fd.c revision 1.86
1 /* $NetBSD: fd.c,v 1.86 2011/06/03 00:52:22 matt 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 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.86 2011/06/03 00:52:22 matt Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/callout.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/buf.h> 44 #include <sys/bufq.h> 45 #include <sys/device.h> 46 #include <sys/ioctl.h> 47 #include <sys/fcntl.h> 48 #include <sys/disklabel.h> 49 #include <sys/disk.h> 50 #include <sys/dkbad.h> 51 #include <sys/proc.h> 52 #include <sys/conf.h> 53 54 #include <machine/cpu.h> 55 #include <amiga/amiga/device.h> 56 #include <amiga/amiga/custom.h> 57 #include <amiga/amiga/cia.h> 58 #include <amiga/amiga/cc.h> 59 60 #include "locators.h" 61 62 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY }; 63 /* 64 * partitions in fd represent different format floppies 65 * partition a is 0 etc.. 66 */ 67 enum fd_parttypes { 68 FDAMIGAPART = 0, 69 FDMSDOSPART, 70 FDMAXPARTS 71 }; 72 73 #define FDBBSIZE (8192) 74 #define FDSBSIZE (8192) 75 76 #define FDUNIT(dev) DISKUNIT(dev) 77 #define FDPART(dev) DISKPART(dev) 78 #define FDMAKEDEV(m, u, p) MAKEDISKDEV((m), (u), (p)) 79 80 /* that's nice, but we don't want to always use this as an amiga drive 81 bunghole :-) */ 82 #define FDNHEADS (2) /* amiga drives always have 2 heads */ 83 #define FDSECSIZE (512) /* amiga drives always have 512 byte sectors */ 84 #define FDSECLWORDS (128) 85 86 #define FDSETTLEDELAY (18000) /* usec delay after seeking after switch dir */ 87 #define FDSTEPDELAY (3500) /* usec delay after steping */ 88 #define FDPRESIDEDELAY (1000) /* usec delay before writing can occur */ 89 #define FDWRITEDELAY (1300) /* usec delay after write */ 90 91 #define FDSTEPOUT (1) /* decrease track step */ 92 #define FDSTEPIN (0) /* increase track step */ 93 94 #define FDCUNITMASK (0x78) /* mask for all units (bits 6-3) */ 95 96 #define FDRETRIES (2) /* default number of retries */ 97 #define FDMAXUNITS (4) /* maximum number of supported units */ 98 99 #define DISKLEN_READ (0) /* fake mask for reading */ 100 #define DISKLEN_WRITE (1 << 14) /* bit for writing */ 101 #define DISKLEN_DMAEN (1 << 15) /* DMA go */ 102 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2) /* largest DMA possible */ 103 104 #define FDMFMSYNC (0x4489) 105 #define FDMFMID (0x5554) 106 #define FDMFMDATA (0x5545) 107 #define FDMFMGAP1 (0x9254) 108 #define FDMFMGAP2 (0xAAAA) 109 #define FDMFMGAP3 (0x9254) 110 #define CRC16POLY (0x1021) /* (x^16) + x^12 + x^5 + x^0 */ 111 112 /* 113 * Msdos-type MFM encode/decode 114 */ 115 static u_char msdecode[128]; 116 static u_char msencode[16] = 117 { 118 0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15, 119 0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55 120 }; 121 static u_short mscrctab[256]; 122 123 /* 124 5554 aaaa aaaa aaa5 2aa4 4452 aa51 125 00 00 03 02 ac 0d 126 */ 127 128 /* 129 * floppy device type 130 */ 131 struct fdtype { 132 u_int driveid; /* drive identification (from drive) */ 133 u_int ncylinders; /* number of cylinders on drive */ 134 u_int amiga_nsectors; /* number of sectors per amiga track */ 135 u_int msdos_nsectors; /* number of sectors per msdos track */ 136 u_int nreadw; /* number of words (short) read per track */ 137 u_int nwritew; /* number of words (short) written per track */ 138 u_int gap; /* track gap size in long words */ 139 const u_int precomp[2]; /* 1st and 2nd precomp values */ 140 const char *desc; /* description of drive type (useq) */ 141 }; 142 143 /* 144 * floppy disk device data 145 */ 146 struct fd_softc { 147 device_t sc_dev; /* generic device info; must come first */ 148 struct disk dkdev; /* generic disk info */ 149 struct bufq_state *bufq;/* queue pending I/O operations */ 150 struct buf curbuf; /* state of current I/O operation */ 151 struct callout calibrate_ch; 152 struct callout motor_ch; 153 struct fdtype *type; 154 void *cachep; /* cached track data (write through) */ 155 int cachetrk; /* cahced track -1 for none */ 156 int hwunit; /* unit for amiga controlling hw */ 157 int unitmask; /* mask for cia select deslect */ 158 int pstepdir; /* previous step direction */ 159 int curcyl; /* current curcyl head positioned on */ 160 int flags; /* misc flags */ 161 int wlabel; 162 int stepdelay; /* useq to delay after seek user setable */ 163 int nsectors; /* number of sectors per track */ 164 int openpart; /* which partition [ab] == [12] is open */ 165 short retries; /* number of times to retry failed io */ 166 short retried; /* number of times current io retried */ 167 int bytespersec; /* number of bytes per sector */ 168 }; 169 170 /* fd_softc->flags */ 171 #define FDF_MOTORON (0x01) /* motor is running */ 172 #define FDF_MOTOROFF (0x02) /* motor is waiting to be turned off */ 173 #define FDF_WMOTOROFF (0x04) /* unit wants a wakeup after off */ 174 #define FDF_DIRTY (0x08) /* track cache needs write */ 175 #define FDF_WRITEWAIT (0x10) /* need to head select delay on next setpos */ 176 #define FDF_HAVELABEL (0x20) /* label is valid */ 177 #define FDF_JUSTFLUSH (0x40) /* don't bother caching track. */ 178 #define FDF_NOTRACK0 (0x80) /* was not able to recalibrate drive */ 179 180 int fdc_wantwakeup; 181 int fdc_side; 182 void *fdc_dmap; 183 struct fd_softc *fdc_indma; 184 int fdc_dmalen; 185 int fdc_dmawrite; 186 187 struct fdcargs { 188 struct fdtype *type; 189 int unit; 190 }; 191 192 int fdcmatch(device_t, cfdata_t, void *); 193 void fdcattach(device_t, device_t, void *); 194 int fdcprint(void *, const char *); 195 