xref: /netbsd-src/sys/arch/amiga/dev/fd.c (revision 89c5a767f8fc7a4633b2d409966e2becbb98ff92)
1 /*	$NetBSD: fd.c,v 1.43 2000/02/07 20:16:48 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Christian E. Hopps
5  * Copyright (c) 1996 Ezra Story
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Christian E. Hopps.
19  *      This product includes software developed by Ezra Story.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/buf.h>
39 #include <sys/device.h>
40 #include <sys/ioctl.h>
41 #include <sys/fcntl.h>
42 #include <sys/disklabel.h>
43 #include <sys/disk.h>
44 #include <sys/dkbad.h>
45 #include <sys/proc.h>
46 #include <machine/cpu.h>
47 #include <amiga/amiga/device.h>
48 #include <amiga/amiga/custom.h>
49 #include <amiga/amiga/cia.h>
50 #include <amiga/amiga/cc.h>
51 
52 #include <sys/conf.h>
53 #include <machine/conf.h>
54 
55 #include "locators.h"
56 
57 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY };
58 /*
59  * partitions in fd represent different format floppies
60  * partition a is 0 etc..
61  */
62 enum fd_parttypes {
63 	FDAMIGAPART = 0,
64 	FDMSDOSPART,
65 	FDMAXPARTS
66 };
67 
68 #define FDBBSIZE	(8192)
69 #define FDSBSIZE	(8192)
70 
71 #define FDUNIT(dev)	DISKUNIT(dev)
72 #define FDPART(dev)	DISKPART(dev)
73 #define FDMAKEDEV(m, u, p)	MAKEDISKDEV((m), (u), (p))
74 
75 /* that's nice, but we don't want to always use this as an amiga drive
76 bunghole :-) */
77 #define FDNHEADS	(2)	/* amiga drives always have 2 heads */
78 #define FDSECSIZE	(512)	/* amiga drives always have 512 byte sectors */
79 #define FDSECLWORDS	(128)
80 
81 #define FDSETTLEDELAY	(18000)	/* usec delay after seeking after switch dir */
82 #define FDSTEPDELAY	(3500)	/* usec delay after steping */
83 #define FDPRESIDEDELAY	(1000)	/* usec delay before writing can occur */
84 #define FDWRITEDELAY	(1300)	/* usec delay after write */
85 
86 #define FDSTEPOUT	(1)	/* decrease track step */
87 #define FDSTEPIN	(0)	/* increase track step */
88 
89 #define FDCUNITMASK	(0x78)	/* mask for all units (bits 6-3) */
90 
91 #define FDRETRIES	(2)	/* default number of retries */
92 #define FDMAXUNITS	(4)	/* maximum number of supported units */
93 
94 #define DISKLEN_READ	(0)	/* fake mask for reading */
95 #define DISKLEN_WRITE	(1 << 14)	/* bit for writing */
96 #define DISKLEN_DMAEN	(1 << 15)	/* dma go */
97 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2)	/* largest dma possible */
98 
99 #define FDMFMSYNC	(0x4489)
100 #define FDMFMID		(0x5554)
101 #define FDMFMDATA	(0x5545)
102 #define FDMFMGAP1	(0x9254)
103 #define FDMFMGAP2	(0xAAAA)
104 #define FDMFMGAP3	(0x9254)
105 #define CRC16POLY	(0x1021) /* (x^16) + x^12 + x^5 + x^0 */
106 
107 /*
108  * Msdos-type MFM encode/decode
109  */
110 static u_char msdecode[128];
111 static u_char msencode[16] =
112 {
113     0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
114     0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
115 };
116 static u_short mscrctab[256];
117 
118 /*
119   5554    aaaa    aaaa    aaa5    2aa4    4452    aa51
120           00      00      03      02      ac      0d
121 */
122 
123 /*
124  * floppy device type
125  */
126 struct fdtype {
127 	u_int driveid;		/* drive identification (from drive) */
128 	u_int ncylinders;	/* number of cylinders on drive */
129 	u_int amiga_nsectors;	/* number of sectors per amiga track */
130 	u_int msdos_nsectors;	/* number of sectors per msdos track */
131 	u_int nreadw;		/* number of words (short) read per track */
132 	u_int nwritew;		/* number of words (short) written per track */
133 	u_int gap;		/* track gap size in long words */
134 	u_int precomp[2];	/* 1st and 2nd precomp values */
135 	char *desc;		/* description of drive type (useq) */
136 };
137 
138 /*
139  * floppy disk device data
140  */
141 struct fd_softc {
142 	struct device sc_dv;	/* generic device info; must come first */
143 	struct disk dkdev;	/* generic disk info */
144 	struct buf_queue bufq;	/* queue pending I/O operations */
145 	struct buf curbuf;	/* state of current I/O operation */
146 	struct fdtype *type;
147 	void *cachep;		/* cached track data (write through) */
148 	int cachetrk;		/* cahced track -1 for none */
149 	int hwunit;		/* unit for amiga controlling hw */
150 	int unitmask;		/* mask for cia select deslect */
151 	int pstepdir;		/* previous step direction */
152 	int curcyl;		/* current curcyl head positioned on */
153 	int flags;		/* misc flags */
154 	int wlabel;
155 	int stepdelay;		/* useq to delay after seek user setable */
156 	int nsectors;		/* number of sectors per track */
157 	int openpart;		/* which partition [ab] == [12] is open */
158 	short retries;		/* number of times to retry failed io */
159 	short retried;		/* number of times current io retried */
160 	int bytespersec;	/* number of bytes per sector */
161 };
162 
163 /* fd_softc->flags */
164 #define FDF_MOTORON	(0x01)	/* motor is running */
165 #define FDF_MOTOROFF	(0x02)	/* motor is waiting to be turned off */
166 #define FDF_WMOTOROFF	(0x04)	/* unit wants a wakeup after off */
167 #define FDF_DIRTY	(0x08)	/* track cache needs write */
168 #define FDF_WRITEWAIT	(0x10)	/* need to head select delay on next setpos */
169 #define FDF_HAVELABEL	(0x20)	/* label is valid */
170 #define FDF_JUSTFLUSH	(0x40)	/* don't bother caching track. */
171 #define FDF_NOTRACK0	(0x80)	/* was not able to recalibrate drive */
172 
173 int fdc_wantwakeup;
174 int fdc_side;
175 void  *fdc_dmap;
176 struct fd_softc *fdc_indma;
177 int fdc_dmalen;
178 int fdc_dmawrite;
179 
180 struct fdcargs {
181 	struct fdtype *type;
182 	int unit;
183 };
184 
185 int	fdcmatch __P((struct device *, struct cfdata *, void *));
186 void	fdcattach __P((struct device *, struct device *, void *));
187 int	fdcprint __P((void *, const char *));
188 int	fdmatch __P((struct device *, struct cfdata *, void *));
189 void	fdattach __P((struct device *, struct device *, void *));
190 
191 void	fdintr __P((int));
192 void	fdidxintr __P((void));
193 void	fdstrategy __P((struct buf *));
194 int	fdloaddisk __P((struct fd_softc *));
195 void	fdgetdefaultlabel __P((struct fd_softc *, struct disklabel *, int));
196 int	fdgetdisklabel __P((struct fd_softc *, dev_t));
197 int	fdsetdisklabel __P((struct fd_softc *, struct disklabel *));
198 int	fdputdisklabel __P((struct fd_softc *, dev_t));
199 struct	fdtype * fdcgetfdtype __P((int));
200 void	fdmotoroff __P((void *));
201 void	fdsetpos __P((struct fd_softc *, int, int));
202 void	fdselunit __P((struct fd_softc *));
203 void	fdstart __P((struct fd_softc *));
204 void	fdcont __P((struct fd_softc *));
205 void	fddmastart __P((struct fd_softc *, int));
206 void	fdcalibrate __P((void *));
207 void	fddmadone __P((struct fd_softc *, int));
208 void	fddone __P((struct fd_softc *));
209 void	fdfindwork __P((int));
210 void	fdminphys __P((struct buf *));
211 void	fdcachetoraw __P((struct fd_softc *));
212 void	amcachetoraw __P((struct fd_softc *));
213 int	amrawtocache __P((struct fd_softc *));
214 u_long	*fdfindsync __P((u_long *, u_long *));
215 int	fdrawtocache __P((struct fd_softc *));
216 void	mscachetoraw __P((struct fd_softc *));
217 int	msrawtocache __P((struct fd_softc *));
218 u_long	*mfmblkencode __P((u_long *, u_long *, u_long *, int));
219 u_long	*mfmblkdecode __P((u_long *, u_long *, u_long *, int));
220 u_short	*msblkdecode __P((u_short *, u_char *, int));
221 u_short	*msblkencode __P((u_short *, u_char *, int, u_short *));
222 
223 struct dkdriver fddkdriver = { fdstrategy };
224 
225 /*
226  * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts
227  * write size is nsectors * mfm secsize + gap bytes + 3 shorts
228  * the extra shorts are to deal with a dma hw bug in the controller
229  * they are probably too much (I belive the bug is 1 short on write and
230  * 3 bits on read) but there is no need to be cheap here.
