	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
+	lp->d_partitions[RAW_PART].p_fstype = FS_ISO9660;
+	lp->d_npartitions = RAW_PART + 1;
+
+	lp->d_magic = DISKMAGIC;
+	lp->d_magic2 = DISKMAGIC;
+	lp->d_checksum = dkcksum(lp);
+}
+
+/*
+ * Find out from the device what it's capacity is
+ */
+u_long
+acd_size(cd, flags)
+	struct acd_softc *cd;
+	int flags;
+{
+	struct read_cd_capacity_data rdcap;
+	struct read_cd_capacity cmd;
+	u_long blksize;
+	u_long size;
+
+	/*
+	 * make up a atapi command and ask the atapi driver to do
+	 * it for you.
+	 */
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_READ_CD_CAPACITY;
+	cmd.len = sizeof(rdcap);
+
+	/*
+	 * If the command works, interpret the result as a 4 byte
+	 * number of blocks and a blocksize
+	 */
+	if (atapi_exec_cmd(cd->ad_link, &cmd , sizeof(cmd),
+	    &rdcap, sizeof(rdcap), B_READ, 0) != 0) {
+#ifdef ATAPI_DEBUG
+		printf("ATAPI_READ_CD_CAPACITY failed\n");
+#endif
+		return 0;
+	}
+
+	blksize = ntohl(rdcap.blksize);
+	if (blksize < 512)
+		blksize = 2048;	/* some drives lie ! */
+	cd->params.blksize = blksize;
+
+	size = ntohl(size);
+	if (size < 100)
+		size = 400000;	/* ditto */
+	cd->params.disksize = size;
+#ifdef ATAPI_DEBUG
+	printf("acd_size: %ld %ld\n",blksize,size);
+#endif
+
+	return size;
+}
+
+#ifdef notyet
+/*
+ * Get the requested page into the buffer given
+ */
+int
+cd_get_mode(cd, data, page)
+	struct acd_softc *cd;
+	struct cd_mode_data *data;
+	int page;
+{
+	struct scsi_mode_sense scsi_cmd;
+	int error;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	bzero(data, sizeof(*data));
+	scsi_cmd.opcode = MODE_SENSE;
+	scsi_cmd.page = page;
+	scsi_cmd.length = sizeof(*data) & 0xff;
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), (u_char *)data, sizeof(*data), CDRETRIES, 20000,
+	    NULL, SCSI_DATA_IN);
+}
+
+/*
+ * Get the requested page into the buffer given
+ */
+int
+cd_set_mode(cd, data)
+	struct acd_softc *cd;
+	struct cd_mode_data *data;
+{
+	struct scsi_mode_select scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = MODE_SELECT;
+	scsi_cmd.byte2 |= SMS_PF;
+	scsi_cmd.length = sizeof(*data) & 0xff;
+	data->header.data_length = 0;
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), (u_char *)data, sizeof(*data), CDRETRIES, 20000,
+	    NULL, SCSI_DATA_OUT);
+}
+
+/*
+ * Get scsi driver to send a "start playing" command
+ */
+int
+cd_play(cd, blkno, nblks)
+	struct acd_softc *cd;
+	int blkno, nblks;
+{
+	struct scsi_play scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = PLAY;
+	_lto4b(blkno, scsi_cmd.blk_addr);
+	_lto2b(nblks, scsi_cmd.xfer_len);
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), 0, 0, CDRETRIES, 200000, NULL, 0);
+}
+
+/*
+ * Get scsi driver to send a "start playing" command
+ */
+int
+cd_play_big(cd, blkno, nblks)
+	struct acd_softc *cd;
+	int blkno, nblks;
+{
+	struct scsi_play_big scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = PLAY_BIG;
+	_lto4b(blkno, scsi_cmd.blk_addr);
+	_lto4b(nblks, scsi_cmd.xfer_len);
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), 0, 0, CDRETRIES, 20000, NULL, 0);
+}
+
+/*
+ * Get scsi driver to send a "start playing" command
+ */
+int
+cd_play_tracks(cd, strack, sindex, etrack, eindex)
+	struct acd_softc *cd;
+	int strack, sindex, etrack, eindex;
+{
+	struct scsi_play_track scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = PLAY_TRACK;
+	scsi_cmd.start_track = strack;
+	scsi_cmd.start_index = sindex;
+	scsi_cmd.end_track = etrack;
+	scsi_cmd.end_index = eindex;
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), 0, 0, CDRETRIES, 20000, NULL, 0);
+}
+
+/*
+ * Get scsi driver to send a "play msf" command
+ */
+int
+cd_play_msf(cd, startm, starts, startf, endm, ends, endf)
+	struct acd_softc *cd;
+	int startm, starts, startf, endm, ends, endf;
+{
+	struct scsi_play_msf scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = PLAY_MSF;
+	scsi_cmd.start_m = startm;
+	scsi_cmd.start_s = starts;
+	scsi_cmd.start_f = startf;
+	scsi_cmd.end_m = endm;
+	scsi_cmd.end_s = ends;
+	scsi_cmd.end_f = endf;
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(scsi_cmd), 0, 0, CDRETRIES, 2000, NULL, 0);
+}
+
+#endif  /* notyet */
+
+/*
+ * Get atapi driver to send a "start up" command
+ */
+int
+acd_pause(acd, go)
+	struct acd_softc *acd;
+	int go;
+{
+	struct pause_resume cmd;
+
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_PAUSE_RESUME;
+	cmd.resume = go & 0xff;
+
+	return atapi_exec_cmd(acd->ad_link, &cmd , sizeof(cmd), 0, 0, 0, 0);
+}
+
+/*
+ * Get atapi driver to send a "RESET" command
+ */
+int
+acd_reset(acd)
+	struct acd_softc *acd;
+{
+#ifdef notyet	
+	return atapi_soft_reset(acd->ad_link);
+#else
+ 	return 0;
+#endif
+}
+
+#ifdef notyet
+/*
+ * Read subchannel
+ */
+int
+cd_read_subchannel(cd, mode, format, track, data, len)
+	struct acd_softc *cd;
+	int mode, format, len;
+	struct cd_sub_channel_info *data;
+{
+	struct scsi_read_subchannel scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.opcode = READ_SUBCHANNEL;
+	if (mode == CD_MSF_FORMAT)
+		scsi_cmd.byte2 |= CD_MSF;
+	scsi_cmd.byte3 = SRS_SUBQ;
+	scsi_cmd.subchan_format = format;
+	scsi_cmd.track = track;
+	_lto2b(len, scsi_cmd.data_len);
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(struct scsi_read_subchannel), (u_char *)data, len,
+	    CDRETRIES, 5000, NULL, SCSI_DATA_IN);
+}
+
+/*
+ * Read table of contents
+ */
+int
+cd_read_toc(cd, mode, start, data, len)
+	struct acd_softc *cd;
+	int mode, start, len;
+	struct cd_toc_entry *data;
+{
+	struct scsi_read_toc scsi_cmd;
+	int ntoc;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+#if 0
+	if (len != sizeof(struct ioc_toc_header))
+		ntoc = ((len) - sizeof(struct ioc_toc_header)) /
+		    sizeof(struct cd_toc_entry);
+	else
+#endif
+		ntoc = len;
+
+	scsi_cmd.opcode = READ_TOC;
+	if (mode == CD_MSF_FORMAT)
+		scsi_cmd.byte2 |= CD_MSF;
+	scsi_cmd.from_track = start;
+	_lto2b(ntoc, scsi_cmd.data_len);
+
+	return scsi_scsi_cmd(cd->ad_link, (struct scsi_generic *)&scsi_cmd,
+	    sizeof(struct scsi_read_toc), (u_char *)data, len, CDRETRIES,
+	    5000, NULL, SCSI_DATA_IN);
+}
+
+#endif /* notyet */
+
+/*
+ * Get the atapi driver to send a full inquiry to the device and use the
+ * results to fill out the disk parameter structure.
+ */
+int
+acd_get_parms(acd, flags)
+	struct acd_softc *acd;
+	int flags;
+{
+
+	/*
+	 * give a number of sectors so that sec * trks * cyls
+	 * is <= disk_size
+	 */
+	if (acd_size(acd, flags) == 0)
+		return ENXIO;
+
+	return 0;
+}
+
+int
+acdsize(dev)
+	dev_t dev;
+{
+
+	/* CD-ROMs are read-only. */
+	return -1;
+}
+
+void acdminphys(bp)
+	struct buf *bp;
+{
+
+	minphys(bp);
+}
+
+int
+acddump(dev, blkno, va, size)
+	dev_t dev;
+	daddr_t blkno;
+	caddr_t va;
+	size_t size;
+{
+
+	/* Not implemented. */
+	return ENXIO;
+}
+
+int
+acddone(acp)
+	struct atapi_command_packet *acp;
+{
+	struct at_dev_link *ad_link = acp->ad_link;
+	struct acd_softc *acd = ad_link->device_softc;
+
+	if (acp->bp != NULL)
+		disk_unbusy(&acd->sc_dk,
+		    (acp->bp->b_bcount - acp->bp->b_resid));
+
+	return (0);     
+}
diff --git a/sys/dev/atapi/atapi.h b/sys/dev/atapi/atapi.h
new file mode 100644
index 00000000000..20ec1948981
--- /dev/null
+++ b/sys/dev/atapi/atapi.h
@@ -0,0 +1,250 @@
+/*	$NetBSD: $	*/
+
+/*
+ * Copyright (c) 1996 Manuel Bouyer.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by Manuel Bouyer.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Definition of atapi commands and associated data structures
+ */
+
+/* 
+ * TEST UNIT READY (mandatory)
+ */
+#define ATAPI_TEST_UNIT_READY		0x00
+
+struct test_unit_ready {
+	u_int8_t	operation_code;
+	u_int8_t	reserved1[15];
+};
+
+/* 
+ * START/STOP UNIT (mandatory)
+ */ 
+#define ATAPI_START_STOP_UNIT		0x1b
+ 
+struct start_stop_unit {
+	u_int8_t	operation_code;
+	u_int8_t	flags;
+#define START_STOP_IMMED	0x01
+	u_int8_t	reserved2[2]; 
+	u_int8_t	how;
+#define SSS_STOP	0x00 
+#define SSS_START	0x01
+#define SSS_LOEJ	0x02
+	u_int8_t	reserved4[11];
+};
+
+/* 
+ * PREVENT/ALLOW MEDIUM REMOVAL (mandatory)
+ */ 
+#define ATAPI_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
+ 
+struct prevent_allow_medium_removal {
+	u_int8_t	operation_code;
+	u_int8_t	reserved1[3];
+	u_int8_t	how;	
+#define PR_PREVENT	0x01
+#define PR_ALLOW	0x00
+	u_int8_t	reserved3[11];
+};
+
+
+/* 
+ * READ CD CAPACITY (mandatory)
+ */
+#define ATAPI_READ_CD_CAPACITY		0x25
+
+struct read_cd_capacity {
+	u_int8_t	operation_code;
+	u_int8_t	reserved1[7];
+	u_int8_t	len;
+	u_int8_t	reserved2[7];
+};
+
+/* 
+ * Volume size info.
+ */
+struct read_cd_capacity_data {
+	u_long	size;		/* Volume size in blocks */
+	u_long	blksize;	/* Block size in bytes */
+};
+
+/*
+ * READ (10) (mandatory)
+ */  
+#define ATAPI_READ			0x28  
+
+struct read {    
+	u_int8_t	operation_code;
+	u_int8_t	reserved1;
+	u_int8_t	lba[4];
+	u_int8_t	reserved2;
+	u_int8_t	length[2];
+	u_int8_t	reserved3[7];
+}; 
+
+/* 
+ * PAUSE/RESUME (optional) 
+ */ 
+#define ATAPI_PAUSE_RESUME		0x4b
+ 
+struct pause_resume {
+	u_int8_t	operation_code;
+	u_int8_t	reserved1[7];
+	u_int8_t	resume;
+#define PA_PAUSE	0x00
+#define PA_RESUME	0x01
+	u_int8_t	reserved3[7];
+};
+
+/*
+ * MODE SENSE (mandatory)
+ */
+#define ATAPI_MODE_SENSE        0x5a
+
+struct mode_sense {
+	u_int8_t	operation_code;
+	u_int8_t	reserved1;
+	u_int8_t	page_code_control;
+#define PAGE_CODE_MASK		0x3f
+#define PAGE_CONTROL_MASK	0xc0
+	u_int8_t	reserved2[4];
+	u_int8_t	length[2];
+	u_int8_t	reserved3[7];
+};
+
+struct cappage {
+	/* Mode data header */
+	u_int8_t	data_length[2];
+	u_int8_t	medium_type;
+#define MDT_UNKNOWN	0x00        
+#define MDT_DATA_120	0x01
+#define MDT_AUDIO_120	0x02
+#define MDT_COMB_120	0x03    
+#define MDT_PHOTO_120	0x04    
+#define MDT_DATA_80	0x05
+#define MDT_AUDIO_80	0x06
+#define MDT_COMB_80	0x07 
+#define MDT_PHOTO_80	0x08
+#define MDT_NO_DISC	0x70
+#define MDT_DOOR_OPEN	0x71
+#define MDT_FMT_ERROR	0x72
+	u_int8_t	reserved1[5];
+
+	/* Capabilities page */
+	u_int8_t	page_code;
+#define CAP_PAGE	0x2a
+	u_int8_t param_len;
+	u_int8_t reserved2[2];
+
+	u_int8_t	format_cap;
+#define FORMAT_AUDIO_PLAY	0x01	/* audio play supported */
+#define FORMAT_COMPOSITE	0x02	/* composite audio/video supported */
+#define FORMAT_DPORT1		0x04	/* digital audio on port 1 */
+#define FORMAT_DPORT2		0x08	/* digital audio on port 2 */
+#define FORMAT_MODE2_FORM1	0x10	/* mode 2 form 1 (XA) read */
+#define FORMAT_MODE2_FORM2	0x20	/* mode 2 form 2 format */
+#define FORMAT_MULTISESSION	0x40	/* multi-session photo-CD */
+
+	u_int8_t	ops_cap;
+#define OPS_CDDA		0x01	/* audio-CD read supported */
+#define OPS_CDDA_STREAM		0x02	/* CDDA streaming */
+#define OPS_RW			0x04	/* combined R-W subchannels */
+#define OPS_RW_CORR		0x08	/* R-W subchannel data corrected */
+#define OPS_C2			0x10	/* C2 error pointers supported */
+#define OPS_ISRC		0x20	/* can return the ISRC info */
+#define OPS_UPC			0x40	/* can return the catalog number UPC */
+
+	u_int8_t	hw_cap;
+#define HW_LOCK			0x01	/* could be locked */
+#define HW_LOCKED		0x02	/* current lock state */
+#define HW_PREVENT		0x04	/* prevent jumper installed */
+#define HW_EJECT		0x08	/* can eject */
+#define HW_MECH_MASK		0xe0	/* loading mechanism type mask */
+
+#define MECH_CADDY		0x00
+#define MECH_TRAY		0x20
+#define MECH_POPUP		0x40
+#define MECH_CHANGER		0x80
+#define MECH_CARTRIDGE		0xa0
+
+	u_int8_t	sep_cap;
+#define SEP_VOL			0x01	/* independent volume controls */
+#define SEP_MUTE		0x02	/* independent mute controls */
+
+	u_int8_t	max_speed[2];	/* max raw data rate in bytes/1000 */
+	u_int8_t   max_vol_levels[2];	/* number of discrete volume levels */
+	u_int8_t	buf_size[2];	/* internal buffer size in bytes/1024 */
+	u_int8_t	cur_speed[2];	/* current data rate in bytes/1000  */
+
+	/* Digital drive output format description (optional?) */
+	u_int8_t	reserved3;
+	u_int8_t	ddofd;
+#define DDOFD_BCKF		0x01	/* data valid on failing edge of BCK */
+#define DDOFD_RCH		0x02	/* hight LRCK indicated left channel */
+#define DDOFD_LSBF		0x04	/* set if LSB first */
+#define DDOFD_DLEN_MASK		0x18	/* mask of DLEN values */
+
+#define DLEN_32			0x00	/* 32 BCKs */
+#define DLEN_16			0x08	/* 16 BCKs */
+#define DLEN_24			0x10	/* 24 BCKs */
+#define DLEN_24_I2S		0x18	/* 24 BCKs (I2S) */
+
+	u_int8_t	reserved4[2];
+};
+
+/* ATAPI error codes */
+#define ATAPI_SK_NO_SENSE		0x0
+#define ATAPI_SK_REC_ERROR		0x1	/* recovered error */
+#define ATAPI_SK_NOT_READY		0x2
+#define ATAPI_SK_MEDIUM_ERROR		0x3
+#define ATAPI_SK_HARDWARE_ERROR		0x4
+#define ATAPI_SK_ILLEGAL_REQUEST	0x5
+#define ATAPI_SK_UNIT_ATTENTION		0x6
+#define ATAPI_SK_DATA_PROTECT		0x7
+					/* 0x8 reserved */
+					/* 0x9-0xa reserved */
+#define ATAPI_SK_ABORTED_COMMAND	0xb
+					/* 0xc-0xd not referenced */
+#define ATAPI_SK_MISCOMPARE		0xe
+					/* 0xf reserved */
+
+#define ATAPI_MCR	0x08	/* media change requested */
+#define ATAPI_ABRT	0x04	/* aborted command */
+#define ATAPI_EOM	0x02	/* end of media */
+#define ATAPI_ILI	0x01	/* illegal length indication */
+
+
+int	atapi_exec_cmd __P((struct at_dev_link *, void *, int,
+	    void *, int, long, int));
+int	atapi_exec_io __P((struct at_dev_link *, void *, int,
+	    struct buf *, int));
+int	atapi_test_unit_ready __P((struct at_dev_link *, int));
+int	atapi_start_stop __P((struct at_dev_link *, int, int));
+int	atapi_prevent __P((struct at_dev_link *, int));
diff --git a/sys/dev/atapi/atapiconf.c b/sys/dev/atapi/atapiconf.c
new file mode 100644
index 00000000000..85095a4c0a4
--- /dev/null
+++ b/sys/dev/atapi/atapiconf.c
@@ -0,0 +1,676 @@
+/*	$NetBSD: $	*/
+
+/*
+ * Copyright (c) 1996 Manuel Bouyer.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by Manuel Bouyer.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/device.h>
+#include <sys/buf.h>
+#include <sys/proc.h>  
+
+#include <dev/atapi/atapilink.h>
+#include <dev/atapi/atapi.h>
+
+#define SILENT_PRINTF(flags,string) if (!(flags & A_SILENT)) printf string
+
+#ifdef ATAPI_DEBUG_CMD
+#define ATAPI_DEBUG_CMD_PRINT(args)	printf args
+#else
+#define ATAPI_DEBUG_CMD_PRINT(args)
+#endif
+
+#ifdef ATAPI_DEBUG_FCTN
+#define ATAPI_DEBUG_FCTN_PRINT(args)	printf args
+#else
+#define ATAPI_DEBUG_FCTN_PRINT(args)
+#endif
+
+struct atapibus_softc {
+	struct	device sc_dev;
+	struct	bus_link *b_link;
+};
+
+LIST_HEAD(pkt_free_list, atapi_command_packet) pkt_free_list;
+
+static void bswap __P((char *, int));
+static void btrim __P((char *, int));
+
+int atapi_error __P((struct atapi_command_packet *));
+void atapi_sense __P((struct atapi_command_packet *, u_int8_t, u_int8_t));
+void at_print_addr __P((struct at_dev_link *, u_int8_t));
+
+int atapibusmatch __P((struct device *, void *, void *));
+void atapibusattach __P((struct device *, struct device *, void *));
+
+struct cfattach atapibus_ca = {
+	sizeof(struct atapibus_softc), atapibusmatch, atapibusattach
+};
+
+struct cfdriver atapibus_cd = {
+	NULL, "atapibus", DV_DULL
+};
+
+
+int
+atapibusmatch(parent, match, aux)
+        struct device *parent;
+        void *match, *aux;
+{
+	struct cfdata *cf = match;
+	struct bus_link *ab_link = aux;
+
+	if (ab_link == NULL)
+		return 0;
+	if (ab_link->type != BUS)
+		return 0;
+	return 1;
+}
+
+int
+atapiprint(aux, bus)
+	void *aux;
+	char *bus;
+{
+	struct at_dev_link *ad_link = aux;
+	struct atapi_identify *id = &ad_link->id;
+	char *dtype, *fixrem;
+
+	/*
+	 * Figure out basic device type.
+	 */
+	switch (id->config.device_type & ATAPI_DEVICE_TYPE_MASK) {
+	case ATAPI_DEVICE_TYPE_DAD:
+		dtype = "direct";
+		break;
+
+	case ATAPI_DEVICE_TYPE_CD:
+		dtype = "cdrom";
+		break;
+
+	case ATAPI_DEVICE_TYPE_OMD:
+		dtype = "optical";
+		break;
+
+	default:
+		dtype = "unknown";
+		break;
+	}
+
+	fixrem = (id->config.cmd_drq_rem & ATAPI_REMOVABLE) ?
+	    "removable" : "fixed";
+
+	/*
+	 * Shuffle string byte order.
+	 * Mitsumi and NEC drives don't need this.
+	 */
+	if (((id->model[0] == 'N' && id->model[1] == 'E') ||
+	    (id->model[0] == 'F' && id->model[1] == 'X')) == 0)
+		bswap(id->model, sizeof(id->model));
+
+	/*
+	 * XXX Poorly named... These appear to actually be in
+	 * XXX network byte order, so bswap() is a no-op on
+	 * XXX big-endian hosts.  Clean me up, please.
+	 */
+	bswap(id->serial_number, sizeof(id->serial_number));
+	bswap(id->firmware_revision, sizeof(id->firmware_revision));
+
+	/*
+	 * Clean up the model name, serial and
+	 * revision numbers.
+	 */
+	btrim(id->model, sizeof(id->model));
+	btrim(id->serial_number, sizeof(id->serial_number));
+	btrim(id->firmware_revision, sizeof(id->firmware_revision));
+
+	if (bus != NULL)
+		printf("%s", bus);
+
+	printf(" drive %d: <%s, %s, %s> type %d/%s %s",
+	    ad_link->drive, id->model, id->serial_number,
+	    id->firmware_revision,
+	    id->config.device_type & ATAPI_DEVICE_TYPE_MASK, dtype, fixrem);
+
+	return UNCONF;
+}
+
+
+void
+atapibusattach(parent, self, aux)
+        struct device *parent, *self;
+        void *aux;
+{
+	struct atapibus_softc *ab = (struct atapibus_softc *)self;
+	struct bus_link *ab_link_proto = aux;
+	struct atapi_identify ids;
+	struct atapi_identify *id = &ids;
+	struct at_dev_link *ad_link;
+	int drive;
+
+	printf("\n");
+
+	ab_link_proto->atapibus_softc = (caddr_t)ab;
+	ab->b_link = ab_link_proto;
+
+	for (drive = 0; drive < 2 ; drive++) {
+		if (wdc_atapi_get_params(ab_link_proto, drive, id)) {
+#ifdef ATAPI_DEBUG_PROBE
+			printf("%s drive %d: cmdsz 0x%x drqtype 0x%x\n",
+			    self->dv_xname, drive,
+			    id->config.cmd_drq_rem & ATAPI_PACKET_SIZE_MASK,
+			    id->config.cmd_drq_rem & ATAPI_DRQ_MASK);
+#endif
+
+			/*
+			 * Allocate a device link and try and attach
+			 * a driver to this device.  If we fail, free
+			 * the link.
+			 */
+			ad_link = malloc(sizeof(*ad_link), M_DEVBUF, M_NOWAIT);
+			if (ad_link == NULL) {
+				printf("%s: can't allocate link for drive %d\n",
+				    self->dv_xname, drive);
+				continue;
+			}
+
+			/* Fill in link. */
+			ad_link->drive = drive;
+			if (id->config.cmd_drq_rem & ATAPI_PACKET_SIZE_16)
+				ad_link->flags |= ACAP_LEN;
+			ad_link->flags |=
+			    (id->config.cmd_drq_rem & ATAPI_DRQ_MASK) << 3;
+			ad_link->bus = ab_link_proto;
+			bcopy(id, &ad_link->id, sizeof(*id));
+
+			/* Try to find a match. */
+			if (config_found(self, ad_link, atapiprint) == NULL)
+				free(ad_link, M_DEVBUF);
+		}
+	}
+}
+
+static void
+bswap (buf, len)
+	char *buf;
+	int len;
+{       
+	u_int16_t *p = (u_int16_t *)(buf + len);
+
+	while (--p >= (u_int16_t *)buf)
+		*p = ntohs(*p);
+}   
+
+static void
+btrim (buf, len)
+	char *buf;
+	int len;
+{
+	char *p; 
+
+	/* Remove the trailing spaces. */
+	for (p = buf; p < buf + len; ++p)
+		if (*p == '\0')
+			*p = ' ';
+
+	for (p = buf + len - 1; p >= buf && *p == ' '; --p)
+		*p = '\0';
+}
+
+int