int fdmatch(device_t, cfdata_t, void *); 196 void fdattach(device_t, device_t, void *); 197 198 void fdintr(int); 199 void fdidxintr(void); 200 int fdloaddisk(struct fd_softc *); 201 void fdgetdefaultlabel(struct fd_softc *, struct disklabel *, int); 202 int fdgetdisklabel(struct fd_softc *, dev_t); 203 int fdsetdisklabel(struct fd_softc *, struct disklabel *); 204 int fdputdisklabel(struct fd_softc *, dev_t); 205 struct fdtype * fdcgetfdtype(int); 206 void fdmotoroff(void *); 207 void fdsetpos(struct fd_softc *, int, int); 208 void fdselunit(struct fd_softc *); 209 void fdstart(struct fd_softc *); 210 void fdcont(struct fd_softc *); 211 void fddmastart(struct fd_softc *, int); 212 void fdcalibrate(void *); 213 void fddmadone(struct fd_softc *, int); 214 void fddone(struct fd_softc *); 215 void fdfindwork(int); 216 void fdminphys(struct buf *); 217 void fdcachetoraw(struct fd_softc *); 218 void amcachetoraw(struct fd_softc *); 219 int amrawtocache(struct fd_softc *); 220 u_long *fdfindsync(u_long *, u_long *); 221 int fdrawtocache(struct fd_softc *); 222 void mscachetoraw(struct fd_softc *); 223 int msrawtocache(struct fd_softc *); 224 u_long *mfmblkencode(u_long *, u_long *, u_long *, int); 225 u_long *mfmblkdecode(u_long *, u_long *, u_long *, int); 226 u_short *msblkdecode(u_short *, u_char *, int); 227 u_short *msblkencode(u_short *, u_char *, int, u_short *); 228 229 /* 230 * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts 231 * write size is nsectors * mfm secsize + gap bytes + 3 shorts 232 * the extra shorts are to deal with a DMA hw bug in the controller 233 * they are probably too much (I belive the bug is 1 short on write and 234 * 3 bits on read) but there is no need to be cheap here. 235 */ 236 #define MAXTRKSZ (22 * FDSECSIZE) 237 struct fdtype fdtype[] = { 238 { 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" }, 239 { 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" }, 240 { 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" } 241 }; 242 int nfdtype = __arraycount(fdtype); 243 244 CFATTACH_DECL_NEW(fd, sizeof(struct fd_softc), 245 fdmatch, fdattach, NULL, NULL); 246 247 extern struct cfdriver fd_cd; 248 249 dev_type_open(fdopen); 250 dev_type_close(fdclose); 251 dev_type_read(fdread); 252 dev_type_write(fdwrite); 253 dev_type_ioctl(fdioctl); 254 dev_type_strategy(fdstrategy); 255 256 const struct bdevsw fd_bdevsw = { 257 fdopen, fdclose, fdstrategy, fdioctl, nodump, nosize, D_DISK 258 }; 259 260 const struct cdevsw fd_cdevsw = { 261 fdopen, fdclose, fdread, fdwrite, fdioctl, 262 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 263 }; 264 265 struct dkdriver fddkdriver = { fdstrategy }; 266 267 CFATTACH_DECL_NEW(fdc, 0, 268 fdcmatch, fdcattach, NULL, NULL); 269 270 /* 271 * all hw access through macros, this helps to hide the active low 272 * properties 273 */ 274 275 #define FDUNITMASK(unit) (1 << (3 + (unit))) 276 277 /* 278 * select units using mask 279 */ 280 #define FDSELECT(um) do { ciab.prb &= ~(um); } while (0) 281 282 /* 283 * deselect units using mask 284 */ 285 #define FDDESELECT(um) do { ciab.prb |= (um); delay(1); } while (0) 286 287 /* 288 * test hw condition bits 289 */ 290 #define FDTESTC(bit) ((ciaa.pra & (1 << (bit))) == 0) 291 292 /* 293 * set motor for select units, true motor on else off 294 */ 295 #define FDSETMOTOR(on) do { \ 296 if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \ 297 } while (0) 298 299 /* 300 * set head for select units 301 */ 302 #define FDSETHEAD(head) do { \ 303 if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \ 304 delay(1); } while (0) 305 306 /* 307 * select direction, true towards spindle else outwards 308 */ 309 #define FDSETDIR(in) do { \ 310 if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \ 311 delay(1); } while (0) 312 313 /* 314 * step the selected units 315 */ 316 #define FDSTEP do { \ 317 ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \ 318 } while (0) 319 320 #define FDDMASTART(len, towrite) do { \ 321 int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \ 322 custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0) 323 324 #define FDDMASTOP do { custom.dsklen = 0; } while (0) 325 326 327 int 328 fdcmatch(device_t pdp, cfdata_t cfp, void *auxp) 329 { 330 static int fdc_matched = 0; 331 332 /* Allow only once instance. */ 333 if (matchname("fdc", auxp) == 0 || fdc_matched) 334 return(0); 335 if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) { 336 printf("fdc: unable to allocate DMA buffer\n"); 337 return(0); 338 } 339 340 fdc_matched = 1; 341 return(1); 342 } 343 344 void 345 fdcattach(device_t pdp, device_t dp, void *auxp) 346 { 347 struct fdcargs args; 348 349 printf(": dmabuf pa 0x%x", (unsigned)kvtop(fdc_dmap)); 350 printf(": dmabuf ka %p\n", fdc_dmap); 351 args.unit = 0; 352 args.type = fdcgetfdtype(args.unit); 353 354 fdc_side = -1; 355 config_found(dp, &args, fdcprint); 356 for (args.unit++; args.unit < FDMAXUNITS; args.unit++) { 357 if ((args.type = fdcgetfdtype(args.unit)) == NULL) 358 continue; 359 config_found(dp, &args, fdcprint); 360 } 361 } 362 363 int 364 fdcprint(void *auxp, const char *pnp) 365 { 366 struct fdcargs *fcp; 367 368 fcp = auxp; 369 if (pnp) 370 aprint_normal("fd%d at %s unit %d:", fcp->unit, pnp, 371 fcp->type->driveid); 372 return(UNCONF); 373 } 374 375 /*ARGSUSED*/ 376 int 377 fdmatch(device_t pdp, cfdata_t cfp, void *auxp) 378 { 379 struct fdcargs *fdap; 380 381 fdap = auxp; 382 if (cfp->cf_loc[FDCCF_UNIT] == fdap->unit || 383 cfp->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT) 