231  */
232 #define MAXTRKSZ (22 * FDSECSIZE)
233 struct fdtype fdtype[] = {
234 	{ 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" },
235 	{ 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" },
236 	{ 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" }
237 };
238 int nfdtype = sizeof(fdtype) / sizeof(*fdtype);
239 
240 struct cfattach fd_ca = {
241 	sizeof(struct fd_softc), fdmatch, fdattach
242 };
243 
244 extern struct cfdriver fd_cd;
245 
246 struct cfattach fdc_ca = {
247 	sizeof(struct device), fdcmatch, fdcattach
248 };
249 
250 /*
251  * all hw access through macros, this helps to hide the active low
252  * properties
253  */
254 
255 #define FDUNITMASK(unit)	(1 << (3 + (unit)))
256 
257 /*
258  * select units using mask
259  */
260 #define FDSELECT(um)	do { ciab.prb &= ~(um); } while (0)
261 
262 /*
263  * deselect units using mask
264  */
265 #define FDDESELECT(um)	do { ciab.prb |= (um); delay(1); } while (0)
266 
267 /*
268  * test hw condition bits
269  */
270 #define FDTESTC(bit)	((ciaa.pra & (1 << (bit))) == 0)
271 
272 /*
273  * set motor for select units, true motor on else off
274  */
275 #define FDSETMOTOR(on)	do { \
276 	if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
277 	} while (0)
278 
279 /*
280  * set head for select units
281  */
282 #define FDSETHEAD(head)	do { \
283 	if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
284 	delay(1); } while (0)
285 
286 /*
287  * select direction, true towards spindle else outwards
288  */
289 #define FDSETDIR(in)	do { \
290 	if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
291 	delay(1); } while (0)
292 
293 /*
294  * step the selected units
295  */
296 #define FDSTEP	do { \
297     ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
298     } while (0)
299 
300 #define FDDMASTART(len, towrite)	do { \
301     int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
302     custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
303 
304 #define FDDMASTOP	do { custom.dsklen = 0; } while (0)
305 
306 
307 int
308 fdcmatch(pdp, cfp, auxp)
309 	struct device *pdp;
310 	struct cfdata *cfp;
311 	void *auxp;
312 {
313 
314 	if (matchname("fdc", auxp) == 0 || cfp->cf_unit != 0)
315 		return(0);
316 	if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
317 		printf("fdc: unable to allocate dma buffer\n");
318 		return(0);
319 	}
320 	return(1);
321 }
322 
323 void
324 fdcattach(pdp, dp, auxp)
325 	struct device *pdp,  *dp;
326 	void *auxp;
327 {
328 	struct fdcargs args;
329 
330 	printf(": dmabuf pa 0x%x", kvtop(fdc_dmap));
331 	printf(": dmabuf ka %p\n", fdc_dmap);
332 	args.unit = 0;
333 	args.type = fdcgetfdtype(args.unit);
334 
335 	fdc_side = -1;
336 	config_found(dp, &args, fdcprint);
337 	for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
338 		if ((args.type = fdcgetfdtype(args.unit)) == NULL)
339 			continue;
340 		config_found(dp, &args, fdcprint);
341 	}
342 }
343 
344 int
345 fdcprint(auxp, pnp)
346 	void *auxp;
347 	const char *pnp;
348 {
349 	struct fdcargs *fcp;
350 
351 	fcp = auxp;
352 	if (pnp)
353 		printf("fd%d at %s unit %d:", fcp->unit, pnp,
354 			fcp->type->driveid);
355 	return(UNCONF);
356 }
357 
358 /*ARGSUSED*/
359 int
360 fdmatch(pdp, cfp, auxp)
361 	struct device *pdp;
362 	struct cfdata *cfp;
363 	void *auxp;
364 {
365 
366 #define cf_unit	cf_loc[FDCCF_UNIT]
367 	struct fdcargs *fdap;
368 
369 	fdap = auxp;
370 	if (cfp->cf_unit == fdap->unit || cfp->cf_unit == FDCCF_UNIT_DEFAULT)
371 		return(1);
372 	return(0);
373 #undef cf_unit
374 }
375 
376 void
377 fdattach(pdp, dp, auxp)
378 	struct device *pdp, *dp;
379 	void *auxp;
380 {
381 	struct fdcargs *ap;
382 	struct fd_softc *sc;
383 	int i;
384 
385 	ap = auxp;
386 	sc = (struct fd_softc *)dp;
387 
388 	BUFQ_INIT(&sc->bufq);
389 
390 	sc->curcyl = sc->cachetrk = -1;
391 	sc->openpart = -1;
392 	sc->type = ap->type;
393 	sc->hwunit = ap->unit;
394 	sc->unitmask = 1 << (3 + ap->unit);
395 	sc->retries = FDRETRIES;
396 	sc->stepdelay = FDSTEPDELAY;
397 	sc->bytespersec = 512;
398 	printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
399 	    sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
400 	    sc->type->amiga_nsectors, sc->type->msdos_nsectors);
401 
402 	/*
403 	 * Initialize and attach the disk structure.
404 	 */
405 	sc->dkdev.dk_name = sc->sc_dv.dv_xname;
406 	sc->dkdev.dk_driver = &fddkdriver;
407 	disk_attach(&sc->dkdev);
408 
409 	/*
410 	 * calibrate the drive
411 	 */
412 	fdsetpos(sc, 0, 0);
413 	fdsetpos(sc, sc->type->ncylinders, 0);
414 	fdsetpos(sc, 0, 0);
415 	fdmotoroff(sc);
416 
417 	/*
418 	 * precalc msdos MFM and CRC
419 	 */
420 	for (i = 0; i < 128; i++)
421 		msdecode[i] = 0xff;
422 	for (i = 0; i < 16; i++)
423 		msdecode[msencode[i]] = i;
424 	for (i = 0; i < 256; i++) {
425 		mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
426 		    (0x1021 * (i >> 4));
427 	}
428 
429 	/*
430 	 * enable disk related interrupts
431 	 */
432 	custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
433 	custom.intena = INTF_SETCLR | INTF_DSKBLK;
434 	ciab.icr = CIA_ICR_FLG;
435 }
436 
437 /*ARGSUSED*/
438 int
439 fdopen(dev, flags, devtype, p)
440 	dev_t dev;
441 	int flags, devtype;
442 	struct proc *p;
443 {
444 	struct fd_softc *sc;
445 	int wasopen, fwork, error, s;
446 
447 	error = 0;
448 
449 	if (FDPART(dev) >= FDMAXPARTS)
450 		return(ENXIO);
451 
452 	if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
453 		return(ENXIO);
454 	if (sc->flags & FDF_NOTRACK0)
455 		return(ENXIO);
456 	if (sc->cachep == NULL)
457 		sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
458 
459 	s = splbio();
460 	/*
461 	 * if we are sleeping in fdclose(); waiting for a chance to
462 	 * shut the motor off, do a sleep here also.
463 	 */
464 	while (sc->flags & FDF_WMOTOROFF)
465 		tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
466 
467 	fwork = 0;
468 	/*
469 	 * if not open let user open request type, otherwise
470 	 * ensure they are trying to open same type.
471 	 */
472 	if (sc->openpart == FDPART(dev))
473 		wasopen = 1;
474 	else if (sc->openpart == -1) {
475 		sc->openpart = FDPART(dev);
476 		wasopen = 0;
477 	} else {
478 		wasopen = 1;
479 		error = EPERM;
480 		goto done;
481 	}
482 
483 	/*
484 	 * wait for current io to complete if any
485 	 */
486 	if (fdc_indma) {
487 		fwork = 1;
488 		fdc_wantwakeup++;
489 		tsleep(fdopen, PRIBIO, "fdopen", 0);
490 	}
491 	if ((error = fdloaddisk(sc)) != 0)
492 		goto done;
493 	if ((error = fdgetdisklabel(sc, dev)) != 0)
494 		goto done;
495 #ifdef FDDEBUG
496 	printf("  open successful\n");
497 #endif
498 done:
499 	/*
500 	 * if we requested that fddone()->fdfindwork() wake us, allow it to
501 	 * complete its job now
502 	 */
503 	if (fwork)
504 		fdfindwork(FDUNIT(dev));
505 	splx(s);
506 
507 	/*
508 	 * if we were not open and we marked us so reverse that.