+atapi_exec_cmd(ad_link, cmd, cmd_size, databuf, datalen, rw, flags)
+	struct at_dev_link *ad_link;
+	void *cmd;
+	int cmd_size;
+	void *databuf;
+	int datalen;
+	long rw;
+	int flags;
+{
+	struct atapi_command_packet *pkt;
+	struct bus_link *b_link = ad_link->bus;
+	int status, s;
+
+	/* Allocate packet. */
+	pkt = atapi_get_pkt(ad_link, flags);
+	if (pkt == NULL)
+		return -1;
+
+	/* Fill it out. */
+	bcopy(cmd, &pkt->cmd_store, cmd_size);
+	pkt->command = &pkt->cmd_store;
+	pkt->command_size = (ad_link->flags & ACAP_LEN) ? 16 : 12;
+	pkt->databuf = databuf;
+	pkt->data_size = datalen;
+	pkt->flags = rw | (flags & 0xff) | (ad_link->flags & 0x0300);
+	pkt->drive = ad_link->drive;
+
+	/* Send it to drive. */
+	wdc_atapi_send_command_packet(b_link, pkt);
+	if ((flags & (A_POLLED | A_NOSLEEP)) == 0) {
+		ATAPI_DEBUG_CMD_PRINT(("atapi_exec_cmd: sleeping\n"));
+
+		s = splbio();
+		while ((pkt->status & ITSDONE) == 0)
+			tsleep(pkt, PRIBIO + 1,"atapicmd", 0);
+		splx(s);
+
+		ATAPI_DEBUG_CMD_PRINT(("atapi_exec_cmd: done sleeping\n"));
+
+		status = pkt->status & STATUS_MASK;
+		atapi_free_pkt(pkt);
+	} else {
+		if ((flags & A_POLLED) != 0) {
+			if ((pkt->status & ERROR) && (pkt->error)) {
+				atapi_error(pkt);
+				SILENT_PRINTF(flags,("\n"));
+			}
+		}
+		status = pkt->status & STATUS_MASK;
+		if ((flags & A_POLLED) != 0)
+			atapi_free_pkt(pkt);
+	}
+
+	return status;
+}
+
+int
+atapi_exec_io(ad_link, cmd, cmd_size, bp, flags)
+	struct at_dev_link *ad_link;
+	void *cmd;
+	int cmd_size;
+	struct buf *bp;
+	int flags;
+{
+	struct atapi_command_packet *pkt;
+	struct bus_link *b_link = ad_link->bus;
+
+	/* Allocate a packet. */
+	pkt = atapi_get_pkt(ad_link, flags);
+	if (pkt == NULL) {
+		printf("atapi_exec_io: no pkt\n");
+		return ERROR;
+	}
+
+	/* Fill it in. */
+	bcopy(cmd, &pkt->cmd_store, cmd_size);
+	pkt->command = &pkt->cmd_store;
+	pkt->command_size = (ad_link->flags & ACAP_LEN) ? 16 : 12;
+	pkt->bp = bp;
+	pkt->databuf = bp->b_data;
+	pkt->data_size = bp->b_bcount;
+	pkt->flags = bp->b_flags & (B_READ|B_WRITE) | (flags & 0xff) |
+	    (ad_link->flags & 0x0300);
+	pkt->drive = ad_link->drive;
+
+	wdc_atapi_send_command_packet(b_link, pkt);
+	return (pkt->status & STATUS_MASK);
+}
+
+void
+atapi_done(acp)
+	struct atapi_command_packet *acp;
+{
+	struct at_dev_link *ad_link = acp->ad_link;
+	struct buf *bp = acp->bp;
+	int error = 0;
+
+	ATAPI_DEBUG_CMD_PRINT(("atapi_done\n"));
+
+	if ((acp->status & ERROR) && (acp->error)) {
+		atapi_error(acp);
+		if (acp->status & RETRY) {
+			if (acp->retries <ATAPI_NRETRIES) {
+				acp->retries++;
+				acp->status = 0;
+				acp->error = 0;
+				SILENT_PRINTF(acp->flags & 0xff,
+				    (", retry #%d\n", acp->retries));
+				wdc_atapi_send_command_packet(ad_link->bus,
+				    acp);
+				return;
+			} else
+				acp->status = ERROR;
+		}
+		SILENT_PRINTF(acp->flags & 0xff,("\n"));
+	}
+	acp->status |= ITSDONE;
+
+	if (ad_link->done) {
+		ATAPI_DEBUG_CMD_PRINT(("calling private done\n"));
+		error = (*ad_link->done)(acp);
+		if (error == EJUSTRETURN)
+			return;
+	}
+	if (acp->bp == NULL) {
+		ATAPI_DEBUG_CMD_PRINT(("atapidone: wakeup acp\n"));
+		wakeup(acp);
+		return;
+	}
+
+	ATAPI_DEBUG_CMD_PRINT(("atapi_done: status %d\n", acp->status));
+
+	switch (acp->status & 0x0f) {
+	case MEDIA_CHANGE:
+		if (ad_link->flags & ADEV_REMOVABLE)
+			ad_link->flags &= ~ADEV_MEDIA_LOADED;
+
+		error = EIO;
+		break;
+
+	case NO_ERROR:
+		error = 0;
+		break;
+
+	case ERROR:
+	case END_OF_MEDIA:
+	default:
+		error = EIO;
+		break;
+	}
+
+	switch (acp->status & 0xf0) {
+	case NOT_READY:
+	case UNIT_ATTENTION:
+		if (ad_link->flags & ADEV_REMOVABLE)
+			ad_link->flags &= ~ADEV_MEDIA_LOADED;
+
+		error = EIO;
+		break;
+	}
+
+	if (error) {
+		bp->b_error = error;
+		bp->b_flags |= B_ERROR;
+		bp->b_resid = bp->b_bcount;
+	} else {
+		bp->b_error = 0;
+		bp->b_resid = acp->data_size;
+	}
+	biodone(bp);
+	atapi_free_pkt(acp);
+}
+
+struct atapi_command_packet *
+atapi_get_pkt(ad_link, flags)
+	struct at_dev_link *ad_link;
+	int flags;
+{
+	struct atapi_command_packet *pkt;
+	int s;
+
+	s = splbio();
+	while (ad_link->openings <= 0) {
+		if (flags & A_NOSLEEP) {
+			splx(s);
+			return 0;
+		}
+
+		ATAPI_DEBUG_CMD_PRINT(("atapi_get_pkt: sleeping\n"));
+
+		ad_link->flags |= ADEV_WAITING;
+		(void)tsleep(ad_link, PRIBIO, "getpkt", 0);
+	}
+
+	ad_link->openings--;
+
+	if ((pkt = pkt_free_list.lh_first) != 0) {
+		LIST_REMOVE(pkt, free_list);
+		splx(s);
+	} else {
+		splx(s);
+		pkt = malloc(sizeof(struct atapi_command_packet), M_DEVBUF,
+		    ((flags & A_NOSLEEP) != 0 ? M_NOWAIT : M_WAITOK));
+		if (pkt == NULL) {
+			printf("atapi_get_pkt: cannot allocate pkt\n");
+			ad_link->openings++;
+			return 0;
+		}
+	}
+
+	bzero(pkt, sizeof(struct atapi_command_packet));
+	pkt->ad_link = ad_link;
+	return pkt;
+}
+
+void
+atapi_free_pkt(pkt)
+	struct atapi_command_packet *pkt;
+{
+	struct at_dev_link *ad_link = pkt->ad_link;
+	int s;
+
+	s = splbio();
+	LIST_INSERT_HEAD(&pkt_free_list, pkt, free_list);
+
+	ad_link->openings++;
+
+	if ((ad_link->flags & ADEV_WAITING) != 0) {
+		ad_link->flags &= ~ADEV_WAITING;
+		wakeup(ad_link);
+	} else {
+		if (ad_link->start) {
+			ATAPI_DEBUG_CMD_PRINT(("atapi_free_pkt: calling private start\n"));
+			(*ad_link->start)((void *)ad_link->device_softc);
+		}
+	}
+	splx(s);
+}
+
+int
+atapi_test_unit_ready(ad_link, flags)
+	struct at_dev_link *ad_link;
+	int flags;
+{	
+	int ret;
+	struct test_unit_ready cmd;
+
+	ATAPI_DEBUG_FCTN_PRINT(("atapi_test_unit_ready: "));
+
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_TEST_UNIT_READY;
+
+	ret = atapi_exec_cmd(ad_link, &cmd, sizeof(cmd), 0, 0, 0, flags);
+
+	ATAPI_DEBUG_FCTN_PRINT(("atapi_test_unit_ready: ret %d\n", ret));
+
+	return ret;
+}
+
+int
+atapi_start_stop(ad_link, how, flags)
+	struct at_dev_link  *ad_link;
+	int how;
+	int flags;
+{
+	struct start_stop_unit cmd;
+	int ret;
+		
+	ATAPI_DEBUG_FCTN_PRINT(("atapi_start_stop: "));
+
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_START_STOP_UNIT;
+	cmd.how = how;
+
+	ret = atapi_exec_cmd(ad_link, &cmd, sizeof(cmd), 0,0,0,flags);
+
+	ATAPI_DEBUG_FCTN_PRINT(("ret %d\n", ret));
+
+	return ret;
+}
+
+int
+atapi_prevent(ad_link, how)
+	struct at_dev_link *ad_link;
+	int how;
+{
+	struct prevent_allow_medium_removal cmd;
+	int ret;
+
+	ATAPI_DEBUG_FCTN_PRINT(("atapi_prevent: "));
+
+	bzero(&cmd, sizeof(cmd));
+	cmd.operation_code = ATAPI_PREVENT_ALLOW_MEDIUM_REMOVAL;
+	cmd.how = how & 0xff;
+
+	ret = atapi_exec_cmd(ad_link, &cmd, sizeof(cmd), 0,0,0,0);
+
+	ATAPI_DEBUG_FCTN_PRINT(("ret %d\n", ret));
+
+	return ret;
+}
+
+int 
+atapi_error(acp)
+	struct atapi_command_packet* acp;
+{
+	int flags, error, ret = -1;
+	struct at_dev_link *ad_link = acp->ad_link;
+
+	flags = acp->flags & 0xff;
+	error = acp->error;
+
+	at_print_addr(ad_link, acp->flags & 0xff);
+
+	if (error & ATAPI_MCR) {
+		SILENT_PRINTF(flags,("media change requested"));
+		acp->status = MEDIA_CHANGE;
+	}
+
+	if (error & ATAPI_ABRT) {      
+		SILENT_PRINTF(flags,("command aborted"));
+		acp->status = ERROR; 
+	}
+
+	if (error & ATAPI_EOM) {
+		SILENT_PRINTF(flags,("end of media"));
+		acp->status = END_OF_MEDIA;
+	}
+
+	if (error & ATAPI_ILI) {
+		SILENT_PRINTF(flags,("illegal length indication"));
+		acp->status = ERROR;
+	}
+
+	if ((error & 0x0f) == 0)
+		ret = 0;
+
+	atapi_sense(acp, error >> 4, flags);
+
+	if (((flags & A_SILENT) == 0) && (acp->status != NO_ERROR)) {
+		int i;
+		printf(", command:");
+		for (i = 0; i < acp->command_size; i++)
+			printf(" %2x", ((u_int8_t *)acp->command)[i]);
+	}
+
+	return ret;
+}
+
+void
+atapi_sense(acp, sense_key, flags)
+	struct atapi_command_packet *acp;
+	u_int8_t sense_key;
+	u_int8_t flags;
+{
+	struct at_dev_link *ad_link = acp->ad_link;
+
+	switch (sense_key) {
+	case ATAPI_SK_NO_SENSE:
+		break;
+
+	case ATAPI_SK_REC_ERROR:
+		SILENT_PRINTF(flags,("recovered error"));
+		acp->status = 0;
+		break;
+
+	case ATAPI_SK_NOT_READY:
+		SILENT_PRINTF(flags,("not ready"));
+		acp->status = NOT_READY;
+		break;
+
+	case ATAPI_SK_MEDIUM_ERROR:
+		SILENT_PRINTF(flags,("medium error"));
+		acp->status = ERROR;
+		break;
+
+	case ATAPI_SK_HARDWARE_ERROR:
+		SILENT_PRINTF(flags,("hardware error"));
+		acp->status = ERROR;
+		break;
+
+	case ATAPI_SK_ILLEGAL_REQUEST:
+		SILENT_PRINTF(flags,("illegal request"));
+		acp->status = ERROR;
+		break;
+
+	case ATAPI_SK_UNIT_ATTENTION:
+		SILENT_PRINTF(flags,("unit attention"));
+		acp->status = UNIT_ATTENTION;
+		if (ad_link->flags & ADEV_REMOVABLE)
+			ad_link->flags &= ~ADEV_MEDIA_LOADED;
+		break;
+
+	case ATAPI_SK_DATA_PROTECT:
+		SILENT_PRINTF(flags,("data protect"));
+		acp->status = ERROR;
+		break;
+
+	case ATAPI_SK_ABORTED_COMMAND:
+		SILENT_PRINTF(flags,("aborted command"));
+		acp->status = RETRY;
+		break;
+
+	case ATAPI_SK_MISCOMPARE:
+		SILENT_PRINTF(flags,("miscompare"));
+		acp->status = ERROR;
+		break;
+
+	default:
+		SILENT_PRINTF(flags,("unexpected sense key %02x", sense_key));
+		acp->status = ERROR;
+	}
+}
+
+void
+at_print_addr(ad_link, flags)
+	struct at_dev_link *ad_link; 
+	u_int8_t flags;
+{
+
+	if (flags & A_SILENT)
+		return;
+
+	printf("%s(%s:%d): ", ad_link->device_softc ?
+	    ((struct device *)ad_link->device_softc)->dv_xname : "probe",
+	    ((struct device *)ad_link->bus->wdc_softc)->dv_xname,
+	    ad_link->drive);
+}
diff --git a/sys/dev/atapi/atapilink.h b/sys/dev/atapi/atapilink.h
new file mode 100644
index 00000000000..7d01102a2a7
--- /dev/null
+++ b/sys/dev/atapi/atapilink.h
@@ -0,0 +1,352 @@
+/*	$NetBSD: $	*/
+
+/*
+ * Copyright (c) 1996 Manuel Bouyer.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by Manuel Bouyer.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#undef ATAPI_DEBUG
+#undef ATAPI_DEBUG_PROBE
+
+struct bus_link {
+	u_int8_t type;  
+#define DRIVE	0
+#define BUS	1
+	caddr_t	wdc_softc;
+	caddr_t	atapibus_softc;
+	struct	wdc_link *ctlr_link;
+	u_int8_t ctrl;
+};
+
+struct atapi_identify {
+	struct	config_s {
+		u_int8_t cmd_drq_rem;
+#define ATAPI_PACKET_SIZE_MASK	0x02
+#define ATAPI_PACKET_SIZE_12	0x00
+#define ATAPI_PACKET_SIZE_16	0x01
+
+#define ATAPI_DRQ_MASK		0x60
+#define ATAPI_MICROPROCESSOR_DRQ 0x00
+#define ATAPI_INTERRUPT_DRQ	0x20
+#define ATAPI_ACCELERATED_DRQ	0x40
+
+#define ATAPI_REMOVABLE		0x80
+
+		u_int8_t device_type;
+#define ATAPI_DEVICE_TYPE_MASK	0x1f
+#define ATAPI_DEVICE_TYPE_DAD	0x00	/* direct access device */
+					/* 0x1-0x4 reserved */
+#define ATAPI_DEVICE_TYPE_CD	0x05	/* CD-ROM */
+					/* 0x6 reserved */
+#define ATAPI_DEVICE_TYPE_OMD	0x07	/* optical memory device */
+					/* 0x8-0x1e reserved */
+#define ATAPI_DEVICE_TYPE_UNKNOWN 0x1f
+
+#define ATAPI_GC_PROTOCOL_MASK	0xc0	/* mask of protocol bits */
+					/* 0x00 and 0x01 are ATA */
+#define ATAPI_GC_PROTO_TYPE_ATAPI 0x80
+#define ATAPI_GC_PROTO_TYPE_RESERVED 0xc0
+	} config;				/* general configuration */
+
+	u_int8_t	cylinders[2];
+	u_int8_t	reserved1[2];
+	u_int8_t	heads[2];
+	u_int8_t	unf_bytes_per_track[2];
+	u_int8_t	unf_bytes_per_sector[2];
+	u_int8_t	sectors_per_track[2];
+	u_int8_t	reserved2[6];
+	char		serial_number[20];
+	u_int8_t	buffer_type[2];
+	u_int8_t	buffer_size[2];
+	u_int8_t	ECC_bytes_available[2];
+	char		firmware_revision[8];
+	char		model[40];
+	u_int8_t	sector_count[2];
+	u_int8_t	double_word[2];		/* == 0 for CD-ROMs */
+
+	struct capabilities_s {
+		u_int8_t vendor;
+		u_int8_t capflags;
+#define ATAPI_CAP_DMA			0x01	/* DMA supported */
+#define ATAPI_CAP_LBA			0x02	/* LBA supported */
+#define ATAPI_IORDY_DISABLE		0x04	/* IORDY can be disabled */
+#define ATAPI_IORDY			0x08	/* IORDY supported */
+	} capabilities;
+
+	u_int8_t	reserved3[2];
+	u_int8_t	PIO_cycle_timing[2];
+	u_int8_t	DMA_cycle_timing[2];
+	u_int8_t	validity[2]; /* of words 54-58, 64-70 in this table */
+
+#define ATAPI_VALID_FIRST	0x0	/* == 1 => words 54-58 are valid */
+#define ATAPI_VALID_SECOND	0x1	/* == 1 => words 64-70 are valid */
+
+	u_int8_t	current_chs[6];	/* cylinder/head/sector */
+	u_int8_t	current_capacity[4];
+	u_int8_t	reserved4[2];
+	u_int8_t	user_addressable_sectors[4];
+	u_int8_t	singleword_DMA_mode[2];
+
+#define ATAPI_SW_DMA_MODE_AVAIL	0x00ff	/* Mode 0 is supported */
+#define ATAPI_SW_DMA_MODE_ACTIVE 0xff00	/* which mode is active */
+
+	u_int8_t	multiword_DMA_mode[2];
+
+#define ATAPI_MW_DMA_MODE_AVAIL	0x00ff	/* Mode 0 is supported */
+#define ATAPI_MW_DMA_MODE_ACTIVE 0xff00	/* which mode is active */
+
+	u_int8_t	enhanced_PIO_mode[2];
+
+#define ATAPI_ENHANCED_PIO_AVAIL 0x0001	/* PIO Mode 3 is supported */
+
+	u_int8_t	blind_PIO_minimum_cycles[2];
+	u_int8_t	mw_dma_tct[2]; /* multi-word DMA transfer cycle time */
+	u_int8_t	min_PIO_tct_no_flow_control[2];
+	u_int8_t	min_PIO_tct_with_flow_control[2];
+	u_int8_t	reserved5[4];
+	u_int8_t	reserved6[114];
+	u_int8_t	vendor[64];	/* vendor unique */
+	u_int8_t	reserved7[192];
+};
+
+struct at_dev_link {
+	void	*device_softc;
+	u_int8_t drive;
+	u_int8_t openings;
+	struct	atapi_identify id;  
+	struct	bus_link *bus;
+	u_int16_t flags;
+#define ADEV_REMOVABLE		0x001	/* media is removable */
+#define ADEV_MEDIA_LOADED	0x002	/* device figures are still valid */  
+#define ADEV_WAITING		0x004	/* a process is waiting for this */
+#define ADEV_OPEN		0x008	/* at least 1 open session */
+#define ACAP_DRQ_MPROC		0x000	/* microprocessor DRQ */
+#define ACAP_DRQ_INTR		0x100	/* interrupt DRQ */
+#define ACAP_DRQ_ACCEL		0x200	/* accelerated DRQ */
+#define ACAP_LEN 		0x400	/* 16 bit commands */
+	void	(*start)();		/* device start routine */
+	int	(*done)();		/* device done routine */
+};
+
+struct atapi_command_packet {
+	void	*ad_link;
+	void	*command;
+	char	cmd_store[16];
+	int	command_size;
+	struct	buf *bp; 
+	void	*databuf;
+	int	data_size;
+	int	flags;	/* handle B_READ/B_WRITE mask 0x00f00000 */
+			/* controller flags maks 0x0000000f */
+			/* ATAPI flags mask 0x000000f0 */
+			/* Capabilities flags 0x00000f00 */
+	u_int8_t drive;
+	u_int16_t status;
+#define STATUS_MASK	0xff
+#define NO_ERROR	0x00
+#define ERROR		0x01
+#define MEDIA_CHANGE	0x02
+#define END_OF_MEDIA	0x03
+#define NOT_READY	0x10
+#define UNIT_ATTENTION	0x20
+#define RETRY		0x40
+#define ITSDONE		0x100
+	u_int8_t error;
+	u_int8_t retries;
+#define ATAPI_NRETRIES 5
+	LIST_ENTRY(atapi_command_packet) free_list;
+};
+
+int	wdc_atapi_get_params __P((struct bus_link *, u_int8_t,
+	    struct atapi_identify *)); 
+void	wdc_atapi_send_command_packet __P((struct bus_link *,
+	    struct atapi_command_packet*));
+
+#define A_POLLED	0x10
+#define A_NOSLEEP	0x20
+#define A_SILENT	0x40
+
+void	atapi_done __P((struct atapi_command_packet *));
+struct	atapi_command_packet *atapi_get_pkt __P((struct at_dev_link *, int));
+void	atapi_free_pkt __P((struct atapi_command_packet *));
+
+/*
+ * Functions used for reading and writing 2, 3, and 4 byte values
+ * in ATAPI commands.
+ */
+
+static __inline void _lto2b __P((u_int32_t val, u_int8_t *bytes));
+static __inline void _lto3b __P((u_int32_t val, u_int8_t *bytes));
+static __inline void _lto4b __P((u_int32_t val, u_int8_t *bytes));
+static __inline u_int32_t _2btol __P((u_int8_t *bytes));
+static __inline u_int32_t _3btol __P((u_int8_t *bytes));
+static __inline u_int32_t _4btol __P((u_int8_t *bytes));
+
+static __inline void _lto2l __P((u_int32_t val, u_int8_t *bytes));
+static __inline void _lto3l __P((u_int32_t val, u_int8_t *bytes));
+static __inline void _lto4l __P((u_int32_t val, u_int8_t *bytes));
+static __inline u_int32_t _2ltol __P((u_int8_t *bytes));
+static __inline u_int32_t _3ltol __P((u_int8_t *bytes));
+static __inline u_int32_t _4ltol __P((u_int8_t *bytes));
+
+static __inline void
+_lto2b(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = (val >> 8) & 0xff;
+	bytes[1] = val & 0xff;
+}
+
+static __inline void
+_lto3b(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = (val >> 16) & 0xff;
+	bytes[1] = (val >> 8) & 0xff;
+	bytes[2] = val & 0xff;
+}
+
+static __inline void
+_lto4b(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = (val >> 24) & 0xff;
+	bytes[1] = (val >> 16) & 0xff;
+	bytes[2] = (val >> 8) & 0xff;
+	bytes[3] = val & 0xff;
+}
+
+static __inline u_int32_t
+_2btol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = (bytes[0] << 8) |
+	     bytes[1];
+	return (rv);
+}
+
+static __inline u_int32_t
+_3btol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = (bytes[0] << 16) |
+	     (bytes[1] << 8) |
+	     bytes[2];
+	return (rv);
+}
+
+static __inline u_int32_t
+_4btol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = (bytes[0] << 24) |
+	     (bytes[1] << 16) |
+	     (bytes[2] << 8) |
+	     bytes[3];
+	return (rv);
+}
+
+static __inline void
+_lto2l(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = val & 0xff;
+	bytes[1] = (val >> 8) & 0xff;
+}
+
+static __inline void
+_lto3l(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = val & 0xff;
+	bytes[1] = (val >> 8) & 0xff;
+	bytes[2] = (val >> 16) & 0xff;
+}
+
+static __inline void
+_lto4l(val, bytes)
+	u_int32_t val;
+	u_int8_t *bytes;
+{
+
+	bytes[0] = val & 0xff;
+	bytes[1] = (val >> 8) & 0xff;
+	bytes[2] = (val >> 16) & 0xff;
+	bytes[3] = (val >> 24) & 0xff;
+}
+
+static __inline u_int32_t
+_2ltol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = bytes[0] |
+	     (bytes[1] << 8);
+	return (rv);
+}
+
+static __inline u_int32_t
+_3ltol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = bytes[0] |
+	     (bytes[1] << 8) |
+	     (bytes[2] << 16);
+	return (rv);
+}
+
+static __inline u_int32_t
+_4ltol(bytes)
+	u_int8_t *bytes;
+{
+	register u_int32_t rv;
+
+	rv = bytes[0] |
+	     (bytes[1] << 8) |
+	     (bytes[2] << 16) |
+	     (bytes[3] << 24);
+	return (rv);
+}
diff --git a/sys/dev/atapi/files.atapi b/sys/dev/atapi/files.atapi
new file mode 100644
index 00000000000..508710c0960
--- /dev/null
+++ b/sys/dev/atapi/files.atapi
@@ -0,0 +1,14 @@
+#
+# Config.new file and device description for machine-independent ATAPI code.
+# Included by ports that need it.  Ports that use it must provide
+# their own "major" declarations for the appropriate devices.
+
+define	atapi {}
+file	dev/atapi/atapiconf.c			atapi
+
+device	atapibus {drive = -1}
+attach	atapibus at atapi
+
+device  acd: disk
+attach	acd at atapibus
+file    dev/atapi/acd.c           acd needs-flag
diff --git a/sys/dev/isa/files.isa b/sys/dev/isa/files.isa
index 48ede3fa3ff..753dc3cb2cb 100644
--- a/sys/dev/isa/files.isa
+++ b/sys/dev/isa/files.isa
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.isa,v 1.18 1996/05/27 01:11:49 deraadt Exp $
+#	$OpenBSD: files.isa,v 1.19 1996/06/08 09:12:44 downsj Exp $
 #	$NetBSD: files.isa,v 1.21 1996/05/16 03:45:55 mycroft Exp $
 #
 # Config.new file and device description for machine-independent ISA code.
@@ -119,12 +119,14 @@ device	pcd: disk, opti
 attach	pcd at isa
 file	dev/isa/pcd.c			pcd needs-flag
 