384 return(1); 385 386 return(0); 387 } 388 389 void 390 fdattach(device_t pdp, device_t dp, void *auxp) 391 { 392 struct fdcargs *ap; 393 struct fd_softc *sc; 394 int i; 395 396 ap = auxp; 397 sc = device_private(dp); 398 sc->sc_dev = dp; 399 400 bufq_alloc(&sc->bufq, "disksort", BUFQ_SORT_CYLINDER); 401 callout_init(&sc->calibrate_ch, 0); 402 callout_init(&sc->motor_ch, 0); 403 404 sc->curcyl = sc->cachetrk = -1; 405 sc->openpart = -1; 406 sc->type = ap->type; 407 sc->hwunit = ap->unit; 408 sc->unitmask = 1 << (3 + ap->unit); 409 sc->retries = FDRETRIES; 410 sc->stepdelay = FDSTEPDELAY; 411 sc->bytespersec = 512; 412 printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n", 413 sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS, 414 sc->type->amiga_nsectors, sc->type->msdos_nsectors); 415 416 /* 417 * Initialize and attach the disk structure. 418 */ 419 disk_init(&sc->dkdev, device_xname(sc->sc_dev), &fddkdriver); 420 disk_attach(&sc->dkdev); 421 422 /* 423 * calibrate the drive 424 */ 425 fdsetpos(sc, 0, 0); 426 fdsetpos(sc, sc->type->ncylinders, 0); 427 fdsetpos(sc, 0, 0); 428 fdmotoroff(sc); 429 430 /* 431 * precalc msdos MFM and CRC 432 */ 433 for (i = 0; i < 128; i++) 434 msdecode[i] = 0xff; 435 for (i = 0; i < 16; i++) 436 msdecode[msencode[i]] = i; 437 for (i = 0; i < 256; i++) { 438 mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^ 439 (0x1021 * (i >> 4)); 440 } 441 442 /* 443 * enable disk related interrupts 444 */ 445 custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK; 446 custom.intena = INTF_SETCLR | INTF_DSKBLK; 447 ciab.icr = CIA_ICR_FLG; 448 } 449 450 /*ARGSUSED*/ 451 int 452 fdopen(dev_t dev, int flags, int devtype, struct lwp *l) 453 { 454 struct fd_softc *sc; 455 int wasopen, fwork, error, s; 456 457 error = 0; 458 459 if (FDPART(dev) >= FDMAXPARTS) 460 return(ENXIO); 461 462 if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL) 463 return(ENXIO); 464 if (sc->flags & FDF_NOTRACK0) 465 return(ENXIO); 466 if (sc->cachep == NULL) 467 sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK); 468 469 s = splbio(); 470 /* 471 * if we are sleeping in fdclose(); waiting for a chance to 472 * shut the motor off, do a sleep here also. 473 */ 474 while (sc->flags & FDF_WMOTOROFF) 475 tsleep(fdmotoroff, PRIBIO, "fdopen", 0); 476 477 fwork = 0; 478 /* 479 * if not open let user open request type, otherwise 480 * ensure they are trying to open same type. 481 */ 482 if (sc->openpart == FDPART(dev)) 483 wasopen = 1; 484 else if (sc->openpart == -1) { 485 sc->openpart = FDPART(dev); 486 wasopen = 0; 487 } else { 488 wasopen = 1; 489 error = EPERM; 490 goto done; 491 } 492 493 /* 494 * wait for current io to complete if any 495 */ 496 if (fdc_indma) { 497 fwork = 1; 498 fdc_wantwakeup++; 499 tsleep(fdopen, PRIBIO, "fdopen", 0); 500 } 501 if ((error = fdloaddisk(sc)) != 0) 502 goto done; 503 if ((error = fdgetdisklabel(sc, dev)) != 0) 504 goto done; 505 #ifdef FDDEBUG 506 printf(" open successful\n"); 507 #endif 508 done: 509 /* 510 * if we requested that fddone()->fdfindwork() wake us, allow it to 511 * complete its job now 512 */ 513 if (fwork) 514 fdfindwork(FDUNIT(dev)); 515 splx(s); 516 517 /* 518 * if we were not open and we marked us so reverse that. 519 */ 520 if (error && wasopen == 0) 521 sc->openpart = -1; 522 return(error); 523 } 524 525 /*ARGSUSED*/ 526 int 527 fdclose(dev_t dev, int flags, int devtype, struct lwp *l) 528 { 529 struct fd_softc *sc; 530 int s; 531 532 #ifdef FDDEBUG 533 printf("fdclose()\n"); 534 #endif 535 sc = getsoftc(fd_cd, FDUNIT(dev)); 536 s = splbio(); 537 if (sc->flags & FDF_MOTORON) { 538 sc->flags |= FDF_WMOTOROFF; 539 tsleep(fdmotoroff, PRIBIO, "fdclose", 0); 540 sc->flags &= ~FDF_WMOTOROFF; 541 wakeup(fdmotoroff); 542 } 543 sc->openpart = -1; 544 splx(s); 545 return(0); 546 } 547 548 int 549 fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) 550 { 551 struct fd_softc *sc; 552 int error, wlab; 553 554 sc = getsoftc(fd_cd, FDUNIT(dev)); 555 556 if ((sc->flags & FDF_HAVELABEL) == 0) 557 return(EBADF); 558 559 switch (cmd) { 560 case DIOCSBAD: 561 return(EINVAL); 562 case DIOCSRETRIES: 563 if (*(int *)addr < 0) 564 return(EINVAL); 565 sc->retries = *(int *)addr; 566 return(0); 567 case DIOCSSTEP: 568 if (*(int *)addr < FDSTEPDELAY) 569 return(EINVAL); 570 sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr; 571 return(0); 572 case DIOCGDINFO: 573 *(struct disklabel *)addr = *(sc->dkdev.dk_label); 574 return(0); 575 case DIOCGPART: 576 ((struct partinfo *)addr)->disklab = sc->dkdev.dk_label; 577 ((struct partinfo *)addr)->part = 578 &sc->dkdev.dk_label->d_partitions[FDPART(dev)]; 579 return(0); 580 case DIOCSDINFO: 581 if ((flag & FWRITE) == 0) 582 return(EBADF); 583 return(fdsetdisklabel(sc, (struct disklabel *)addr)); 584 case DIOCWDINFO: 585 if ((flag & FWRITE) == 0) 586 return(EBADF); 587 if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0) 588 return(error); 589 wlab = sc->wlabel; 590 sc->wlabel = 1; 591 error = fdputdisklabel(sc, dev); 592 sc->wlabel = wlab; 593 return(error); 594 case DIOCWLABEL: 595 if ((flag & FWRITE) == 0) 596 return(EBADF); 597 sc->wlabel = *(int *)addr; 598 return(0); 599 case DIOCGDEFLABEL: 600 fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev)); 601 return(0); 602 default: 603 return(ENOTTY); 604 } 605 } 606 607 int 608 fdread(dev_t dev, struct uio *uio, int flags) 609 { 610 return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio)); 611 } 612 613 int 614 fdwrite(dev_t dev, struct uio *uio, int flags) 615 { 