509 	 */
510 	if (error && wasopen == 0)
511 		sc->openpart = -1;
512 	return(error);
513 }
514 
515 /*ARGSUSED*/
516 int
517 fdclose(dev, flags, devtype, p)
518 	dev_t dev;
519 	int flags, devtype;
520 	struct proc *p;
521 {
522 	struct fd_softc *sc;
523 	int s;
524 
525 #ifdef FDDEBUG
526 	printf("fdclose()\n");
527 #endif
528 	sc = getsoftc(fd_cd, FDUNIT(dev));
529 	s = splbio();
530 	if (sc->flags & FDF_MOTORON) {
531 		sc->flags |= FDF_WMOTOROFF;
532 		tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
533 		sc->flags &= ~FDF_WMOTOROFF;
534 		wakeup(fdmotoroff);
535 	}
536 	sc->openpart = -1;
537 	splx(s);
538 	return(0);
539 }
540 
541 int
542 fdioctl(dev, cmd, addr, flag, p)
543 	dev_t dev;
544 	u_long cmd;
545 	caddr_t addr;
546 	int flag;
547 	struct proc *p;
548 {
549 	struct fd_softc *sc;
550 	int error, wlab;
551 
552 	sc = getsoftc(fd_cd, FDUNIT(dev));
553 
554 	if ((sc->flags & FDF_HAVELABEL) == 0)
555 		return(EBADF);
556 
557 	switch (cmd) {
558 	case DIOCSBAD:
559 		return(EINVAL);
560 	case DIOCSRETRIES:
561 		if (*(int *)addr < 0)
562 			return(EINVAL);
563 		sc->retries = *(int *)addr;
564 		return(0);
565 	case DIOCSSTEP:
566 		if (*(int *)addr < FDSTEPDELAY)
567 			return(EINVAL);
568 		sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
569 		return(0);
570 	case DIOCGDINFO:
571 		*(struct disklabel *)addr = *(sc->dkdev.dk_label);
572 		return(0);
573 	case DIOCGPART:
574 		((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
575 		((struct partinfo *)addr)->part =
576 		    &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
577 		return(0);
578 	case DIOCSDINFO:
579 		if ((flag & FWRITE) == 0)
580 			return(EBADF);
581 		return(fdsetdisklabel(sc, (struct disklabel *)addr));
582 	case DIOCWDINFO:
583 		if ((flag & FWRITE) == 0)
584 			return(EBADF);
585 		if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
586 			return(error);
587 		wlab = sc->wlabel;
588 		sc->wlabel = 1;
589 		error = fdputdisklabel(sc, dev);
590 		sc->wlabel = wlab;
591 		return(error);
592 	case DIOCWLABEL:
593 		if ((flag & FWRITE) == 0)
594 			return(EBADF);
595 		sc->wlabel = *(int *)addr;
596 		return(0);
597 	case DIOCGDEFLABEL:
598 		fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
599 		return(0);
600 	default:
601 		return(ENOTTY);
602 	}
603 }
604 
605 /*
606  * no dumps to floppy disks thank you.
607  */
608 int
609 fdsize(dev)
610 	dev_t dev;
611 {
612 	return(-1);
613 }
614 
615 int
616 fdread(dev, uio, flags)
617 	dev_t	dev;
618 	struct	uio *uio;
619 	int	flags;
620 {
621 	return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
622 }
623 
624 int
625 fdwrite(dev, uio, flags)
626 	dev_t	dev;
627 	struct	uio *uio;
628 	int	flags;
629 {
630 	return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
631 }
632 
633 
634 void
635 fdintr(flag)
636 	int	flag;
637 {
638 	int s;
639 
640 	s = splbio();
641 	if (fdc_indma)
642 		fddmadone(fdc_indma, 0);
643 	splx(s);
644 }
645 
646 void
647 fdidxintr()
648 {
649 	if (fdc_indma && fdc_dmalen) {
650 		/*
651 		 * turn off intr and start actual dma
652 		 */
653 		ciab.icr = CIA_ICR_FLG;
654 		FDDMASTART(fdc_dmalen, fdc_dmawrite);
655 		fdc_dmalen = 0;
656 	}
657 }
658 
659 void
660 fdstrategy(bp)
661 	struct buf *bp;
662 {
663 	struct disklabel *lp;
664 	struct fd_softc *sc;
665 	int unit, part, s;
666 
667 	unit = FDUNIT(bp->b_dev);
668 	part = FDPART(bp->b_dev);
669 	sc = getsoftc(fd_cd, unit);
670 
671 #ifdef FDDEBUG
672 	printf("fdstrategy: 0x%x\n", bp);
673 #endif
674 	/*
675 	 * check for valid partition and bounds
676 	 */
677 	lp = sc->dkdev.dk_label;
678 	if ((sc->flags & FDF_HAVELABEL) == 0) {
679 		bp->b_error = EIO;
680 		goto bad;
681 	}
682 	if (bounds_check_with_label(bp, lp, sc->wlabel) <= 0)
683 		goto done;
684 
685 	/*
686 	 * trans count of zero or bounds check indicates io is done
687 	 * we are done.
688 	 */
689 	if (bp->b_bcount == 0)
690 		goto done;
691 
692 	bp->b_rawblkno = bp->b_blkno;
693 
694 	/*
695 	 * queue the buf and kick the low level code
696 	 */
697 	s = splbio();
698 	disksort_cylinder(&sc->bufq, bp);
699 	fdstart(sc);
700 	splx(s);
701 	return;
702 bad:
703 	bp->b_flags |= B_ERROR;
704 done:
705 	bp->b_resid = bp->b_bcount;
706 	biodone(bp);
707 }
708 
709 /*
710  * make sure disk is loaded and label is up-to-date.
711  */
712 int
713 fdloaddisk(sc)
714 	struct fd_softc *sc;
715 {
716 	/*
717 	 * if diskchange is low step drive to 0 then up one then to zero.
718 	 */
719 	fdselunit(sc);			/* make sure the unit is selected */
720 	if (FDTESTC(FDB_CHANGED)) {
721 		fdsetpos(sc, 0, 0);
722 		sc->cachetrk = -1;		/* invalidate the cache */
723 		sc->flags &= ~FDF_HAVELABEL;
724 		fdsetpos(sc, FDNHEADS, 0);
725 		fdsetpos(sc, 0, 0);
726 		if (FDTESTC(FDB_CHANGED)) {
727 			fdmotoroff(sc);
728 			FDDESELECT(sc->unitmask);
729 			return(ENXIO);
730 		}
731 	}
732 	FDDESELECT(sc->unitmask);
733 	fdmotoroff(sc);
734 	sc->type = fdcgetfdtype(sc->hwunit);
735 	if (sc->type == NULL)
736 		return(ENXIO);
737 	if (sc->openpart == FDMSDOSPART)
738 		sc->nsectors = sc->type->msdos_nsectors;
739 	else
740 		sc->nsectors = sc->type->amiga_nsectors;
741 	return(0);
742 }
743 
744 void
745 fdgetdefaultlabel(sc, lp, part)
746 	struct fd_softc *sc;
747 	struct disklabel *lp;
748 	int part;		/* XXX ick */
749 {
750 
751 	bzero(lp, sizeof(struct disklabel));
752 	lp->d_secsize = FDSECSIZE;
753 	lp->d_ntracks = FDNHEADS;
754 	lp->d_ncylinders = sc->type->ncylinders;
755 	lp->d_nsectors = sc->nsectors;
756 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
757 	lp->d_type = DTYPE_FLOPPY;
758 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
759 	lp->d_rpm = 300; 		/* good guess I suppose. */
760 	lp->d_interleave = 1;		/* should change when adding msdos */
761 	sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
762 	lp->d_bbsize = 0;
763 	lp->d_sbsize = 0;
764 	lp->d_partitions[part].p_size = lp->d_secperunit;
765 	lp->d_partitions[part].p_fstype = FS_UNUSED;
766 	lp->d_partitions[part].p_fsize = 1024;
767 	lp->d_partitions[part].p_frag = 8;
768 	lp->d_partitions[part].p_cpg = 2;	/* adosfs: reserved blocks */
769 	lp->d_npartitions = part + 1;
770 	lp->d_magic = lp->d_magic2 = DISKMAGIC;
771 	lp->d_checksum = dkcksum(lp);
772 }
773 
774 /*
775  * read disk label, if present otherwise create one
776  * return a new label if raw part and none found, otherwise err.
777  */
778 int
779 fdgetdisklabel(sc, dev)
780 	struct fd_softc *sc;
781 	dev_t dev;
782 {
783 	struct disklabel *lp, *dlp;
784 	struct cpu_disklabel *clp;
785 	struct buf *bp;
786 	int error, part;
787 
788 	if (sc->flags & FDF_HAVELABEL &&
789 	    sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
790 		return(0);
791 #ifdef FDDEBUG
792 	printf("fdgetdisklabel()\n");
793 #endif
794 	part = FDPART(dev);
795 	lp = sc->dkdev.dk_label;
796 	clp =  sc->dkdev.dk_cpulabel;
797 	bzero(lp, sizeof(struct disklabel));
798 	bzero(clp, sizeof(struct cpu_disklabel));
799 
800 	lp->d_secsize = FDSECSIZE;
801 	lp->d_ntracks = FDNHEADS;
802 	lp->d_ncylinders = sc->type->ncylinders;
803 	lp->d_nsectors = sc->nsectors;
804 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
805 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
806 	lp->d_npartitions = part + 1;
807 	lp->d_partitions[part].p_size = lp->d_secperunit;
808 	lp->d_partitions[part].p_fstype = FS_UNUSED;
809 	lp->d_partitions[part].p_fsize = 1024;
810 	lp->d_partitions[part].p_frag = 8;
811 	lp->d_partitions[part].p_cpg = 2;	/* for adosfs: reserved blks */
812 
813 	sc->flags |= FDF_HAVELABEL;
814 
815 	bp = (void *)geteblk((int)lp->d_secsize);
816 	bp->b_dev = dev;
817 	bp->b_blkno = 0;
818 	bp->b_cylinder = 0;
819 	bp->b_bcount = FDSECSIZE;
820 	bp->b_flags = B_BUSY | B_READ;
821 	fdstrategy(bp);
822 	if ((error = biowait(bp)) != 0)
823 		goto nolabel;
824 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
825 	if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
826 	    dkcksum(dlp)) {
827 		error = EINVAL;
828 		goto nolabel;
829 	}
830 	bcopy(dlp, lp, sizeof(struct disklabel));
831 	if (lp->d_trkseek > FDSTEPDELAY)
832 		sc->stepdelay = lp->d_trkseek;
833 	brelse(bp);
834 	return(0);
835 nolabel:
836 	fdgetdefaultlabel(sc, lp, part);
837 	brelse(bp);
838 	return(0);
839 }
840 
841 /*
842  * set the incore copy of this units disklabel
843  */
844 int
845 fdsetdisklabel(sc, lp)
846 	struct fd_softc *sc;
847 	struct disklabel *lp;
848 {
849 	struct disklabel *clp;
850 	struct partition *pp;
851 
852 	/*
853 	 * must have at least opened raw unit to fetch the
854 	 * raw_part stuff.