-# ISA "wd" (ESDI/IDE/etc.) controllers
-device	wdc {drive = -1}
-attach	wdc at isa
-device	wd: disk, isadma
-attach	wd at wdc
-file	dev/isa/wd.c			wdc needs-flag
+# ISA "wd" (ESDI/IDE/etc.) controllers, ATAPI bus
+define       ata {drive = -1}
+device       wdc {drive = -1}: atapi, ata
+attach       wdc at isa
+device       wd: disk, isadma
+attach       wd at wdc
+file dev/isa/wdc.c                   wdc needs-flag
+file dev/isa/wd.c                    wd needs-flag
 
 # Wangtek- and Archive-compatible tape controller boards
 device	wt: tape, isadma
diff --git a/sys/dev/isa/wd.c b/sys/dev/isa/wd.c
index 82c2ac91ac5..d9061bd00eb 100644
--- a/sys/dev/isa/wd.c
+++ b/sys/dev/isa/wd.c
@@ -1,5 +1,4 @@
-/*	$OpenBSD: wd.c,v 1.14 1996/06/01 09:35:36 deraadt Exp $	*/
-/*	$NetBSD: wd.c,v 1.150 1996/05/12 23:54:03 mycroft Exp $	*/
+/*	$NetBSD: wd.c,v 1.150 1996/05/12 23:54:03 mycroft Exp $ */
 
 /*
  * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
@@ -56,21 +55,8 @@
 #include <machine/pio.h>
 
 #include <dev/isa/isavar.h>
-#include <dev/isa/isadmavar.h>
 #include <dev/isa/wdreg.h>
-
-#define	WAITTIME	(8 * hz)	/* time to wait for a completion
-					   (long enough for disk spin-ups) */
-#define	RECOVERYTIME	(hz / 2)	/* time to recover from an error */
-
-#define WDCDELAY	100
-#define WDCNDELAY	100000		/* delay = 100us; so 10s for a controller state change */
-#if 0
-/* If you enable this, it will report any delays more than 100us * N long. */
-#define WDCNDELAY_DEBUG	10
-#endif
-
-#define	WDIORETRIES	3		/* number of retries before giving up */
+#include <dev/isa/wdlink.h>
 
 #define	WDUNIT(dev)			DISKUNIT(dev)
 #define	WDPART(dev)			DISKPART(dev)
@@ -78,82 +64,22 @@
 
 #define	WDLABELDEV(dev)	(MAKEWDDEV(major(dev), WDUNIT(dev), RAW_PART))
 
+#ifdef WDDEBUG
+#define WDDEBUG_PRINT(args)		printf args
+#else
+#define WDDEBUG_PRINT(args)
+#endif
+
 struct wd_softc {
 	struct device sc_dev;
 	struct disk sc_dk;
-
-	/* Information about the current transfer: */
-	daddr_t sc_blkno;	/* starting block number */
-	int sc_bcount;		/* byte count left */
-	int sc_skip;		/* bytes already transferred */
-	int sc_nblks;		/* number of blocks currently transferring */
-	int sc_nbytes;		/* number of bytes currently transferring */
-
-	/* Long-term state: */
-	int sc_drive;			/* physical unit number */
-	int sc_state;			/* control state */
-#define	RECAL		0		/* recalibrate */
-#define	RECAL_WAIT	1		/* done recalibrating */
-#define	GEOMETRY	2		/* upload geometry */
-#define	GEOMETRY_WAIT	3		/* done uploading geometry */
-#define	MULTIMODE	4		/* set multiple mode */
-#define	MULTIMODE_WAIT	5		/* done setting multiple mode */
-#define	OPEN		6		/* done with open */
-	int sc_mode;			/* transfer mode */
-#define	WDM_PIOSINGLE	0		/* single-sector PIO */
-#define	WDM_PIOMULTI	1		/* multi-sector PIO */
-#define	WDM_DMA		2		/* DMA */
-	int sc_multiple;		/* multiple for WDM_PIOMULTI */
-	int sc_flags;			/* drive characteistics found */
-#define	WDF_LOCKED	0x01
-#define	WDF_WANTED	0x02
-#define	WDF_WLABEL	0x04		/* label is writable */
-#define	WDF_LABELLING	0x08		/* writing label */
-/* XXX Nothing resets this yet, but disk change sensing will when ATAPI is
-   implemented. */
-#define	WDF_LOADED	0x10		/* parameters loaded */
-#define	WDF_32BIT	0x20		/* can do 32-bit transfer */
-
-	struct wdparams sc_params;	/* ESDI/ATA drive parameters */
-	daddr_t	sc_badsect[127];	/* 126 plus trailing -1 marker */
-
-	TAILQ_ENTRY(wd_softc) sc_drivechain;
+	struct wd_link *d_link;
 	struct buf sc_q;
 };
 
-struct wdc_softc {
-	struct device sc_dev;
-	void *sc_ih;
-
-	int sc_iobase;			/* I/O port base */
-	int sc_drq;			/* DMA channel */
-
-	TAILQ_HEAD(drivehead, wd_softc) sc_drives;
-	int sc_flags;
-#define	WDCF_ACTIVE	0x01		/* controller is active */
-#define	WDCF_SINGLE	0x02		/* sector at a time mode */
-#define	WDCF_ERROR	0x04		/* processing a disk error */
-#define	WDCF_WANTED	0x08		/* XXX locking for wd_get_parms() */
-	int sc_errors;			/* errors during current transfer */
-	u_char sc_status;		/* copy of status register */
-	u_char sc_error;		/* copy of error register */
-};
-
-int	wdcprobe 	__P((struct device *, void *, void *));
-void	wdcattach 	__P((struct device *, struct device *, void *));
-int	wdcintr		__P((void *));
-
-struct cfattach wdc_ca = {
-	sizeof(struct wdc_softc), wdcprobe, wdcattach
-};
-
-struct cfdriver wdc_cd = {
-	NULL, "wdc", DV_DULL
-};
-
-int wdprobe __P((struct device *, void *, void *));
-void wdattach __P((struct device *, struct device *, void *));
-int wdprint __P((void *, char *));
+int	wdprobe		__P((struct device *, void *, void *));
+void	wdattach	__P((struct device *, struct device *, void *));
+int	wdprint		__P((void *, char *));
 
 struct cfattach wd_ca = {
 	sizeof(struct wd_softc), wdprobe, wdattach
@@ -175,123 +101,29 @@ cdev_decl(wd);
 bdev_decl(wd);
 
 void	wdfinish	__P((struct wd_softc *, struct buf *));
-int 	dcintr		__P((void *));
-void	wdcstart	__P((struct wdc_softc *));
-int	wdcommand	__P((struct wd_softc *, int, int, int, int, int));
-int	wdcommandshort	__P((struct wdc_softc *, int, int));
-int	wdcontrol	__P((struct wd_softc *));
-int	wdsetctlr	__P((struct wd_softc *));
+int	wdsetctlr	__P((struct wd_link *));
 static void bad144intern __P((struct wd_softc *));
-int	wdcreset	__P((struct wdc_softc *));
-void	wdcrestart	__P((void *arg));
-void	wdcunwedge	__P((struct wdc_softc *));
-void	wdctimeout	__P((void *arg));
-void	wderror		__P((void *, struct buf *, char *));
-int	wdcwait		__P((struct wdc_softc *, int));
-int	wdlock		__P((struct wd_softc *));
-void	wdunlock	__P((struct wd_softc *));
-
-/* ST506 spec says that if READY or SEEKCMPLT go off, then the read or write
-   command is aborted. */
-#define	wait_for_drq(d)		wdcwait(d, WDCS_DRDY | WDCS_DSC | WDCS_DRQ)
-#define	wait_for_ready(d)	wdcwait(d, WDCS_DRDY | WDCS_DSC)
-#define	wait_for_unbusy(d)	wdcwait(d, 0)
-
-int
-wdcprobe(parent, match, aux)
-	struct device *parent;
-	void *match, *aux;
-{
-	struct wdc_softc *wdc = match;
-	struct isa_attach_args *ia = aux;
-	int iobase;
-
-	wdc->sc_iobase = iobase = ia->ia_iobase;
-
-	/* Check if we have registers that work. */
-	outb(iobase+wd_error, 0x5a);	/* Error register not writable, */
-	outb(iobase+wd_cyl_lo, 0xa5);	/* but all of cyllo are. */
-	if (inb(iobase+wd_error) == 0x5a || inb(iobase+wd_cyl_lo) != 0xa5)
-		return 0;
-
-	if (wdcreset(wdc) != 0) {
-		delay(500000);
-		if (wdcreset(wdc) != 0)
-			return 0;
-	}
-
-	/* Select drive 0. */
-	outb(iobase+wd_sdh, WDSD_IBM | 0);
-
-	/* Wait for controller to become ready. */
-	if (wait_for_unbusy(wdc) < 0)
-		return 0;
-    
-	/* Start drive diagnostics. */
-	outb(iobase+wd_command, WDCC_DIAGNOSE);
-
-	/* Wait for command to complete. */
-	if (wait_for_unbusy(wdc) < 0)
-		return 0;
-
-	ia->ia_iosize = 8;
-	ia->ia_msize = 0;
-	return 1;
-}
-
-struct wdc_attach_args {
-	int wa_drive;
-};
-
-int
-wdprint(aux, wdc)
-	void *aux;
-	char *wdc;
-{
-	struct wdc_attach_args *wa = aux;
-
-	if (!wdc)
-		printf(" drive %d", wa->wa_drive);
-	return QUIET;
-}
-
-void
-wdcattach(parent, self, aux)
-	struct device *parent, *self;
-	void *aux;
-{
-	struct wdc_softc *wdc = (void *)self;
-	struct isa_attach_args *ia = aux;
-	struct wdc_attach_args wa;
-
-	TAILQ_INIT(&wdc->sc_drives);
-	wdc->sc_drq = ia->ia_drq;
-
-	printf("\n");
-
-	wdc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq, IST_EDGE,
-	    IPL_BIO, wdcintr, wdc, wdc->sc_dev.dv_xname);
-
-	for (wa.wa_drive = 0; wa.wa_drive < 2; wa.wa_drive++)
-		(void)config_found(self, (void *)&wa, wdprint);
-}
+int	wdlock		__P((struct wd_link *));
+void	wdunlock	__P((struct wd_link *));
 
 int
 wdprobe(parent, match, aux)
 	struct device *parent;
 	void *match, *aux;
 {
-	struct wdc_softc *wdc = (void *)parent;
+	caddr_t *wdc = (void *)parent;
 	struct cfdata *cf = match;
-	struct wdc_attach_args *wa = aux;
-	int drive = wa->wa_drive;
+	struct wd_link *d_link = aux;
+	int drive;
+	
+	if (d_link == NULL)
+		return 0;
+	if (d_link->type != DRIVE)
+		return 0;
 
+	drive = d_link->sc_drive;
 	if (cf->cf_loc[0] != -1 && cf->cf_loc[0] != drive)
 		return 0;
-	
-	if (wdcommandshort(wdc, drive, WDCC_RECAL) != 0 ||
-	    wait_for_ready(wdc) != 0)
-		return 0;
 
 	return 1;
 }
@@ -302,12 +134,14 @@ wdattach(parent, self, aux)
 	void *aux;
 {
 	struct wd_softc *wd = (void *)self;
-	struct wdc_softc *wdc = (void *)parent;
-	struct wdc_attach_args *wa = aux;
+	struct caddr_t *wdc = (void *)parent;
+	struct wd_link *d_link= aux;
 	int i, blank;
 	char buf[41], c, *p, *q;
 
-	wd->sc_drive = wa->wa_drive;
+	wd->d_link = d_link;
+	d_link->openings = 1;
+	d_link->wd_softc = (caddr_t)wd;
 
 	/*
 	 * Initialize and attach the disk structure.
@@ -318,9 +152,11 @@ wdattach(parent, self, aux)
 
 	dk_establish(&wd->sc_dk, &wd->sc_dev);
 
-	wd_get_parms(wd);
-	for (blank = 0, p = wd->sc_params.wdp_model, q = buf, i = 0;
-	     i < sizeof(wd->sc_params.wdp_model); i++) {
+	d_link->sc_lp = wd->sc_dk.dk_label;
+
+	wdc_get_parms(d_link);
+	for (blank = 0, p = d_link->sc_params.wdp_model, q = buf, i = 0;
+	     i < sizeof(d_link->sc_params.wdp_model); i++) {
 		c = *p++;
 		if (c == '\0')
 			break;
@@ -335,34 +171,36 @@ wdattach(parent, self, aux)
 	}
 	*q++ = '\0';
 
-	printf(": %dMB, %d cyl, %d head, %d sec, %d bytes/sec <%s>\n",
-	    wd->sc_params.wdp_cylinders *
-	    (wd->sc_params.wdp_heads * wd->sc_params.wdp_sectors) /
+	printf(": <%s>\n", buf);
+	printf("%s: %dMB, %d cyl, %d head, %d sec, %d bytes/sec\n",
+	    self->dv_xname,
+	    d_link->sc_params.wdp_cylinders *
+	    (d_link->sc_params.wdp_heads * d_link->sc_params.wdp_sectors) /
 	    (1048576 / DEV_BSIZE),
-	    wd->sc_params.wdp_cylinders,
-	    wd->sc_params.wdp_heads,
-	    wd->sc_params.wdp_sectors,
-	    DEV_BSIZE,
-	    buf);
-
-	if ((wd->sc_params.wdp_capabilities & WD_CAP_DMA) != 0 &&
-	    wdc->sc_drq != DRQUNK) {
-		wd->sc_mode = WDM_DMA;
-	} else if (wd->sc_params.wdp_maxmulti > 1) {
-		wd->sc_mode = WDM_PIOMULTI;
-		wd->sc_multiple = min(wd->sc_params.wdp_maxmulti, 16);
+	    d_link->sc_params.wdp_cylinders,
+	    d_link->sc_params.wdp_heads,
+	    d_link->sc_params.wdp_sectors,
+	    DEV_BSIZE);
+
+	if ((d_link->sc_params.wdp_capabilities & WD_CAP_DMA) != 0 &&
+	    d_link->sc_mode == WDM_DMA) {
+		d_link->sc_mode = WDM_DMA;
+	} else if (d_link->sc_params.wdp_maxmulti > 1) {
+		d_link->sc_mode = WDM_PIOMULTI;
+		d_link->sc_multiple = min(d_link->sc_params.wdp_maxmulti, 16);
 	} else {
-		wd->sc_mode = WDM_PIOSINGLE;
-		wd->sc_multiple = 1;
+		d_link->sc_mode = WDM_PIOSINGLE;
+		d_link->sc_multiple = 1;
 	}
 
 	printf("%s: using", wd->sc_dev.dv_xname);
-	if (wd->sc_mode == WDM_DMA)
+	if (d_link->sc_mode == WDM_DMA)
 		printf(" dma transfers,");
 	else
 		printf(" %d-sector %d-bit pio transfers,",
-		    wd->sc_multiple, (wd->sc_flags & WDF_32BIT) == 0 ? 16 : 32);
-	if ((wd->sc_params.wdp_capabilities & WD_CAP_LBA) != 0)
+		    d_link->sc_multiple,
+		    (d_link->sc_flags & WDF_32BIT) == 0 ? 16 : 32);
+	if ((d_link->sc_params.wdp_capabilities & WD_CAP_LBA) != 0)
 		printf(" lba addressing\n");
 	else
 		printf(" chs addressing\n");
@@ -377,6 +215,7 @@ wdstrategy(bp)
 	struct buf *bp;
 {
 	struct wd_softc *wd = wd_cd.cd_devs[WDUNIT(bp->b_dev)];
+	struct wd_link *d_link= wd->d_link;
 	int s;
     
 	/* Valid request?  */
@@ -388,7 +227,7 @@ wdstrategy(bp)
 	}
     
 	/* If device invalidated (e.g. media change, door open), error. */
-	if ((wd->sc_flags & WDF_LOADED) == 0) {
+	if ((d_link->sc_flags & WDF_LOADED) == 0) {
 		bp->b_error = EIO;
 		goto bad;
 	}
@@ -403,23 +242,13 @@ wdstrategy(bp)
 	 */
 	if (WDPART(bp->b_dev) != RAW_PART &&
 	    bounds_check_with_label(bp, wd->sc_dk.dk_label,
-	    (wd->sc_flags & (WDF_WLABEL|WDF_LABELLING)) != 0) <= 0)
+	    (d_link->sc_flags & (WDF_WLABEL|WDF_LABELLING)) != 0) <= 0)
 		goto done;
     
 	/* Queue transfer on drive, activate drive and controller if idle. */
 	s = splbio();
 	disksort(&wd->sc_q, bp);
-	if (!wd->sc_q.b_active)
-		wdstart(wd);
-#if 0
-	else {
-		struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
-		if ((wdc->sc_flags & (WDCF_ACTIVE|WDCF_ERROR)) == 0) {
-			printf("wdstrategy: controller inactive\n");
-			wdcstart(wdc);
-		}
-	}
-#endif
+	wdstart(wd);
 	splx(s);
 	return;
     
