xref: /netbsd-src/sys/arch/amiga/dev/fd.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: fd.c,v 1.39 1997/10/11 16:13:19 mhitch 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 b_cylin	b_resid
72 #define FDUNIT(dev)	DISKUNIT(dev)
73 #define FDPART(dev)	DISKPART(dev)
74 #define FDMAKEDEV(m, u, p)	MAKEDISKDEV((m), (u), (p))
75 
76 /* that's nice, but we don't want to always use this as an amiga drive
77 bunghole :-) */
78 #define FDNHEADS	(2)	/* amiga drives always have 2 heads */
79 #define FDSECSIZE	(512)	/* amiga drives always have 512 byte sectors */
80 #define FDSECLWORDS	(128)
81 
82 #define FDSETTLEDELAY	(18000)	/* usec delay after seeking after switch dir */
83 #define FDSTEPDELAY	(3500)	/* usec delay after steping */
84 #define FDPRESIDEDELAY	(1000)	/* usec delay before writing can occur */
85 #define FDWRITEDELAY	(1300)	/* usec delay after write */
86 
87 #define FDSTEPOUT	(1)	/* decrease track step */
88 #define FDSTEPIN	(0)	/* increase track step */
89 
90 #define FDCUNITMASK	(0x78)	/* mask for all units (bits 6-3) */
91 
92 #define FDRETRIES	(2)	/* default number of retries */
93 #define FDMAXUNITS	(4)	/* maximum number of supported units */
94 
95 #define DISKLEN_READ	(0)	/* fake mask for reading */
96 #define DISKLEN_WRITE	(1 << 14)	/* bit for writing */
97 #define DISKLEN_DMAEN	(1 << 15)	/* dma go */
98 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2)	/* largest dma possible */
99 
100 #define FDMFMSYNC	(0x4489)
101 #define FDMFMID		(0x5554)
102 #define FDMFMDATA	(0x5545)
103 #define FDMFMGAP1	(0x9254)
104 #define FDMFMGAP2	(0xAAAA)
105 #define FDMFMGAP3	(0x9254)
106 #define CRC16POLY	(0x1021) /* (x^16) + x^12 + x^5 + x^0 */
107 
108 /*
109  * Msdos-type MFM encode/decode
110  */
111 static u_char msdecode[128];
112 static u_char msencode[16] =
113 {
114     0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
115     0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
116 };
117 static u_short mscrctab[256];
118 
119 /*
120   5554    aaaa    aaaa    aaa5    2aa4    4452    aa51
121           00      00      03      02      ac      0d
122 */
123 
124 /*
125  * floppy device type
126  */
127 struct fdtype {
128 	u_int driveid;		/* drive identification (from drive) */
129 	u_int ncylinders;	/* number of cylinders on drive */
130 	u_int amiga_nsectors;	/* number of sectors per amiga track */
131 	u_int msdos_nsectors;	/* number of sectors per msdos track */
132 	u_int nreadw;		/* number of words (short) read per track */
133 	u_int nwritew;		/* number of words (short) written per track */
134 	u_int gap;		/* track gap size in long words */
135 	u_int precomp[2];	/* 1st and 2nd precomp values */
136 	char *desc;		/* description of drive type (useq) */
137 };
138 
139 /*
140  * floppy disk device data
141  */
142 struct fd_softc {
143 	struct device sc_dv;	/* generic device info; must come first */
144 	struct disk dkdev;	/* generic disk info */
145 	struct buf bufq;	/* queue of buf's */
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 struct cfdriver fd_cd = {
245 	NULL, "fd", DV_DISK, NULL, 0
246 };
247 
248 struct cfattach fdc_ca = {
249 	sizeof(struct device), fdcmatch, fdcattach
250 };
251 
252 struct cfdriver fdc_cd = {
253 	NULL, "fdc", DV_DULL, NULL, 0
254 };
255 
256 /*
257  * all hw access through macros, this helps to hide the active low
258  * properties
259  */
260 
261 #define FDUNITMASK(unit)	(1 << (3 + (unit)))
262 
263 /*
264  * select units using mask
265  */
266 #define FDSELECT(um)	do { ciab.prb &= ~(um); } while (0)
267 
268 /*
269  * deselect units using mask
270  */
271 #define FDDESELECT(um)	do { ciab.prb |= (um); delay(1); } while (0)
272 
273 /*
274  * test hw condition bits
275  */
276 #define FDTESTC(bit)	((ciaa.pra & (1 << (bit))) == 0)
277 
278 /*
279  * set motor for select units, true motor on else off
280  */
281 #define FDSETMOTOR(on)	do { \
282 	if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
283 	} while (0)
284 
285 /*
286  * set head for select units
287  */
288 #define FDSETHEAD(head)	do { \
289 	if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
290 	delay(1); } while (0)
291 
292 /*
293  * select direction, true towards spindle else outwards
294  */
295 #define FDSETDIR(in)	do { \
296 	if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
297 	delay(1); } while (0)
298 
299 /*
300  * step the selected units
301  */
302 #define FDSTEP	do { \
303     ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
304     } while (0)
305 
306 #define FDDMASTART(len, towrite)	do { \
307     int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
308     custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
309 
310 #define FDDMASTOP	do { custom.dsklen = 0; } while (0)
311 
312 
313 int
314 fdcmatch(pdp, cfp, auxp)
315 	struct device *pdp;
316 	struct cfdata *cfp;
317 	void *auxp;
318 {
319 
320 	if (matchname("fdc", auxp) == 0 || cfp->cf_unit != 0)
321 		return(0);
322 	if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
323 		printf("fdc: unable to allocate dma buffer\n");
324 		return(0);
325 	}
326 	return(1);
327 }
328 
329 void
330 fdcattach(pdp, dp, auxp)
331 	struct device *pdp,  *dp;
332 	void *auxp;
333 {
334 	struct fdcargs args;
335 
336 	printf(": dmabuf pa 0x%x", kvtop(fdc_dmap));
337 	printf(": dmabuf ka %p\n", fdc_dmap);
338 	args.unit = 0;
339 	args.type = fdcgetfdtype(args.unit);
340 
341 	fdc_side = -1;
342 	config_found(dp, &args, fdcprint);
343 	for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
344 		if ((args.type = fdcgetfdtype(args.unit)) == NULL)
345 			continue;
346 		config_found(dp, &args, fdcprint);
347 	}
348 }
349 
350 int
351 fdcprint(auxp, pnp)
352 	void *auxp;
353 	const char *pnp;
354 {
355 	struct fdcargs *fcp;
356 
357 	fcp = auxp;
358 	if (pnp)
359 		printf("fd%d at %s unit %d:", fcp->unit, pnp,
360 			fcp->type->driveid);
361 	return(UNCONF);
362 }
363 
364 /*ARGSUSED*/
365 int
366 fdmatch(pdp, cfp, auxp)
367 	struct device *pdp;
368 	struct cfdata *cfp;
369 	void *auxp;
370 {
371 
372 #define cf_unit	cf_loc[FDCCF_UNIT]
373 	struct fdcargs *fdap;
374 
375 	fdap = auxp;
376 	if (cfp->cf_unit == fdap->unit || cfp->cf_unit == FDCCF_UNIT_DEFAULT)
377 		return(1);
378 	return(0);
379 #undef cf_unit
380 }
381 
382 void
383 fdattach(pdp, dp, auxp)
384 	struct device *pdp, *dp;
385 	void *auxp;
386 {
387 	struct fdcargs *ap;
388 	struct fd_softc *sc;
389 	int i;
390 
391 	ap = auxp;
392 	sc = (struct fd_softc *)dp;
393 
394 	sc->curcyl = sc->cachetrk = -1;
395 	sc->openpart = -1;
396 	sc->type = ap->type;
397 	sc->hwunit = ap->unit;
398 	sc->unitmask = 1 << (3 + ap->unit);
399 	sc->retries = FDRETRIES;
400 	sc->stepdelay = FDSTEPDELAY;
401 	sc->bytespersec = 512;
402 	printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
403 	    sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
404 	    sc->type->amiga_nsectors, sc->type->msdos_nsectors);
405 
406 	/*
407 	 * Initialize and attach the disk structure.