855 	 */
856 	if ((sc->flags & FDF_HAVELABEL) == 0)
857 		return(EINVAL);
858 	clp = sc->dkdev.dk_label;
859 	/*
860 	 * make sure things check out and we only have one valid
861 	 * partition
862 	 */
863 #ifdef FDDEBUG
864 	printf("fdsetdisklabel\n");
865 #endif
866 	if (lp->d_secsize != FDSECSIZE ||
867 	    lp->d_nsectors != clp->d_nsectors ||
868 	    lp->d_ntracks != FDNHEADS ||
869 	    lp->d_ncylinders != clp->d_ncylinders ||
870 	    lp->d_secpercyl != clp->d_secpercyl ||
871 	    lp->d_secperunit != clp->d_secperunit ||
872 	    lp->d_magic != DISKMAGIC ||
873 	    lp->d_magic2 != DISKMAGIC ||
874 	    lp->d_npartitions == 0 ||
875 	    lp->d_npartitions > FDMAXPARTS ||
876 	    (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
877 	    dkcksum(lp))
878 		return(EINVAL);
879 	/*
880 	 * if any partitions are present make sure they
881 	 * represent the currently open type
882 	 */
883 	if ((pp = &lp->d_partitions[0])->p_size) {
884 		if ((pp = &lp->d_partitions[1])->p_size == 0)
885 			goto done;
886 		else if (sc->openpart != 1)
887 			return(EINVAL);
888 	} else if (sc->openpart != 0)
889 		return(EINVAL);
890 	/*
891 	 * make sure selected partition is within bounds
892 	 * XXX on the second check, its to handle a bug in
893 	 * XXX the cluster routines as they require mutliples
894 	 * XXX of NBPG currently
895 	 */
896 	if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
897 	    (pp->p_frag * pp->p_fsize % NBPG))
898 		return(EINVAL);
899 done:
900 	bcopy(lp, clp, sizeof(struct disklabel));
901 	return(0);
902 }
903 
904 /*
905  * write out the incore copy of this units disklabel
906  */
907 int
908 fdputdisklabel(sc, dev)
909 	struct fd_softc *sc;
910 	dev_t dev;
911 {
912 	struct disklabel *lp, *dlp;
913 	struct buf *bp;
914 	int error;
915 
916 	if ((sc->flags & FDF_HAVELABEL) == 0)
917 		return(EBADF);
918 #ifdef FDDEBUG
919 	printf("fdputdisklabel\n");
920 #endif
921 	/*
922 	 * get buf and read in sector 0
923 	 */
924 	lp = sc->dkdev.dk_label;
925 	bp = (void *)geteblk((int)lp->d_secsize);
926 	bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
927 	bp->b_blkno = 0;
928 	bp->b_cylinder = 0;
929 	bp->b_bcount = FDSECSIZE;
930 	bp->b_flags = B_BUSY | B_READ;
931 	fdstrategy(bp);
932 	if ((error = biowait(bp)) != 0)
933 		goto done;
934 	/*
935 	 * copy disklabel to buf and write it out syncronous
936 	 */
937 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
938 	bcopy(lp, dlp, sizeof(struct disklabel));
939 	bp->b_blkno = 0;
940 	bp->b_cylinder = 0;
941 	bp->b_flags = B_WRITE;
942 	fdstrategy(bp);
943 	error = biowait(bp);
944 done:
945 	brelse(bp);
946 	return(error);
947 }
948 
949 /*
950  * figure out drive type or NULL if none.
951  */
952 struct fdtype *
953 fdcgetfdtype(unit)
954 	int unit;
955 {
956 	struct fdtype *ftp;
957 	u_long id, idb;
958 	int cnt, umask;
959 
960 	id = 0;
961 	umask = 1 << (3 + unit);
962 
963 	FDDESELECT(FDCUNITMASK);
964 
965 	FDSETMOTOR(1);
966 	delay(1);
967 	FDSELECT(umask);
968 	delay(1);
969 	FDDESELECT(umask);
970 
971 	FDSETMOTOR(0);
972 	delay(1);
973 	FDSELECT(umask);
974 	delay(1);
975 	FDDESELECT(umask);
976 
977 	for (idb = 0x80000000; idb; idb >>= 1) {
978 		FDSELECT(umask);
979 		delay(1);
980 		if (FDTESTC(FDB_READY) == 0)
981 			id |= idb;
982 		FDDESELECT(umask);
983 		delay(1);
984 	}
985 #ifdef FDDEBUG
986 	printf("fdcgettype unit %d id 0x%lx\n", unit, id);
987 #endif
988 
989 	for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
990 		if (ftp->driveid == id)
991 			return(ftp);
992 	/*
993 	 * 3.5dd's at unit 0 do not always return id.
994 	 */
995 	if (unit == 0)
996 		return(fdtype);
997 	return(NULL);
998 }
999 
1000 /*
1001  * turn motor off if possible otherwise mark as needed and will be done
1002  * later.
1003  */
1004 void
1005 fdmotoroff(arg)
1006 	void *arg;
1007 {
1008 	struct fd_softc *sc;
1009 	int s;
1010 
1011 	sc = arg;
1012 	s = splbio();
1013 
1014 #ifdef FDDEBUG
1015 	printf("fdmotoroff: unit %d\n", sc->hwunit);
1016 #endif
1017 	if ((sc->flags & FDF_MOTORON) == 0)
1018 		goto done;
1019 	/*
1020 	 * if we have a timeout on a dma operation let fddmadone()
1021 	 * deal with it.
1022 	 */
1023 	if (fdc_indma == sc) {
1024 		fddmadone(sc, 1);
1025 		goto done;
1026 	}
1027 #ifdef FDDEBUG
1028 	printf(" motor was on, turning off\n");
1029 #endif
1030 
1031 	/*
1032 	 * flush cache if needed
1033 	 */
1034 	if (sc->flags & FDF_DIRTY) {
1035 		sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1036 #ifdef FDDEBUG
1037 		printf("  flushing dirty buffer first\n");
1038 #endif
1039 		/*
1040 		 * if dma'ing done for now, fddone() will call us again
1041 		 */
1042 		if (fdc_indma)
1043 			goto done;
1044 		fddmastart(sc, sc->cachetrk);
1045 		goto done;
1046 	}
1047 
1048 	/*
1049 	 * if controller is busy just schedule us to be called back
1050 	 */
1051 	if (fdc_indma) {
1052 		/*
1053 		 * someone else has the controller now
1054 		 * just set flag and let fddone() call us again.
1055 		 */
1056 		sc->flags |= FDF_MOTOROFF;
1057 		goto done;
1058 	}
1059 
1060 #ifdef FDDEBUG
1061 	printf("  hw turning unit off\n");
1062 #endif
1063 
1064 	sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1065 	FDDESELECT(FDCUNITMASK);
1066 	FDSETMOTOR(0);
1067 	delay(1);
1068 	FDSELECT(sc->unitmask);
1069 	delay(4);
1070 	FDDESELECT(sc->unitmask);
1071 	delay(1);
1072 	if (sc->flags & FDF_WMOTOROFF)
1073 		wakeup(fdmotoroff);
1074 done:
1075 	splx(s);
1076 }
1077 
1078 /*
1079  * select drive seek to track exit with motor on.
1080  * fdsetpos(x, 0, 0) does calibrates the drive.