@@ -438,57 +267,47 @@ void
 wdstart(wd)
 	struct wd_softc *wd;
 {
-	struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
-	int active = wdc->sc_drives.tqh_first != 0;
-
-	/* Link onto controller queue. */
-	wd->sc_q.b_active = 1;
-	TAILQ_INSERT_TAIL(&wdc->sc_drives, wd, sc_drivechain);
-    
-	disk_busy(&wd->sc_dk);
-
-	/* If controller not already active, start it. */
-	if (!active)
-		wdcstart(wdc);
-}
-
-/*
- * Finish an I/O operation.  Clean up the drive and controller state, set the
- * residual count, and inform the upper layers that the operation is complete.
- */
-void
-wdfinish(wd, bp)
-	struct wd_softc *wd;
-	struct buf *bp;
-{
-	struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
+	struct buf *dp, *bp=0;
+	struct wd_link *d_link = wd->d_link;
+	struct wdc_link *ctlr_link = d_link->ctlr_link;
+	struct wdc_xfer *xfer;
+	int blkno, nblks;
+	u_long p_offset; 
+
+	while (d_link->openings > 0) {
+
+		/* Is there a buf for us ? */
+		dp = &wd->sc_q;
+		if ((bp = dp->b_actf) == NULL)  /* yes, an assign */
+                 	return;
+		dp->b_actf = bp->b_actf;
+		
+		/* 
+		 * Make the command. First lock the device
+		 */
+		d_link->openings--;
+		if (WDPART(bp->b_dev) != RAW_PART)
+			p_offset =
+		  wd->sc_dk.dk_label->d_partitions[WDPART(bp->b_dev)].p_offset;
+		else
+			p_offset = 0;
 
-	wdc->sc_flags &= ~(WDCF_SINGLE | WDCF_ERROR);
-	wdc->sc_errors = 0;
-	/*
-	 * Move this drive to the end of the queue to give others a `fair'
-	 * chance.
-	 */
-	if (wd->sc_drivechain.tqe_next) {
-		TAILQ_REMOVE(&wdc->sc_drives, wd, sc_drivechain);
-		if (bp->b_actf) {
-			TAILQ_INSERT_TAIL(&wdc->sc_drives, wd, sc_drivechain);
-		} else
-			wd->sc_q.b_active = 0;
-	}
-	bp->b_resid = wd->sc_bcount;
-	wd->sc_skip = 0;
-	wd->sc_q.b_actf = bp->b_actf;
+		xfer = wdc_get_xfer(ctlr_link, 0);
+		if (xfer == NULL)
+			panic("wdc_xfer");
 
-	disk_unbusy(&wd->sc_dk, (bp->b_bcount - bp->b_resid));
+		xfer->d_link = d_link;
+		xfer->c_bp = bp;
+		xfer->c_p_offset = p_offset;
+		xfer->databuf = bp->b_data;
+		xfer->c_bcount = bp->b_bcount;
+		xfer->c_flags |= bp->b_flags & (B_READ|B_WRITE);
+		xfer->c_blkno = bp->b_blkno;
 
-	if (!wd->sc_q.b_actf) {
-		TAILQ_REMOVE(&wdc->sc_drives, wd, sc_drivechain);
-		wd->sc_q.b_active = 0;
-	} else
+		/* Instrumentation. */
 		disk_busy(&wd->sc_dk);
-
-	biodone(bp);
+		wdc_exec_xfer(wd->d_link,xfer);
+	}
 }
 
 int
@@ -498,6 +317,7 @@ wdread(dev, uio, flags)
 	int flags;
 {
 
+	WDDEBUG_PRINT(("wdread\n"));
 	return (physio(wdstrategy, NULL, dev, B_READ, minphys, uio));
 }
 
@@ -508,388 +328,37 @@ wdwrite(dev, uio, flags)
 	int flags;
 {
 
+	WDDEBUG_PRINT(("wdwrite\n"));
 	return (physio(wdstrategy, NULL, dev, B_WRITE, minphys, uio));
 }
 
 /*
- * Start I/O on a controller.  This does the calculation, and starts a read or
- * write operation.  Called to from wdstart() to start a transfer, from
- * wdcintr() to continue a multi-sector transfer or start the next transfer, or
- * wdcrestart() after recovering from an error.
- */
-void
-wdcstart(wdc)
-	struct wdc_softc *wdc;
-{
-	struct wd_softc *wd;
-	struct buf *bp;
-	struct disklabel *lp;
-	int nblks;
-
-#ifdef DIAGNOSTIC
-	if ((wdc->sc_flags & WDCF_ACTIVE) != 0)
-		panic("wdcstart: controller still active");
-#endif
-
-	/*
-	 * XXX
-	 * This is a kluge.  See comments in wd_get_parms().
-	 */
-	if ((wdc->sc_flags & WDCF_WANTED) != 0) {
-		wdc->sc_flags &= ~WDCF_WANTED;
-		wakeup(wdc);
-		return;
-	}
-
-loop:
-	/* Is there a drive for the controller to do a transfer with? */
-	wd = wdc->sc_drives.tqh_first;
-	if (wd == NULL)
-		return;
-    
-	/* Is there a transfer to this drive?  If not, deactivate drive. */
-	bp = wd->sc_q.b_actf;
-    
-	if (wdc->sc_errors >= WDIORETRIES) {
-		wderror(wd, bp, "hard error");
-		bp->b_error = EIO;
-		bp->b_flags |= B_ERROR;
-		wdfinish(wd, bp);
-		goto loop;
-	}
-
-	/* Do control operations specially. */
-	if (wd->sc_state < OPEN) {
-		/*
-		 * Actually, we want to be careful not to mess with the control
-		 * state if the device is currently busy, but we can assume
-		 * that we never get to this point if that's the case.
-		 */
-		if (wdcontrol(wd) == 0) {
-			/* The drive is busy.  Wait. */
-			return;
-		}
-	}
-
-	/*
-	 * WDCF_ERROR is set by wdcunwedge() and wdcintr() when an error is
-	 * encountered.  If we are in multi-sector mode, then we switch to
-	 * single-sector mode and retry the operation from the start.
-	 */
-	if (wdc->sc_flags & WDCF_ERROR) {
-		wdc->sc_flags &= ~WDCF_ERROR;
-		if ((wdc->sc_flags & WDCF_SINGLE) == 0) {
-			wdc->sc_flags |= WDCF_SINGLE;
-			wd->sc_skip = 0;
-		}
-	}
-
-	lp = wd->sc_dk.dk_label;
-
-	/* When starting a transfer... */
-	if (wd->sc_skip == 0) {
-		int part = WDPART(bp->b_dev);
-		daddr_t blkno;
-
-#ifdef WDDEBUG
-		printf("\n%s: wdcstart %s %d@%d; map ", wd->sc_dev.dv_xname,
-		    (bp->b_flags & B_READ) ? "read" : "write", bp->b_bcount,
-		    bp->b_blkno);
-#endif
-		wd->sc_bcount = bp->b_bcount;
-		blkno = bp->b_blkno;
-		if (part != RAW_PART)
-			blkno += lp->d_partitions[part].p_offset;
-		wd->sc_blkno = blkno / (lp->d_secsize / DEV_BSIZE);
-	} else {
-#ifdef WDDEBUG
-		printf(" %d)%x", wd->sc_skip, inb(wdc->sc_iobase+wd_altsts));
-#endif
-	}
-
-	/* When starting a multi-sector transfer, or doing single-sector
-	    transfers... */
-	if (wd->sc_skip == 0 || (wdc->sc_flags & WDCF_SINGLE) != 0 ||
-	    wd->sc_mode == WDM_DMA) {
-		daddr_t blkno = wd->sc_blkno;
-		long cylin, head, sector;
-		int command;
-
-		if ((wdc->sc_flags & WDCF_SINGLE) != 0)
-			nblks = 1;
-		else if (wd->sc_mode != WDM_DMA)
-			nblks = wd->sc_bcount / lp->d_secsize;
-		else
-			nblks = min(wd->sc_bcount / lp->d_secsize, 8);
-
-		/* Check for bad sectors and adjust transfer, if necessary. */
-		if ((lp->d_flags & D_BADSECT) != 0
-#ifdef B_FORMAT
-		    && (bp->b_flags & B_FORMAT) == 0
-#endif
-		    ) {
-			long blkdiff;
-			int i;
-
-			for (i = 0; (blkdiff = wd->sc_badsect[i]) != -1; i++) {
-				blkdiff -= blkno;
-				if (blkdiff < 0)
-					continue;
-				if (blkdiff == 0) {
-					/* Replace current block of transfer. */
-					blkno =
-					    lp->d_secperunit - lp->d_nsectors - i - 1;
-				}
-				if (blkdiff < nblks) {
-					/* Bad block inside transfer. */
-					wdc->sc_flags |= WDCF_SINGLE;
-					nblks = 1;
-				}
-				break;
-			}
-			/* Tranfer is okay now. */
-		}
-
-		if ((wd->sc_params.wdp_capabilities & WD_CAP_LBA) != 0) {
-			sector = (blkno >> 0) & 0xff;
-			cylin = (blkno >> 8) & 0xffff;
-			head = (blkno >> 24) & 0xf;
-			head |= WDSD_LBA;
-		} else {
-			sector = blkno % lp->d_nsectors;
-			sector++;	/* Sectors begin with 1, not 0. */
-			blkno /= lp->d_nsectors;
-			head = blkno % lp->d_ntracks;
-			blkno /= lp->d_ntracks;
-			cylin = blkno;
-			head |= WDSD_CHS;
-		}
-
-		if (wd->sc_mode == WDM_PIOSINGLE ||
-		    (wdc->sc_flags & WDCF_SINGLE) != 0)
-			wd->sc_nblks = 1;
-		else if (wd->sc_mode == WDM_PIOMULTI)
-			wd->sc_nblks = min(nblks, wd->sc_multiple);
-		else
-			wd->sc_nblks = nblks;
-		wd->sc_nbytes = wd->sc_nblks * lp->d_secsize;
-    
-#ifdef B_FORMAT
-		if (bp->b_flags & B_FORMAT) {
-			sector = lp->d_gap3;
-			nblks = lp->d_nsectors;
-			command = WDCC_FORMAT;
-		} else
-#endif
-		switch (wd->sc_mode) {
-		case WDM_DMA:
-			command = (bp->b_flags & B_READ) ?
-			    WDCC_READDMA : WDCC_WRITEDMA;
-			/* Start the DMA channel and bounce the buffer if
-			   necessary. */
-			isa_dmastart(
-			    bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE,
-			    bp->b_data + wd->sc_skip,
-			    wd->sc_nbytes, wdc->sc_drq);
-			break;
-		case WDM_PIOMULTI:
-			command = (bp->b_flags & B_READ) ?
-			    WDCC_READMULTI : WDCC_WRITEMULTI;
-			break;
-		case WDM_PIOSINGLE:
-			command = (bp->b_flags & B_READ) ?
-			    WDCC_READ : WDCC_WRITE;
-			break;
-		default:
-#ifdef DIAGNOSTIC
-			panic("bad wd mode");
-#endif
-			return;
-		}
-	
-		/* Initiate command! */
-		if (wdcommand(wd, command, cylin, head, sector, nblks) != 0) {
-			wderror(wd, NULL,
-			    "wdcstart: timeout waiting for unbusy");
-			wdcunwedge(wdc);
-			return;
-		}
-
-#ifdef WDDEBUG
-		printf("sector %d cylin %d head %d addr %x sts %x\n", sector,
-		    cylin, head, bp->b_data, inb(wdc->sc_iobase+wd_altsts));
-#endif
-	} else if (wd->sc_nblks > 1) {
-		/* The number of blocks in the last stretch may be smaller. */
-		nblks = wd->sc_bcount / lp->d_secsize;
-		if (wd->sc_nblks > nblks) {
-			wd->sc_nblks = nblks;
-			wd->sc_nbytes = wd->sc_bcount;
-		}
-	}
-
-	/* If this was a write and not using DMA, push the data. */
-	if (wd->sc_mode != WDM_DMA &&
-	    (bp->b_flags & (B_READ|B_WRITE)) == B_WRITE) {
-		if (wait_for_drq(wdc) < 0) {
-			wderror(wd, NULL, "wdcstart: timeout waiting for drq");
-			wdcunwedge(wdc);
-			return;
-		}
-
-		/* Push out data. */
-		if ((wd->sc_flags & WDF_32BIT) == 0)
-			outsw(wdc->sc_iobase+wd_data, bp->b_data + wd->sc_skip,
-			    wd->sc_nbytes >> 1);
-		else
-			outsl(wdc->sc_iobase+wd_data, bp->b_data + wd->sc_skip,
-			    wd->sc_nbytes >> 2);
-	}
-
-	wdc->sc_flags |= WDCF_ACTIVE;
-	timeout(wdctimeout, wdc, WAITTIME);
-}
-
-/*
- * Interrupt routine for the controller.  Acknowledge the interrupt, check for
- * errors on the current operation, mark it done if necessary, and start the
- * next request.  Also check for a partially done transfer, and continue with
- * the next chunk if so.
- */
-int
-wdcintr(arg)
-	void *arg;
-{
-	struct wdc_softc *wdc = arg;
-	struct wd_softc *wd;
-	struct buf *bp;
-
-	if ((wdc->sc_flags & WDCF_ACTIVE) == 0)
-		/* leave it alone if we didn't ask for this interrupt */
-		return 0;
-
-	wdc->sc_flags &= ~WDCF_ACTIVE;
-	untimeout(wdctimeout, wdc);
-
-	wd = wdc->sc_drives.tqh_first;
-	bp = wd->sc_q.b_actf;
-
-#ifdef WDDEBUG
-	printf("I%s ", wdc->sc_dev.dv_xname);
-#endif
-
-	if (wait_for_unbusy(wdc) < 0) {
-		wderror(wd, NULL, "wdcintr: timeout waiting for unbusy");
-		wdc->sc_status |= WDCS_ERR;	/* XXX */
-	}
-    
-	/* Is it not a transfer, but a control operation? */
-	if (wd->sc_state < OPEN) {
-		if (wdcontrol(wd) == 0) {
-			/* The drive is busy.  Wait. */
-			return 1;
-		}
-		wdcstart(wdc);
-		return 1;
-	}
-
-	/* Turn off the DMA channel and unbounce the buffer. */
-	if (wd->sc_mode == WDM_DMA)
-		isa_dmadone(bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE,
-		    bp->b_data + wd->sc_skip, wd->sc_nbytes, wdc->sc_drq);
-
-	/* Have we an error? */
-	if (wdc->sc_status & WDCS_ERR) {
-#ifdef WDDEBUG
-		wderror(wd, NULL, "wdcintr");
-#endif
-		if ((wdc->sc_flags & WDCF_SINGLE) == 0) {
-			wdc->sc_flags |= WDCF_ERROR;
-			goto restart;
-		}
-
-#ifdef B_FORMAT
-		if (bp->b_flags & B_FORMAT)
-			goto bad;
-#endif
-	
-		wdcunwedge(wdc);
-		if (wdc->sc_errors < WDIORETRIES)
-			return 1;
-		wderror(wd, bp, "hard error");
-
-#ifdef B_FORMAT
-	bad:
-#endif
-		bp->b_error = EIO;
-		bp->b_flags |= B_ERROR;
-		goto done;
-	}
-
-	/* If this was a read and not using DMA, fetch the data. */
-	if (wd->sc_mode != WDM_DMA &&
-	    (bp->b_flags & (B_READ|B_WRITE)) == B_READ) {
-		if ((wdc->sc_status & (WDCS_DRDY | WDCS_DSC | WDCS_DRQ))
-		    != (WDCS_DRDY | WDCS_DSC | WDCS_DRQ)) {
-			wderror(wd, NULL, "wdcintr: read intr before drq");
-			wdcunwedge(wdc);
-			return 1;
-		}
-
-		/* Pull in data. */
-		if ((wd->sc_flags & WDF_32BIT) == 0)
-			insw(wdc->sc_iobase+wd_data, bp->b_data + wd->sc_skip, 
-			    wd->sc_nbytes >> 1);
-		else
-			insl(wdc->sc_iobase+wd_data, bp->b_data + wd->sc_skip, 
-			    wd->sc_nbytes >> 2);
-	}
-    
-	/* If we encountered any abnormalities, flag it as a soft error. */
-	if (wdc->sc_errors > 0 ||
-	    (wdc->sc_status & WDCS_CORR) != 0) {
-		wderror(wd, bp, "soft error (corrected)");
-		wdc->sc_errors = 0;
-	}
-    
-	/* Adjust pointers for the next block, if any. */
-	wd->sc_blkno += wd->sc_nblks;
-	wd->sc_skip += wd->sc_nbytes;
-	wd->sc_bcount -= wd->sc_nbytes;
-
-	/* See if this transfer is complete. */
-	if (wd->sc_bcount > 0)
-		goto restart;
-
-done:
-	/* Done with this transfer, with or without error. */
-	wdfinish(wd, bp);
-
-restart:
-	/* Start the next operation, if any. */
-	wdcstart(wdc);
-
-	return 1;
-}
-
-/*
  * Wait interruptibly for an exclusive lock.
  *
  * XXX
  * Several drivers do this; it should be abstracted and made MP-safe.
  */
 int
-wdlock(wd)
-	struct wd_softc *wd;
+wdlock(d_link)
+	struct wd_link *d_link;
 {
 	int error;
+	int s;
+
+	WDDEBUG_PRINT(("wdlock\n"));
+
+	s = splbio();
 
-	while ((wd->sc_flags & WDF_LOCKED) != 0) {
-		wd->sc_flags |= WDF_WANTED;
-		if ((error = tsleep(wd, PRIBIO | PCATCH, "wdlck", 0)) != 0)
+	while ((d_link->sc_flags & WDF_LOCKED) != 0) {
+		d_link->sc_flags |= WDF_WANTED;
+		if ((error = tsleep(d_link, PRIBIO | PCATCH,
+		    "wdlck", 0)) != 0) {
+			splx(s);
 			return error;
+		}
 	}
-	wd->sc_flags |= WDF_LOCKED;
+	d_link->sc_flags |= WDF_LOCKED;
+	splx(s);
 	return 0;
 }
 
@@ -897,14 +366,16 @@ wdlock(wd)
  * Unlock and wake up any waiters.
  */
 void
-wdunlock(wd)
-	struct wd_softc *wd;
+wdunlock(d_link)
+	struct wd_link *d_link;
 {
 
-	wd->sc_flags &= ~WDF_LOCKED;
-	if ((wd->sc_flags & WDF_WANTED) != 0) {
-		wd->sc_flags &= ~WDF_WANTED;
-		wakeup(wd);
+	WDDEBUG_PRINT(("wdunlock"));
+
+	d_link->sc_flags &= ~WDF_LOCKED;
+	if ((d_link->sc_flags & WDF_WANTED) != 0) {
+		d_link->sc_flags &= ~WDF_WANTED;
+		wakeup(d_link);
 	}
 }
 
@@ -915,9 +386,12 @@ wdopen(dev, flag, fmt, p)
 	struct proc *p;
 {
 	struct wd_softc *wd;
+	struct wd_link *d_link;
 	int unit, part;
 	int error;
-    
+
+	WDDEBUG_PRINT(("wdopen\n"));
+
 	unit = WDUNIT(dev);
 	if (unit >= wd_cd.cd_ndevs)
 		return ENXIO;
@@ -925,7 +399,8 @@ wdopen(dev, flag, fmt, p)
 	if (wd == 0)
 		return ENXIO;
     
-	if ((error = wdlock(wd)) != 0)
+	d_link = wd->d_link;
+	if ((error = wdlock(d_link)) != 0)
 		return error;
 
 	if (wd->sc_dk.dk_openmask != 0) {
@@ -933,16 +408,16 @@ wdopen(dev, flag, fmt, p)
 		 * If any partition is open, but the disk has been invalidated,
 		 * disallow further opens.
 		 */
-		if ((wd->sc_flags & WDF_LOADED) == 0) {
+		if ((d_link->sc_flags & WDF_LOADED) == 0) {
 			error = EIO;
 			goto bad3;
 		}
 	} else {
-		if ((wd->sc_flags & WDF_LOADED) == 0) {
-			wd->sc_flags |= WDF_LOADED;
+		if ((d_link->sc_flags & WDF_LOADED) == 0) {
+			d_link->sc_flags |= WDF_LOADED;
 
 			/* Load the physical device parameters. */
-			if (wd_get_parms(wd) != 0) {
+			if (wdc_get_parms(d_link) != 0) {
 				error = ENXIO;
 				goto bad2;
 			}
@@ -973,18 +448,18 @@ wdopen(dev, flag, fmt, p)
 	}
 	wd->sc_dk.dk_openmask = wd->sc_dk.dk_copenmask | wd->sc_dk.dk_bopenmask;
 
-	wdunlock(wd);
+	wdunlock(d_link);
 	return 0;
 
 bad2:
-	wd->sc_flags &= ~WDF_LOADED;
+	d_link->sc_flags &= ~WDF_LOADED;
 
 bad:
 	if (wd->sc_dk.dk_openmask == 0) {
 	}
 
 bad3:
-	wdunlock(wd);
+	wdunlock(d_link);
 	return error;
 }
 
@@ -998,7 +473,7 @@ wdclose(dev, flag, fmt, p)
 	int part = WDPART(dev);
 	int error;
     
-	if ((error = wdlock(wd)) != 0)
+	if ((error = wdlock(wd->d_link)) != 0)
 		return error;
 
 	switch (fmt) {
@@ -1015,7 +490,7 @@ wdclose(dev, flag, fmt, p)
 		/* XXXX Must wait for I/O to complete! */
 	}
 
-	wdunlock(wd);
+	wdunlock(wd->d_link);
 	return 0;
 }
 
@@ -1027,22 +502,25 @@ wdgetdisklabel(wd)
 	struct wd_softc *wd;
 {
 	struct disklabel *lp = wd->sc_dk.dk_label;
+	struct wd_link *d_link = wd->d_link;
 	char *errstring;
 
+	WDDEBUG_PRINT(("wdgetdisklabel\n"));
+
 	bzero(lp, sizeof(struct disklabel));
 	bzero(wd->sc_dk.dk_cpulabel, sizeof(struct cpu_disklabel));
 
 	lp->d_secsize = DEV_BSIZE;
-	lp->d_ntracks = wd->sc_params.wdp_heads;
-	lp->d_nsectors = wd->sc_params.wdp_sectors;
-	lp->d_ncylinders = wd->sc_params.wdp_cylinders;
+	lp->d_ntracks = d_link->sc_params.wdp_heads;
+	lp->d_nsectors = d_link->sc_params.wdp_sectors;
+	lp->d_ncylinders = d_link->sc_params.wdp_cylinders;
 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
 
 #if 0
 	strncpy(lp->d_typename, "ST506 disk", 16);
 	lp->d_type = DTYPE_ST506;
 #endif
-	strncpy(lp->d_packname, wd->sc_params.wdp_model, 16);
+	strncpy(lp->d_packname, d_link->sc_params.wdp_model, 16);
 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
 	lp->d_rpm = 3600;
 	lp->d_interleave = 1;
@@ -1058,10 +536,10 @@ wdgetdisklabel(wd)
 	lp->d_magic2 = DISKMAGIC;
 	lp->d_checksum = dkcksum(lp);
 
-	wd->sc_badsect[0] = -1;
+	d_link->sc_badsect[0] = -1;
 
-	if (wd->sc_state > RECAL)
-		wd->sc_state = RECAL;
+	if (d_link->sc_state > RECAL)
+		d_link->sc_state = RECAL;
 	errstring = readdisklabel(MAKEWDDEV(0, wd->sc_dev.dv_unit, RAW_PART),
 	    wdstrategy, lp, wd->sc_dk.dk_cpulabel);
 	if (errstring) {
@@ -1071,8 +549,8 @@ wdgetdisklabel(wd)
 		 * assume the DOS geometry is now in the label and try
 		 * again.  XXX This is a kluge.
 		 */
-		if (wd->sc_state > GEOMETRY)
-			wd->sc_state = GEOMETRY;
+		if (d_link->sc_state > GEOMETRY)
+			d_link->sc_state = GEOMETRY;
 		errstring = readdisklabel(MAKEWDDEV(0, wd->sc_dev.dv_unit, RAW_PART),
 		    wdstrategy, lp, wd->sc_dk.dk_cpulabel);
 	}
@@ -1081,270 +559,55 @@ wdgetdisklabel(wd)
 		return;
 	}
 