408 	 */
409 	sc->dkdev.dk_name = sc->sc_dv.dv_xname;
410 	sc->dkdev.dk_driver = &fddkdriver;
411 	disk_attach(&sc->dkdev);
412 
413 	/*
414 	 * calibrate the drive
415 	 */
416 	fdsetpos(sc, 0, 0);
417 	fdsetpos(sc, sc->type->ncylinders, 0);
418 	fdsetpos(sc, 0, 0);
419 	fdmotoroff(sc);
420 
421 	/*
422 	 * precalc msdos MFM and CRC
423 	 */
424 	for (i = 0; i < 128; i++)
425 		msdecode[i] = 0xff;
426 	for (i = 0; i < 16; i++)
427 		msdecode[msencode[i]] = i;
428 	for (i = 0; i < 256; i++) {
429 		mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
430 		    (0x1021 * (i >> 4));
431 	}
432 
433 	/*
434 	 * enable disk related interrupts
435 	 */
436 	custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
437 	custom.intena = INTF_SETCLR | INTF_DSKBLK;
438 	ciab.icr = CIA_ICR_FLG;
439 }
440 
441 /*ARGSUSED*/
442 int
443 fdopen(dev, flags, devtype, p)
444 	dev_t dev;
445 	int flags, devtype;
446 	struct proc *p;
447 {
448 	struct fd_softc *sc;
449 	int wasopen, fwork, error, s;
450 
451 	error = 0;
452 
453 	if (FDPART(dev) >= FDMAXPARTS)
454 		return(ENXIO);
455 
456 	if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
457 		return(ENXIO);
458 	if (sc->flags & FDF_NOTRACK0)
459 		return(ENXIO);
460 	if (sc->cachep == NULL)
461 		sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
462 
463 	s = splbio();
464 	/*
465 	 * if we are sleeping in fdclose(); waiting for a chance to
466 	 * shut the motor off, do a sleep here also.
467 	 */
468 	while (sc->flags & FDF_WMOTOROFF)
469 		tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
470 
471 	fwork = 0;
472 	/*
473 	 * if not open let user open request type, otherwise
474 	 * ensure they are trying to open same type.
475 	 */
476 	if (sc->openpart == FDPART(dev))
477 		wasopen = 1;
478 	else if (sc->openpart == -1) {
479 		sc->openpart = FDPART(dev);
480 		wasopen = 0;
481 	} else {
482 		wasopen = 1;
483 		error = EPERM;
484 		goto done;
485 	}
486 
487 	/*
488 	 * wait for current io to complete if any
489 	 */
490 	if (fdc_indma) {
491 		fwork = 1;
492 		fdc_wantwakeup++;
493 		tsleep(fdopen, PRIBIO, "fdopen", 0);
494 	}
495 	if ((error = fdloaddisk(sc)) != 0)
496 		goto done;
497 	if ((error = fdgetdisklabel(sc, dev)) != 0)
498 		goto done;
499 #ifdef FDDEBUG
500 	printf("  open successful\n");
501 #endif
502 done:
503 	/*
504 	 * if we requested that fddone()->fdfindwork() wake us, allow it to
505 	 * complete its job now
506 	 */
507 	if (fwork)
508 		fdfindwork(FDUNIT(dev));
509 	splx(s);
510 
511 	/*
512 	 * if we were not open and we marked us so reverse that.
513 	 */
514 	if (error && wasopen == 0)
515 		sc->openpart = -1;
516 	return(error);
517 }
518 
519 /*ARGSUSED*/
520 int
521 fdclose(dev, flags, devtype, p)
522 	dev_t dev;
523 	int flags, devtype;
524 	struct proc *p;
525 {
526 	struct fd_softc *sc;
527 	int s;
528 
529 #ifdef FDDEBUG
530 	printf("fdclose()\n");
531 #endif
532 	sc = getsoftc(fd_cd, FDUNIT(dev));
533 	s = splbio();
534 	if (sc->flags & FDF_MOTORON) {
535 		sc->flags |= FDF_WMOTOROFF;
536 		tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
537 		sc->flags &= ~FDF_WMOTOROFF;
538 		wakeup(fdmotoroff);
539 	}
540 	sc->openpart = -1;
541 	splx(s);
542 	return(0);
543 }
544 
545 int
546 fdioctl(dev, cmd, addr, flag, p)
547 	dev_t dev;
548 	u_long cmd;
549 	caddr_t addr;
550 	int flag;
551 	struct proc *p;
552 {
553 	struct fd_softc *sc;
554 	int error, wlab;
555 
556 	sc = getsoftc(fd_cd, FDUNIT(dev));
557 
558 	if ((sc->flags & FDF_HAVELABEL) == 0)
559 		return(EBADF);
560 
561 	switch (cmd) {
562 	case DIOCSBAD:
563 		return(EINVAL);
564 	case DIOCSRETRIES:
565 		if (*(int *)addr < 0)
566 			return(EINVAL);
567 		sc->retries = *(int *)addr;
568 		return(0);
569 	case DIOCSSTEP:
570 		if (*(int *)addr < FDSTEPDELAY)
571 			return(EINVAL);
572 		sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
573 		return(0);
574 	case DIOCGDINFO:
575 		*(struct disklabel *)addr = *(sc->dkdev.dk_label);
576 		return(0);
577 	case DIOCGPART:
578 		((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
579 		((struct partinfo *)addr)->part =
580 		    &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
581 		return(0);
582 	case DIOCSDINFO:
583 		if ((flag & FWRITE) == 0)
584 			return(EBADF);
585 		return(fdsetdisklabel(sc, (struct disklabel *)addr));
586 	case DIOCWDINFO:
587 		if ((flag & FWRITE) == 0)
588 			return(EBADF);
589 		if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
590 			return(error);
591 		wlab = sc->wlabel;
592 		sc->wlabel = 1;
593 		error = fdputdisklabel(sc, dev);
594 		sc->wlabel = wlab;
595 		return(error);
596 	case DIOCWLABEL:
597 		if ((flag & FWRITE) == 0)
598 			return(EBADF);
599 		sc->wlabel = *(int *)addr;
600 		return(0);
601 	case DIOCGDEFLABEL:
602 		fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
603 		return(0);
604 	default:
605 		return(ENOTTY);
606 	}
607 }
608 
609 /*
610  * no dumps to floppy disks thank you.
611  */
612 int
613 fdsize(dev)
614 	dev_t dev;
615 {
616 	return(-1);
617 }
618 
619 int
620 fdread(dev, uio, flags)
621 	dev_t	dev;
622 	struct	uio *uio;
623 	int	flags;
624 {
625 	return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
626 }
627 
628 int
629 fdwrite(dev, uio, flags)
630 	dev_t	dev;
631 	struct	uio *uio;
632 	int	flags;
633 {
634 	return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
635 }
636 
637 
638 void
639 fdintr(flag)
640 	int	flag;
641 {
642 	int s;
643 
644 	s = splbio();
645 	if (fdc_indma)
646 		fddmadone(fdc_indma, 0);
647 	splx(s);
648 }
649 
650 void
651 fdidxintr()
652 {
653 	if (fdc_indma && fdc_dmalen) {
654 		/*
655 		 * turn off intr and start actual dma
656 		 */
657 		ciab.icr = CIA_ICR_FLG;
658 		FDDMASTART(fdc_dmalen, fdc_dmawrite);
659 		fdc_dmalen = 0;
660 	}
661 }
662 
663 void
664 fdstrategy(bp)
665 	struct buf *bp;
666 {
667 	struct disklabel *lp;
668 	struct fd_softc *sc;
669 	struct buf *dp;
670 	int unit, part, s;
671 
672 	unit = FDUNIT(bp->b_dev);
673 	part = FDPART(bp->b_dev);
674 	sc = getsoftc(fd_cd, unit);
675 
676 #ifdef FDDEBUG
677 	printf("fdstrategy: 0x%x\n", bp);
678 #endif
679 	/*
680 	 * check for valid partition and bounds
681 	 */
682 	lp = sc->dkdev.dk_label;
683 	if ((sc->flags & FDF_HAVELABEL) == 0) {
684 		bp->b_error = EIO;
685 		goto bad;
686 	}
687 	if (bounds_check_with_label(bp, lp, sc->wlabel) <= 0)
688 		goto done;
689 
690 	/*
691 	 * trans count of zero or bounds check indicates io is done
692 	 * we are done.