616 return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio)); 617 } 618 619 620 void 621 fdintr(int flag) 622 { 623 int s; 624 625 s = splbio(); 626 if (fdc_indma) 627 fddmadone(fdc_indma, 0); 628 splx(s); 629 } 630 631 void 632 fdidxintr(void) 633 { 634 if (fdc_indma && fdc_dmalen) { 635 /* 636 * turn off intr and start actual dma 637 */ 638 ciab.icr = CIA_ICR_FLG; 639 FDDMASTART(fdc_dmalen, fdc_dmawrite); 640 fdc_dmalen = 0; 641 } 642 } 643 644 void 645 fdstrategy(struct buf *bp) 646 { 647 struct disklabel *lp; 648 struct fd_softc *sc; 649 int unit, part, s; 650 651 unit = FDUNIT(bp->b_dev); 652 part = FDPART(bp->b_dev); 653 sc = getsoftc(fd_cd, unit); 654 655 #ifdef FDDEBUG 656 printf("fdstrategy: %p\n", bp); 657 #endif 658 /* 659 * check for valid partition and bounds 660 */ 661 lp = sc->dkdev.dk_label; 662 if ((sc->flags & FDF_HAVELABEL) == 0) { 663 bp->b_error = EIO; 664 goto done; 665 } 666 if (bounds_check_with_label(&sc->dkdev, bp, sc->wlabel) <= 0) 667 goto done; 668 669 /* 670 * trans count of zero or bounds check indicates io is done 671 * we are done. 672 */ 673 if (bp->b_bcount == 0) 674 goto done; 675 676 bp->b_rawblkno = bp->b_blkno; 677 678 /* 679 * queue the buf and kick the low level code 680 */ 681 s = splbio(); 682 bufq_put(sc->bufq, bp); 683 fdstart(sc); 684 splx(s); 685 return; 686 done: 687 bp->b_resid = bp->b_bcount; 688 biodone(bp); 689 } 690 691 /* 692 * make sure disk is loaded and label is up-to-date. 693 */ 694 int 695 fdloaddisk(struct fd_softc *sc) 696 { 697 /* 698 * if diskchange is low step drive to 0 then up one then to zero. 699 */ 700 fdselunit(sc); /* make sure the unit is selected */ 701 if (FDTESTC(FDB_CHANGED)) { 702 fdsetpos(sc, 0, 0); 703 sc->cachetrk = -1; /* invalidate the cache */ 704 sc->flags &= ~FDF_HAVELABEL; 705 fdsetpos(sc, FDNHEADS, 0); 706 fdsetpos(sc, 0, 0); 707 if (FDTESTC(FDB_CHANGED)) { 708 fdmotoroff(sc); 709 FDDESELECT(sc->unitmask); 710 return(ENXIO); 711 } 712 } 713 FDDESELECT(sc->unitmask); 714 fdmotoroff(sc); 715 sc->type = fdcgetfdtype(sc->hwunit); 716 if (sc->type == NULL) 717 return(ENXIO); 718 if (sc->openpart == FDMSDOSPART) 719 sc->nsectors = sc->type->msdos_nsectors; 720 else 721 sc->nsectors = sc->type->amiga_nsectors; 722 return(0); 723 } 724 725 void 726 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part) 727 /* (variable part) XXX ick */ 728 { 729 730 memset(lp, 0, sizeof(struct disklabel)); 731 lp->d_secsize = FDSECSIZE; 732 lp->d_ntracks = FDNHEADS; 733 lp->d_ncylinders = sc->type->ncylinders; 734 lp->d_nsectors = sc->nsectors; 735 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 736 lp->d_type = DTYPE_FLOPPY; 737 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 738 lp->d_rpm = 300; /* good guess I suppose. */ 739 lp->d_interleave = 1; /* should change when adding msdos */ 740 sc->stepdelay = lp->d_trkseek = FDSTEPDELAY; 741 lp->d_bbsize = 0; 742 lp->d_sbsize = 0; 743 lp->d_partitions[part].p_size = lp->d_secperunit; 744 lp->d_partitions[part].p_fstype = FS_UNUSED; 745 lp->d_partitions[part].p_fsize = 1024; 746 lp->d_partitions[part].p_frag = 8; 747 lp->d_partitions[part].p_cpg = 2; /* adosfs: reserved blocks */ 748 lp->d_npartitions = part + 1; 749 lp->d_magic = lp->d_magic2 = DISKMAGIC; 750 lp->d_checksum = dkcksum(lp); 751 } 752 753 /* 754 * read disk label, if present otherwise create one 755 * return a new label if raw part and none found, otherwise err. 756 */ 757 int 758 fdgetdisklabel(struct fd_softc *sc, dev_t dev) 759 { 760 struct disklabel *lp, *dlp; 761 struct cpu_disklabel *clp; 762 struct buf *bp; 763 int error, part; 764 765 if (sc->flags & FDF_HAVELABEL && 766 sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1)) 767 return(0); 768 #ifdef FDDEBUG 769 printf("fdgetdisklabel()\n"); 770 #endif 771 part = FDPART(dev); 772 lp = sc->dkdev.dk_label; 773 clp = sc->dkdev.dk_cpulabel; 774 memset(lp, 0, sizeof(struct disklabel)); 775 memset(clp, 0, sizeof(struct cpu_disklabel)); 776 777 lp->d_secsize = FDSECSIZE; 778 lp->d_ntracks = FDNHEADS; 779 lp->d_ncylinders = sc->type->ncylinders; 780 lp->d_nsectors = sc->nsectors; 781 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 782 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 783 lp->d_npartitions = part + 1; 784 lp->d_partitions[part].p_size = lp->d_secperunit; 785 lp->d_partitions[part].p_fstype = FS_UNUSED; 786 lp->d_partitions[part].p_fsize = 1024; 787 lp->d_partitions[part].p_frag = 8; 788 lp->d_partitions[part].p_cpg = 2; /* for adosfs: reserved blks */ 789 790 sc->flags |= FDF_HAVELABEL; 791 792 bp = (void *)geteblk((int)lp->d_secsize); 793 bp->b_dev = dev; 794 bp->b_blkno = 0; 795 bp->b_cylinder = 0; 796 bp->b_bcount = FDSECSIZE; 797 bp->b_flags |= B_READ; 798 fdstrategy(bp); 799 if ((error = biowait(bp)) != 0) 800 goto nolabel; 801 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 802 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC || 803 dkcksum(dlp)) { 804 error = EINVAL; 805 goto nolabel; 806 } 807 memcpy(lp, dlp, sizeof(struct disklabel)); 808 if (lp->d_trkseek > FDSTEPDELAY) 809 sc->stepdelay = lp->d_trkseek; 810 brelse(bp, 0); 811 return(0); 812 nolabel: 813 fdgetdefaultlabel(sc, lp, part); 814 brelse(bp, 0); 815 return(0); 816 } 817 818 /* 819 * set the incore copy of this units disklabel 820 */ 821 int 822 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp) 823 { 824 struct disklabel *clp; 825 struct partition *pp; 826 827 /* 828 * must have at least opened raw unit to fetch the 829 * raw_part stuff. 