1081  */
1082 void
1083 fdsetpos(sc, trk, towrite)
1084 	struct fd_softc *sc;
1085 	int trk, towrite;
1086 {
1087 	int nstep, sdir, ondly, ncyl, nside;
1088 
1089 	FDDESELECT(FDCUNITMASK);
1090 	FDSETMOTOR(1);
1091 	delay(1);
1092 	FDSELECT(sc->unitmask);
1093 	delay(1);
1094 	if ((sc->flags & FDF_MOTORON) == 0) {
1095 		ondly = 0;
1096 		while (FDTESTC(FDB_READY) == 0) {
1097 			delay(1000);
1098 			if (++ondly >= 1000)
1099 				break;
1100 		}
1101 	}
1102 	sc->flags |= FDF_MOTORON;
1103 
1104 	ncyl = trk / FDNHEADS;
1105 	nside = trk % FDNHEADS;
1106 
1107 	if (sc->curcyl == ncyl && fdc_side == nside)
1108 		return;
1109 
1110 	if (towrite)
1111 		sc->flags |= FDF_WRITEWAIT;
1112 
1113 #ifdef FDDEBUG
1114 	printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1115 	    trk % FDNHEADS, towrite);
1116 #endif
1117 	nstep = ncyl - sc->curcyl;
1118 	if (nstep) {
1119 		/*
1120 		 * figure direction
1121 		 */
1122 		if (nstep > 0 && ncyl != 0) {
1123 			sdir = FDSTEPIN;
1124 			FDSETDIR(1);
1125 		} else {
1126 			nstep = -nstep;
1127 			sdir = FDSTEPOUT;
1128 			FDSETDIR(0);
1129 		}
1130 		if (ncyl == 0) {
1131 			/*
1132 			 * either just want cylinder 0 or doing
1133 			 * a calibrate.
1134 			 */
1135 			nstep = 256;
1136 			while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1137 				FDSTEP;
1138 				delay(sc->stepdelay);
1139 			}
1140 			if (nstep < 0)
1141 				sc->flags |= FDF_NOTRACK0;
1142 		} else {
1143 			/*
1144 			 * step the needed amount amount.
1145 			 */
1146 			while (nstep--) {
1147 				FDSTEP;
1148 				delay(sc->stepdelay);
1149 			}
1150 		}
1151 		/*
1152 		 * if switched directions
1153 		 * allow drive to settle.
1154 		 */
1155 		if (sc->pstepdir != sdir)
1156 			delay(FDSETTLEDELAY);
1157 		sc->pstepdir = sdir;
1158 		sc->curcyl = ncyl;
1159 	}
1160 	if (nside == fdc_side)
1161 		return;
1162 	/*
1163 	 * select side
1164 	 */
1165 	fdc_side = nside;
1166 	FDSETHEAD(nside);
1167 	delay(FDPRESIDEDELAY);
1168 }
1169 
1170 void
1171 fdselunit(sc)
1172 	struct fd_softc *sc;
1173 {
1174 	FDDESELECT(FDCUNITMASK);		/* deselect all */
1175 	FDSETMOTOR(sc->flags & FDF_MOTORON);	/* set motor to unit's state */
1176 	delay(1);
1177 	FDSELECT(sc->unitmask);			/* select unit */
1178 	delay(1);
1179 }
1180 
1181 /*
1182  * process next buf on device queue.
1183  * normall sequence of events:
1184  * fdstart() -> fddmastart();
1185  * fdidxintr();
1186  * fdintr() -> fddmadone() -> fddone();
1187  * if the track is in the cache then fdstart() will short-circuit
1188  * to fddone() else if the track cache is dirty it will flush.  If
1189  * the buf is not an entire track it will cache the requested track.
1190  */
1191 void
1192 fdstart(sc)
1193 	struct fd_softc *sc;
1194 {
1195 	int trk, error, write;
1196 	struct buf *bp, *dp;
1197 	int changed;
1198 
1199 #ifdef FDDEBUG
1200 	printf("fdstart: unit %d\n", sc->hwunit);
1201 #endif
1202 
1203 	/*
1204 	 * if dma'ing just return. we must have been called from fdstartegy.
1205 	 */
1206 	if (fdc_indma)
1207 		return;
1208 
1209 	/*
1210 	 * get next buf if there.
1211 	 */
1212 	dp = &sc->curbuf;
1213 	if ((bp = BUFQ_FIRST(&sc->bufq)) == NULL) {
1214 #ifdef FDDEBUG
1215 		printf("  nothing to do\n");
1216 #endif
1217 		return;
1218 	}
1219 
1220 	/*
1221 	 * Mark us as busy now, in case fddone() gets called in one
1222 	 * of the cases below.
1223 	 */
1224 	disk_busy(&sc->dkdev);
1225 
1226 	/*
1227 	 * make sure same disk is loaded
1228 	 */
1229 	fdselunit(sc);
1230 	changed = FDTESTC(FDB_CHANGED);
1231 	FDDESELECT(sc->unitmask);
1232 	if (changed) {
1233 		/*
1234 		 * disk missing, invalidate all future io on
1235 		 * this unit until re-open()'ed also invalidate
1236 		 * all current io
1237 		 */
1238 printf("fdstart: disk changed\n");
1239 #ifdef FDDEBUG
1240 		printf("  disk was removed invalidating all io\n");
1241 #endif
1242 		sc->flags &= ~FDF_HAVELABEL;
1243 		for (;;) {
1244 			bp->b_flags |= B_ERROR;
1245 			bp->b_error = EIO;
1246 			if (BUFQ_NEXT(bp) == NULL)
1247 				break;
1248 			biodone(bp);
1249 			bp = BUFQ_NEXT(bp);
1250 		}
1251 		/*
1252 		 * do fddone() on last buf to allow other units to start.
1253 		 */
1254 		BUFQ_INSERT_HEAD(&sc->bufq, bp);
1255 		fddone(sc);
1256 		return;
1257 	}
1258 
1259 	/*
1260 	 * we have a valid buf, setup our local version
1261 	 * we use this count to allow reading over multiple tracks.
1262 	 * into a single buffer
1263 	 */
1264 	dp->b_bcount = bp->b_bcount;
1265 	dp->b_blkno = bp->b_blkno;
1266 	dp->b_data = bp->b_data;
1267 	dp->b_flags = bp->b_flags;
1268 	dp->b_resid = 0;
1269 
1270 	if (bp->b_flags & B_READ)
1271 		write = 0;
1272 	else if (FDTESTC(FDB_PROTECT) == 0)
1273 		write = 1;
1274 	else {
1275 		error = EPERM;
1276 		goto bad;
1277 	}
1278 
1279 	/*
1280 	 * figure trk given blkno
1281 	 */
1282 	trk = bp->b_blkno / sc->nsectors;
1283 
1284 	/*
1285 	 * check to see if same as currently cached track
1286 	 * if so we need to do no dma read.
1287 	 */
1288 	if (trk == sc->cachetrk) {
1289 		fddone(sc);
1290 		return;
1291 	}
1292 
1293 	/*
1294 	 * if we will be overwriting the entire cache, don't bother to
1295 	 * fetch it.
1296 	 */
1297 	if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1298 	    bp->b_blkno % sc->nsectors == 0) {
1299 		if (sc->flags & FDF_DIRTY)
1300 			sc->flags |= FDF_JUSTFLUSH;
1301 		else {
1302 			sc->cachetrk = trk;
1303 			fddone(sc);
1304 			return;
1305 		}
1306 	}
1307 
1308 	/*
1309 	 * start dma read of `trk'
1310 	 */
1311 	fddmastart(sc, trk);
1312 	return;
1313 bad:
1314 	bp->b_flags |= B_ERROR;
1315 	bp->b_error = error;
1316 	fddone(sc);
1317 }
1318 
1319 /*
1320  * continue a started operation on next track. always begin at
1321  * sector 0 on the next track.
1322  */
1323 void
1324 fdcont(sc)
1325 	struct fd_softc *sc;
1326 {
1327 	struct buf *dp, *bp;
1328 	int trk, write;
1329 
1330 	dp = &sc->curbuf;
1331 	bp = BUFQ_FIRST(&sc->bufq);
1332 	dp->b_data += (dp->b_bcount - bp->b_resid);
1333 	dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1334 	dp->b_bcount = bp->b_resid;
1335 
1336 	/*
1337 	 * figure trk given blkno
1338 	 */
1339 	trk = dp->b_blkno / sc->nsectors;
1340 #ifdef DEBUG
1341 	if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1342 		panic("fdcont: confused");
1343 #endif
1344 	if (dp->b_flags & B_READ)
1345 		write = 0;
1346 	else
1347 		write = 1;
1348 	/*
1349 	 * if we will be overwriting the entire cache, don't bother to
1350 	 * fetch it.
1351 	 */
1352 	if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1353 		if (sc->flags & FDF_DIRTY)
1354 			sc->flags |= FDF_JUSTFLUSH;
1355 		else {
1356 			sc->cachetrk = trk;
1357 			fddone(sc);
1358 			return;
1359 		}
1360 	}
1361 	/*
1362 	 * start dma read of `trk'
1363 	 */
1364 	fddmastart(sc, trk);
1365 	return;
1366 }
1367 
1368 void
1369 fddmastart(sc, trk)
1370 	struct fd_softc *sc;
1371 	int trk;
1372 {
1373 	int adkmask, ndmaw, write, dmatrk;
1374 
1375 #ifdef FDDEBUG
1376 	printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1377 	    trk / FDNHEADS, trk % FDNHEADS);
1378 #endif
1379 	/*
1380 	 * flush the cached track if dirty else read requested track.