693 	 */
694 	if (bp->b_bcount == 0)
695 		goto done;
696 
697 	/*
698 	 * queue the buf and kick the low level code
699 	 */
700 	s = splbio();
701 	dp = &sc->bufq;
702 	disksort(dp, bp);
703 	fdstart(sc);
704 	splx(s);
705 	return;
706 bad:
707 	bp->b_flags |= B_ERROR;
708 done:
709 	bp->b_resid = bp->b_bcount;
710 	biodone(bp);
711 }
712 
713 /*
714  * make sure disk is loaded and label is up-to-date.
715  */
716 int
717 fdloaddisk(sc)
718 	struct fd_softc *sc;
719 {
720 	/*
721 	 * if diskchange is low step drive to 0 then up one then to zero.
722 	 */
723 	fdselunit(sc);			/* make sure the unit is selected */
724 	if (FDTESTC(FDB_CHANGED)) {
725 		fdsetpos(sc, 0, 0);
726 		sc->cachetrk = -1;		/* invalidate the cache */
727 		sc->flags &= ~FDF_HAVELABEL;
728 		fdsetpos(sc, FDNHEADS, 0);
729 		fdsetpos(sc, 0, 0);
730 		if (FDTESTC(FDB_CHANGED)) {
731 			fdmotoroff(sc);
732 			FDDESELECT(sc->unitmask);
733 			return(ENXIO);
734 		}
735 	}
736 	FDDESELECT(sc->unitmask);
737 	fdmotoroff(sc);
738 	sc->type = fdcgetfdtype(sc->hwunit);
739 	if (sc->type == NULL)
740 		return(ENXIO);
741 	if (sc->openpart == FDMSDOSPART)
742 		sc->nsectors = sc->type->msdos_nsectors;
743 	else
744 		sc->nsectors = sc->type->amiga_nsectors;
745 	return(0);
746 }
747 
748 void
749 fdgetdefaultlabel(sc, lp, part)
750 	struct fd_softc *sc;
751 	struct disklabel *lp;
752 	int part;		/* XXX ick */
753 {
754 
755 	bzero(lp, sizeof(struct disklabel));
756 	lp->d_secsize = FDSECSIZE;
757 	lp->d_ntracks = FDNHEADS;
758 	lp->d_ncylinders = sc->type->ncylinders;
759 	lp->d_nsectors = sc->nsectors;
760 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
761 	lp->d_type = DTYPE_FLOPPY;
762 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
763 	lp->d_rpm = 300; 		/* good guess I suppose. */
764 	lp->d_interleave = 1;		/* should change when adding msdos */
765 	sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
766 	lp->d_bbsize = 0;
767 	lp->d_sbsize = 0;
768 	lp->d_partitions[part].p_size = lp->d_secperunit;
769 	lp->d_partitions[part].p_fstype = FS_UNUSED;
770 	lp->d_partitions[part].p_fsize = 1024;
771 	lp->d_partitions[part].p_frag = 8;
772 	lp->d_partitions[part].p_cpg = 2;	/* adosfs: reserved blocks */
773 	lp->d_npartitions = part + 1;
774 	lp->d_magic = lp->d_magic2 = DISKMAGIC;
775 	lp->d_checksum = dkcksum(lp);
776 }
777 
778 /*
779  * read disk label, if present otherwise create one
780  * return a new label if raw part and none found, otherwise err.
781  */
782 int
783 fdgetdisklabel(sc, dev)
784 	struct fd_softc *sc;
785 	dev_t dev;
786 {
787 	struct disklabel *lp, *dlp;
788 	struct cpu_disklabel *clp;
789 	struct buf *bp;
790 	int error, part;
791 
792 	if (sc->flags & FDF_HAVELABEL &&
793 	    sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
794 		return(0);
795 #ifdef FDDEBUG
796 	printf("fdgetdisklabel()\n");
797 #endif
798 	part = FDPART(dev);
799 	lp = sc->dkdev.dk_label;
800 	clp =  sc->dkdev.dk_cpulabel;
801 	bzero(lp, sizeof(struct disklabel));
802 	bzero(clp, sizeof(struct cpu_disklabel));
803 
804 	lp->d_secsize = FDSECSIZE;
805 	lp->d_ntracks = FDNHEADS;
806 	lp->d_ncylinders = sc->type->ncylinders;
807 	lp->d_nsectors = sc->nsectors;
808 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
809 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
810 	lp->d_npartitions = part + 1;
811 	lp->d_partitions[part].p_size = lp->d_secperunit;
812 	lp->d_partitions[part].p_fstype = FS_UNUSED;
813 	lp->d_partitions[part].p_fsize = 1024;
814 	lp->d_partitions[part].p_frag = 8;
815 	lp->d_partitions[part].p_cpg = 2;	/* for adosfs: reserved blks */
816 
817 	sc->flags |= FDF_HAVELABEL;
818 
819 	bp = (void *)geteblk((int)lp->d_secsize);
820 	bp->b_dev = dev;
821 	bp->b_blkno = 0;
822 	bp->b_cylin = 0;
823 	bp->b_bcount = FDSECSIZE;
824 	bp->b_flags = B_BUSY | B_READ;
825 	fdstrategy(bp);
826 	if ((error = biowait(bp)) != 0)
827 		goto nolabel;
828 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
829 	if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
830 	    dkcksum(dlp)) {
831 		error = EINVAL;
832 		goto nolabel;
833 	}
834 	bcopy(dlp, lp, sizeof(struct disklabel));
835 	if (lp->d_trkseek > FDSTEPDELAY)
836 		sc->stepdelay = lp->d_trkseek;
837 	brelse(bp);
838 	return(0);
839 nolabel:
840 	fdgetdefaultlabel(sc, lp, part);
841 	brelse(bp);
842 	return(0);
843 }
844 
845 /*
846  * set the incore copy of this units disklabel
847  */
848 int
849 fdsetdisklabel(sc, lp)
850 	struct fd_softc *sc;
851 	struct disklabel *lp;
852 {
853 	struct disklabel *clp;
854 	struct partition *pp;
855 
856 	/*
857 	 * must have at least opened raw unit to fetch the
858 	 * raw_part stuff.
859 	 */
860 	if ((sc->flags & FDF_HAVELABEL) == 0)
861 		return(EINVAL);
862 	clp = sc->dkdev.dk_label;
863 	/*
864 	 * make sure things check out and we only have one valid
865 	 * partition
866 	 */
867 #ifdef FDDEBUG
868 	printf("fdsetdisklabel\n");
869 #endif
870 	if (lp->d_secsize != FDSECSIZE ||
871 	    lp->d_nsectors != clp->d_nsectors ||
872 	    lp->d_ntracks != FDNHEADS ||
873 	    lp->d_ncylinders != clp->d_ncylinders ||
874 	    lp->d_secpercyl != clp->d_secpercyl ||
875 	    lp->d_secperunit != clp->d_secperunit ||
876 	    lp->d_magic != DISKMAGIC ||
877 	    lp->d_magic2 != DISKMAGIC ||
878 	    lp->d_npartitions == 0 ||
879 	    lp->d_npartitions > FDMAXPARTS ||
880 	    (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
881 	    dkcksum(lp))
882 		return(EINVAL);
883 	/*
884 	 * if any partitions are present make sure they
885 	 * represent the currently open type
886 	 */
887 	if ((pp = &lp->d_partitions[0])->p_size) {
888 		if ((pp = &lp->d_partitions[1])->p_size == 0)
889 			goto done;
890 		else if (sc->openpart != 1)
891 			return(EINVAL);
892 	} else if (sc->openpart != 0)
893 		return(EINVAL);
894 	/*
895 	 * make sure selected partition is within bounds
896 	 * XXX on the second check, its to handle a bug in
897 	 * XXX the cluster routines as they require mutliples
898 	 * XXX of CLBYTES currently
899 	 */
900 	if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
901 	    (pp->p_frag * pp->p_fsize % CLBYTES))
902 		return(EINVAL);
903 done:
904 	bcopy(lp, clp, sizeof(struct disklabel));
905 	return(0);
906 }
907 
908 /*
909  * write out the incore copy of this units disklabel
910  */
911 int
912 fdputdisklabel(sc, dev)
913 	struct fd_softc *sc;
914 	dev_t dev;
915 {
916 	struct disklabel *lp, *dlp;
917 	struct buf *bp;
918 	int error;
919 
920 	if ((sc->flags & FDF_HAVELABEL) == 0)
921 		return(EBADF);
922 #ifdef FDDEBUG
923 	printf("fdputdisklabel\n");
924 #endif
925 	/*
926 	 * get buf and read in sector 0
927 	 */
928 	lp = sc->dkdev.dk_label;
929 	bp = (void *)geteblk((int)lp->d_secsize);
930 	bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
931 	bp->b_blkno = 0;
932 	bp->b_cylin = 0;
933 	bp->b_bcount = FDSECSIZE;
934 	bp->b_flags = B_BUSY | B_READ;
935 	fdstrategy(bp);
936 	if ((error = biowait(bp)) != 0)
937 		goto done;
938 	/*
939 	 * copy disklabel to buf and write it out syncronous
940 	 */
941 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
942 	bcopy(lp, dlp, sizeof(struct disklabel));
943 	bp->b_blkno = 0;
944 	bp->b_cylin = 0;
945 	bp->b_flags = B_WRITE;
946 	fdstrategy(bp);
947 	error = biowait(bp);
948 done:
949 	brelse(bp);
950 	return(error);
951 }
952 
953 /*
954  * figure out drive type or NULL if none.