-	if (wd->sc_state > GEOMETRY)
-		wd->sc_state = GEOMETRY;
+	if (d_link->sc_state > GEOMETRY)
+		d_link->sc_state = GEOMETRY;
 	if ((lp->d_flags & D_BADSECT) != 0)
 		bad144intern(wd);
 }
 
-/*
- * Implement operations needed before read/write.
- * Returns 0 if operation still in progress, 1 if completed.
- */
-int
-wdcontrol(wd)
-	struct wd_softc *wd;
-{
-	struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
-    
-	switch (wd->sc_state) {
-	case RECAL:			/* Set SDH, step rate, do recal. */
-		if (wdcommandshort(wdc, wd->sc_drive, WDCC_RECAL) != 0) {
-			wderror(wd, NULL, "wdcontrol: recal failed (1)");
-			goto bad;
-		}
-		wd->sc_state = RECAL_WAIT;
-		break;
-
-	case RECAL_WAIT:
-		if (wdc->sc_status & WDCS_ERR) {
-			wderror(wd, NULL, "wdcontrol: recal failed (2)");
-			goto bad;
-		}
-		/* fall through */
-	case GEOMETRY:
-		if ((wd->sc_params.wdp_capabilities & WD_CAP_LBA) != 0)
-			goto multimode;
-		if (wdsetctlr(wd) != 0) {
-			/* Already printed a message. */
-			goto bad;
-		}
-		wd->sc_state = GEOMETRY_WAIT;
-		break;
-
-	case GEOMETRY_WAIT:
-		if (wdc->sc_status & WDCS_ERR) {
-			wderror(wd, NULL, "wdcontrol: geometry failed");
-			goto bad;
-		}
-		/* fall through */
-	case MULTIMODE:
-	multimode:
-		if (wd->sc_mode != WDM_PIOMULTI)
-			goto open;
-		outb(wdc->sc_iobase+wd_seccnt, wd->sc_multiple);
-		if (wdcommandshort(wdc, wd->sc_drive, WDCC_SETMULTI) != 0) {
-			wderror(wd, NULL, "wdcontrol: setmulti failed (1)");
-			goto bad;
-		}
-		wd->sc_state = MULTIMODE_WAIT;
-		break;
-
-	case MULTIMODE_WAIT:
-		if (wdc->sc_status & WDCS_ERR) {
-			wderror(wd, NULL, "wdcontrol: setmulti failed (2)");
-			goto bad;
-		}
-		/* fall through */
-	case OPEN:
-	open:
-		wdc->sc_errors = 0;
-		wd->sc_state = OPEN;
-		/*
-		 * The rest of the initialization can be done by normal means.
-		 */
-		return 1;
-
-	bad:
-		wdcunwedge(wdc);
-		return 0;
-	}
-
-	wdc->sc_flags |= WDCF_ACTIVE;
-	timeout(wdctimeout, wdc, WAITTIME);
-	return 0;
-}
-
-/*
- * Wait for the drive to become ready and send a command.
- * Return -1 if busy for too long or 0 otherwise.
- * Assumes interrupts are blocked.
- */
-int
-wdcommand(wd, command, cylin, head, sector, count)
-	struct wd_softc *wd;
-	int command;
-	int cylin, head, sector, count;
-{
-	struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
-	int iobase = wdc->sc_iobase;
-	int stat;
-    
-	/* Select drive, head, and addressing mode. */
-	outb(iobase+wd_sdh, WDSD_IBM | (wd->sc_drive << 4) | head);
-
-	/* Wait for it to become ready to accept a command. */
-	if (command == WDCC_IDP)
-		stat = wait_for_unbusy(wdc);
-	else
-		stat = wdcwait(wdc, WDCS_DRDY);
-	if (stat < 0)
-		return -1;
-    
-	/* Load parameters. */
-	if (wd->sc_dk.dk_label->d_type == DTYPE_ST506)
-		outb(iobase+wd_precomp, wd->sc_dk.dk_label->d_precompcyl / 4);
-	else
-		outb(iobase+wd_features, 0);
-	outb(iobase+wd_cyl_lo, cylin);
-	outb(iobase+wd_cyl_hi, cylin >> 8);
-	outb(iobase+wd_sector, sector);
-	outb(iobase+wd_seccnt, count);
-
-	/* Send command. */
-	outb(iobase+wd_command, command);
-
-	return 0;
-}
-
-/*
- * Simplified version of wdcommand().
- */
-int
-wdcommandshort(wdc, drive, command)
-	struct wdc_softc *wdc;
-	int drive;
-	int command;
-{
-	int iobase = wdc->sc_iobase;
-
-	/* Select drive. */
-	outb(iobase+wd_sdh, WDSD_IBM | (drive << 4));
-
-	if (wdcwait(wdc, WDCS_DRDY) < 0)
-		return -1;
-
-	outb(iobase+wd_command, command);
-
-	return 0;
-}
 
 /*
  * Tell the drive what geometry to use.
  */
 int
-wdsetctlr(wd)
-	struct wd_softc *wd;
+wdsetctlr(d_link)
+	struct wd_link *d_link;
 {
+	struct wd_softc *wd=(struct wd_softc *)d_link->wd_softc;
 
-#ifdef WDDEBUG
-	printf("wd(%d,%d) C%dH%dS%d\n", wd->sc_dev.dv_unit, wd->sc_drive,
-	    wd->sc_dk.dk_label->d_ncylinders, wd->sc_dk.dk_label->d_ntracks,
-	    wd->sc_dk.dk_label->d_nsectors);
-#endif
-    
-	if (wdcommand(wd, WDCC_IDP, wd->sc_dk.dk_label->d_ncylinders,
+	WDDEBUG_PRINT(("wd(%d,%d) C%dH%dS%d\n", wd->sc_dev.dv_unit,
+	    d_link->sc_drive, wd->sc_dk.dk_label->d_ncylinders,
+	    wd->sc_dk.dk_label->d_ntracks, wd->sc_dk.dk_label->d_nsectors));
+
+	if (wdccommand(d_link, WDCC_IDP, d_link->sc_drive,
+	    wd->sc_dk.dk_label->d_ncylinders,
 	    wd->sc_dk.dk_label->d_ntracks - 1, 0,
 	    wd->sc_dk.dk_label->d_nsectors) != 0) {
-		wderror(wd, NULL, "wdsetctlr: geometry upload failed");
+		wderror(d_link, NULL, "wdsetctlr: geometry upload failed");
 		return -1;
 	}
 
 	return 0;
 }
 
-/*
- * Get the drive parameters, if ESDI or ATA, or create fake ones for ST506.
- */
 int
-wd_get_parms(wd)
-	struct wd_softc *wd;
-{
-	struct wdc_softc *wdc = (void *)wd->sc_dev.dv_parent;
-	int i;
-	char tb[DEV_BSIZE];
-	int s, error;
-
-	/*
-	 * XXX
-	 * The locking done here, and the length of time this may keep the rest
-	 * of the system suspended, is a kluge.  This should be rewritten to
-	 * set up a transfer and queue it through wdstart(), but it's called
-	 * infrequently enough that this isn't a pressing matter.
-	 */
-
-	s = splbio();
-
-	while ((wdc->sc_flags & WDCF_ACTIVE) != 0) {
-		wdc->sc_flags |= WDCF_WANTED;
-		if ((error = tsleep(wdc, PRIBIO | PCATCH, "wdprm", 0)) != 0) {
-			splx(s);
-			return error;
-		}
-	}
-
-	if (wdcommandshort(wdc, wd->sc_drive, WDCC_IDENTIFY) != 0 ||
-	    wait_for_drq(wdc) != 0) {
-		/*
-		 * We `know' there's a drive here; just assume it's old.
-		 * This geometry is only used to read the MBR and print a
-		 * (false) attach message.
-		 */
-		strncpy(wd->sc_dk.dk_label->d_typename, "ST506",
-		    sizeof wd->sc_dk.dk_label->d_typename);
-		wd->sc_dk.dk_label->d_type = DTYPE_ST506;
-
-		strncpy(wd->sc_params.wdp_model, "unknown",
-		    sizeof wd->sc_params.wdp_model);
-		wd->sc_params.wdp_config = WD_CFG_FIXED;
-		wd->sc_params.wdp_cylinders = 1024;
-		wd->sc_params.wdp_heads = 8;
-		wd->sc_params.wdp_sectors = 17;
-		wd->sc_params.wdp_maxmulti = 0;
-		wd->sc_params.wdp_usedmovsd = 0;
-		wd->sc_params.wdp_capabilities = 0;
-	} else {
-		strncpy(wd->sc_dk.dk_label->d_typename, "ESDI/IDE",
-		    sizeof wd->sc_dk.dk_label->d_typename);
-		wd->sc_dk.dk_label->d_type = DTYPE_ESDI;
-
-		/* Read in parameter block. */
-		insw(wdc->sc_iobase+wd_data, tb, sizeof(tb) / sizeof(short));
-		bcopy(tb, &wd->sc_params, sizeof(struct wdparams));
-
-		/* Shuffle string byte order. */
-		for (i = 0; i < sizeof(wd->sc_params.wdp_model); i += 2) {
-			u_short *p;
-			p = (u_short *)(wd->sc_params.wdp_model + i);
-			*p = ntohs(*p);
-		}
-	}
-
-	/* Clear any leftover interrupt. */
-	(void) inb(wdc->sc_iobase+wd_status);
-
-	/* Restart the queue. */
-	wdcstart(wdc);
-
-	splx(s);
-	return 0;
-}
-
-int
-wdioctl(dev, cmd, addr, flag, p)
+wdioctl(dev, xfer, addr, flag, p)
 	dev_t dev;
-	u_long cmd;
+	u_long xfer;
 	caddr_t addr;
 	int flag;
 	struct proc *p;
 {
 	struct wd_softc *wd = wd_cd.cd_devs[WDUNIT(dev)];
+	struct wd_link *d_link = wd->d_link;
 	int error;
-    
-	if ((wd->sc_flags & WDF_LOADED) == 0)
+
+	WDDEBUG_PRINT(("wdioctl\n"));
+
+	if ((d_link->sc_flags & WDF_LOADED) == 0)
 		return EIO;
 
-	switch (cmd) {
+	switch (xfer) {
 	case DIOCSBAD:
 		if ((flag & FWRITE) == 0)
 			return EBADF;
@@ -1368,33 +631,33 @@ wdioctl(dev, cmd, addr, flag, p)
 		if ((flag & FWRITE) == 0)
 			return EBADF;
 
-		if ((error = wdlock(wd)) != 0)
+		if ((error = wdlock(wd->d_link)) != 0)
 			return error;
-		wd->sc_flags |= WDF_LABELLING;
+		d_link->sc_flags |= WDF_LABELLING;
 
 		error = setdisklabel(wd->sc_dk.dk_label,
 		    (struct disklabel *)addr, /*wd->sc_dk.dk_openmask : */0,
 		    wd->sc_dk.dk_cpulabel);
 		if (error == 0) {
-			if (wd->sc_state > GEOMETRY)
-				wd->sc_state = GEOMETRY;
-			if (cmd == DIOCWDINFO)
+			if (d_link->sc_state > GEOMETRY)
+				d_link->sc_state = GEOMETRY;
+			if (xfer == DIOCWDINFO)
 				error = writedisklabel(WDLABELDEV(dev),
 				    wdstrategy, wd->sc_dk.dk_label,
 				    wd->sc_dk.dk_cpulabel);
 		}
 
-		wd->sc_flags &= ~WDF_LABELLING;
-		wdunlock(wd);
+		d_link->sc_flags &= ~WDF_LABELLING;
+		wdunlock(d_link);
 		return error;
 	
 	case DIOCWLABEL:
 		if ((flag & FWRITE) == 0)
 			return EBADF;
 		if (*(int *)addr)
-			wd->sc_flags |= WDF_WLABEL;
+			d_link->sc_flags |= WDF_WLABEL;
 		else
-			wd->sc_flags &= ~WDF_WLABEL;
+			d_link->sc_flags &= ~WDF_WLABEL;
 		return 0;
 	
 #ifdef notyet
@@ -1451,7 +714,9 @@ wdsize(dev)
 	struct wd_softc *wd;
 	int part;
 	int size;
-    
+
+	WDDEBUG_PRINT(("wdsize\n"));
+
 	if (wdopen(dev, 0, S_IFBLK, NULL) != 0)
 		return -1;
 	wd = wd_cd.cd_devs[WDUNIT(dev)];
@@ -1473,6 +738,9 @@ static int wddumprecalibrated;
 
 /*
  * Dump core after a system crash.
+ *
+ * XXX:  This needs work!  Currently, it's a major hack: the
+ * use of wdc_softc is very bad and should go away.
  */
 int
 wddump(dev, blkno, va, size)
@@ -1484,6 +752,7 @@ wddump(dev, blkno, va, size)
 	struct wd_softc *wd;	/* disk unit to do the I/O */
 	struct wdc_softc *wdc;	/* disk controller to do the I/O */
 	struct disklabel *lp;	/* disk's disklabel */
+	struct wd_link *d_link;
 	int	unit, part;
 	int	nblks;		/* total number of sectors left to write */
 
@@ -1496,13 +765,14 @@ wddump(dev, blkno, va, size)
 	if (unit >= wd_cd.cd_ndevs)
 		return ENXIO;
 	wd = wd_cd.cd_devs[unit];
-	if (wd == 0)
+	if (wd == (struct wd_softc *)0)
 		return ENXIO;
+	d_link = wd->d_link;
 
 	part = WDPART(dev);
 
 	/* Make sure it was initialized. */
-	if (wd->sc_state < OPEN)
+	if (d_link->sc_state < OPEN)
 		return ENXIO;
 
 	wdc = (void *)wd->sc_dev.dv_parent;
@@ -1524,10 +794,10 @@ wddump(dev, blkno, va, size)
 	/* Recalibrate, if first dump transfer. */
 	if (wddumprecalibrated == 0) {
 		wddumprecalibrated = 1;
-		if (wdcommandshort(wdc, wd->sc_drive, WDCC_RECAL) != 0 ||
-		    wait_for_ready(wdc) != 0 || wdsetctlr(wd) != 0 ||
+		if (wdccommandshort(wdc, d_link->sc_drive, WDCC_RECAL) != 0 ||
+		    wait_for_ready(wdc) != 0 || wdsetctlr(d_link) != 0 ||
 		    wait_for_ready(wdc) != 0) {
-			wderror(wd, NULL, "wddump: recal failed");
+			wderror(d_link, NULL, "wddump: recal failed");
 			return EIO;
 		}
 	}
@@ -1540,7 +810,7 @@ wddump(dev, blkno, va, size)
 			long blkdiff;
 			int i;
 
-			for (i = 0; (blkdiff = wd->sc_badsect[i]) != -1; i++) {
+			for (i = 0; (blkdiff = d_link->sc_badsect[i]) != -1; i++) {
 				blkdiff -= xlt_blkno;
 				if (blkdiff < 0)
 					continue;
@@ -1554,7 +824,7 @@ wddump(dev, blkno, va, size)
 			/* Tranfer is okay now. */
 		}
 
-		if ((wd->sc_params.wdp_capabilities & WD_CAP_LBA) != 0) {
+		if ((d_link->sc_params.wdp_capabilities & WD_CAP_LBA) != 0) {
 			sector = (xlt_blkno >> 0) & 0xff;
 			cylin = (xlt_blkno >> 8) & 0xffff;
 			head = (xlt_blkno >> 24) & 0xf;
@@ -1570,17 +840,19 @@ wddump(dev, blkno, va, size)
 		}
 
 #ifndef WD_DUMP_NOT_TRUSTED
-		if (wdcommand(wd, WDCC_WRITE, cylin, head, sector, 1) != 0 ||
+		if (wdccommand(d_link, WDCC_WRITE, d_link->sc_drive, cylin, head, sector, 1) != 0 ||
 		    wait_for_drq(wdc) != 0) {
-			wderror(wd, NULL, "wddump: write failed");
+			wderror(d_link, NULL, "wddump: write failed");
 			return EIO;
 		}
 	
-		outsw(wdc->sc_iobase+wd_data, va, lp->d_secsize >> 1);
+		/* XXX XXX XXX */
+		outsw(wdc->sc_iobase + wd_data, va, lp->d_secsize >> 1);
 	
 		/* Check data request (should be done). */
 		if (wait_for_ready(wdc) != 0) {
-			wderror(wd, NULL, "wddump: timeout waiting for ready");
+			wderror(d_link, NULL,
+			    "wddump: timeout waiting for ready");
 			return EIO;
 		}
 #else	/* WD_DUMP_NOT_TRUSTED */
@@ -1600,6 +872,8 @@ wddump(dev, blkno, va, size)
 	return 0;
 }
 #else /* __BDEVSW_DUMP_NEW_TYPE */
+
+
 int
 wddump(dev, blkno, va, size)
         dev_t dev;
@@ -1622,157 +896,45 @@ bad144intern(wd)
 {
 	struct dkbad *bt = &wd->sc_dk.dk_cpulabel->bad;
 	struct disklabel *lp = wd->sc_dk.dk_label;
+	struct wd_link *d_link = wd->d_link;
 	int i = 0;
 
+	WDDEBUG_PRINT(("bad144intern\n"));
+
 	for (; i < 126; i++) {
 		if (bt->bt_bad[i].bt_cyl == 0xffff)
 			break;
-		wd->sc_badsect[i] =
+		d_link->sc_badsect[i] =
 		    bt->bt_bad[i].bt_cyl * lp->d_secpercyl +
 		    (bt->bt_bad[i].bt_trksec >> 8) * lp->d_nsectors +
 		    (bt->bt_bad[i].bt_trksec & 0xff);
 	}
 	for (; i < 127; i++)
-		wd->sc_badsect[i] = -1;
-}
-
-int
-wdcreset(wdc)
-	struct wdc_softc *wdc;
-{
-	int iobase = wdc->sc_iobase;
-
-	/* Reset the device. */
-	outb(iobase+wd_ctlr, WDCTL_RST | WDCTL_IDS);
-	delay(1000);
-	outb(iobase+wd_ctlr, WDCTL_IDS);
-	delay(1000);
-	(void) inb(iobase+wd_error);
-	outb(iobase+wd_ctlr, WDCTL_4BIT);
-
-	if (wait_for_unbusy(wdc) < 0) {
-		printf("%s: reset failed\n", wdc->sc_dev.dv_xname);
-		return 1;
-	}
-
-	return 0;
-}
-
-void
-wdcrestart(arg)
-	void *arg;
-{
-	struct wdc_softc *wdc = arg;
-	int s;
-
-	s = splbio();
-	wdcstart(wdc);
-	splx(s);
-}
-
-/*
- * Unwedge the controller after an unexpected error.  We do this by resetting
- * it, marking all drives for recalibration, and stalling the queue for a short
- * period to give the reset time to finish.
- * NOTE: We use a timeout here, so this routine must not be called during
- * autoconfig or dump.
- */
-void
-wdcunwedge(wdc)
-	struct wdc_softc *wdc;
-{
-	int unit;
-
-	untimeout(wdctimeout, wdc);
-	(void) wdcreset(wdc);
-
-	/* Schedule recalibrate for all drives on this controller. */
-	for (unit = 0; unit < wd_cd.cd_ndevs; unit++) {
-		struct wd_softc *wd = wd_cd.cd_devs[unit];
-		if (!wd || (void *)wd->sc_dev.dv_parent != wdc)
-			continue;
-		if (wd->sc_state > RECAL)
-			wd->sc_state = RECAL;
-	}
-
-	wdc->sc_flags |= WDCF_ERROR;
-	++wdc->sc_errors;
-
-	/* Wake up in a little bit and restart the operation. */
-	timeout(wdcrestart, wdc, RECOVERYTIME);
-}
-
-int
-wdcwait(wdc, mask)
-	struct wdc_softc *wdc;
-	int mask;
-{
-	int iobase = wdc->sc_iobase;
-	int timeout = 0;
-	u_char status;
-#ifdef WDCNDELAY_DEBUG
-	extern int cold;
-#endif
-
-	for (;;) {
-		wdc->sc_status = status = inb(iobase+wd_status);
-		if ((status & WDCS_BSY) == 0 && (status & mask) == mask)
-			break;
-		if (++timeout > WDCNDELAY)
-			return -1;
-		delay(WDCDELAY);
-	}
-	if (status & WDCS_ERR) {
-		wdc->sc_error = inb(iobase+wd_error);
-		return WDCS_ERR;
-	}
-#ifdef WDCNDELAY_DEBUG
-	/* After autoconfig, there should be no long delays. */
-	if (!cold && timeout > WDCNDELAY_DEBUG)
-		printf("%s: warning: busy-wait took %dus\n",
-		    wdc->sc_dev.dv_xname, WDCDELAY * timeout);
-#endif
-	return 0;
+		d_link->sc_badsect[i] = -1;
 }
 
 void
-wdctimeout(arg)
-	void *arg;
+wderror(d_link, bp, msg)
+	struct wd_link *d_link;
+	struct buf *bp;
+	char *msg;
 {
-	struct wdc_softc *wdc = (struct wdc_softc *)arg;
-	int s;
+	struct wd_softc *wd = (struct wd_softc *)d_link->wd_softc;
 
-	s = splbio();
-	if ((wdc->sc_flags & WDCF_ACTIVE) != 0) {
-		struct wd_softc *wd = wdc->sc_drives.tqh_first;
-		struct buf *bp = wd->sc_q.b_actf;
-
-		wdc->sc_flags &= ~WDCF_ACTIVE;
-		wderror(wdc, NULL, "lost interrupt");
-		printf("%s: lost interrupt: %sing %d@%s:%d\n",
-		    wdc->sc_dev.dv_xname,
-		    (bp->b_flags & B_READ) ? "read" : "writ",
-		    wd->sc_nblks, wd->sc_dev.dv_xname, wd->sc_blkno);
-		wdcunwedge(wdc);
+	if (bp) {
+		diskerr(bp, "wd", msg, LOG_PRINTF, bp->b_bcount,
+		    wd->sc_dk.dk_label);
+		printf("\n");
 	} else
-		wderror(wdc, NULL, "missing untimeout");
-	splx(s);
+		printf("%s: %s\n", wd->sc_dev.dv_xname, msg);
 }
 
 void
-wderror(dev, bp, msg)
-	void *dev;
+wddone(d_link, bp)
+	struct wd_link *d_link;
 	struct buf *bp;
-	char *msg;
 {
-	struct wd_softc *wd = dev;
-	struct wdc_softc *wdc = dev;
+	struct wd_softc *wd = (void *)d_link->wd_softc;
 