1381 	 */
1382 	if (sc->flags & FDF_DIRTY) {
1383 		fdcachetoraw(sc);
1384 		ndmaw = sc->type->nwritew;
1385 		dmatrk = sc->cachetrk;
1386 		write = 1;
1387 	} else {
1388 		ndmaw = sc->type->nreadw;
1389 		dmatrk = trk;
1390 		write = 0;
1391 	}
1392 
1393 #ifdef FDDEBUG
1394 	printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1395 #endif
1396 	sc->cachetrk = trk;
1397 	fdc_indma = sc;
1398 	fdsetpos(sc, dmatrk, write);
1399 
1400 	/*
1401 	 * setup dma stuff
1402 	 */
1403 	if (write == 0) {
1404 		custom.adkcon = ADKF_MSBSYNC;
1405 		custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1406 		custom.dsksync = FDMFMSYNC;
1407 	} else {
1408 		custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1409 		    ADKF_MSBSYNC;
1410 		adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1411 		if (dmatrk >= sc->type->precomp[0])
1412 			adkmask |= ADKF_PRECOMP0;
1413 		if (dmatrk >= sc->type->precomp[1])
1414 			adkmask |= ADKF_PRECOMP1;
1415 		custom.adkcon = adkmask;
1416 	}
1417 	custom.dskpt = (u_char *)kvtop(fdc_dmap);
1418 
1419 	/*
1420 	 * If writing an MSDOS track, activate disk index pulse
1421 	 * interrupt, dma will be started in the intr routine fdidxintr()
1422 	 * Otherwise, start the DMA here.
1423 	 */
1424 	if (write && sc->openpart == FDMSDOSPART) {
1425 		fdc_dmalen = ndmaw;
1426 		fdc_dmawrite = write;
1427 		ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1428 	} else {
1429 		FDDMASTART(ndmaw, write);
1430 		fdc_dmalen = 0;
1431 	}
1432 
1433 #ifdef FDDEBUG
1434 	printf("  dma started\n");
1435 #endif
1436 }
1437 
1438 /*
1439  * recalibrate the drive
1440  */
1441 void
1442 fdcalibrate(arg)
1443 	void *arg;
1444 {
1445 	struct fd_softc *sc;
1446 	static int loopcnt;
1447 
1448 	sc = arg;
1449 
1450 	if (loopcnt == 0) {
1451 		/*
1452 		 * seek cyl 0
1453 		 */
1454 		fdc_indma = sc;
1455 		sc->stepdelay += 900;
1456 		if (sc->cachetrk > 1)
1457 			fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1458 		sc->stepdelay -= 900;
1459 	}
1460 	if (loopcnt++ & 1)
1461 		fdsetpos(sc, sc->cachetrk, 0);
1462 	else
1463 		fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1464 	/*
1465 	 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and dma
1466 	 */
1467 	if (loopcnt < 8)
1468 		timeout(fdcalibrate, sc, hz / 8);
1469 	else {
1470 		loopcnt = 0;
1471 		fdc_indma = NULL;
1472 		timeout(fdmotoroff, sc, 3 * hz / 2);
1473 		fddmastart(sc, sc->cachetrk);
1474 	}
1475 }
1476 
1477 void
1478 fddmadone(sc, timeo)
1479 	struct fd_softc *sc;
1480 	int timeo;
1481 {
1482 #ifdef FDDEBUG
1483 	printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1484 #endif
1485 	fdc_indma = NULL;
1486 	untimeout(fdmotoroff, sc);
1487 	FDDMASTOP;
1488 
1489 	/*
1490 	 * guarantee the drive has been at current head and cyl
1491 	 * for at least FDWRITEDELAY after a write.
1492 	 */
1493 	if (sc->flags & FDF_WRITEWAIT) {
1494 		delay(FDWRITEDELAY);
1495 		sc->flags &= ~FDF_WRITEWAIT;
1496 	}
1497 
1498 	if ((sc->flags & FDF_MOTOROFF) == 0) {
1499 		/*
1500 		 * motor runs for 1.5 seconds after last dma
1501 		 */
1502 		timeout(fdmotoroff, sc, 3 * hz / 2);
1503 	}
1504 	if (sc->flags & FDF_DIRTY) {
1505 		/*
1506 		 * if buffer dirty, the last dma cleaned it
1507 		 */
1508 		sc->flags &= ~FDF_DIRTY;
1509 		if (timeo)
1510 			printf("%s: write of track cache timed out.\n",
1511 			    sc->sc_dv.dv_xname);
1512 		if (sc->flags & FDF_JUSTFLUSH) {
1513 			sc->flags &= ~FDF_JUSTFLUSH;
1514 			/*
1515 			 * we are done dma'ing
1516 			 */
1517 			fddone(sc);
1518 			return;
1519 		}
1520 		/*
1521 		 * load the cache
1522 		 */
1523 		fddmastart(sc, sc->cachetrk);
1524 		return;
1525 	}
1526 #ifdef FDDEBUG
1527 	else if (sc->flags & FDF_MOTOROFF)
1528 		panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1529 #endif
1530 
1531 	/*
1532 	 * cache loaded decode it into cache buffer
1533 	 */
1534 	if (timeo == 0 && fdrawtocache(sc) == 0)
1535 		sc->retried = 0;
1536 	else {
1537 #ifdef FDDEBUG
1538 		if (timeo)
1539 			printf("%s: fddmadone: cache load timed out.\n",
1540 			    sc->sc_dv.dv_xname);
1541 #endif
1542 		if (sc->retried >= sc->retries) {
1543 			sc->retried = 0;
1544 			sc->cachetrk = -1;
1545 		} else {
1546 			sc->retried++;
1547 			/*
1548 			 * this will be restarted at end of calibrate loop.
1549 			 */
1550 			untimeout(fdmotoroff, sc);
1551 			fdcalibrate(sc);
1552 			return;
1553 		}
1554 	}
1555 	fddone(sc);
1556 }
1557 
1558 void
1559 fddone(sc)
1560 	struct fd_softc *sc;
1561 {
1562 	struct buf *dp, *bp;
1563 	char *data;
1564 	int sz;
1565 
1566 #ifdef FDDEBUG
1567 	printf("fddone: unit %d\n", sc->hwunit);
1568 #endif
1569 	/*
1570 	 * check to see if unit is just flushing the cache,
1571 	 * that is we have no io queued.
1572 	 */
1573 	if (sc->flags & FDF_MOTOROFF)
1574 		goto nobuf;
1575 
1576 	dp = &sc->curbuf;
1577 	if ((bp = BUFQ_FIRST(&sc->bufq)) == NULL)
1578 		panic ("fddone");
1579 	/*
1580 	 * check for an error that may have occured
1581 	 * while getting the track.
1582 	 */
1583 	if (sc->cachetrk == -1) {
1584 		sc->retried = 0;
1585 		bp->b_flags |= B_ERROR;
1586 		bp->b_error = EIO;
1587 	} else if ((bp->b_flags & B_ERROR) == 0) {
1588 		data = sc->cachep;
1589 		/*
1590 		 * get offset of data in track cache and limit
1591 		 * the copy size to not exceed the cache's end.
1592 		 */
1593 		data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1594 		sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1595 		sz *= FDSECSIZE;
1596 		sz = min(dp->b_bcount, sz);
1597 		if (bp->b_flags & B_READ)
1598 			bcopy(data, dp->b_data, sz);
1599 		else {
1600 			bcopy(dp->b_data, data, sz);
1601 			sc->flags |= FDF_DIRTY;
1602 		}
1603 		bp->b_resid = dp->b_bcount - sz;
1604 		if (bp->b_resid == 0) {
1605 			bp->b_error = 0;
1606 		} else {
1607 			/*
1608 			 * not done yet need to read next track
1609 			 */
1610 			fdcont(sc);
1611 			return;
1612 		}
1613 	}
1614 	/*
1615 	 * remove from queue.
1616 	 */
1617 	BUFQ_REMOVE(&sc->bufq, bp);
1618 
1619 	disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid));
1620 
1621 	biodone(bp);
1622 nobuf:
1623 	fdfindwork(sc->sc_dv.dv_unit);
1624 }
1625 
1626 void
1627 fdfindwork(unit)
1628 	int unit;
1629 {
1630 	struct fd_softc *ssc, *sc;
1631 	int i, last;
1632 
1633 	/*
1634 	 * first see if we have any fdopen()'s waiting
1635 	 */
1636 	if (fdc_wantwakeup) {
1637 		wakeup(fdopen);
1638 		fdc_wantwakeup--;
1639 		return;
1640 	}
1641 
1642 	/*
1643 	 * start next available unit, linear search from the next unit
1644 	 * wrapping and finally this unit.