955  */
956 struct fdtype *
957 fdcgetfdtype(unit)
958 	int unit;
959 {
960 	struct fdtype *ftp;
961 	u_long id, idb;
962 	int cnt, umask;
963 
964 	id = 0;
965 	umask = 1 << (3 + unit);
966 
967 	FDDESELECT(FDCUNITMASK);
968 
969 	FDSETMOTOR(1);
970 	delay(1);
971 	FDSELECT(umask);
972 	delay(1);
973 	FDDESELECT(umask);
974 
975 	FDSETMOTOR(0);
976 	delay(1);
977 	FDSELECT(umask);
978 	delay(1);
979 	FDDESELECT(umask);
980 
981 	for (idb = 0x80000000; idb; idb >>= 1) {
982 		FDSELECT(umask);
983 		delay(1);
984 		if (FDTESTC(FDB_READY) == 0)
985 			id |= idb;
986 		FDDESELECT(umask);
987 		delay(1);
988 	}
989 #ifdef FDDEBUG
990 	printf("fdcgettype unit %d id 0x%lx\n", unit, id);
991 #endif
992 
993 	for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
994 		if (ftp->driveid == id)
995 			return(ftp);
996 	/*
997 	 * 3.5dd's at unit 0 do not always return id.
998 	 */
999 	if (unit == 0)
1000 		return(fdtype);
1001 	return(NULL);
1002 }
1003 
1004 /*
1005  * turn motor off if possible otherwise mark as needed and will be done
1006  * later.
1007  */
1008 void
1009 fdmotoroff(arg)
1010 	void *arg;
1011 {
1012 	struct fd_softc *sc;
1013 	int s;
1014 
1015 	sc = arg;
1016 	s = splbio();
1017 
1018 #ifdef FDDEBUG
1019 	printf("fdmotoroff: unit %d\n", sc->hwunit);
1020 #endif
1021 	if ((sc->flags & FDF_MOTORON) == 0)
1022 		goto done;
1023 	/*
1024 	 * if we have a timeout on a dma operation let fddmadone()
1025 	 * deal with it.
1026 	 */
1027 	if (fdc_indma == sc) {
1028 		fddmadone(sc, 1);
1029 		goto done;
1030 	}
1031 #ifdef FDDEBUG
1032 	printf(" motor was on, turning off\n");
1033 #endif
1034 
1035 	/*
1036 	 * flush cache if needed
1037 	 */
1038 	if (sc->flags & FDF_DIRTY) {
1039 		sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1040 #ifdef FDDEBUG
1041 		printf("  flushing dirty buffer first\n");
1042 #endif
1043 		/*
1044 		 * if dma'ing done for now, fddone() will call us again
1045 		 */
1046 		if (fdc_indma)
1047 			goto done;
1048 		fddmastart(sc, sc->cachetrk);
1049 		goto done;
1050 	}
1051 
1052 	/*
1053 	 * if controller is busy just schedule us to be called back
1054 	 */
1055 	if (fdc_indma) {
1056 		/*
1057 		 * someone else has the controller now
1058 		 * just set flag and let fddone() call us again.
1059 		 */
1060 		sc->flags |= FDF_MOTOROFF;
1061 		goto done;
1062 	}
1063 
1064 #ifdef FDDEBUG
1065 	printf("  hw turning unit off\n");
1066 #endif
1067 
1068 	sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1069 	FDDESELECT(FDCUNITMASK);
1070 	FDSETMOTOR(0);
1071 	delay(1);
1072 	FDSELECT(sc->unitmask);
1073 	delay(4);
1074 	FDDESELECT(sc->unitmask);
1075 	delay(1);
1076 	if (sc->flags & FDF_WMOTOROFF)
1077 		wakeup(fdmotoroff);
1078 done:
1079 	splx(s);
1080 }
1081 
1082 /*
1083  * select drive seek to track exit with motor on.
1084  * fdsetpos(x, 0, 0) does calibrates the drive.
1085  */
1086 void
1087 fdsetpos(sc, trk, towrite)
1088 	struct fd_softc *sc;
1089 	int trk, towrite;
1090 {
1091 	int nstep, sdir, ondly, ncyl, nside;
1092 
1093 	FDDESELECT(FDCUNITMASK);
1094 	FDSETMOTOR(1);
1095 	delay(1);
1096 	FDSELECT(sc->unitmask);
1097 	delay(1);
1098 	if ((sc->flags & FDF_MOTORON) == 0) {
1099 		ondly = 0;
1100 		while (FDTESTC(FDB_READY) == 0) {
1101 			delay(1000);
1102 			if (++ondly >= 1000)
1103 				break;
1104 		}
1105 	}
1106 	sc->flags |= FDF_MOTORON;
1107 
1108 	ncyl = trk / FDNHEADS;
1109 	nside = trk % FDNHEADS;
1110 
1111 	if (sc->curcyl == ncyl && fdc_side == nside)
1112 		return;
1113 
1114 	if (towrite)
1115 		sc->flags |= FDF_WRITEWAIT;
1116 
1117 #ifdef FDDEBUG
1118 	printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1119 	    trk % FDNHEADS, towrite);
1120 #endif
1121 	nstep = ncyl - sc->curcyl;
1122 	if (nstep) {
1123 		/*
1124 		 * figure direction
1125 		 */
1126 		if (nstep > 0 && ncyl != 0) {
1127 			sdir = FDSTEPIN;
1128 			FDSETDIR(1);
1129 		} else {
1130 			nstep = -nstep;
1131 			sdir = FDSTEPOUT;
1132 			FDSETDIR(0);
1133 		}
1134 		if (ncyl == 0) {
1135 			/*
1136 			 * either just want cylinder 0 or doing
1137 			 * a calibrate.
1138 			 */
1139 			nstep = 256;
1140 			while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1141 				FDSTEP;
1142 				delay(sc->stepdelay);
1143 			}
1144 			if (nstep < 0)
1145 				sc->flags |= FDF_NOTRACK0;
1146 		} else {
1147 			/*
1148 			 * step the needed amount amount.
1149 			 */
1150 			while (nstep--) {
1151 				FDSTEP;
1152 				delay(sc->stepdelay);
1153 			}
1154 		}
1155 		/*
1156 		 * if switched directions
1157 		 * allow drive to settle.
1158 		 */
1159 		if (sc->pstepdir != sdir)
1160 			delay(FDSETTLEDELAY);
1161 		sc->pstepdir = sdir;
1162 		sc->curcyl = ncyl;
1163 	}
1164 	if (nside == fdc_side)
1165 		return;
1166 	/*
1167 	 * select side
1168 	 */
1169 	fdc_side = nside;
1170 	FDSETHEAD(nside);
1171 	delay(FDPRESIDEDELAY);
1172 }
1173 
1174 void
1175 fdselunit(sc)
1176 	struct fd_softc *sc;
1177 {
1178 	FDDESELECT(FDCUNITMASK);		/* deselect all */
1179 	FDSETMOTOR(sc->flags & FDF_MOTORON);	/* set motor to unit's state */
1180 	delay(1);
1181 	FDSELECT(sc->unitmask);			/* select unit */
1182 	delay(1);
1183 }
1184 
1185 /*
1186  * process next buf on device queue.