-	if (bp) {
-		diskerr(bp, "wd", msg, LOG_PRINTF, wd->sc_skip / DEV_BSIZE,
-		    wd->sc_dk.dk_label);
-		printf("\n");
-	} else
-		printf("%s: %s: status %b error %b\n", wdc->sc_dev.dv_xname,
-		    msg, wdc->sc_status, WDCS_BITS, wdc->sc_error, WDERR_BITS);
+	disk_unbusy(&wd->sc_dk, (bp->b_bcount - bp->b_resid));
 }
diff --git a/sys/dev/isa/wdc.c b/sys/dev/isa/wdc.c
new file mode 100644
index 00000000000..c0e79d93e16
--- /dev/null
+++ b/sys/dev/isa/wdc.c
@@ -0,0 +1,1686 @@
+/*	$NetBSD: wd.c,v 1.150 1996/05/12 23:54:03 mycroft Exp $ */
+
+/*
+ * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
+ *
+ * DMA and multi-sector PIO handling are derived from code contributed by
+ * Onno van der Linden.
+ *
+ * Atapi support added by Manuel Bouyer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Charles M. Hannum.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#undef ATAPI_DEBUG_WDC
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/buf.h>
+#include <sys/uio.h>
+#include <sys/malloc.h>
+#include <sys/device.h>
+#include <sys/disklabel.h>
+#include <sys/disk.h>
+#include <sys/syslog.h>
+#include <sys/proc.h>
+
+#include <vm/vm.h>
+
+#include <machine/cpu.h>
+#include <machine/intr.h>
+#include <machine/pio.h>
+
+#include <dev/isa/isavar.h>
+#include <dev/isa/isadmavar.h>
+#include <dev/isa/wdreg.h>
+#include <dev/isa/wdlink.h>
+
+#include <dev/atapi/atapilink.h>
+
+#define	WAITTIME	(10 * hz)	/* time to wait for a completion */
+	/* this is a lot for hard drives, but not for cdroms */
+#define RECOVERYTIME hz/2
+#define WDCDELAY	100
+#define WDCNDELAY	100000	/* delay = 100us; so 10s for a controller state change */
+#if 0
+/* If you enable this, it will report any delays more than 100us * N long. */
+#define WDCNDELAY_DEBUG	50
+#endif
+
+#define	WDIORETRIES	3		/* number of retries before giving up */
+
+#define	WDPART(dev)			DISKPART(dev)
+
+LIST_HEAD(xfer_free_list, wdc_xfer) xfer_free_list;
+
+int	wdcprobe	__P((struct device *, void *, void *));
+void	wdcattach	__P((struct device *, struct device *, void *));
+int	wdcintr		__P((void *));
+
+struct cfattach wdc_ca = {
+	sizeof(struct wdc_softc), wdcprobe, wdcattach
+};
+
+struct cfdriver wdc_cd = {
+	NULL, "wdc", DV_DULL
+};
+
+int	wdc_ata_intr	__P((struct wdc_softc *,struct wdc_xfer *));
+void	wdcstart	__P((struct wdc_softc *));
+void	wdc_ata_start	__P((struct wdc_softc *,struct wdc_xfer *));
+void	wdc_atapi_start	__P((struct wdc_softc *,struct wdc_xfer *));
+int	wdcreset	__P((struct wdc_softc *));
+void	wdcrestart	__P((void *arg));
+void	wdcunwedge	__P((struct wdc_softc *));
+void	wdctimeout	__P((void *arg));
+int	wdccontrol	__P((struct wd_link *));
+void	wdc_ata_done	__P((struct wdc_softc *, struct wdc_xfer *));
+void	wdc_free_xfer	__P((struct wdc_xfer *));
+void	wdcerror	__P((struct wdc_softc*, char *));
+void	wdcbit_bucket	__P(( struct wdc_softc *, int));
+int	wdc_atapi_intr	__P((struct wdc_softc *, struct wdc_xfer *));
+void	wdc_atapi_done	__P((struct wdc_softc *, struct wdc_xfer *));
+
+#ifdef ATAPI_DEBUG
+static int wdc_nxfer;
+#endif
+
+#ifdef WDDEBUG
+#define WDDEBUG_PRINT(args)	printf args
+#else
+#define WDDEBUG_PRINT(args)
+#endif
+
+int
+wdcprobe(parent, match, aux)
+	struct device *parent;
+	void *match, *aux;
+{
+	struct wdc_softc *wdc = match;
+	struct isa_attach_args *ia = aux;
+	int iobase;
+
+	wdc->sc_iobase = iobase = ia->ia_iobase;
+
+	/* Check if we have registers that work. */
+	outb(iobase+wd_error, 0x5a);	/* Error register not writable, */
+	outb(iobase+wd_cyl_lo, 0xa5);	/* but all of cyllo are. */
+	if (inb(iobase+wd_error) == 0x5a || inb(iobase+wd_cyl_lo) != 0xa5) {
+		/*
+		 * Test for a controller with no IDE master, just one
+		 * ATAPI device. Select drive 1, and try again.
+		 */
+		outb(iobase+wd_sdh, WDSD_IBM | 0x10);
+		outb(iobase+wd_error, 0x5a);
+		outb(iobase+wd_cyl_lo, 0xa5);
+		if (inb(iobase+wd_error) == 0x5a || inb(iobase+wd_cyl_lo)
+		    != 0xa5)
+			return 0;
+		wdc->sc_flags |= WDCF_ONESLAVE;
+	}
+
+	if (wdcreset(wdc) != 0) {
+		delay(500000);
+		if (wdcreset(wdc) != 0)
+			return 0;
+	}
+
+	/* Select drive 0 or ATAPI slave device */
+	if (wdc->sc_flags & WDCF_ONESLAVE)
+		outb(iobase+wd_sdh, WDSD_IBM | 0x10);
+	else
+		outb(iobase+wd_sdh, WDSD_IBM);
+
+	/* Wait for controller to become ready. */
+	if (wait_for_unbusy(wdc) < 0)
+		return 0;
+    
+	/* Start drive diagnostics. */
+	outb(iobase+wd_command, WDCC_DIAGNOSE);
+
+	/* Wait for command to complete. */
+	if (wait_for_unbusy(wdc) < 0)
+		return 0;
+
+	ia->ia_iosize = 8;
+	ia->ia_msize = 0;
+	return 1;
+}
+
+int
+wdprint(aux, wdc)
+	void *aux;
+	char *wdc;
+{
+	struct wd_link *d_link = aux;
+
+	if (!wdc)
+		printf(" drive %d", d_link->sc_drive);
+	return QUIET;
+}
+
+void
+wdcattach(parent, self, aux)
+	struct device *parent, *self;
+	void *aux;
+{
+	struct wdc_softc *wdc = (void *)self;
+	struct isa_attach_args *ia = aux;
+	int drive;
+
+	TAILQ_INIT(&wdc->sc_xfer);
+	wdc->sc_drq = ia->ia_drq;
+
+	printf("\n");
+
+	wdc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq, IST_EDGE,
+	    IPL_BIO, wdcintr, wdc, wdc->sc_dev.dv_xname);
+
+	wdc->ctlr_link.flags = 0;
+#ifdef ATAPI_DEBUG
+	wdc_nxfer = 0;
+#endif
+
+	/*
+	 * Attach standard IDE/ESDI/etc. disks to the controller.
+	 */
+	for (drive = 0; drive < 2; drive++) {
+		/* controller active while autoconf */
+		wdc->sc_flags |= WDCF_ACTIVE;
+
+		if (wdccommandshort(wdc, drive, WDCC_RECAL) != 0 ||
+            	    wait_for_ready(wdc) != 0) {
+			wdc->d_link[drive] = NULL;
+			wdc->sc_flags &= ~WDCF_ACTIVE;
+		} else {
+			wdc->sc_flags &= ~WDCF_ACTIVE;
+			wdc->d_link[drive] = malloc(sizeof(struct wd_link),
+			    M_DEVBUF, M_NOWAIT);
+			if (wdc->d_link[drive] == NULL) {
+				printf("%s: can't allocate link for drive %d\n",
+				    self->dv_xname, drive);
+				continue;
+			}
+			bzero(wdc->d_link[drive],sizeof(struct wd_link));
+			wdc->d_link[drive]->type = DRIVE;
+			wdc->d_link[drive]->wdc_softc =(caddr_t) wdc;
+			wdc->d_link[drive]->ctlr_link = &(wdc->ctlr_link);
+			wdc->d_link[drive]->sc_drive = drive;
+			if (wdc->sc_drq != DRQUNK) 
+				wdc->d_link[drive]->sc_mode = WDM_DMA;
+			else
+				wdc->d_link[drive]->sc_mode = 0;
+
+			(void)config_found(self, (void *)wdc->d_link[drive],
+			    wdprint);
+		}
+	}
+
+	/*
+	 * Attach an ATAPI bus, if configured.
+	 */
+	wdc->ab_link = malloc(sizeof(struct bus_link), M_DEVBUF, M_NOWAIT);
+	if (wdc->ab_link == NULL) {
+		printf("%s: can't allocate ATAPI link\n", self->dv_xname);
+		return;
+	}
+	bzero(wdc->ab_link,sizeof(struct bus_link));
+	wdc->ab_link->type = BUS;
+	wdc->ab_link->wdc_softc = (caddr_t)wdc;
+	wdc->ab_link->ctlr_link = &(wdc->ctlr_link);
+	wdc->ab_link->ctrl = self->dv_unit;
+	(void)config_found(self, (void *)wdc->ab_link, NULL);
+}
+
+/*
+ * Start I/O on a controller.  This does the calculation, and starts a read or
+ * write operation.  Called to from wdstart() to start a transfer, from
+ * wdcintr() to continue a multi-sector transfer or start the next transfer, or
+ * wdcrestart() after recovering from an error.
+ */
+void
+wdcstart(wdc)
+	struct wdc_softc *wdc;
+{
+	struct wdc_xfer *xfer;
+
+	if ((wdc->sc_flags & WDCF_ACTIVE) != 0 ) {
+		WDDEBUG_PRINT(("wdcstart: already active\n"));
+		return; /* controller aleady active */
+	}
+#ifdef DIAGNOSTIC
+	if ((wdc->sc_flags & WDCF_IRQ_WAIT) != 0)
+		panic("wdcstart: controller waiting for irq\n");
+#endif
+	/*
+	 * XXX
+	 * This is a kluge.  See comments in wd_get_parms().
+	 */
+	if ((wdc->sc_flags & WDCF_WANTED) != 0) {
+#ifdef ATAPI_DEBUG_WDC
+		printf("WDCF_WANTED\n");
+#endif
+		wdc->sc_flags &= ~WDCF_WANTED;
+		wakeup(wdc);
+		return;
+	}
+	/* is there a xfer ? */
+	xfer = wdc->sc_xfer.tqh_first;
+	if (xfer == NULL) {
+#ifdef ATAPI_DEBUG2
+		printf("wdcstart: null xfer\n");
+#endif
+		return;
+	}
+	wdc->sc_flags |= WDCF_ACTIVE;
+	if (xfer->c_flags & C_ATAPI) {
+#ifdef ATAPI_DEBUG_WDC
+		printf("wdcstart: atapi\n");
+#endif
+		wdc_atapi_start(wdc,xfer);
+	} else {
+		wdc_ata_start(wdc,xfer);
+	}
+}
+
+
+void
+wdc_ata_start(wdc, xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct wd_link *d_link;
+	struct buf *bp = xfer->c_bp;
+	int nblks;
+
+	d_link=xfer->d_link;
+
+loop:
+    
+	if (wdc->sc_errors >= WDIORETRIES) {
+		wderror(d_link, bp, "hard error");
+		xfer->c_flags |= C_ERROR;
+		wdc_ata_done(wdc, xfer);
+		return;
+	}
+
+	/* Do control operations specially. */
+	if (d_link->sc_state < OPEN) {
+		/*
+		 * Actually, we want to be careful not to mess with the control
+		 * state if the device is currently busy, but we can assume
+		 * that we never get to this point if that's the case.
+		 */
+		if (wdccontrol(d_link) == 0) {
+			/* The drive is busy.  Wait. */
+			return;
+		}
+	}
+
+	/*
+	 * WDCF_ERROR is set by wdcunwedge() and wdcintr() when an error is
+	 * encountered.  If we are in multi-sector mode, then we switch to
+	 * single-sector mode and retry the operation from the start.
+	 */
+	if (wdc->sc_flags & WDCF_ERROR) {
+		wdc->sc_flags &= ~WDCF_ERROR;
+		if ((wdc->sc_flags & WDCF_SINGLE) == 0) {
+			wdc->sc_flags |= WDCF_SINGLE;
+			xfer->c_skip = 0;
+		}
+	}
+
+
+	/* When starting a transfer... */
+	if (xfer->c_skip == 0) {
+		daddr_t blkno;
+
+		WDDEBUG_PRINT(("\n%s: wdc_ata_start %s %d@%d; map ",
+		    wdc->sc_dev.dv_xname,
+		    (xfer->c_flags & B_READ) ? "read" : "write",
+		    xfer->c_bcount, xfer->c_blkno));
+
+		blkno = xfer->c_blkno+xfer->c_p_offset;
+		xfer->c_blkno = blkno / (d_link->sc_lp->d_secsize / DEV_BSIZE);
+	} else {
+		WDDEBUG_PRINT((" %d)%x", xfer->c_skip,
+		    inb(wdc->sc_iobase + wd_altsts)));
+	}
+
+	/*
+	 * When starting a multi-sector transfer, or doing single-sector
+	 * transfers...
+	 */
+	if (xfer->c_skip == 0 || (wdc->sc_flags & WDCF_SINGLE) != 0 ||
+	    d_link->sc_mode == WDM_DMA) {
+		daddr_t blkno = xfer->c_blkno;
+		long cylin, head, sector;
+		int command;
+
+		if ((wdc->sc_flags & WDCF_SINGLE) != 0)
+			nblks = 1;
+		else if (d_link->sc_mode != WDM_DMA)
+			nblks = xfer->c_bcount / d_link->sc_lp->d_secsize;
+		else
+			nblks =
+			    min(xfer->c_bcount / d_link->sc_lp->d_secsize, 8);
+
+		/* Check for bad sectors and adjust transfer, if necessary. */
+		if ((d_link->sc_lp->d_flags & D_BADSECT) != 0
+#ifdef B_FORMAT
+		    && (bp->b_flags & B_FORMAT) == 0
+#endif
+		    ) {
+			long blkdiff;
+			int i;
+
+			for (i = 0;
+			    (blkdiff = d_link->sc_badsect[i]) != -1; i++) {
+				blkdiff -= blkno;
+				if (blkdiff < 0)
+					continue;
+				if (blkdiff == 0) {
+					/* Replace current block of transfer. */
+					blkno =
+					    d_link->sc_lp->d_secperunit -
+					    d_link->sc_lp->d_nsectors - i - 1;
+				}
+				if (blkdiff < nblks) {
+					/* Bad block inside transfer. */
+					wdc->sc_flags |= WDCF_SINGLE;
+					nblks = 1;
+				}
+				break;
+			}
+			/* Tranfer is okay now. */
+		}
+
+		if ((d_link->sc_params.wdp_capabilities & WD_CAP_LBA) != 0) {
+			sector = (blkno >> 0) & 0xff;
+			cylin = (blkno >> 8) & 0xffff;
+			head = (blkno >> 24) & 0xf;
+			head |= WDSD_LBA;
+		} else {
+			sector = blkno % d_link->sc_lp->d_nsectors;
+			sector++;	/* Sectors begin with 1, not 0. */
+			blkno /= d_link->sc_lp->d_nsectors;
+			head = blkno % d_link->sc_lp->d_ntracks;
+			blkno /= d_link->sc_lp->d_ntracks;
+			cylin = blkno;
+			head |= WDSD_CHS;
+		}
+
+		if (d_link->sc_mode == WDM_PIOSINGLE ||
+		    (wdc->sc_flags & WDCF_SINGLE) != 0)
+			xfer->c_nblks = 1;
+		else if (d_link->sc_mode == WDM_PIOMULTI)
+			xfer->c_nblks = min(nblks, d_link->sc_multiple);
+		else
+			xfer->c_nblks = nblks;
+		xfer->c_nbytes = xfer->c_nblks * d_link->sc_lp->d_secsize;
+    
+#ifdef B_FORMAT
+		if (bp->b_flags & B_FORMAT) {
+			sector = d_link->sc_lp->d_gap3;
+			nblks = d_link->sc_lp->d_nsectors;
+			command = WDCC_FORMAT;
+		} else
+#endif
+		switch (d_link->sc_mode) {
+		case WDM_DMA:
+			command = (xfer->c_flags & B_READ) ?
+			    WDCC_READDMA : WDCC_WRITEDMA;
+			/*
+			 * Start the DMA channel and bounce the buffer if
+			 * necessary.
+			 */
+			isa_dmastart(xfer->c_flags & B_READ ?
+			    DMAMODE_READ : DMAMODE_WRITE,
+			    xfer->databuf + xfer->c_skip,
+			    xfer->c_nbytes, wdc->sc_drq);
+			break;
+
+		case WDM_PIOMULTI:
+			command = (xfer->c_flags & B_READ) ?
+			    WDCC_READMULTI : WDCC_WRITEMULTI;
+			break;
+
+		case WDM_PIOSINGLE:
+			command = (xfer->c_flags & B_READ) ?
+			    WDCC_READ : WDCC_WRITE;
+			break;
+
+		default:
+#ifdef DIAGNOSTIC
+			panic("bad wd mode");
+#endif
+			return;
+		}
+	
+		/* Initiate command! */
+		if (wdccommand(d_link, command, d_link->sc_drive,
+		    cylin, head, sector, nblks) != 0) {
+			wderror(d_link, NULL,
+			    "wdc_ata_start: timeout waiting for unbusy");
+			wdcunwedge(wdc);
+			return;
+		}
+
+		WDDEBUG_PRINT(("sector %d cylin %d head %d addr %x sts %x\n",
+		    sector, cylin, head, xfer->databuf,
+		    inb(wdc->sc_iobase + wd_altsts)));
+
+	} else if (xfer->c_nblks > 1) {
+		/* The number of blocks in the last stretch may be smaller. */
+		nblks = xfer->c_bcount / d_link->sc_lp->d_secsize;
+		if (xfer->c_nblks > nblks) {
+			xfer->c_nblks = nblks;
+			xfer->c_nbytes = xfer->c_bcount;
+		}
+	}
+
+	/* If this was a write and not using DMA, push the data. */
+	if (d_link->sc_mode != WDM_DMA &&
+	    (xfer->c_flags & (B_READ|B_WRITE)) == B_WRITE) {
+		if (wait_for_drq(wdc) < 0) {
+			wderror(d_link, NULL,
+			    "wdc_ata_start: timeout waiting for drq");
+			wdcunwedge(wdc);
+			return;
+		}
+
+		/* Push out data. */
+		if ((d_link->sc_flags & WDF_32BIT) == 0)
+			outsw(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip,
+			    xfer->c_nbytes >> 1);
+		else
+			outsl(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip,
+			    xfer->c_nbytes >> 2);
+	}
+
+	wdc->sc_flags |= WDCF_IRQ_WAIT;
+	WDDEBUG_PRINT(("wdc_ata_start: timeout "));
+	timeout(wdctimeout, wdc, WAITTIME);
+	WDDEBUG_PRINT(("done\n"));
+}
+
+void
+wdc_atapi_start(wdc, xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct atapi_command_packet *acp = xfer->atapi_cmd;
+
+#ifdef ATAPI_DEBUG_WDC
+	printf("wdc_atapi_start, acp flags %lx\n",acp->flags);
+#endif
+	if (wdc->sc_errors >= WDIORETRIES) {
+		acp->status |= ERROR;
+		acp->error = inb (wdc->sc_iobase + wd_error);
+		wdc_atapi_done(wdc, xfer);
+		return;
+	}
+	if (wait_for_unbusy(wdc) != 0) {
+		if ((wdc->sc_status & WDCS_ERR) == 0) {
+			printf("wdc_atapi_start: not ready, st = %02x\n",
+			    wdc->sc_status);
+			acp->status = ERROR;
+			return;
+		}
+	}
+
+	if (wdccommand((struct wd_link*)xfer->d_link, ATAPI_PACKET_COMMAND,
+	    acp->drive, acp->data_size, 0, 0, 0) != 0) {
+		printf("wdc_atapi_start: can't send atapi paket command\n");
+		acp->status = ERROR;
+		wdc->sc_flags |= WDCF_IRQ_WAIT;
+		return;
+	}
+	if ((acp->flags & 0x0300) != ACAP_DRQ_INTR) {
+		int i, phase;
+		for (i=20000; i>0; --i) {
+			phase = (inb(wdc->sc_iobase + wd_ireason) &
+			    (WDCI_CMD | WDCI_IN)) |
+			    (inb(wdc->sc_iobase + wd_status) & WDCS_DRQ);
+			if (phase == PHASE_CMDOUT)
+				break;
+			delay(10);
+		}
+		if (phase != PHASE_CMDOUT ) {
+			printf("wdc_atapi_start: timout waiting PHASE_CMDOUT");
+			acp->status = ERROR;
+			wdc_atapi_done(wdc, xfer);
+			return;
+		}
+		outsw(wdc->sc_iobase + wd_data, acp->command,
+		    acp->command_size / sizeof(short));
+	}
+	wdc->sc_flags |= WDCF_IRQ_WAIT;
+
+#ifdef ATAPI_DEBUG2
+	printf("wdc_atapi_start: timeout\n");
+#endif
+	timeout(wdctimeout, wdc, WAITTIME);
+	return;
+}
+
+
+/*
+ * Interrupt routine for the controller.  Acknowledge the interrupt, check for
+ * errors on the current operation, mark it done if necessary, and start the
+ * next request.  Also check for a partially done transfer, and continue with
+ * the next chunk if so.
+ */
+int
+wdcintr(arg)
+	void *arg;
+{
+	struct wdc_softc *wdc = arg;
+	struct wdc_xfer *xfer;
+
+	if ((wdc->sc_flags & WDCF_IRQ_WAIT) == 0) {
+		/* Clear the pending interrupt and abort. */
+		u_char s = inb(wdc->sc_iobase+wd_status);
+		u_char e = inb(wdc->sc_iobase+wd_error);
+		u_char i = inb(wdc->sc_iobase+wd_seccnt);
+
+#ifdef ATAPI_DEBUG_WDC
+		printf("wdcintr: inactive controller, "
+		    "punting st=%02x er=%02x irr=%02x\n", s, e, i);
+#endif
+
+		if (s & WDCS_DRQ) {
+			int len = inb (wdc->sc_iobase + wd_cyl_lo) +
+			    256 * inb (wdc->sc_iobase + wd_cyl_hi);
+#ifdef ATAPI_DEBUG_WDC
+			printf ("wdcintr: clearing up %d bytes\n", len);
+#endif
+			wdcbit_bucket (wdc, len);
+		}
+		return 0;
+	}
+
+	WDDEBUG_PRINT(("wdcintr\n"));
+
+	wdc->sc_flags &= ~WDCF_IRQ_WAIT;
+	xfer = wdc->sc_xfer.tqh_first;
+	if (xfer->c_flags & C_ATAPI) {
+		(void) wdc_atapi_intr(wdc,xfer);
+		return 0;
+	} else {
+		return wdc_ata_intr(wdc,xfer);
+	}
+}
+
+
+int
+wdc_ata_intr(wdc,xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct wd_link *d_link;
+
+	d_link = xfer->d_link;
+
+	if (wait_for_unbusy(wdc) < 0) {
+		wdcerror(wdc, "wdcintr: timeout waiting for unbusy");
+		wdc->sc_status |= WDCS_ERR;	/* XXX */
+	}
+
+	untimeout(wdctimeout, wdc);
+
+	/* Is it not a transfer, but a control operation? */
+	if (d_link->sc_state < OPEN) {
+		if (wdccontrol(d_link) == 0) {
+			/* The drive is busy.  Wait. */
+			return 1;
+		}
+		WDDEBUG_PRINT(("wdc_ata_start from wdc_ata_intr(open) flags %d\n",
+		    dc->sc_flags));
+		wdc_ata_start(wdc,xfer);
+		return 1;
+	}
+
+	/* Turn off the DMA channel and unbounce the buffer. */
+	if (d_link->sc_mode == WDM_DMA)
+		isa_dmadone(xfer->c_flags & B_READ ?
+		    DMAMODE_READ : DMAMODE_WRITE,
+		    xfer->databuf + xfer->c_skip, xfer->c_nbytes,
+		    wdc->sc_drq);
+
+	/* Have we an error? */
+	if (wdc->sc_status & WDCS_ERR) {
+#ifdef WDDEBUG
+		wderror(d_link, NULL, "wdc_ata_start");
+#endif
+		if ((wdc->sc_flags & WDCF_SINGLE) == 0) {
+			wdc->sc_flags |= WDCF_ERROR;
+			goto restart;
+		}
+
+#ifdef B_FORMAT
+		if (bp->b_flags & B_FORMAT)
+			goto bad;
+#endif
+
+		wdcunwedge(wdc);
+		if (++wdc->sc_errors < WDIORETRIES)
+			return 1;
+
+		wderror(d_link, xfer->c_bp, "hard error");
+
+#ifdef B_FORMAT
+	bad:
+#endif
+		xfer->c_flags |= C_ERROR;
+		goto done;
+	}
+
+	/* If this was a read and not using DMA, fetch the data. */
+	if (d_link->sc_mode != WDM_DMA &&
+	    (xfer->c_flags & (B_READ|B_WRITE)) == B_READ) {
+		if ((wdc->sc_status & (WDCS_DRDY | WDCS_DSC | WDCS_DRQ))
+		    != (WDCS_DRDY | WDCS_DSC | WDCS_DRQ)) {
+			wderror(d_link, NULL, "wdcintr: read intr before drq");
+			wdcunwedge(wdc);
+			return 1;
+		}
+
+		/* Pull in data. */
+		if ((d_link->sc_flags & WDF_32BIT) == 0)
+			insw(wdc->sc_iobase+wd_data,
+			    xfer->databuf + xfer->c_skip, xfer->c_nbytes >> 1);
+		else
+			insl(wdc->sc_iobase+wd_data,
+			    xfer->databuf + xfer->c_skip, xfer->c_nbytes >> 2);
+	}
+    
+	/* If we encountered any abnormalities, flag it as a soft error. */
+	if (wdc->sc_errors > 0 ||
+	    (wdc->sc_status & WDCS_CORR) != 0) {
+		wderror(d_link, xfer->c_bp, "soft error (corrected)");
+		wdc->sc_errors = 0;
+	}
+    
+	/* Adjust pointers for the next block, if any. */
+	xfer->c_blkno += xfer->c_nblks;
+	xfer->c_skip += xfer->c_nbytes;
+	xfer->c_bcount -= xfer->c_nbytes;
+
+	/* See if this transfer is complete. */
+	if (xfer->c_bcount > 0)
+		goto restart;
+
+done:
+	/* Done with this transfer, with or without error. */
+	wdc_ata_done(wdc, xfer);
+	return 0;
+
+restart:
+	/* Start the next operation */
+	WDDEBUG_PRINT(("wdc_ata_start from wdcintr flags %d\n",
+	    wdc->sc_flags));
+	wdc_ata_start(wdc, xfer);
+
+	return 1;
+}
+
+int
+wdcreset(wdc)
+	struct wdc_softc *wdc;
+{
+	int iobase = wdc->sc_iobase;
+
+	/* Reset the device. */
+	outb(iobase+wd_ctlr, WDCTL_RST | WDCTL_IDS);
+	delay(1000);
+	outb(iobase+wd_ctlr, WDCTL_IDS);
+	delay(1000);
+	(void) inb(iobase+wd_error);
+	outb(iobase+wd_ctlr, WDCTL_4BIT);
+
+	if (wait_for_unbusy(wdc) < 0) {
+		printf("%s: reset failed\n", wdc->sc_dev.dv_xname);
+		return 1;
+	}
+
+	return 0;
+}
+
+void
+wdcrestart(arg)
+	void *arg;
+{
+	struct wdc_softc *wdc = arg;
+	int s;
+
+	s = splbio();
+	wdcstart(wdc);
+	splx(s);
+}
+
+/*
+ * Unwedge the controller after an unexpected error.  We do this by resetting
+ * it, marking all drives for recalibration, and stalling the queue for a short
+ * period to give the reset time to finish.
+ * NOTE: We use a timeout here, so this routine must not be called during
+ * autoconfig or dump.
+ */
+void
+wdcunwedge(wdc)
+	struct wdc_softc *wdc;
+{
+	int unit;
+
+#ifdef ATAPI_DEBUG
+	printf("wdcunwedge\n");
+#endif
+
+	untimeout(wdctimeout, wdc);
+	wdc->sc_flags &= ~WDCF_IRQ_WAIT;
+	(void) wdcreset(wdc);
+
+	/* Schedule recalibrate for all drives on this controller. */
+	for (unit = 0; unit < 2; unit++) {
+		if (!wdc->d_link[unit]) continue;
+		if (wdc->d_link[unit]->sc_state > RECAL)
+			wdc->d_link[unit]->sc_state = RECAL;
+	}
+
+	wdc->sc_flags |= WDCF_ERROR;
+	++wdc->sc_errors;
+
+	/* Wake up in a little bit and restart the operation. */
+	WDDEBUG_PRINT(("wdcrestart from wdcunwedge\n"));
+	wdc->sc_flags &= ~WDCF_ACTIVE;
+	timeout(wdcrestart, wdc, RECOVERYTIME);
+}
+
+int
+wdcwait(wdc, mask)
+	struct wdc_softc *wdc;
+	int mask;
+{
+	int iobase = wdc->sc_iobase;
+	int timeout = 0;
+	u_char status;
+#ifdef WDCNDELAY_DEBUG
+	extern int cold;
+#endif
+
+	WDDEBUG_PRINT(("wdcwait\n"));
+
+	for (;;) {
+		wdc->sc_status = status = inb(iobase+wd_status);
+		/*
+		 * XXX
+		 * If a single slave ATAPI device is attached, it may
+		 * have released the bus. Select it and try again.
+		 */
+		if (status == 0xff && wdc->sc_flags & WDCF_ONESLAVE) {
+			outb(iobase+wd_sdh, WDSD_IBM | 0x10);
+			wdc->sc_status = status = inb(iobase+wd_status);
+		}
+		if ((status & WDCS_BSY) == 0 && (status & mask) == mask)
+			break;
+		if (++timeout > WDCNDELAY) {
+#ifdef ATAPI_DEBUG2
+			printf("wdcwait: timeout, status %x\n", status);
+#endif
+			return -1;
+		}
+		delay(WDCDELAY);
+	}
+	if (status & WDCS_ERR) {
+		wdc->sc_error = inb(iobase+wd_error);
+		return WDCS_ERR;
+	}
+#ifdef WDCNDELAY_DEBUG
+	/* After autoconfig, there should be no long delays. */
+	if (!cold && timeout > WDCNDELAY_DEBUG) {
+		struct wdc_xfer *xfer = wdc->sc_xfer.tqh_first;
+		if (xfer == NULL)
+			printf("%s: warning: busy-wait took %dus\n",
+	    		wdc->sc_dev.dv_xname, WDCDELAY * timeout);
+		else 
+			printf("%s(%s): warning: busy-wait took %dus\n",
+				wdc->sc_dev.dv_xname,
+			    ((struct device*)xfer->d_link->wd_softc)->dv_xname,
+				WDCDELAY * timeout);
+	}
+#endif
+	return 0;
+}
+
+void
+wdctimeout(arg)
+	void *arg;
+{
+	struct wdc_softc *wdc = (struct wdc_softc *)arg;
+	int s;
+
+	WDDEBUG_PRINT(("wdctimeout\n"));
+
+	s = splbio();
+	if ((wdc->sc_flags & WDCF_IRQ_WAIT) != 0) {
+		wdc->sc_flags &= ~WDCF_IRQ_WAIT;
+		wdcerror(wdc, "lost interrupt");
+		wdcunwedge(wdc);
+	} else
+		wdcerror(wdc, "missing untimeout");
+	splx(s);
+}
+
+/*
+ * Wait for the drive to become ready and send a command.
+ * Return -1 if busy for too long or 0 otherwise.
+ * Assumes interrupts are blocked.
+ */
+int
+wdccommand(d_link, command, drive, cylin, head, sector, count)
+        struct wd_link *d_link;
+        int command;
+        int drive, cylin, head, sector, count;
+{
+	struct wdc_softc *wdc = (void*)d_link->wdc_softc;
+        int iobase = wdc->sc_iobase;
+        int stat;
+
+	WDDEBUG_PRINT(("wdccommand drive %d\n", drive));
+
+#if defined(DIAGNOSTIC) && defined(WDCDEBUG)
+	if ((wdc->sc_flags & WDCF_ACTIVE) == 0)
+		printf("wdccommand: controler not active (drive %d)\n", drive);
+#endif
+
+        /* Select drive, head, and addressing mode. */
+        outb(iobase+wd_sdh, WDSD_IBM | (drive << 4) | head);
+
+        /* Wait for it to become ready to accept a command. */
+        if (command == WDCC_IDP || d_link->type == BUS)
+                stat = wait_for_unbusy(wdc);
+        else
+                stat = wdcwait(wdc, WDCS_DRDY);
+
+        if (stat < 0) {