830 */ 831 if ((sc->flags & FDF_HAVELABEL) == 0) 832 return(EINVAL); 833 clp = sc->dkdev.dk_label; 834 /* 835 * make sure things check out and we only have one valid 836 * partition 837 */ 838 #ifdef FDDEBUG 839 printf("fdsetdisklabel\n"); 840 #endif 841 if (lp->d_secsize != FDSECSIZE || 842 lp->d_nsectors != clp->d_nsectors || 843 lp->d_ntracks != FDNHEADS || 844 lp->d_ncylinders != clp->d_ncylinders || 845 lp->d_secpercyl != clp->d_secpercyl || 846 lp->d_secperunit != clp->d_secperunit || 847 lp->d_magic != DISKMAGIC || 848 lp->d_magic2 != DISKMAGIC || 849 lp->d_npartitions == 0 || 850 lp->d_npartitions > FDMAXPARTS || 851 (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) || 852 dkcksum(lp)) 853 return(EINVAL); 854 /* 855 * if any partitions are present make sure they 856 * represent the currently open type 857 */ 858 if ((pp = &lp->d_partitions[0])->p_size) { 859 if ((pp = &lp->d_partitions[1])->p_size == 0) 860 goto done; 861 else if (sc->openpart != 1) 862 return(EINVAL); 863 } else if (sc->openpart != 0) 864 return(EINVAL); 865 /* 866 * make sure selected partition is within bounds 867 * XXX on the second check, its to handle a bug in 868 * XXX the cluster routines as they require mutliples 869 * XXX of PAGE_SIZE currently 870 */ 871 if ((pp->p_offset + pp->p_size >= lp->d_secperunit) || 872 (pp->p_frag * pp->p_fsize % PAGE_SIZE)) 873 return(EINVAL); 874 done: 875 memcpy(clp, lp, sizeof(struct disklabel)); 876 return(0); 877 } 878 879 /* 880 * write out the incore copy of this units disklabel 881 */ 882 int 883 fdputdisklabel(struct fd_softc *sc, dev_t dev) 884 { 885 struct disklabel *lp, *dlp; 886 struct buf *bp; 887 int error; 888 889 if ((sc->flags & FDF_HAVELABEL) == 0) 890 return(EBADF); 891 #ifdef FDDEBUG 892 printf("fdputdisklabel\n"); 893 #endif 894 /* 895 * get buf and read in sector 0 896 */ 897 lp = sc->dkdev.dk_label; 898 bp = geteblk((int)lp->d_secsize); 899 bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART); 900 bp->b_blkno = 0; 901 bp->b_cylinder = 0; 902 bp->b_bcount = FDSECSIZE; 903 bp->b_flags |= B_READ; 904 fdstrategy(bp); 905 if ((error = biowait(bp)) != 0) 906 goto done; 907 /* 908 * copy disklabel to buf and write it out synchronous 909 */ 910 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 911 memcpy(dlp, lp, sizeof(struct disklabel)); 912 bp->b_blkno = 0; 913 bp->b_cylinder = 0; 914 bp->b_flags &= ~(B_READ); 915 bp->b_oflags &= ~(BO_DONE); 916 bp->b_flags |= B_WRITE; 917 fdstrategy(bp); 918 error = biowait(bp); 919 done: 920 brelse(bp, 0); 921 return(error); 922 } 923 924 /* 925 * figure out drive type or NULL if none. 926 */ 927 struct fdtype * 928 fdcgetfdtype(int unit) 929 { 930 struct fdtype *ftp; 931 u_long id, idb; 932 int cnt, umask; 933 934 id = 0; 935 umask = 1 << (3 + unit); 936 937 FDDESELECT(FDCUNITMASK); 938 939 FDSETMOTOR(1); 940 delay(1); 941 FDSELECT(umask); 942 delay(1); 943 FDDESELECT(umask); 944 945 FDSETMOTOR(0); 946 delay(1); 947 FDSELECT(umask); 948 delay(1); 949 FDDESELECT(umask); 950 951 for (idb = 0x80000000; idb; idb >>= 1) { 952 FDSELECT(umask); 953 delay(1); 954 if (FDTESTC(FDB_READY) == 0) 955 id |= idb; 956 FDDESELECT(umask); 957 delay(1); 958 } 959 #ifdef FDDEBUG 960 printf("fdcgettype unit %d id 0x%lx\n", unit, id); 961 #endif 962 963 for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++) 964 if (ftp->driveid == id) 965 return(ftp); 966 /* 967 * 3.5dd's at unit 0 do not always return id. 968 */ 969 if (unit == 0) 970 return(fdtype); 971 return(NULL); 972 } 973 974 /* 975 * turn motor off if possible otherwise mark as needed and will be done 976 * later. 977 */ 978 void 979 fdmotoroff(void *arg) 980 { 981 struct fd_softc *sc; 982 int s; 983 984 sc = arg; 985 s = splbio(); 986 987 #ifdef FDDEBUG 988 printf("fdmotoroff: unit %d\n", sc->hwunit); 989 #endif 990 if ((sc->flags & FDF_MOTORON) == 0) 991 goto done; 992 /* 993 * if we have a timeout on a DMA operation let fddmadone() 994 * deal with it. 995 */ 996 if (fdc_indma == sc) { 997 fddmadone(sc, 1); 998 goto done; 999 } 1000 #ifdef FDDEBUG 1001 printf(" motor was on, turning off\n"); 1002 #endif 1003 1004 /* 1005 * flush cache if needed 1006 */ 1007 if (sc->flags & FDF_DIRTY) { 1008 sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF; 1009 #ifdef FDDEBUG 1010 printf(" flushing dirty buffer first\n"); 1011 #endif 1012 /* 1013 * if DMA'ing done for now, fddone() will call us again 1014 */ 1015 if (fdc_indma) 1016 goto done; 1017 fddmastart(sc, sc->cachetrk); 1018 goto done; 1019 } 1020 1021 /* 1022 * if controller is busy just schedule us to be called back 1023 */ 1024 if (fdc_indma) { 1025 /* 1026 * someone else has the controller now 1027 * just set flag and let fddone() call us again. 1028 */ 1029 sc->flags |= FDF_MOTOROFF; 1030 goto done; 1031 } 1032 1033 #ifdef FDDEBUG 1034 printf(" hw turning unit off\n"); 1035 #endif 1036 1037 sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF); 1038 FDDESELECT(FDCUNITMASK); 1039 FDSETMOTOR(0); 1040 delay(1); 1041 FDSELECT(sc->unitmask); 1042 delay(4); 1043 FDDESELECT(sc->unitmask); 1044 delay(1); 1045 if (sc->flags & FDF_WMOTOROFF) 1046 wakeup(fdmotoroff); 1047 done: 1048 splx(s); 1049 } 1050 1051 /* 1052 * select drive seek to track exit with motor on. 1053 * fdsetpos(x, 0, 0) does calibrates the drive. 