1187  * normall sequence of events:
1188  * fdstart() -> fddmastart();
1189  * fdidxintr();
1190  * fdintr() -> fddmadone() -> fddone();
1191  * if the track is in the cache then fdstart() will short-circuit
1192  * to fddone() else if the track cache is dirty it will flush.  If
1193  * the buf is not an entire track it will cache the requested track.
1194  */
1195 void
1196 fdstart(sc)
1197 	struct fd_softc *sc;
1198 {
1199 	int trk, error, write;
1200 	struct buf *bp, *dp;
1201 	int changed;
1202 
1203 #ifdef FDDEBUG
1204 	printf("fdstart: unit %d\n", sc->hwunit);
1205 #endif
1206 
1207 	/*
1208 	 * if dma'ing just return. we must have been called from fdstartegy.
1209 	 */
1210 	if (fdc_indma)
1211 		return;
1212 
1213 	/*
1214 	 * get next buf if there.
1215 	 */
1216 	dp = &sc->bufq;
1217 	if ((bp = dp->b_actf) == NULL) {
1218 #ifdef FDDEBUG
1219 		printf("  nothing to do\n");
1220 #endif
1221 		return;
1222 	}
1223 
1224 	/*
1225 	 * Mark us as busy now, in case fddone() gets called in one
1226 	 * of the cases below.
1227 	 */
1228 	disk_busy(&sc->dkdev);
1229 
1230 	/*
1231 	 * make sure same disk is loaded
1232 	 */
1233 	fdselunit(sc);
1234 	changed = FDTESTC(FDB_CHANGED);
1235 	FDDESELECT(sc->unitmask);
1236 	if (changed) {
1237 		/*
1238 		 * disk missing, invalidate all future io on
1239 		 * this unit until re-open()'ed also invalidate
1240 		 * all current io
1241 		 */
1242 printf("fdstart: disk changed\n");
1243 #ifdef FDDEBUG
1244 		printf("  disk was removed invalidating all io\n");
1245 #endif
1246 		sc->flags &= ~FDF_HAVELABEL;
1247 		for (;;) {
1248 			bp->b_flags |= B_ERROR;
1249 			bp->b_error = EIO;
1250 			if (bp->b_actf == NULL)
1251 				break;
1252 			biodone(bp);
1253 			bp = bp->b_actf;
1254 		}
1255 		/*
1256 		 * do fddone() on last buf to allow other units to start.
1257 		 */
1258 		dp->b_actf = bp;
1259 		fddone(sc);
1260 		return;
1261 	}
1262 
1263 	/*
1264 	 * we have a valid buf, setup our local version
1265 	 * we use this count to allow reading over multiple tracks.
1266 	 * into a single buffer
1267 	 */
1268 	dp->b_bcount = bp->b_bcount;
1269 	dp->b_blkno = bp->b_blkno;
1270 	dp->b_data = bp->b_data;
1271 	dp->b_flags = bp->b_flags;
1272 	dp->b_resid = 0;
1273 
1274 	if (bp->b_flags & B_READ)
1275 		write = 0;
1276 	else if (FDTESTC(FDB_PROTECT) == 0)
1277 		write = 1;
1278 	else {
1279 		error = EPERM;
1280 		goto bad;
1281 	}
1282 
1283 	/*
1284 	 * figure trk given blkno
1285 	 */
1286 	trk = bp->b_blkno / sc->nsectors;
1287 
1288 	/*
1289 	 * check to see if same as currently cached track
1290 	 * if so we need to do no dma read.
1291 	 */
1292 	if (trk == sc->cachetrk) {
1293 		fddone(sc);
1294 		return;
1295 	}
1296 
1297 	/*
1298 	 * if we will be overwriting the entire cache, don't bother to
1299 	 * fetch it.
1300 	 */
1301 	if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1302 	    bp->b_blkno % sc->nsectors == 0) {
1303 		if (sc->flags & FDF_DIRTY)
1304 			sc->flags |= FDF_JUSTFLUSH;
1305 		else {
1306 			sc->cachetrk = trk;
1307 			fddone(sc);
1308 			return;
1309 		}
1310 	}
1311 
1312 	/*
1313 	 * start dma read of `trk'
1314 	 */
1315 	fddmastart(sc, trk);
1316 	return;
1317 bad:
1318 	bp->b_flags |= B_ERROR;
1319 	bp->b_error = error;
1320 	fddone(sc);
1321 }
1322 
1323 /*
1324  * continue a started operation on next track. always begin at
1325  * sector 0 on the next track.
1326  */
1327 void
1328 fdcont(sc)
1329 	struct fd_softc *sc;
1330 {
1331 	struct buf *dp, *bp;
1332 	int trk, write;
1333 
1334 	dp = &sc->bufq;
1335 	bp = dp->b_actf;
1336 	dp->b_data += (dp->b_bcount - bp->b_resid);
1337 	dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1338 	dp->b_bcount = bp->b_resid;
1339 
1340 	/*
1341 	 * figure trk given blkno
1342 	 */
1343 	trk = dp->b_blkno / sc->nsectors;
1344 #ifdef DEBUG
1345 	if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1346 		panic("fdcont: confused");
1347 #endif
1348 	if (dp->b_flags & B_READ)
1349 		write = 0;
1350 	else
1351 		write = 1;
1352 	/*
1353 	 * if we will be overwriting the entire cache, don't bother to
1354 	 * fetch it.
1355 	 */
1356 	if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1357 		if (sc->flags & FDF_DIRTY)
1358 			sc->flags |= FDF_JUSTFLUSH;
1359 		else {
1360 			sc->cachetrk = trk;
1361 			fddone(sc);
1362 			return;
1363 		}
1364 	}
1365 	/*
1366 	 * start dma read of `trk'
1367 	 */
1368 	fddmastart(sc, trk);
1369 	return;
1370 }
1371 
1372 void
1373 fddmastart(sc, trk)
1374 	struct fd_softc *sc;
1375 	int trk;
1376 {
1377 	int adkmask, ndmaw, write, dmatrk;
1378 
1379 #ifdef FDDEBUG
1380 	printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1381 	    trk / FDNHEADS, trk % FDNHEADS);
1382 #endif
1383 	/*
1384 	 * flush the cached track if dirty else read requested track.
1385 	 */
1386 	if (sc->flags & FDF_DIRTY) {
1387 		fdcachetoraw(sc);
1388 		ndmaw = sc->type->nwritew;
1389 		dmatrk = sc->cachetrk;
1390 		write = 1;
1391 	} else {
1392 		ndmaw = sc->type->nreadw;
1393 		dmatrk = trk;
1394 		write = 0;
1395 	}
1396 
1397 #ifdef FDDEBUG
1398 	printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1399 #endif
1400 	sc->cachetrk = trk;
1401 	fdc_indma = sc;
1402 	fdsetpos(sc, dmatrk, write);
1403 
1404 	/*
1405 	 * setup dma stuff
1406 	 */
1407 	if (write == 0) {
1408 		custom.adkcon = ADKF_MSBSYNC;
1409 		custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1410 		custom.dsksync = FDMFMSYNC;
1411 	} else {
1412 		custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1413 		    ADKF_MSBSYNC;
1414 		adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1415 		if (dmatrk >= sc->type->precomp[0])
1416 			adkmask |= ADKF_PRECOMP0;
1417 		if (dmatrk >= sc->type->precomp[1])
1418 			adkmask |= ADKF_PRECOMP1;
1419 		custom.adkcon = adkmask;
1420 	}
1421 	custom.dskpt = (u_char *)kvtop(fdc_dmap);
1422 
1423 	/*
1424 	 * If writing an MSDOS track, activate disk index pulse
1425 	 * interrupt, dma will be started in the intr routine fdidxintr()
1426 	 * Otherwise, start the DMA here.