+#ifdef ATAPI_DEBUG
+		printf("wdcommand: xfer failed (wait_for_unbusy) status %d\n",
+		    stat);
+#endif
+                return -1;
+	}
+
+        /* Load parameters. */
+        if (d_link->type == DRIVE && d_link->sc_lp->d_type == DTYPE_ST506)
+                outb(iobase + wd_precomp, d_link->sc_lp->d_precompcyl / 4);
+        else
+                outb(iobase + wd_features, 0);
+        outb(iobase + wd_cyl_lo, cylin);
+        outb(iobase + wd_cyl_hi, cylin >> 8);
+        outb(iobase + wd_sector, sector);
+        outb(iobase + wd_seccnt, count);
+
+        /* Send command. */
+        outb(iobase + wd_command, command);
+
+        return 0;
+}
+
+/*
+ * Simplified version of wdccommand().
+ */
+int
+wdccommandshort(wdc, drive, command)
+	struct wdc_softc *wdc;
+        int drive;
+        int command;
+{
+	int iobase = wdc->sc_iobase;
+
+	WDDEBUG_PRINT(("wdccommandshort\n"));
+
+#if defined(DIAGNOSTIC) && defined(WDCDEBUG)
+	if ((wdc->sc_flags & WDCF_ACTIVE) == 0)
+		printf("wdccommandshort: controler not active (drive %d)\n",
+		    drive);
+#endif
+
+        /* Select drive. */
+        outb(iobase + wd_sdh, WDSD_IBM | (drive << 4));
+
+        if (wdcwait(wdc, WDCS_DRDY) < 0)
+                return -1;
+
+        outb(iobase + wd_command, command);
+
+	return 0;
+}
+
+void
+wdc_ata_done(wdc, xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct buf *bp = xfer->c_bp;
+	struct wd_link *d_link = xfer->d_link;
+	int s;
+
+	WDDEBUG_PRINT(("wdc_ata_done\n"));
+
+	/* remove this command from xfer queue */
+	s = splbio();
+	TAILQ_REMOVE(&wdc->sc_xfer, xfer, c_xferchain);
+	wdc->sc_flags &= ~(WDCF_SINGLE | WDCF_ERROR | WDCF_ACTIVE);
+	wdc->sc_errors = 0;
+	if (bp) {
+		if (xfer->c_flags & C_ERROR) {
+			bp->b_flags |= B_ERROR;
+			bp->b_error = EIO;
+		}
+		bp->b_resid = xfer->c_bcount;
+		wddone(d_link, bp);
+		biodone(bp);
+	} else {
+		wakeup(xfer->databuf);
+	}
+	xfer->c_skip = 0;
+	wdc_free_xfer(xfer);
+	d_link->openings++;
+	wdstart((void*)d_link->wd_softc);
+	WDDEBUG_PRINT(("wdcstart from wdc_ata_done, flags %d\n",
+	    wdc->sc_flags));
+	wdcstart(wdc);
+	splx(s);
+}
+
+void
+wdc_exec_xfer(d_link, xfer)
+	struct wd_link *d_link;
+	struct wdc_xfer *xfer;
+{
+	struct wdc_softc *wdc=(struct wdc_softc *)d_link->wdc_softc;
+	int s;
+
+	WDDEBUG_PRINT(("wdc_exec_xfer\n"));
+
+	s = splbio();
+
+	/* insert at the end of command list */
+	TAILQ_INSERT_TAIL(&wdc->sc_xfer,xfer , c_xferchain)
+	WDDEBUG_PRINT(("wdcstart from wdc_exec_xfer, flags %d\n",
+	    wdc->sc_flags));
+	wdcstart(wdc);
+	splx(s);
+}   
+
+struct wdc_xfer *
+wdc_get_xfer(c_link,flags)
+	struct wdc_link *c_link;
+	int flags;
+{
+	struct wdc_xfer *xfer;
+	int s;
+
+	s = splbio();
+	if (xfer = xfer_free_list.lh_first) {
+		LIST_REMOVE(xfer, free_list);
+		splx(s);
+#ifdef DIAGNOSTIC
+		if ((xfer->c_flags & C_INUSE) != 0)
+			panic("wdc_get_xfer: xfer already in use\n");
+#endif
+	} else {
+		splx(s);
+#ifdef ATAPI_DEBUG
+		printf("wdc:making xfer %d\n",wdc_nxfer);
+#endif
+		xfer = malloc(sizeof(*xfer), M_DEVBUF,
+		    ((flags & IDE_NOSLEEP) != 0 ? M_NOWAIT : M_WAITOK));
+		if (xfer == NULL)
+			return 0;
+
+#ifdef DIAGNOSTIC
+		xfer->c_flags &= ~C_INUSE;
+#endif
+#ifdef ATAPI_DEBUG
+		wdc_nxfer++;
+#endif
+	}
+#ifdef DIAGNOSTIC
+	if ((xfer->c_flags & C_INUSE) != 0)
+		panic("wdc_get_xfer: xfer already in use\n");
+#endif
+	bzero(xfer,sizeof(struct wdc_xfer));
+	xfer->c_flags = C_INUSE;
+	xfer->c_link = c_link;
+	return xfer;
+}
+
+void
+wdc_free_xfer(xfer)
+	struct wdc_xfer *xfer;
+{
+	int s;
+
+	s = splbio();
+	xfer->c_flags &= ~C_INUSE;
+	LIST_INSERT_HEAD(&xfer_free_list, xfer, free_list);
+	splx(s);
+}
+
+/*
+ * Implement operations needed before read/write.
+ * Returns 0 if operation still in progress, 1 if completed.
+ */
+int
+wdccontrol(d_link)
+	struct wd_link *d_link;
+{
+	struct wdc_softc *wdc = (void *)d_link->wdc_softc;
+
+	WDDEBUG_PRINT(("wdccontrol\n"));
+
+	switch (d_link->sc_state) {
+	case RECAL:	/* Set SDH, step rate, do recal. */
+		if (wdccommandshort(wdc, d_link->sc_drive, WDCC_RECAL) != 0) {
+			wderror(d_link, NULL, "wdccontrol: recal failed (1)");
+			goto bad;
+		}
+		d_link->sc_state = RECAL_WAIT;
+		break;
+
+	case RECAL_WAIT:
+		if (wdc->sc_status & WDCS_ERR) {
+			wderror(d_link, NULL, "wdccontrol: recal failed (2)");
+			goto bad;
+		}
+		/* fall through */
+
+	case GEOMETRY:
+		if ((d_link->sc_params.wdp_capabilities & WD_CAP_LBA) != 0)
+			goto multimode;
+		if (wdsetctlr(d_link) != 0) {
+			/* Already printed a message. */
+			goto bad;
+		}
+		d_link->sc_state = GEOMETRY_WAIT;
+		break;
+
+	case GEOMETRY_WAIT:
+		if (wdc->sc_status & WDCS_ERR) {
+			wderror(d_link, NULL, "wdccontrol: geometry failed");
+			goto bad;
+		}
+		/* fall through */
+
+	case MULTIMODE:
+	multimode:
+		if (d_link->sc_mode != WDM_PIOMULTI)
+			goto open;
+		outb(wdc->sc_iobase + wd_seccnt, d_link->sc_multiple);
+		if (wdccommandshort(wdc, d_link->sc_drive,
+		    WDCC_SETMULTI) != 0) {
+			wderror(d_link, NULL,
+			    "wdccontrol: setmulti failed (1)");
+			goto bad;
+		}
+		d_link->sc_state = MULTIMODE_WAIT;
+		break;
+
+	case MULTIMODE_WAIT:
+		if (wdc->sc_status & WDCS_ERR) {
+			wderror(d_link, NULL,
+			    "wdccontrol: setmulti failed (2)");
+			goto bad;
+		}
+		/* fall through */
+
+	case OPEN:
+	open:
+		wdc->sc_errors = 0;
+		d_link->sc_state = OPEN;
+		/*
+		 * The rest of the initialization can be done by normal means.
+		 */
+		return 1;
+
+	bad:
+		wdcunwedge(wdc);
+		return 0;
+	}
+
+	wdc->sc_flags |= WDCF_IRQ_WAIT;
+	timeout(wdctimeout, wdc, WAITTIME);
+	return 0;
+}
+
+/*
+ * Get the drive parameters, if ESDI or ATA, or create fake ones for ST506.
+ */
+int
+wdc_get_parms(d_link)
+	struct wd_link *d_link;
+{
+	struct wdc_softc *wdc = (struct wdc_softc *)d_link->wdc_softc;
+	int i;
+	char tb[DEV_BSIZE];
+	int s, error;
+
+	/*
+	 * XXX
+	 * The locking done here, and the length of time this may keep the rest
+	 * of the system suspended, is a kluge.  This should be rewritten to
+	 * set up a transfer and queue it through wdstart(), but it's called
+	 * infrequently enough that this isn't a pressing matter.
+	 */
+
+	s = splbio();
+
+	while ((wdc->sc_flags & WDCF_ACTIVE) != 0) {
+		wdc->sc_flags |= WDCF_WANTED;
+		if ((error = tsleep(wdc, PRIBIO | PCATCH, "wdprm", 0)) != 0) {
+			splx(s);
+			return error;
+		}
+	}
+
+	wdc->sc_flags |= WDCF_ACTIVE;
+
+	if (wdccommandshort(wdc, d_link->sc_drive, WDCC_IDENTIFY) != 0 ||
+	    wait_for_drq(wdc) != 0) {
+		/*
+		 * We `know' there's a drive here; just assume it's old.
+		 * This geometry is only used to read the MBR and print a
+		 * (false) attach message.
+		 */
+		strncpy(d_link->sc_lp->d_typename, "ST506",
+		    sizeof d_link->sc_lp->d_typename);
+		d_link->sc_lp->d_type = DTYPE_ST506;
+
+		strncpy(d_link->sc_params.wdp_model, "unknown",
+		    sizeof d_link->sc_params.wdp_model);
+		d_link->sc_params.wdp_config = WD_CFG_FIXED;
+		d_link->sc_params.wdp_cylinders = 1024;
+		d_link->sc_params.wdp_heads = 8;
+		d_link->sc_params.wdp_sectors = 17;
+		d_link->sc_params.wdp_maxmulti = 0;
+		d_link->sc_params.wdp_usedmovsd = 0;
+		d_link->sc_params.wdp_capabilities = 0;
+	} else {
+		strncpy(d_link->sc_lp->d_typename, "ESDI/IDE",
+		    sizeof d_link->sc_lp->d_typename);
+		d_link->sc_lp->d_type = DTYPE_ESDI;
+
+		/* Read in parameter block. */
+		insw(wdc->sc_iobase + wd_data, tb, sizeof(tb) / sizeof(short));
+		bcopy(tb, &d_link->sc_params, sizeof(struct wdparams));
+
+		/* Shuffle string byte order. */
+		for (i = 0; i < sizeof(d_link->sc_params.wdp_model); i += 2) {
+			u_short *p;
+			p = (u_short *)(d_link->sc_params.wdp_model + i);
+			*p = ntohs(*p);
+		}
+	}
+
+	/* Clear any leftover interrupt. */
+	(void) inb(wdc->sc_iobase + wd_status);
+
+	/* Restart the queue. */
+	WDDEBUG_PRINT(("wdcstart from wdc_get_parms flags %d\n",
+	    wdc->sc_flags));
+	wdc->sc_flags &= ~WDCF_ACTIVE;
+	wdcstart(wdc);
+
+	splx(s);
+	return 0;
+}
+
+void
+wdcerror(wdc, msg) 
+	struct wdc_softc *wdc;
+	char *msg;
+{
+	struct wdc_xfer *xfer = wdc->sc_xfer.tqh_first;
+	if (xfer == NULL)
+		printf("%s: %s\n", wdc->sc_dev.dv_xname, msg);
+	else
+		printf("%s(%s): %s\n", wdc->sc_dev.dv_xname, 
+		    ((struct device*)xfer->d_link->wd_softc)->dv_xname, msg);
+}
+
+int
+wdc_atapi_get_params(ab_link, drive, id)
+	struct bus_link *ab_link;
+	u_int8_t drive;
+	struct atapi_identify *id;
+{
+	struct wdc_softc *wdc = (void*)ab_link->wdc_softc;
+	int status, len, excess = 0;
+	int s, error;
+
+	if (wdc->d_link[drive] != 0) {
+#ifdef ATAPI_DEBUG_PROBE
+		printf("wdc_atapi_get_params: WD drive %d\n", drive);
+#endif
+		return 0;
+	}
+
+	/*
+	 * If there is only one ATAPI slave ion the bus,don't probe
+	 * drive 0 (master)
+	 */
+
+	if (wdc->sc_flags & WDCF_ONESLAVE && drive != 1)
+		return 0;
+
+#ifdef ATAPI_DEBUG_PROBE
+	printf("wdc_atapi_get_params: probing drive %d\n", drive);
+#endif
+
+	/*
+	 * XXX
+	 * The locking done here, and the length of time this may keep the rest
+	 * of the system suspended, is a kluge.  This should be rewritten to
+	 * set up a transfer and queue it through wdstart(), but it's called
+	 * infrequently enough that this isn't a pressing matter.
+	 */
+
+	s = splbio();
+
+	while ((wdc->sc_flags & WDCF_ACTIVE) != 0) {
+		wdc->sc_flags |= WDCF_WANTED;
+		if ((error = tsleep(wdc, PRIBIO | PCATCH, "atprm", 0)) != 0) {
+			splx(s);
+			return error;
+		}
+	}
+
+	wdc->sc_flags |= WDCF_ACTIVE;
+	error = 1;
+	(void)wdcreset(wdc);
+	if ((status = wdccommand((struct wd_link*)ab_link,
+	    ATAPI_SOFT_RESET, drive, 0, 0, 0, 0)) != 0) {
+#ifdef ATAPI_DEBUG
+		printf("wdc_atapi_get_params: ATAPI_SOFT_RESET"
+		    "failed for drive %d: status %d error %d\n",
+		    drive, status, wdc->sc_error);
+#endif
+		error = 0;
+		goto end;
+	} 
+	if ((status = wait_for_unbusy(wdc)) != 0) {
+#ifdef ATAPI_DEBUG
+	printf("wdc_atapi_get_params: wait_for_unbusy failed "
+	    "for drive %d: status %d error %d\n",
+	    drive, status, wdc->sc_error);
+#endif
+		error = 0;
+		goto end;
+	}
+
+	if (wdccommand((struct wd_link*)ab_link, ATAPI_IDENTIFY_DEVICE,
+	    drive, sizeof(struct atapi_identify), 0, 0, 0) != 0 ||
+	    atapi_ready(wdc) != 0) {
+#ifdef ATAPI_DEBUG_PROBE
+		printf("ATAPI_IDENTIFY_DEVICE failed for drive %d\n", drive);
+#endif
+		error = 0;
+		goto end;
+	}
+	len = inb(wdc->sc_iobase + wd_cyl_lo) + 256 *
+	    inb(wdc->sc_iobase + wd_cyl_hi);
+	if (len != sizeof(struct atapi_identify)) {
+		printf("Warning drive %d returned %d/%d of "
+		    "indentify device data\n", drive, len,
+		    sizeof(struct atapi_identify));
+		excess = len - sizeof(struct atapi_identify);
+		if (excess < 0)
+			excess = 0;
+	}
+	insw(wdc->sc_iobase + wd_data, id,
+	    sizeof(struct atapi_identify)/sizeof(short));
+	wdcbit_bucket(wdc, excess);
+
+ end:	/* Restart the queue. */
+	WDDEBUG_PRINT(("wdcstart from wdc_atapi_get_parms flags %d\n",
+	    wdc->sc_flags));
+	wdc->sc_flags &= ~WDCF_ACTIVE;
+	wdcstart(wdc);
+	splx(s);
+	return error;
+}
+
+void
+wdc_atapi_send_command_packet(ab_link, acp)
+	struct bus_link *ab_link;
+	struct atapi_command_packet *acp;
+{
+	struct wdc_softc *wdc = (void*)ab_link->wdc_softc;
+	struct wdc_xfer *xfer;
+	u_int8_t flags = acp->flags & 0xff;
+	int s;
+	
+	if (flags & A_POLLED) {   /* Must use the queue and wdc_atapi_start */
+		struct wdc_xfer xfer_s;
+		int i;
+#ifdef ATAPI_DEBUG_WDC
+		printf("wdc_atapi_send_cmd: "
+		    "flags %ld drive %d cmdlen %d datalen %d",
+		    acp->flags, acp->drive, acp->command_size, acp->data_size);
+#endif
+		xfer = &xfer_s;
+		bzero(xfer, sizeof(xfer_s));
+		xfer->c_flags = C_INUSE|C_ATAPI|acp->flags;
+		xfer->d_link = (struct wd_link *)ab_link;
+		xfer->c_link = ab_link->ctlr_link;
+		xfer->c_bp = acp->bp;
+		xfer->atapi_cmd = acp;
+		xfer->c_blkno = 0;
+		xfer->databuf = acp->databuf;
+		xfer->c_bcount = acp->data_size;
+		if (wait_for_unbusy (wdc) != 0)  {
+			if ((wdc->sc_status & WDCS_ERR) == 0) {
+				printf("wdc_atapi_send_command: not ready, "
+				    "st = %02x\n", wdc->sc_status);
+				acp->status = ERROR;
+				return;
+			}
+		}
+
+		if (wdccommand((struct wd_link*)ab_link,
+		    ATAPI_PACKET_COMMAND, acp->drive, acp->data_size,
+		    0, 0, 0) != 0) {
+			printf("can't send atapi paket command\n");
+			acp->status = ERROR;
+			return;
+		}
+
+		/* Wait for cmd i/o phase. */
+		for (i = 20000; i > 0; --i) {
+			int phase;
+			phase = (inb(wdc->sc_iobase + wd_ireason) &
+			    (WDCI_CMD | WDCI_IN)) |
+			    (inb(wdc->sc_iobase + wd_status) & WDCS_DRQ);
+			if (phase == PHASE_CMDOUT)
+				break;
+			delay(10);
+		}
+#ifdef ATAPI_DEBUG_WDC
+		printf("Wait for cmd i/o phase: i = %d\n", i);
+#endif
+
+		outsw(wdc->sc_iobase + wd_data, acp->command,
+		    acp->command_size/ sizeof (short));
+
+		/* Wait for data i/o phase. */
+		for ( i= 20000; i > 0; --i) {
+			int phase;
+			phase = (inb(wdc->sc_iobase + wd_ireason) &
+			    (WDCI_CMD | WDCI_IN)) |
+			    (inb(wdc->sc_iobase + wd_status) & WDCS_DRQ);
+			if (phase != PHASE_CMDOUT)
+				break;
+			delay(10);
+		}
+
+#ifdef ATAPI_DEBUG_WDC
+		printf("Wait for data i/o phase: i = %d\n", i);
+#endif
+		while (wdc_atapi_intr(wdc, xfer)) {
+			for (i = 2000; i > 0; --i)
+				if ((inb(wdc->sc_iobase + wd_status)
+				    & WDCS_DRQ) == 0)
+					break;
+#ifdef ATAPI_DEBUG_WDC
+			printf("wdc_atapi_intr: i = %d\n", i);
+#endif
+		}
+		wdc->sc_flags &= ~(WDCF_IRQ_WAIT | WDCF_SINGLE | WDCF_ERROR);
+		wdc->sc_errors = 0;
+		xfer->c_skip = 0;
+		return;
+	} else {	/* POLLED */
+		xfer = wdc_get_xfer(ab_link->ctlr_link,
+		    flags & A_NOSLEEP ? IDE_NOSLEEP : 0);
+		if (xfer == NULL) {
+			acp->status = ERROR;
+			return;
+		}
+		xfer->c_flags |= C_ATAPI|acp->flags;
+		xfer->d_link = (struct wd_link*) ab_link;
+		xfer->c_link = ab_link->ctlr_link;
+		xfer->c_bp = acp->bp;
+		xfer->atapi_cmd = acp;
+		xfer->c_blkno = 0;
+		xfer->databuf = acp->databuf;
+		xfer->c_bcount = acp->data_size;
+		wdc_exec_xfer((struct wd_link*)ab_link,xfer);
+		return;
+	}
+}
+
+
+/* 
+ * the bit bucket
+ */
+void
+wdcbit_bucket(wdc, size)
+	struct wdc_softc *wdc; 
+	int size;
+{
+	int iobase = wdc->sc_iobase; 
+	int i;
+
+	for (i = 0 ; i < size / 2 ; i++) {
+		short null; 
+		(void)insw(iobase + wd_data, &null, 1);
+	} 
+
+	if (size % 2)
+		(void)inb(iobase + wd_data);
+}
+
+int
+wdc_atapi_intr(wdc, xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct atapi_command_packet *acp = xfer->atapi_cmd;
+	int len, phase, i;
+	int err, st, ire;
+
+	if (wait_for_unbusy(wdc) < 0) {
+		printf("wdc_atapi_intr: controller busy\n");
+		acp->status = ERROR;
+		acp->error = inb (wdc->sc_iobase + wd_error);
+		return 0;
+	}
+
+#ifdef ATAPI_DEBUG2
+	printf("wdc_atapi_intr: %s\n", wdc->sc_dev.dv_xname);
+#endif
+
+	len = inb(wdc->sc_iobase + wd_cyl_lo) +
+	    256 * inb(wdc->sc_iobase + wd_cyl_hi);
+
+	st = inb(wdc->sc_iobase + wd_status);
+	err = inb(wdc->sc_iobase + wd_error);
+	ire = inb(wdc->sc_iobase + wd_ireason);
+	
+	phase = (ire & (WDCI_CMD | WDCI_IN)) | (st & WDCS_DRQ);
+#ifdef ATAPI_DEBUG_WDC
+	printf("wdc_atapi_intr: len %d st %d err %d ire %d :",
+	    len, st, err, ire);
+#endif
+	switch (phase) {
+	case PHASE_CMDOUT:
+		/* send packet command */
+#ifdef ATAPI_DEBUG_WDC
+		printf("PHASE_CMDOUT\n");
+#endif
+
+#ifdef ATAPI_DEBUG_WDC
+		{
+			int i;
+			char *c = (char *)acp->command;   
+			printf("wdc_atapi_intr: cmd ");
+			for (i = 0; i < acp->command_size; i++)
+				printf("%x ", c[i]);
+			printf("\n");
+		}
+#endif
+
+		wdc->sc_flags |= WDCF_IRQ_WAIT;
+		outsw(wdc->sc_iobase + wd_data, acp->command,
+		    acp->command_size/ sizeof (short));
+		return 1;
+
+	case PHASE_DATAOUT:
+		/* write data */
+#ifdef ATAPI_DEBUG_WDC
+		printf("PHASE_DATAOUT\n");
+#endif
+		if ((acp->flags & (B_READ|B_WRITE)) != B_WRITE) {
+			printf("wdc_atapi_intr: bad data phase\n");
+			acp->status = ERROR;
+			return 1;
+		}
+		wdc->sc_flags |= WDCF_IRQ_WAIT;
+		if (xfer->c_bcount < len) {
+			printf("wdc_atapi_intr: warning: write only "
+			    "%d of %d requested bytes\n", xfer->c_bcount, len);
+			outsw(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip,
+			    xfer->c_bcount / sizeof(short));
+			for (i = xfer->c_bcount; i < len; i += sizeof(short))
+				outw(wdc->sc_iobase + wd_data, 0);
+			xfer->c_bcount = 0;
+			return 1;
+		} else {
+			outsw(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip, len / sizeof(short));
+			xfer->c_skip += len;
+			xfer->c_bcount -= len;
+			return 1;
+		}
+	
+	case PHASE_DATAIN:
+		/* Read data */
+#ifdef ATAPI_DEBUG_WDC
+		printf("PHASE_DATAIN\n");
+#endif
+		if ((acp->flags & (B_READ|B_WRITE)) != B_READ) {
+			printf("wdc_atapi_intr: bad data phase\n");
+			acp->status = ERROR;
+			return 1;
+		}
+		wdc->sc_flags |= WDCF_IRQ_WAIT;
+		if (xfer->c_bcount < len) {
+			printf("wdc_atapi_intr: warning: reading only "
+			    "%d of %d bytes\n", xfer->c_bcount, len);
+			insw(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip,
+			    xfer->c_bcount / sizeof(short));
+			wdcbit_bucket(wdc, len - xfer->c_bcount);
+			xfer->c_bcount = 0;
+			return 1;
+		} else {
+			insw(wdc->sc_iobase + wd_data,
+			    xfer->databuf + xfer->c_skip, len / sizeof(short));
+			xfer->c_skip += len;
+			xfer->c_bcount -=len;
+			return 1;
+		}
+
+	case PHASE_ABORTED:
+	case PHASE_COMPLETED:
+#ifdef ATAPI_DEBUG_WDC
+		printf("PHASE_COMPLETED\n");
+#endif
+		if (st & WDCS_ERR) {
+			acp->error = inb(wdc->sc_iobase + wd_error);
+			acp->status = ERROR;
+		}
+#ifdef ATAPI_DEBUG_WDC
+		if (xfer->c_bcount != 0) {
+			printf("wdc_atapi_intr warning: bcount value "
+			    "is %d after io\n", xfer->c_bcount);
+		}
+#endif
+		break;
+
+	default: 
+		printf("wdc_atapi_intr: unknown phase %d\n", phase);
+		acp->status = ERROR;
+	}
+
+	wdc_atapi_done(wdc, xfer);
+	return (0);
+}
+
+
+void
+wdc_atapi_done(wdc, xfer)
+	struct wdc_softc *wdc;
+	struct wdc_xfer *xfer;
+{
+	struct atapi_command_packet *acp = xfer->atapi_cmd;
+	int s;
+
+	acp->data_size = xfer->c_bcount;
+
+	s = splbio();
+
+	/* remove this command from xfer queue */
+	wdc->sc_errors = 0;
+	xfer->c_skip = 0;
+	if ((xfer->c_flags & A_POLLED) == 0) {
+		untimeout(wdctimeout, wdc);
+		TAILQ_REMOVE(&wdc->sc_xfer, xfer, c_xferchain);
+		wdc->sc_flags &= ~(WDCF_SINGLE | WDCF_ERROR | WDCF_ACTIVE);
+		wdc_free_xfer(xfer);
+#ifdef ATAPI_DEBUG
+		printf("wdc_atapi_done: atapi_done\n");
+#endif
+		atapi_done(acp);
+#ifdef WDDEBUG
+		printf("wdcstart from wdc_atapi_intr, flags %d\n",
+		    wdc->sc_flags);
+#endif
+		wdcstart(wdc);
+	} else
+		wdc->sc_flags &= ~(WDCF_SINGLE | WDCF_ERROR | WDCF_ACTIVE);
+
+	splx(s);
+}
diff --git a/sys/dev/isa/wdlink.h b/sys/dev/isa/wdlink.h
new file mode 100644
index 00000000000..0a6ba4e6362
--- /dev/null
+++ b/sys/dev/isa/wdlink.h
@@ -0,0 +1,151 @@
+/*	$NetBSD: $	*/
+
+/*
+ * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
+ *
+ * DMA and multi-sector PIO handling are derived from code contributed by
+ * Onno van der Linden.
+ *
+ * Atapi support added by Manuel Bouyer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by Charles M. Hannum.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#undef WDDEBUG
+/* #undef DIAGNOSTIC */
+
+struct wdc_link {
+	int flags;
+	int openings;
+};
+
+struct wdc_softc {
+	struct device sc_dev;
+	void *sc_ih;
+	struct wd_link *d_link[2];
+	struct bus_link *ab_link;
+	struct wdc_link ctlr_link;
+	int sc_iobase;			/* I/O port base */
+	int sc_drq;			/* DMA channel */
+
+	TAILQ_HEAD(xferhead, wdc_xfer) sc_xfer;
+	int sc_flags;
+#define	WDCF_ACTIVE		0x01	/* controller is active */
+#define	WDCF_SINGLE		0x02	/* sector at a time mode */
+#define	WDCF_ERROR		0x04	/* processing a disk error */
+#define	WDCF_WANTED		0x08	/* XXX locking for wd_get_parms() */
+#define	WDCF_IRQ_WAIT		0x10	/* controller is waiting for irq */
+#define	WDCF_ONESLAVE		0x20	/* ctrl. has one ATAPI slave attached */
+	int sc_errors;			/* errors during current transfer */
+	u_char sc_status;		/* copy of status register */
+	u_char sc_error;		/* copy of error register */
+};
+
+struct wd_link {
+	u_char type;  
+#define DRIVE 0
+#define BUS 1
+	caddr_t wdc_softc;
+	caddr_t wd_softc;
+	struct wdc_link *ctlr_link;
+	struct wdparams sc_params;
+
+	/* Long-term state: */
+	u_int8_t openings;
+	int sc_drive;			/* physical unit number */
+	int sc_state;			/* control state */
+#define RECAL		0		/* recalibrate */
+#define RECAL_WAIT	1		/* done recalibrating */
+#define GEOMETRY	2		/* upload geometry */
+#define GEOMETRY_WAIT	3		/* done uploading geometry */
+#define MULTIMODE	4		/* set multiple mode */
+#define MULTIMODE_WAIT	5		/* done setting multiple mode */
+#define OPEN		6		/* done with open */
+	int sc_mode;			/* transfer mode */
+#define WDM_PIOSINGLE	0		/* single-sector PIO */
+#define WDM_PIOMULTI	1		/* multi-sector PIO */
+#define WDM_DMA		2		/* DMA */
+	int sc_multiple;		/* multiple for WDM_PIOMULTI */
+	int sc_flags;			/* drive characteistics found */
+#define WDF_LOCKED	0x01
+#define WDF_WANTED	0x02
+#define WDF_WLABEL	0x04		/* label is writable */
+#define WDF_LABELLING	0x08		/* writing label */
+
+/*
+ * XXX Nothing resets this yet, but disk change sensing will when ATAPI is
+ * implemented.
+ */
+#define WDF_LOADED	0x10		/* parameters loaded */
+#define WDF_32BIT	0x20		/* can do 32-bit transfer */
+#define WDF_WAIT	0x40		/* waiting for resourses */
+
+	daddr_t sc_badsect[127];	/* 126 plus trailing -1 marker */
+	struct disklabel *sc_lp;	/* label info for this disk */
+};
+
+struct wdc_xfer {
+	struct wdc_link *c_link;	/* controller structure info */
+	struct wd_link *d_link;		/* drive/bus structure info */
+	volatile long c_flags;		/* handle also B_READ and B_WRITE */
+#define C_INUSE 0x01
+#define C_ATAPI 0x02
+#define C_ERROR 0x04
+
+	/* Information about the current transfer  */
+	struct buf *c_bp;
+	void *atapi_cmd;
+	void *databuf;
+	daddr_t c_blkno;	/* starting block number */
+	int c_bcount;		/* byte count left */
+	int c_skip;		/* bytes already transferred */
+	int c_nblks;		/* number of blocks currently transferring */
+	int c_nbytes;		/* number of bytes currently transferring */
+	u_long c_p_offset;	/* offset of the partition */
+	TAILQ_ENTRY(wdc_xfer) c_xferchain;
+	LIST_ENTRY(wdc_xfer) free_list;
+};
+
+void	wdc_exec_xfer		__P((struct wd_link *, struct wdc_xfer *));
+struct	wdc_xfer *wdc_get_xfer	__P((struct wdc_link *, int));
+int	wdc_get_parms		__P((struct wd_link *));
+void	wderror			__P((struct wd_link* , struct buf *, char *));
+void	wddone			__P((struct wd_link*, struct buf*));
+int	wdccommand		__P((struct wd_link *, int, int, int, int, int, int));
+int	wdccommandshort		__P((struct wdc_softc *, int, int));
+int	wdcwait			__P((struct wdc_softc *, int));
+
+/*
+ * ST506 spec says that if READY or SEEKCMPLT go off, then the read or write
+ * command is aborted.
+ */
+#define	wait_for_drq(d)		wdcwait(d, WDCS_DRDY | WDCS_DSC | WDCS_DRQ)
+#define	wait_for_unbusy(d)	wdcwait(d, 0)
+#define	wait_for_ready(d)	wdcwait(d, WDCS_DRDY | WDCS_DSC)
+#define	atapi_ready(d)		wdcwait(d, WDCS_DRQ)
+
+#define IDE_NOSLEEP 0x01
diff --git a/sys/dev/isa/wdreg.h b/sys/dev/isa/wdreg.h
index 9e3954eca8d..ad3bb8bb107 100644
--- a/sys/dev/isa/wdreg.h
+++ b/sys/dev/isa/wdreg.h
@@ -46,6 +46,7 @@
 #define	wd_precomp	0x001	/* write precompensation (W) */
 #define	wd_features	0x001	/* features (W) */
 #define	wd_seccnt	0x002	/* sector count (R/W) */
+#define wd_ireason	0x002   /* interrupt reason (R/W) (for atapi) */
 #define	wd_sector	0x003	/* first sector number (R/W) */
 #define	wd_cyl_lo	0x004	/* cylinder address, low byte (R/W) */
 #define	wd_cyl_hi	0x005	/* cylinder address, high byte (R/W) */
@@ -118,6 +119,52 @@
 #define	WDSD_CHS	0x00	/* cylinder/head/sector addressing */
 #define	WDSD_LBA	0x40	/* logical block addressing */
 