1054 */ 1055 void 1056 fdsetpos(struct fd_softc *sc, int trk, int towrite) 1057 { 1058 int nstep, sdir, ondly, ncyl, nside; 1059 1060 FDDESELECT(FDCUNITMASK); 1061 FDSETMOTOR(1); 1062 delay(1); 1063 FDSELECT(sc->unitmask); 1064 delay(1); 1065 if ((sc->flags & FDF_MOTORON) == 0) { 1066 ondly = 0; 1067 while (FDTESTC(FDB_READY) == 0) { 1068 delay(1000); 1069 if (++ondly >= 1000) 1070 break; 1071 } 1072 } 1073 sc->flags |= FDF_MOTORON; 1074 1075 ncyl = trk / FDNHEADS; 1076 nside = trk % FDNHEADS; 1077 1078 if (sc->curcyl == ncyl && fdc_side == nside) 1079 return; 1080 1081 if (towrite) 1082 sc->flags |= FDF_WRITEWAIT; 1083 1084 #ifdef FDDEBUG 1085 printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS, 1086 trk % FDNHEADS, towrite); 1087 #endif 1088 nstep = ncyl - sc->curcyl; 1089 if (nstep) { 1090 /* 1091 * figure direction 1092 */ 1093 if (nstep > 0 && ncyl != 0) { 1094 sdir = FDSTEPIN; 1095 FDSETDIR(1); 1096 } else { 1097 nstep = -nstep; 1098 sdir = FDSTEPOUT; 1099 FDSETDIR(0); 1100 } 1101 if (ncyl == 0) { 1102 /* 1103 * either just want cylinder 0 or doing 1104 * a calibrate. 1105 */ 1106 nstep = 256; 1107 while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) { 1108 FDSTEP; 1109 delay(sc->stepdelay); 1110 } 1111 if (nstep < 0) 1112 sc->flags |= FDF_NOTRACK0; 1113 } else { 1114 /* 1115 * step the needed amount amount. 1116 */ 1117 while (nstep--) { 1118 FDSTEP; 1119 delay(sc->stepdelay); 1120 } 1121 } 1122 /* 1123 * if switched directions 1124 * allow drive to settle. 1125 */ 1126 if (sc->pstepdir != sdir) 1127 delay(FDSETTLEDELAY); 1128 sc->pstepdir = sdir; 1129 sc->curcyl = ncyl; 1130 } 1131 if (nside == fdc_side) 1132 return; 1133 /* 1134 * select side 1135 */ 1136 fdc_side = nside; 1137 FDSETHEAD(nside); 1138 delay(FDPRESIDEDELAY); 1139 } 1140 1141 void 1142 fdselunit(struct fd_softc *sc) 1143 { 1144 FDDESELECT(FDCUNITMASK); /* deselect all */ 1145 FDSETMOTOR(sc->flags & FDF_MOTORON); /* set motor to unit's state */ 1146 delay(1); 1147 FDSELECT(sc->unitmask); /* select unit */ 1148 delay(1); 1149 } 1150 1151 /* 1152 * process next buf on device queue. 1153 * normall sequence of events: 1154 * fdstart() -> fddmastart(); 1155 * fdidxintr(); 1156 * fdintr() -> fddmadone() -> fddone(); 1157 * if the track is in the cache then fdstart() will short-circuit 1158 * to fddone() else if the track cache is dirty it will flush. If 1159 * the buf is not an entire track it will cache the requested track. 1160 */ 1161 void 1162 fdstart(struct fd_softc *sc) 1163 { 1164 int trk, error, write; 1165 struct buf *bp, *dp; 1166 int changed; 1167 1168 #ifdef FDDEBUG 1169 printf("fdstart: unit %d\n", sc->hwunit); 1170 #endif 1171 1172 /* 1173 * if DMA'ing just return. we must have been called from fdstartegy. 1174 */ 1175 if (fdc_indma) 1176 return; 1177 1178 /* 1179 * get next buf if there. 1180 */ 1181 dp = &sc->curbuf; 1182 if ((bp = bufq_peek(sc->bufq)) == NULL) { 1183 #ifdef FDDEBUG 1184 printf(" nothing to do\n"); 1185 #endif 1186 return; 1187 } 1188 1189 /* 1190 * Mark us as busy now, in case fddone() gets called in one 1191 * of the cases below. 1192 */ 1193 disk_busy(&sc->dkdev); 1194 1195 /* 1196 * make sure same disk is loaded 1197 */ 1198 fdselunit(sc); 1199 changed = FDTESTC(FDB_CHANGED); 1200 FDDESELECT(sc->unitmask); 1201 if (changed) { 1202 /* 1203 * disk missing, invalidate all future io on 1204 * this unit until re-open()'ed also invalidate 1205 * all current io 1206 */ 1207 printf("fdstart: disk changed\n"); 1208 #ifdef FDDEBUG 1209 printf(" disk was removed invalidating all io\n"); 1210 #endif 1211 sc->flags &= ~FDF_HAVELABEL; 1212 for (;;) { 1213 bp = bufq_get(sc->bufq); 1214 bp->b_error = EIO; 1215 if (bufq_peek(sc->bufq) == NULL) 1216 break; 1217 biodone(bp); 1218 } 1219 /* 1220 * do fddone() on last buf to allow other units to start. 1221 */ 1222 bufq_put(sc->bufq, bp); 1223 fddone(sc); 1224 return; 1225 } 1226 1227 /* 1228 * we have a valid buf, setup our local version 1229 * we use this count to allow reading over multiple tracks. 1230 * into a single buffer 1231 */ 1232 dp->b_bcount = bp->b_bcount; 1233 dp->b_blkno = bp->b_blkno; 1234 dp->b_data = bp->b_data; 1235 dp->b_flags = bp->b_flags; 1236 dp->b_resid = 0; 1237 1238 if (bp->b_flags & B_READ) 1239 write = 0; 1240 else if (FDTESTC(FDB_PROTECT) == 0) 1241 write = 1; 1242 else { 1243 error = EPERM; 1244 goto done; 1245 } 1246 1247 /* 1248 * figure trk given blkno 1249 */ 1250 trk = bp->b_blkno / sc->nsectors; 1251 1252 /* 1253 * check to see if same as currently cached track 1254 * if so we need to do no DMA read. 1255 */ 1256 if (trk == sc->cachetrk) { 1257 fddone(sc); 1258 return; 1259 } 1260 1261 /* 1262 * if we will be overwriting the entire cache, don't bother to 1263 * fetch it. 1264 */ 1265 if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write && 1266 bp->b_blkno % sc->nsectors == 0) { 1267 if (sc->flags & FDF_DIRTY) 1268 sc->flags |= FDF_JUSTFLUSH; 1269 else { 1270 sc->cachetrk = trk; 1271 fddone(sc); 1272 return; 1273 } 1274 } 1275 1276 /* 1277 * start DMA read of `trk' 1278 */ 1279 fddmastart(sc, trk); 1280 return; 1281 done: 1282 bp->b_error = error; 1283 fddone(sc); 1284 } 1285 1286 /* 1287 * continue a started operation on next track. always begin at 1288 * sector 0 on the next track. 