1427 	 */
1428 	if (write && sc->openpart == FDMSDOSPART) {
1429 		fdc_dmalen = ndmaw;
1430 		fdc_dmawrite = write;
1431 		ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1432 	} else {
1433 		FDDMASTART(ndmaw, write);
1434 		fdc_dmalen = 0;
1435 	}
1436 
1437 #ifdef FDDEBUG
1438 	printf("  dma started\n");
1439 #endif
1440 }
1441 
1442 /*
1443  * recalibrate the drive
1444  */
1445 void
1446 fdcalibrate(arg)
1447 	void *arg;
1448 {
1449 	struct fd_softc *sc;
1450 	static int loopcnt;
1451 
1452 	sc = arg;
1453 
1454 	if (loopcnt == 0) {
1455 		/*
1456 		 * seek cyl 0
1457 		 */
1458 		fdc_indma = sc;
1459 		sc->stepdelay += 900;
1460 		if (sc->cachetrk > 1)
1461 			fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1462 		sc->stepdelay -= 900;
1463 	}
1464 	if (loopcnt++ & 1)
1465 		fdsetpos(sc, sc->cachetrk, 0);
1466 	else
1467 		fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1468 	/*
1469 	 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and dma
1470 	 */
1471 	if (loopcnt < 8)
1472 		timeout(fdcalibrate, sc, hz / 8);
1473 	else {
1474 		loopcnt = 0;
1475 		fdc_indma = NULL;
1476 		timeout(fdmotoroff, sc, 3 * hz / 2);
1477 		fddmastart(sc, sc->cachetrk);
1478 	}
1479 }
1480 
1481 void
1482 fddmadone(sc, timeo)
1483 	struct fd_softc *sc;
1484 	int timeo;
1485 {
1486 #ifdef FDDEBUG
1487 	printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1488 #endif
1489 	fdc_indma = NULL;
1490 	untimeout(fdmotoroff, sc);
1491 	FDDMASTOP;
1492 
1493 	/*
1494 	 * guarantee the drive has been at current head and cyl
1495 	 * for at least FDWRITEDELAY after a write.
1496 	 */
1497 	if (sc->flags & FDF_WRITEWAIT) {
1498 		delay(FDWRITEDELAY);
1499 		sc->flags &= ~FDF_WRITEWAIT;
1500 	}
1501 
1502 	if ((sc->flags & FDF_MOTOROFF) == 0) {
1503 		/*
1504 		 * motor runs for 1.5 seconds after last dma
1505 		 */
1506 		timeout(fdmotoroff, sc, 3 * hz / 2);
1507 	}
1508 	if (sc->flags & FDF_DIRTY) {
1509 		/*
1510 		 * if buffer dirty, the last dma cleaned it
1511 		 */
1512 		sc->flags &= ~FDF_DIRTY;
1513 		if (timeo)
1514 			printf("%s: write of track cache timed out.\n",
1515 			    sc->sc_dv.dv_xname);
1516 		if (sc->flags & FDF_JUSTFLUSH) {
1517 			sc->flags &= ~FDF_JUSTFLUSH;
1518 			/*
1519 			 * we are done dma'ing
1520 			 */
1521 			fddone(sc);
1522 			return;
1523 		}
1524 		/*
1525 		 * load the cache
1526 		 */
1527 		fddmastart(sc, sc->cachetrk);
1528 		return;
1529 	}
1530 #ifdef FDDEBUG
1531 	else if (sc->flags & FDF_MOTOROFF)
1532 		panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1533 #endif
1534 
1535 	/*
1536 	 * cache loaded decode it into cache buffer
1537 	 */
1538 	if (timeo == 0 && fdrawtocache(sc) == 0)
1539 		sc->retried = 0;
1540 	else {
1541 #ifdef FDDEBUG
1542 		if (timeo)
1543 			printf("%s: fddmadone: cache load timed out.\n",
1544 			    sc->sc_dv.dv_xname);
1545 #endif
1546 		if (sc->retried >= sc->retries) {
1547 			sc->retried = 0;
1548 			sc->cachetrk = -1;
1549 		} else {
1550 			sc->retried++;
1551 			/*
1552 			 * this will be restarted at end of calibrate loop.
1553 			 */
1554 			untimeout(fdmotoroff, sc);
1555 			fdcalibrate(sc);
1556 			return;
1557 		}
1558 	}
1559 	fddone(sc);
1560 }
1561 
1562 void
1563 fddone(sc)
1564 	struct fd_softc *sc;
1565 {
1566 	struct buf *dp, *bp;
1567 	char *data;
1568 	int sz;
1569 
1570 #ifdef FDDEBUG
1571 	printf("fddone: unit %d\n", sc->hwunit);
1572 #endif
1573 	/*
1574 	 * check to see if unit is just flushing the cache,
1575 	 * that is we have no io queued.
1576 	 */
1577 	if (sc->flags & FDF_MOTOROFF)
1578 		goto nobuf;
1579 
1580 	dp = &sc->bufq;
1581 	if ((bp = dp->b_actf) == NULL)
1582 		panic ("fddone");
1583 	/*
1584 	 * check for an error that may have occured
1585 	 * while getting the track.
1586 	 */
1587 	if (sc->cachetrk == -1) {
1588 		sc->retried = 0;
1589 		bp->b_flags |= B_ERROR;
1590 		bp->b_error = EIO;
1591 	} else if ((bp->b_flags & B_ERROR) == 0) {
1592 		data = sc->cachep;
1593 		/*
1594 		 * get offset of data in track cache and limit
1595 		 * the copy size to not exceed the cache's end.
1596 		 */
1597 		data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1598 		sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1599 		sz *= FDSECSIZE;
1600 		sz = min(dp->b_bcount, sz);
1601 		if (bp->b_flags & B_READ)
1602 			bcopy(data, dp->b_data, sz);
1603 		else {
1604 			bcopy(dp->b_data, data, sz);
1605 			sc->flags |= FDF_DIRTY;
1606 		}
1607 		bp->b_resid = dp->b_bcount - sz;
1608 		if (bp->b_resid == 0) {
1609 			bp->b_error = 0;
1610 		} else {
1611 			/*
1612 			 * not done yet need to read next track
1613 			 */
1614 			fdcont(sc);
1615 			return;
1616 		}
1617 	}
1618 	/*
1619 	 * remove from queue.
1620 	 */
1621 	dp->b_actf = bp->b_actf;
1622 
1623 	disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid));
1624 
1625 	biodone(bp);
1626 nobuf:
1627 	fdfindwork(sc->sc_dv.dv_unit);
1628 }
1629 
1630 void
1631 fdfindwork(unit)
1632 	int unit;
1633 {
1634 	struct fd_softc *ssc, *sc;
1635 	int i, last;
1636 
1637 	/*
1638 	 * first see if we have any fdopen()'s waiting
1639 	 */
1640 	if (fdc_wantwakeup) {
1641 		wakeup(fdopen);
1642 		fdc_wantwakeup--;
1643 		return;
1644 	}
1645 
1646 	/*
1647 	 * start next available unit, linear search from the next unit
1648 	 * wrapping and finally this unit.
1649 	 */
1650 	last = 0;
1651 	ssc = NULL;
1652 	for (i = unit + 1; last == 0; i++) {
1653 		if (i == unit)
1654 			last = 1;
1655 		if (i >= fd_cd.cd_ndevs) {
1656 			i = -1;
1657 			continue;
1658 		}
1659 		if ((sc = fd_cd.cd_devs[i]) == NULL)
1660 			continue;
1661 
1662 		/*
1663 		 * if unit has requested to be turned off
1664 		 * and it has no buf's queued do it now
1665 		 */
1666 		if (sc->flags & FDF_MOTOROFF) {
1667 			if (sc->bufq.b_actf == NULL)
1668 				fdmotoroff(sc);
1669 			else {
1670 				/*
1671 				 * we gained a buf request while
1672 				 * we waited, forget the motoroff
1673 				 */
1674 				sc->flags &= ~FDF_MOTOROFF;
1675 			}
1676 			/*
1677 			 * if we now have dma unit must have needed
1678 			 * flushing, quit
1679 			 */
1680 			if (fdc_indma)
1681 				return;
1682 		}
1683 		/*
1684 		 * if we have no start unit and the current unit has
1685 		 * io waiting choose this unit to start.