+/* Commands for ATAPI devices */
+#define ATAPI_CHECK_POWER_MODE      0xe5 
+#define ATAPI_EXEC_DRIVE_DIAGS      0x90
+#define ATAPI_IDLE_IMMEDIATE        0xe1
+#define ATAPI_NOP           0x00
+#define ATAPI_PACKET_COMMAND        0xa0 
+#define ATAPI_IDENTIFY_DEVICE       0xa1 
+#define ATAPI_SOFT_RESET        0x08
+#define ATAPI_SET_FEATURES      0xef
+#define ATAPI_SLEEP         0xe6
+#define ATAPI_STANDBY_IMMEDIATE     0xe0
+
+/* ireason */
+#define WDCI_CMD         0x01    /* command(1) or data(0) */
+#define WDCI_IN          0x02    /* transfer to(1) or from(0) the host */
+#define WDCI_RELEASE     0x04    /* bus released until completion */
+
+#define PHASE_CMDOUT    (WDCS_DRQ | WDCI_CMD)  
+#define PHASE_DATAIN    (WDCS_DRQ | WDCI_IN)
+#define PHASE_DATAOUT   WDCS_DRQ
+#define PHASE_COMPLETED (WDCI_IN | WDCI_CMD)
+#define PHASE_ABORTED   0
+
+/* Commands for ATAPI devices */
+#define ATAPI_CHECK_POWER_MODE      0xe5 
+#define ATAPI_EXEC_DRIVE_DIAGS      0x90
+#define ATAPI_IDLE_IMMEDIATE        0xe1
+#define ATAPI_NOP           0x00
+#define ATAPI_PACKET_COMMAND        0xa0 
+#define ATAPI_IDENTIFY_DEVICE       0xa1 
+#define ATAPI_SOFT_RESET        0x08
+#define ATAPI_SET_FEATURES      0xef
+#define ATAPI_SLEEP         0xe6
+#define ATAPI_STANDBY_IMMEDIATE     0xe0
+
+/* ireason */
+#define WDCI_CMD         0x01    /* command(1) or data(0) */
+#define WDCI_IN          0x02    /* transfer to(1) or from(0) the host */
+#define WDCI_RELEASE     0x04    /* bus released until completion */
+
+#define PHASE_CMDOUT    (WDCS_DRQ | WDCI_CMD)  
+#define PHASE_DATAIN    (WDCS_DRQ | WDCI_IN)
+#define PHASE_DATAOUT   WDCS_DRQ
+#define PHASE_COMPLETED (WDCI_IN | WDCI_CMD)
+#define PHASE_ABORTED   0
+
 
 #ifdef _KERNEL
 /*