1289 */ 1290 void 1291 fdcont(struct fd_softc *sc) 1292 { 1293 struct buf *dp, *bp; 1294 int trk, write; 1295 1296 dp = &sc->curbuf; 1297 bp = bufq_peek(sc->bufq); 1298 dp->b_data = (char*)dp->b_data + (dp->b_bcount - bp->b_resid); 1299 dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE; 1300 dp->b_bcount = bp->b_resid; 1301 1302 /* 1303 * figure trk given blkno 1304 */ 1305 trk = dp->b_blkno / sc->nsectors; 1306 #ifdef DEBUG 1307 if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0) 1308 panic("fdcont: confused"); 1309 #endif 1310 if (dp->b_flags & B_READ) 1311 write = 0; 1312 else 1313 write = 1; 1314 /* 1315 * if we will be overwriting the entire cache, don't bother to 1316 * fetch it. 1317 */ 1318 if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) { 1319 if (sc->flags & FDF_DIRTY) 1320 sc->flags |= FDF_JUSTFLUSH; 1321 else { 1322 sc->cachetrk = trk; 1323 fddone(sc); 1324 return; 1325 } 1326 } 1327 /* 1328 * start DMA read of `trk' 1329 */ 1330 fddmastart(sc, trk); 1331 return; 1332 } 1333 1334 void 1335 fddmastart(struct fd_softc *sc, int trk) 1336 { 1337 int adkmask, ndmaw, write, dmatrk; 1338 1339 #ifdef FDDEBUG 1340 printf("fddmastart: unit %d cyl %d head %d", sc->hwunit, 1341 trk / FDNHEADS, trk % FDNHEADS); 1342 #endif 1343 /* 1344 * flush the cached track if dirty else read requested track. 1345 */ 1346 if (sc->flags & FDF_DIRTY) { 1347 fdcachetoraw(sc); 1348 ndmaw = sc->type->nwritew; 1349 dmatrk = sc->cachetrk; 1350 write = 1; 1351 } else { 1352 ndmaw = sc->type->nreadw; 1353 dmatrk = trk; 1354 write = 0; 1355 } 1356 1357 #ifdef FDDEBUG 1358 printf(" %s", write ? " flushing cache\n" : " loading cache\n"); 1359 #endif 1360 sc->cachetrk = trk; 1361 fdc_indma = sc; 1362 fdsetpos(sc, dmatrk, write); 1363 1364 /* 1365 * setup dma stuff 1366 */ 1367 if (write == 0) { 1368 custom.adkcon = ADKF_MSBSYNC; 1369 custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST; 1370 custom.dsksync = FDMFMSYNC; 1371 } else { 1372 custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC | 1373 ADKF_MSBSYNC; 1374 adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC; 1375 if (dmatrk >= sc->type->precomp[0]) 1376 adkmask |= ADKF_PRECOMP0; 1377 if (dmatrk >= sc->type->precomp[1]) 1378 adkmask |= ADKF_PRECOMP1; 1379 custom.adkcon = adkmask; 1380 } 1381 custom.dskpt = (u_char *)kvtop(fdc_dmap); 1382 1383 /* 1384 * If writing an MSDOS track, activate disk index pulse 1385 * interrupt, DMA will be started in the intr routine fdidxintr() 1386 * Otherwise, start the DMA here. 1387 */ 1388 if (write && sc->openpart == FDMSDOSPART) { 1389 fdc_dmalen = ndmaw; 1390 fdc_dmawrite = write; 1391 ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG; 1392 } else { 1393 FDDMASTART(ndmaw, write); 1394 fdc_dmalen = 0; 1395 } 1396 1397 #ifdef FDDEBUG 1398 printf(" DMA started\n"); 1399 #endif 1400 } 1401 1402 /* 1403 * recalibrate the drive 1404 */ 1405 void 1406 fdcalibrate(void *arg) 1407 { 1408 struct fd_softc *sc; 1409 static int loopcnt; 1410 1411 sc = arg; 1412 1413 if (loopcnt == 0) { 1414 /* 1415 * seek cyl 0 1416 */ 1417 fdc_indma = sc; 1418 sc->stepdelay += 900; 1419 if (sc->cachetrk > 1) 1420 fdsetpos(sc, sc->cachetrk % FDNHEADS, 0); 1421 sc->stepdelay -= 900; 1422 } 1423 if (loopcnt++ & 1) 1424 fdsetpos(sc, sc->cachetrk, 0); 1425 else 1426 fdsetpos(sc, sc->cachetrk + FDNHEADS, 0); 1427 /* 1428 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and DMA 1429 */ 1430 if (loopcnt < 8) 1431 callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc); 1432 else { 1433 loopcnt = 0; 1434 fdc_indma = NULL; 1435 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1436 fddmastart(sc, sc->cachetrk); 1437 } 1438 } 1439 1440 void 1441 fddmadone(struct fd_softc *sc, int timeo) 1442 { 1443 #ifdef FDDEBUG 1444 printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo); 1445 #endif 1446 fdc_indma = NULL; 1447 callout_stop(&sc->motor_ch); 1448 FDDMASTOP; 1449 1450 /* 1451 * guarantee the drive has been at current head and cyl 1452 * for at least FDWRITEDELAY after a write. 1453 */ 1454 if (sc->flags & FDF_WRITEWAIT) { 1455 delay(FDWRITEDELAY); 1456 sc->flags &= ~FDF_WRITEWAIT; 1457 } 1458 1459 if ((sc->flags & FDF_MOTOROFF) == 0) { 1460 /* 1461 * motor runs for 1.5 seconds after last DMA 1462 */ 1463 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1464 } 1465 if (sc->flags & FDF_DIRTY) { 1466 /* 1467 * if buffer dirty, the last DMA cleaned it 1468 */ 1469 sc->flags &= ~FDF_DIRTY; 1470 if (timeo) 1471 aprint_error_dev(sc->sc_dev, 1472 "write of track cache timed out.\n"); 1473 if (sc->flags & FDF_JUSTFLUSH) { 1474 sc->flags &= ~FDF_JUSTFLUSH; 1475 /* 1476 * we are done DMA'ing 1477 */ 1478 fddone(sc); 1479 return; 1480 } 1481 /* 1482 * load the cache 1483 */ 1484 fddmastart(sc, sc->cachetrk); 1485 return; 1486 } 1487 #ifdef FDDEBUG 1488 else if (sc->flags & FDF_MOTOROFF) 1489 panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY"); 1490 #endif 1491 1492 /* 1493 * cache loaded decode it into cache buffer 1494 */ 1495 if (timeo == 0 && fdrawtocache(sc) == 0) 1496 sc->retried = 0; 1497 else { 1498 #ifdef FDDEBUG 1499 if (timeo) 1500 aprint_debug_dev(sc->sc_dev, 1501 "fddmadone: cache load timed out.\n"); 1502 #endif 1503 if (sc->retried >= sc->retries) { 1504 sc->retried = 0; 1505 sc->cachetrk = -1; 1506 } else { 1507 sc->retried++; 1508 /* 1509 * this will be restarted at end of calibrate loop. 1510 */ 1511 callout_stop(&sc->motor_ch); 1512 fdcalibrate(sc); 1513 return; 1514 } 1515 } 1516 fddone(sc); 1517 } 1518 1519 void 1520 fddone(struct fd_softc *sc) 1521 { 1522 struct buf *dp, *bp; 1523 char *data; 1524 int sz; 1525 1526 #ifdef FDDEBUG 1527 printf("fddone: unit %d\n", sc->hwunit); 1528 #endif 1529 /* 1530 * check to see if unit is just flushing the cache, 1531 * that is we have no io queued. 1532 */ 1533 if (sc->flags & FDF_MOTOROFF) 1534 goto nobuf; 1535 1536 dp = &sc->curbuf; 1537 if ((bp = bufq_peek(sc->bufq)) == NULL) 1538 panic ("fddone"); 1539 /* 1540 * check for an error that may have occurred 1541 * while getting the track. 