1645 	 */
1646 	last = 0;
1647 	ssc = NULL;
1648 	for (i = unit + 1; last == 0; i++) {
1649 		if (i == unit)
1650 			last = 1;
1651 		if (i >= fd_cd.cd_ndevs) {
1652 			i = -1;
1653 			continue;
1654 		}
1655 		if ((sc = fd_cd.cd_devs[i]) == NULL)
1656 			continue;
1657 
1658 		/*
1659 		 * if unit has requested to be turned off
1660 		 * and it has no buf's queued do it now
1661 		 */
1662 		if (sc->flags & FDF_MOTOROFF) {
1663 			if (BUFQ_FIRST(&sc->bufq) == NULL)
1664 				fdmotoroff(sc);
1665 			else {
1666 				/*
1667 				 * we gained a buf request while
1668 				 * we waited, forget the motoroff
1669 				 */
1670 				sc->flags &= ~FDF_MOTOROFF;
1671 			}
1672 			/*
1673 			 * if we now have dma unit must have needed
1674 			 * flushing, quit
1675 			 */
1676 			if (fdc_indma)
1677 				return;
1678 		}
1679 		/*
1680 		 * if we have no start unit and the current unit has
1681 		 * io waiting choose this unit to start.
1682 		 */
1683 		if (ssc == NULL && BUFQ_FIRST(&sc->bufq) != NULL)
1684 			ssc = sc;
1685 	}
1686 	if (ssc)
1687 		fdstart(ssc);
1688 }
1689 
1690 /*
1691  * min byte count to whats left of the track in question
1692  */
1693 void
1694 fdminphys(bp)
1695 	struct buf *bp;
1696 {
1697 	struct fd_softc *sc;
1698 	int trk, sec, toff, tsz;
1699 
1700 	if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1701 		panic("fdminphys: couldn't get softc");
1702 
1703 	trk = bp->b_blkno / sc->nsectors;
1704 	sec = bp->b_blkno % sc->nsectors;
1705 
1706 	toff = sec * FDSECSIZE;
1707 	tsz = sc->nsectors * FDSECSIZE;
1708 #ifdef FDDEBUG
1709 	printf("fdminphys: before %d", bp->b_bcount);
1710 #endif
1711 	bp->b_bcount = min(bp->b_bcount, tsz - toff);
1712 #ifdef FDDEBUG
1713 	printf(" after %d\n", bp->b_bcount);
1714 #endif
1715 	minphys(bp);
1716 }
1717 
1718 /*
1719  * encode the track cache into raw MFM ready for dma
1720  * when we go to multiple disk formats, this will call type dependent
1721  * functions
1722  */
1723 void fdcachetoraw(sc)
1724 	struct fd_softc *sc;
1725 {
1726 	if (sc->openpart == FDMSDOSPART)
1727 		mscachetoraw(sc);
1728 	else
1729 		amcachetoraw(sc);
1730 }
1731 
1732 /*
1733  * decode raw MFM from dma into units track cache.
1734  * when we go to multiple disk formats, this will call type dependent
1735  * functions
1736  */
1737 int
1738 fdrawtocache(sc)
1739 	struct fd_softc *sc;
1740 {
1741 
1742 	if (sc->openpart == FDMSDOSPART)
1743 		return(msrawtocache(sc));
1744 	else
1745 		return(amrawtocache(sc));
1746 }
1747 
1748 void
1749 amcachetoraw(sc)
1750 	struct fd_softc *sc;
1751 {
1752 	static u_long mfmnull[4];
1753 	u_long *rp, *crp, *dp, hcksum, dcksum, info, zero;
1754 	int sec, i;
1755 
1756 	rp = fdc_dmap;
1757 
1758 	/*
1759 	 * not yet one sector (- 1 long) gap.
1760 	 * for now use previous drivers values
1761 	 */
1762 	for (i = 0; i < sc->type->gap; i++)
1763 		*rp++ = 0xaaaaaaaa;
1764 	/*
1765 	 * process sectors
1766 	 */
1767 	dp = sc->cachep;
1768 	zero = 0;
1769 	info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1770 	for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1771 		hcksum = dcksum = 0;
1772 		/*
1773 		 * sector format
1774 		 *	offset		description
1775 		 *-----------------------------------
1776 		 *  0			null
1777 		 *  1			sync
1778 		 * oddbits	evenbits
1779 		 *----------------------
1780 		 *  2		3	[0xff]b [trk]b [sec]b [togap]b
1781 		 *  4-7		8-11	null
1782 		 * 12		13	header cksum [2-11]
1783 		 * 14		15	data cksum [16-271]
1784 		 * 16-143	144-271	data
1785 		 */
1786 		*rp = 0xaaaaaaaa;
1787 		if (*(rp - 1) & 0x1)
1788 			*rp &= 0x7fffffff;	/* clock bit correction */
1789 		rp++;
1790 		*rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1791 		rp = mfmblkencode(&info, rp, &hcksum, 1);
1792 		rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1793 		rp = mfmblkencode(&hcksum, rp, NULL, 1);
1794 
1795 		crp = rp;
1796 		rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1797 		dp += FDSECLWORDS;
1798 		crp = mfmblkencode(&dcksum, crp, NULL, 1);
1799 		if (*(crp - 1) & 0x1)
1800 			*crp &= 0x7fffffff;	/* clock bit correction */
1801 		else if ((*crp & 0x40000000) == 0)
1802 			*crp |= 0x80000000;
1803 	}
1804 	*rp = 0xaaa80000;
1805 	if (*(rp - 1) & 0x1)
1806 		*rp &= 0x7fffffff;
1807 }
1808 
1809 u_long *
1810 fdfindsync(rp, ep)
1811 	u_long *rp, *ep;
1812 {
1813 	u_short *sp;
1814 
1815 	sp = (u_short *)rp;
1816 	while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1817 		sp++;
1818 	while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1819 		sp++;
1820 	if ((u_long *)sp < ep)
1821 		return((u_long *)sp);
1822 	return(NULL);
1823 }
1824 
1825 int
1826 amrawtocache(sc)
1827 	struct fd_softc *sc;
1828 {
1829 	u_long mfmnull[4];
1830 	u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1831 	int cnt, doagain;
1832 
1833 	doagain = 1;
1834 	srp = rp = fdc_dmap;
1835 	erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1836 	cnt = 0;
1837 again:
1838 	if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1839 #ifdef DIAGNOSTIC
1840 		printf("%s: corrupted track (%d) data.\n",
1841 		    sc->sc_dv.dv_xname, sc->cachetrk);
1842 #endif
1843 		return(-1);
1844 	}
1845 
1846 	/*
1847 	 * process sectors
1848 	 */
1849 	for (; cnt < sc->nsectors; cnt++) {
1850 		hcksum = dcksum = 0;
1851 		rp = mfmblkdecode(rp, &info, &hcksum, 1);
1852 		rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1853 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1854 		if (cktmp != hcksum) {
1855 #ifdef FDDEBUG
1856 			printf("  info 0x%x hchksum 0x%x trkhcksum 0x%x\n",
1857 			    info, hcksum, cktmp);
1858 #endif
1859 			goto again;
1860 		}
1861 		if (((info >> 16) & 0xff) != sc->cachetrk) {
1862 #ifdef DEBUG
1863 			printf("%s: incorrect track found: 0x%lx %d\n",
1864 			    sc->sc_dv.dv_xname, info, sc->cachetrk);
1865 #endif
1866 			goto again;
1867 		}
1868 #ifdef FDDEBUG
1869 		printf("  info 0x%x\n", info);
1870 #endif
1871 
1872 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1873 		dp = sc->cachep;
1874 		dp += FDSECLWORDS * ((info >> 8) & 0xff);
1875 		crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1876 		if (cktmp != dcksum) {
1877 #ifdef FDDEBUG
1878 			printf("  info 0x%x dchksum 0x%x trkdcksum 0x%x\n",
1879 			    info, dcksum, cktmp);
1880 #endif
1881 			goto again;
1882 		}
1883 
1884 		/*
1885 		 * if we are at gap then we can no longer be sure
1886 		 * of correct sync marks
1887 		 */
1888 		if ((info && 0xff) == 1)
1889 			doagain = 1;
1890 		else
1891 			doagain = 0;
1892 		srp = rp = fdfindsync(crp, erp);
1893 	}
1894 	return(0);
1895 }
1896 
1897 void
1898 mscachetoraw(sc)
1899 	struct fd_softc *sc;
1900 {
1901 	u_short *rp, *erp, crc;
1902 	u_char *cp, tb[5];
1903 	int sec, i;
1904 
1905 	rp = (u_short *)fdc_dmap;
1906 	erp = rp + sc->type->nwritew;
1907 	cp = sc->cachep;
1908 
1909 	/*
1910 	 * initial track filler  (828 * GAP1)
1911 	 */
1912 	for (i = 0; i < sc->type->gap; i++) {
1913 		*rp++ = FDMFMGAP1;
1914 		*rp++ = FDMFMGAP1;
1915 	}
1916 
1917 	for (sec = 0; sec < sc->nsectors; sec++) {
1918 
1919 		/*
1920 		 * leading sector gap