1686 		 */
1687 		if (ssc == NULL && sc->bufq.b_actf)
1688 			ssc = sc;
1689 	}
1690 	if (ssc)
1691 		fdstart(ssc);
1692 }
1693 
1694 /*
1695  * min byte count to whats left of the track in question
1696  */
1697 void
1698 fdminphys(bp)
1699 	struct buf *bp;
1700 {
1701 	struct fd_softc *sc;
1702 	int trk, sec, toff, tsz;
1703 
1704 	if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1705 		panic("fdminphys: couldn't get softc");
1706 
1707 	trk = bp->b_blkno / sc->nsectors;
1708 	sec = bp->b_blkno % sc->nsectors;
1709 
1710 	toff = sec * FDSECSIZE;
1711 	tsz = sc->nsectors * FDSECSIZE;
1712 #ifdef FDDEBUG
1713 	printf("fdminphys: before %d", bp->b_bcount);
1714 #endif
1715 	bp->b_bcount = min(bp->b_bcount, tsz - toff);
1716 #ifdef FDDEBUG
1717 	printf(" after %d\n", bp->b_bcount);
1718 #endif
1719 	minphys(bp);
1720 }
1721 
1722 /*
1723  * encode the track cache into raw MFM ready for dma
1724  * when we go to multiple disk formats, this will call type dependent
1725  * functions
1726  */
1727 void fdcachetoraw(sc)
1728 	struct fd_softc *sc;
1729 {
1730 	if (sc->openpart == FDMSDOSPART)
1731 		mscachetoraw(sc);
1732 	else
1733 		amcachetoraw(sc);
1734 }
1735 
1736 /*
1737  * decode raw MFM from dma into units track cache.
1738  * when we go to multiple disk formats, this will call type dependent
1739  * functions
1740  */
1741 int
1742 fdrawtocache(sc)
1743 	struct fd_softc *sc;
1744 {
1745 
1746 	if (sc->openpart == FDMSDOSPART)
1747 		return(msrawtocache(sc));
1748 	else
1749 		return(amrawtocache(sc));
1750 }
1751 
1752 void
1753 amcachetoraw(sc)
1754 	struct fd_softc *sc;
1755 {
1756 	static u_long mfmnull[4];
1757 	u_long *rp, *crp, *dp, hcksum, dcksum, info, zero;
1758 	int sec, i;
1759 
1760 	rp = fdc_dmap;
1761 
1762 	/*
1763 	 * not yet one sector (- 1 long) gap.
1764 	 * for now use previous drivers values
1765 	 */
1766 	for (i = 0; i < sc->type->gap; i++)
1767 		*rp++ = 0xaaaaaaaa;
1768 	/*
1769 	 * process sectors
1770 	 */
1771 	dp = sc->cachep;
1772 	zero = 0;
1773 	info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1774 	for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1775 		hcksum = dcksum = 0;
1776 		/*
1777 		 * sector format
1778 		 *	offset		description
1779 		 *-----------------------------------
1780 		 *  0			null
1781 		 *  1			sync
1782 		 * oddbits	evenbits
1783 		 *----------------------
1784 		 *  2		3	[0xff]b [trk]b [sec]b [togap]b
1785 		 *  4-7		8-11	null
1786 		 * 12		13	header cksum [2-11]
1787 		 * 14		15	data cksum [16-271]
1788 		 * 16-143	144-271	data
1789 		 */
1790 		*rp = 0xaaaaaaaa;
1791 		if (*(rp - 1) & 0x1)
1792 			*rp &= 0x7fffffff;	/* clock bit correction */
1793 		rp++;
1794 		*rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1795 		rp = mfmblkencode(&info, rp, &hcksum, 1);
1796 		rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1797 		rp = mfmblkencode(&hcksum, rp, NULL, 1);
1798 
1799 		crp = rp;
1800 		rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1801 		dp += FDSECLWORDS;
1802 		crp = mfmblkencode(&dcksum, crp, NULL, 1);
1803 		if (*(crp - 1) & 0x1)
1804 			*crp &= 0x7fffffff;	/* clock bit correction */
1805 		else if ((*crp & 0x40000000) == 0)
1806 			*crp |= 0x80000000;
1807 	}
1808 	*rp = 0xaaa80000;
1809 	if (*(rp - 1) & 0x1)
1810 		*rp &= 0x7fffffff;
1811 }
1812 
1813 u_long *
1814 fdfindsync(rp, ep)
1815 	u_long *rp, *ep;
1816 {
1817 	u_short *sp;
1818 
1819 	sp = (u_short *)rp;
1820 	while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1821 		sp++;
1822 	while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1823 		sp++;
1824 	if ((u_long *)sp < ep)
1825 		return((u_long *)sp);
1826 	return(NULL);
1827 }
1828 
1829 int
1830 amrawtocache(sc)
1831 	struct fd_softc *sc;
1832 {
1833 	u_long mfmnull[4];
1834 	u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1835 	int cnt, doagain;
1836 
1837 	doagain = 1;
1838 	srp = rp = fdc_dmap;
1839 	erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1840 	cnt = 0;
1841 again:
1842 	if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1843 #ifdef DIAGNOSTIC
1844 		printf("%s: corrupted track (%d) data.\n",
1845 		    sc->sc_dv.dv_xname, sc->cachetrk);
1846 #endif
1847 		return(-1);
1848 	}
1849 
1850 	/*
1851 	 * process sectors
1852 	 */
1853 	for (; cnt < sc->nsectors; cnt++) {
1854 		hcksum = dcksum = 0;
1855 		rp = mfmblkdecode(rp, &info, &hcksum, 1);
1856 		rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1857 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1858 		if (cktmp != hcksum) {
1859 #ifdef FDDEBUG
1860 			printf("  info 0x%x hchksum 0x%x trkhcksum 0x%x\n",
1861 			    info, hcksum, cktmp);
1862 #endif
1863 			goto again;
1864 		}
1865 		if (((info >> 16) & 0xff) != sc->cachetrk) {
1866 #ifdef DEBUG
1867 			printf("%s: incorrect track found: 0x%lx %d\n",
1868 			    sc->sc_dv.dv_xname, info, sc->cachetrk);
1869 #endif
1870 			goto again;
1871 		}
1872 #ifdef FDDEBUG
1873 		printf("  info 0x%x\n", info);
1874 #endif
1875 
1876 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1877 		dp = sc->cachep;
1878 		dp += FDSECLWORDS * ((info >> 8) & 0xff);
1879 		crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1880 		if (cktmp != dcksum) {
1881 #ifdef FDDEBUG
1882 			printf("  info 0x%x dchksum 0x%x trkdcksum 0x%x\n",
1883 			    info, dcksum, cktmp);
1884 #endif
1885 			goto again;
1886 		}
1887 
1888 		/*
1889 		 * if we are at gap then we can no longer be sure
1890 		 * of correct sync marks
1891 		 */
1892 		if ((info && 0xff) == 1)
1893 			doagain = 1;
1894 		else
1895 			doagain = 0;
1896 		srp = rp = fdfindsync(crp, erp);
1897 	}
1898 	return(0);
1899 }
1900 
1901 void
1902 mscachetoraw(sc)
1903 	struct fd_softc *sc;
1904 {
1905 	u_short *rp, *erp, crc;
1906 	u_char *cp, tb[5];
1907 	int sec, i;
1908 
1909 	rp = (u_short *)fdc_dmap;
1910 	erp = rp + sc->type->nwritew;
1911 	cp = sc->cachep;
1912 
1913 	/*
1914 	 * initial track filler  (828 * GAP1)
1915 	 */
1916 	for (i = 0; i < sc->type->gap; i++) {
1917 		*rp++ = FDMFMGAP1;
1918 		*rp++ = FDMFMGAP1;
1919 	}
1920 
1921 	for (sec = 0; sec < sc->nsectors; sec++) {
1922 
1923 		/*
1924 		 * leading sector gap
1925 		 * (12 * GAP2) + (3 * SYNC)
1926 		 */
1927 		for (i = 0; i < 12; i++)
1928 			*rp++ = FDMFMGAP2;
1929 		*rp++ = FDMFMSYNC;
1930 		*rp++ = FDMFMSYNC;
1931 		*rp++ = FDMFMSYNC;
1932 
1933 		/*
1934 		 * sector information
1935 		 * (ID) + track + side + sector + sector size + CRC16
1936 		 */
1937 		*rp++ = FDMFMID;
1938 		tb[0] = sc->cachetrk / FDNHEADS;
1939 		tb[1] = sc->cachetrk % FDNHEADS;
1940 		tb[2] = sec + 1;
1941 		i = sc->bytespersec;