1921 		 * (12 * GAP2) + (3 * SYNC)
1922 		 */
1923 		for (i = 0; i < 12; i++)
1924 			*rp++ = FDMFMGAP2;
1925 		*rp++ = FDMFMSYNC;
1926 		*rp++ = FDMFMSYNC;
1927 		*rp++ = FDMFMSYNC;
1928 
1929 		/*
1930 		 * sector information
1931 		 * (ID) + track + side + sector + sector size + CRC16
1932 		 */
1933 		*rp++ = FDMFMID;
1934 		tb[0] = sc->cachetrk / FDNHEADS;
1935 		tb[1] = sc->cachetrk % FDNHEADS;
1936 		tb[2] = sec + 1;
1937 		i = sc->bytespersec;
1938 		tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1939 		rp = msblkencode(rp, tb, 4, &crc);
1940 		tb[0] = crc >> 8;
1941 		tb[1] = crc & 0xff;
1942 		tb[2] = 0x4e; /* GAP1 decoded */
1943 		rp = msblkencode(rp, tb, 3, 0);
1944 
1945 		/*
1946 		 * sector info/data gap
1947 		 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1948 		 */
1949 		for (i = 0; i < 21; i++)
1950 			*rp++ = FDMFMGAP1;
1951 		for (i = 0; i < 12; i++)
1952 			*rp++ = FDMFMGAP2;
1953 		*rp++ = FDMFMSYNC;
1954 		*rp++ = FDMFMSYNC;
1955 		*rp++ = FDMFMSYNC;
1956 
1957 		/*
1958 		 * sector data
1959 		 * (DATA) + ...data... + CRC16
1960 		 */
1961 		*rp++ = FDMFMDATA;
1962 		rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1963 		cp += sc->bytespersec;
1964 		tb[0] = crc >> 8;
1965 		tb[1] = crc & 0xff;
1966 		tb[2] = 0x4e; /* GAP3 decoded */
1967 		rp = msblkencode(rp, tb, 3, 0);
1968 
1969 		/*
1970 		 * trailing sector gap
1971 		 * (80 * GAP3)
1972 		 */
1973 		for (i = 0; i < 79; i++)
1974 			*rp++ = FDMFMGAP3;
1975 	}
1976 
1977 	/*
1978 	 * fill rest of track with GAP3
1979 	 */
1980 	while (rp != erp)
1981 		*rp++ = FDMFMGAP3;
1982 
1983 }
1984 
1985 int
1986 msrawtocache(sc)
1987 	struct fd_softc *sc;
1988 {
1989 	u_short *rp, *srp, *erp;
1990 	u_char tb[5], *cp;
1991 	int ct, sec, retry;
1992 
1993 	srp = rp = (u_short *)fdc_dmap;
1994 	erp = rp + sc->type->nreadw;
1995 	cp = sc->cachep;
1996 
1997 	for (ct = 0; ct < sc->nsectors; ct++) {
1998 		retry = 1;
1999 		do {
2000 			/*
2001 			 * skip leading gap to sync
2002 			 */
2003 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
2004 #ifdef DIAGNOSTIC
2005 				printf("%s: corrupted track (%d) data.\n",
2006 				sc->sc_dv.dv_xname, sc->cachetrk);
2007 #endif
2008 				return(-1);
2009 			}
2010 
2011 			/*
2012 			 * Grab sector info
2013 			 */
2014 			if (*rp++ != FDMFMID)
2015 				continue;
2016 			rp = msblkdecode(rp, tb, 4);
2017 #ifdef FDDEBUG
2018 			printf("sector id: sector %d, track %d, side %d,"
2019 			    "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
2020 #endif
2021 			if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
2022 			    tb[2] > sc->nsectors)
2023 				continue;
2024 
2025 			sec = tb[2];
2026 			sc->bytespersec = 128 << tb[3];
2027 			rp += 2; /* skip CRC-16 */
2028 
2029 			/*
2030 			 * skip gap and read in data
2031 			 */
2032 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
2033 				return(-1);
2034 			if (*rp++ != FDMFMDATA)
2035 				continue;
2036 			rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
2037 			    sc->bytespersec);
2038 			rp += 2; /* skip CRC-16 */
2039 
2040 			retry = 0;
2041 		} while (retry);
2042 	}
2043 	return(0);
2044 }
2045 
2046 /*
2047  * encode len longwords of `dp' data in amiga mfm block format (`rp')
2048  * this format specified that the odd bits are at current pos and even
2049  * bits at len + current pos
2050  */
2051 u_long *
2052 mfmblkencode(dp, rp, cp, len)
2053 	u_long *dp, *rp, *cp;
2054 	int len;
2055 {
2056 	u_long *sdp, *edp, d, dtmp, correct;
2057 
2058 	sdp = dp;
2059 	edp = dp + len;
2060 
2061 	if (*(rp - 1) & 0x1)
2062 		correct = 1;
2063 	else
2064 		correct = 0;
2065 	/*
2066 	 * do odd bits
2067 	 */
2068 	while (dp < edp) {
2069 		d = (*dp >> 1) & 0x55555555;	/* remove clock bits */
2070 		dtmp = d ^ 0x55555555;
2071 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2072 		/*
2073 		 * correct upper clock bit if needed
2074 		 */
2075 		if (correct)
2076 			d &= 0x7fffffff;
2077 		if (d & 0x1)
2078 			correct = 1;
2079 		else
2080 			correct = 0;
2081 		/*
2082 		 * do checksums and store in raw buffer
2083 		 */
2084 		if (cp)
2085 			*cp ^= d;
2086 		*rp++ = d;
2087 		dp++;
2088 	}
2089 	/*
2090 	 * do even bits
2091 	 */
2092 	dp = sdp;
2093 	while (dp < edp) {
2094 		d = *dp & 0x55555555;	/* remove clock bits */
2095 		dtmp = d ^ 0x55555555;
2096 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2097 		/*
2098 		 * correct upper clock bit if needed
2099 		 */
2100 		if (correct)
2101 			d &= 0x7fffffff;
2102 		if (d & 0x1)
2103 			correct = 1;
2104 		else
2105 			correct = 0;
2106 		/*
2107 		 * do checksums and store in raw buffer
2108 		 */
2109 		if (cp)
2110 			*cp ^= d;
2111 		*rp++ = d;
2112 		dp++;
2113 	}
2114 	if (cp)
2115 		*cp &= 0x55555555;
2116 	return(rp);
2117 }
2118 
2119 /*
2120  * decode len longwords of `dp' data in amiga mfm block format (`rp')
2121  * this format specified that the odd bits are at current pos and even
2122  * bits at len + current pos
2123  */
2124 u_long *
2125 mfmblkdecode(rp, dp, cp, len)
2126 	u_long *rp, *dp, *cp;
2127 	int len;
2128 {
2129 	u_long o, e;
2130 	int cnt;
2131 
2132 	cnt = len;
2133 	while (cnt--) {
2134 		o = *rp;
2135 		e = *(rp + len);
2136 		if (cp) {
2137 			*cp ^= o;
2138 			*cp ^= e;
2139 		}
2140 		o &= 0x55555555;
2141 		e &= 0x55555555;
2142 		*dp++ = (o << 1) | e;
2143 		rp++;
2144 	}
2145 	if (cp)
2146 		*cp &= 0x55555555;
2147 	return(rp + len);
2148 }
2149 
2150 /*
2151  * decode len words in standard MFM format to len bytes
2152  * of data.
2153  */
2154 u_short *
2155 msblkdecode(rp, cp, len)
2156 	u_short *rp;
2157 	u_char *cp;
2158 	int len;
2159 {
2160 	while (len--) {
2161 		*cp++ = msdecode[*rp & 0x7f] |
2162 		    (msdecode[(*rp >> 8) & 0x7f] << 4);
2163 		rp++;
2164 	}
2165 
2166 	return(rp);
2167 }
2168 
2169 /*
2170  * encode len bytes of data into len words in standard MFM format.
2171  * If a pointer is supplied for crc, calculate the CRC-16 of the data
2172  * as well.
2173  */
2174 u_short *
2175 msblkencode(rp, cp, len, crc)
2176 	u_short *rp;
2177 	u_char *cp;
2178 	int len;
2179 	u_short *crc;
2180 {
2181 	u_short td;
2182 	u_short mycrc;
2183 
2184 	/* preload crc for header (4 bytes)
2185 	 * or data (anything else)
2186 	 */
2187 	mycrc = (len == 4) ? 0xb230 : 0xe295;
2188 
2189 	while (len--) {
2190 		td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2191 
2192 		/* Check for zeros in top bit of encode and bottom
2193 		 * bit of previous encode.  if so, slap a one in betweem
2194 		 * them.
2195 		 */
2196 		if ((td & 0x140) == 0)
2197 			td |= 0x80;
2198 		if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2199 			td |= 0x8000;
2200 
2201 		*rp++ = td;
2202 
2203 		/*
2204 		 * calc crc if requested
2205 		 */
2206 		if (crc)
2207 			mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2208 
2209 		cp++;
2210 	}
2211 
2212 	if (crc)
2213 		*crc = mycrc;
2214 
2215 	return(rp);
2216 }
2217 
2218 int
2219 fddump(dev, blkno, va, size)
2220 	dev_t	dev;
2221 	daddr_t	blkno;
2222 	caddr_t	va;
2223 	size_t	size;
2224 {
2225 	return (EINVAL);
2226 }
2227