1942 		tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1943 		rp = msblkencode(rp, tb, 4, &crc);
1944 		tb[0] = crc >> 8;
1945 		tb[1] = crc & 0xff;
1946 		tb[2] = 0x4e; /* GAP1 decoded */
1947 		rp = msblkencode(rp, tb, 3, 0);
1948 
1949 		/*
1950 		 * sector info/data gap
1951 		 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1952 		 */
1953 		for (i = 0; i < 21; i++)
1954 			*rp++ = FDMFMGAP1;
1955 		for (i = 0; i < 12; i++)
1956 			*rp++ = FDMFMGAP2;
1957 		*rp++ = FDMFMSYNC;
1958 		*rp++ = FDMFMSYNC;
1959 		*rp++ = FDMFMSYNC;
1960 
1961 		/*
1962 		 * sector data
1963 		 * (DATA) + ...data... + CRC16
1964 		 */
1965 		*rp++ = FDMFMDATA;
1966 		rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1967 		cp += sc->bytespersec;
1968 		tb[0] = crc >> 8;
1969 		tb[1] = crc & 0xff;
1970 		tb[2] = 0x4e; /* GAP3 decoded */
1971 		rp = msblkencode(rp, tb, 3, 0);
1972 
1973 		/*
1974 		 * trailing sector gap
1975 		 * (80 * GAP3)
1976 		 */
1977 		for (i = 0; i < 79; i++)
1978 			*rp++ = FDMFMGAP3;
1979 	}
1980 
1981 	/*
1982 	 * fill rest of track with GAP3
1983 	 */
1984 	while (rp != erp)
1985 		*rp++ = FDMFMGAP3;
1986 
1987 }
1988 
1989 int
1990 msrawtocache(sc)
1991 	struct fd_softc *sc;
1992 {
1993 	u_short *rp, *srp, *erp;
1994 	u_char tb[5], *cp;
1995 	int ct, sec, retry;
1996 
1997 	srp = rp = (u_short *)fdc_dmap;
1998 	erp = rp + sc->type->nreadw;
1999 	cp = sc->cachep;
2000 
2001 	for (ct = 0; ct < sc->nsectors; ct++) {
2002 		retry = 1;
2003 		do {
2004 			/*
2005 			 * skip leading gap to sync
2006 			 */
2007 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
2008 #ifdef DIAGNOSTIC
2009 				printf("%s: corrupted track (%d) data.\n",
2010 				sc->sc_dv.dv_xname, sc->cachetrk);
2011 #endif
2012 				return(-1);
2013 			}
2014 
2015 			/*
2016 			 * Grab sector info
2017 			 */
2018 			if (*rp++ != FDMFMID)
2019 				continue;
2020 			rp = msblkdecode(rp, tb, 4);
2021 #ifdef FDDEBUG
2022 			printf("sector id: sector %d, track %d, side %d,"
2023 			    "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
2024 #endif
2025 			if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
2026 			    tb[2] > sc->nsectors)
2027 				continue;
2028 
2029 			sec = tb[2];
2030 			sc->bytespersec = 128 << tb[3];
2031 			rp += 2; /* skip CRC-16 */
2032 
2033 			/*
2034 			 * skip gap and read in data
2035 			 */
2036 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
2037 				return(-1);
2038 			if (*rp++ != FDMFMDATA)
2039 				continue;
2040 			rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
2041 			    sc->bytespersec);
2042 			rp += 2; /* skip CRC-16 */
2043 
2044 			retry = 0;
2045 		} while (retry);
2046 	}
2047 	return(0);
2048 }
2049 
2050 /*
2051  * encode len longwords of `dp' data in amiga mfm block format (`rp')
2052  * this format specified that the odd bits are at current pos and even
2053  * bits at len + current pos
2054  */
2055 u_long *
2056 mfmblkencode(dp, rp, cp, len)
2057 	u_long *dp, *rp, *cp;
2058 	int len;
2059 {
2060 	u_long *sdp, *edp, d, dtmp, correct;
2061 
2062 	sdp = dp;
2063 	edp = dp + len;
2064 
2065 	if (*(rp - 1) & 0x1)
2066 		correct = 1;
2067 	else
2068 		correct = 0;
2069 	/*
2070 	 * do odd bits
2071 	 */
2072 	while (dp < edp) {
2073 		d = (*dp >> 1) & 0x55555555;	/* remove clock bits */
2074 		dtmp = d ^ 0x55555555;
2075 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2076 		/*
2077 		 * correct upper clock bit if needed
2078 		 */
2079 		if (correct)
2080 			d &= 0x7fffffff;
2081 		if (d & 0x1)
2082 			correct = 1;
2083 		else
2084 			correct = 0;
2085 		/*
2086 		 * do checksums and store in raw buffer
2087 		 */
2088 		if (cp)
2089 			*cp ^= d;
2090 		*rp++ = d;
2091 		dp++;
2092 	}
2093 	/*
2094 	 * do even bits
2095 	 */
2096 	dp = sdp;
2097 	while (dp < edp) {
2098 		d = *dp & 0x55555555;	/* remove clock bits */
2099 		dtmp = d ^ 0x55555555;
2100 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2101 		/*
2102 		 * correct upper clock bit if needed
2103 		 */
2104 		if (correct)
2105 			d &= 0x7fffffff;
2106 		if (d & 0x1)
2107 			correct = 1;
2108 		else
2109 			correct = 0;
2110 		/*
2111 		 * do checksums and store in raw buffer
2112 		 */
2113 		if (cp)
2114 			*cp ^= d;
2115 		*rp++ = d;
2116 		dp++;
2117 	}
2118 	if (cp)
2119 		*cp &= 0x55555555;
2120 	return(rp);
2121 }
2122 
2123 /*
2124  * decode len longwords of `dp' data in amiga mfm block format (`rp')
2125  * this format specified that the odd bits are at current pos and even
2126  * bits at len + current pos
2127  */
2128 u_long *
2129 mfmblkdecode(rp, dp, cp, len)
2130 	u_long *rp, *dp, *cp;
2131 	int len;
2132 {
2133 	u_long o, e;
2134 	int cnt;
2135 
2136 	cnt = len;
2137 	while (cnt--) {
2138 		o = *rp;
2139 		e = *(rp + len);
2140 		if (cp) {
2141 			*cp ^= o;
2142 			*cp ^= e;
2143 		}
2144 		o &= 0x55555555;
2145 		e &= 0x55555555;
2146 		*dp++ = (o << 1) | e;
2147 		rp++;
2148 	}
2149 	if (cp)
2150 		*cp &= 0x55555555;
2151 	return(rp + len);
2152 }
2153 
2154 /*
2155  * decode len words in standard MFM format to len bytes
2156  * of data.
2157  */
2158 u_short *
2159 msblkdecode(rp, cp, len)
2160 	u_short *rp;
2161 	u_char *cp;
2162 	int len;
2163 {
2164 	while (len--) {
2165 		*cp++ = msdecode[*rp & 0x7f] |
2166 		    (msdecode[(*rp >> 8) & 0x7f] << 4);
2167 		rp++;
2168 	}
2169 
2170 	return(rp);
2171 }
2172 
2173 /*
2174  * encode len bytes of data into len words in standard MFM format.
2175  * If a pointer is supplied for crc, calculate the CRC-16 of the data
2176  * as well.
2177  */
2178 u_short *
2179 msblkencode(rp, cp, len, crc)
2180 	u_short *rp;
2181 	u_char *cp;
2182 	int len;
2183 	u_short *crc;
2184 {
2185 	u_short td;
2186 	u_short mycrc;
2187 
2188 	/* preload crc for header (4 bytes)
2189 	 * or data (anything else)
2190 	 */
2191 	mycrc = (len == 4) ? 0xb230 : 0xe295;
2192 
2193 	while (len--) {
2194 		td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2195 
2196 		/* Check for zeros in top bit of encode and bottom
2197 		 * bit of previous encode.  if so, slap a one in betweem
2198 		 * them.
2199 		 */
2200 		if ((td & 0x140) == 0)
2201 			td |= 0x80;
2202 		if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2203 			td |= 0x8000;
2204 
2205 		*rp++ = td;
2206 
2207 		/*
2208 		 * calc crc if requested
2209 		 */
2210 		if (crc)
2211 			mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2212 
2213 		cp++;
2214 	}
2215 
2216 	if (crc)
2217 		*crc = mycrc;
2218 
2219 	return(rp);
2220 }
2221 
2222 int
2223 fddump(dev, blkno, va, size)
2224 	dev_t	dev;
2225 	daddr_t	blkno;
2226 	caddr_t	va;
2227 	size_t	size;
2228 {
2229 	return (EINVAL);
2230 }
2231