1542 */ 1543 if (sc->cachetrk == -1) { 1544 sc->retried = 0; 1545 bp->b_error = EIO; 1546 } else if (bp->b_error == 0) { 1547 data = sc->cachep; 1548 /* 1549 * get offset of data in track cache and limit 1550 * the copy size to not exceed the cache's end. 1551 */ 1552 data += (dp->b_blkno % sc->nsectors) * FDSECSIZE; 1553 sz = sc->nsectors - dp->b_blkno % sc->nsectors; 1554 sz *= FDSECSIZE; 1555 sz = min(dp->b_bcount, sz); 1556 if (bp->b_flags & B_READ) 1557 memcpy(dp->b_data, data, sz); 1558 else { 1559 memcpy(data, dp->b_data, sz); 1560 sc->flags |= FDF_DIRTY; 1561 } 1562 bp->b_resid = dp->b_bcount - sz; 1563 if (bp->b_resid == 0) { 1564 bp->b_error = 0; 1565 } else { 1566 /* 1567 * not done yet need to read next track 1568 */ 1569 fdcont(sc); 1570 return; 1571 } 1572 } 1573 /* 1574 * remove from queue. 1575 */ 1576 (void)bufq_get(sc->bufq); 1577 1578 disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid), 1579 (bp->b_flags & B_READ)); 1580 1581 biodone(bp); 1582 nobuf: 1583 fdfindwork(device_unit(sc->sc_dev)); 1584 } 1585 1586 void 1587 fdfindwork(int unit) 1588 { 1589 struct fd_softc *ssc, *sc; 1590 int i, last; 1591 1592 /* 1593 * first see if we have any fdopen()'s waiting 1594 */ 1595 if (fdc_wantwakeup) { 1596 wakeup(fdopen); 1597 fdc_wantwakeup--; 1598 return; 1599 } 1600 1601 /* 1602 * start next available unit, linear search from the next unit 1603 * wrapping and finally this unit. 1604 */ 1605 last = 0; 1606 ssc = NULL; 1607 for (i = unit + 1; last == 0; i++) { 1608 if (i == unit) 1609 last = 1; 1610 if (i >= fd_cd.cd_ndevs) { 1611 i = -1; 1612 continue; 1613 } 1614 if ((sc = device_lookup_private(&fd_cd, i)) == NULL) 1615 continue; 1616 1617 /* 1618 * if unit has requested to be turned off 1619 * and it has no buf's queued do it now 1620 */ 1621 if (sc->flags & FDF_MOTOROFF) { 1622 if (bufq_peek(sc->bufq) == NULL) 1623 fdmotoroff(sc); 1624 else { 1625 /* 1626 * we gained a buf request while 1627 * we waited, forget the motoroff 1628 */ 1629 sc->flags &= ~FDF_MOTOROFF; 1630 } 1631 /* 1632 * if we now have DMA unit must have needed 1633 * flushing, quit 1634 */ 1635 if (fdc_indma) 1636 return; 1637 } 1638 /* 1639 * if we have no start unit and the current unit has 1640 * io waiting choose this unit to start. 1641 */ 1642 if (ssc == NULL && bufq_peek(sc->bufq) != NULL) 1643 ssc = sc; 1644 } 1645 if (ssc) 1646 fdstart(ssc); 1647 } 1648 1649 /* 1650 * min byte count to whats left of the track in question 1651 */ 1652 void 1653 fdminphys(struct buf *bp) 1654 { 1655 struct fd_softc *sc; 1656 int trk, sec, toff, tsz; 1657 1658 if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL) 1659 panic("fdminphys: couldn't get softc"); 1660 1661 trk = bp->b_blkno / sc->nsectors; 1662 sec = bp->b_blkno % sc->nsectors; 1663 1664 toff = sec * FDSECSIZE; 1665 tsz = sc->nsectors * FDSECSIZE; 1666 #ifdef FDDEBUG 1667 printf("fdminphys: before %ld", bp->b_bcount); 1668 #endif 1669 bp->b_bcount = min(bp->b_bcount, tsz - toff); 1670 #ifdef FDDEBUG 1671 printf(" after %ld\n", bp->b_bcount); 1672 #endif 1673 minphys(bp); 1674 } 1675 1676 /* 1677 * encode the track cache into raw MFM ready for DMA 1678 * when we go to multiple disk formats, this will call type dependent 1679 * functions 1680 */ 1681 void fdcachetoraw(struct fd_softc *sc) 1682 { 1683 if (sc->openpart == FDMSDOSPART) 1684 mscachetoraw(sc); 1685 else 1686 amcachetoraw(sc); 1687 } 1688 1689 /* 1690 * decode raw MFM from DMA into units track cache. 1691 * when we go to multiple disk formats, this will call type dependent 1692 * functions 1693 */ 1694 int 1695 fdrawtocache(struct fd_softc *sc) 1696 { 1697 1698 if (sc->openpart == FDMSDOSPART) 1699 return(msrawtocache(sc)); 1700 else 1701 return(amrawtocache(sc)); 1702 } 1703 1704 void 1705 amcachetoraw(struct fd_softc *sc) 1706 { 1707 static u_long mfmnull[4]; 1708 u_long *rp, *crp, *dp, hcksum, dcksum, info, zero; 1709 int sec, i; 1710 1711 rp = fdc_dmap; 1712 1713 /* 1714 * not yet one sector (- 1 long) gap. 1715 * for now use previous drivers values 1716 */ 1717 for (i = 0; i < sc->type->gap; i++) 1718 *rp++ = 0xaaaaaaaa; 1719 /* 1720 * process sectors 1721 */ 1722 dp = sc->cachep; 1723 zero = 0; 1724 info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors; 1725 for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) { 1726 hcksum = dcksum = 0; 1727 /* 1728 * sector format 1729 * offset description 1730 *----------------------------------- 1731 * 0 null 1732 * 1 sync 1733 * oddbits evenbits 1734 *---------------------- 1735 * 2 3 [0xff]b [trk]b [sec]b [togap]b 1736 * 4-7 8-11 null 1737 * 12 13 header cksum [2-11] 1738 * 14 15 data cksum [16-271] 1739 * 16-143 144-271 data 1740 */ 1741 *rp = 0xaaaaaaaa; 1742 if (*(rp - 1) & 0x1) 1743 *rp &= 0x7fffffff; /* clock bit correction */ 1744 rp++; 1745 *rp++ = (FDMFMSYNC << 16) | FDMFMSYNC; 1746 rp = mfmblkencode(&info, rp, &hcksum, 1); 1747 rp = mfmblkencode(mfmnull, rp, &hcksum, 4); 1748 rp = mfmblkencode(&hcksum, rp, NULL, 1); 1749 1750 crp = rp; 1751 rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS); 1752 dp += FDSECLWORDS; 1753 crp = mfmblkencode(&dcksum, crp, NULL, 1); 1754 if (*(crp - 1) & 0x1) 1755 *crp &= 0x7fffffff; /* clock bit correction */ 1756 else if ((*crp & 0x40000000) == 0) 1757 *crp |= 0x80000000; 1758 } 1759 *rp = 0xaaa80000; 1760 if (*(rp - 1) & 0x1) 1761 *rp &= 0x7fffffff; 1762 } 1763 1764 u_long * 1765 fdfindsync(u_long *rp, u_long *ep) 1766 { 1767 u_short *sp; 1768 1769 sp = (u_short *)rp; 1770 while ((u_long *)sp < ep && *sp != FDMFMSYNC) 1771 sp++; 1772 while ((u_long *)sp < ep && *sp == FDMFMSYNC) 1773 sp++; 1774 if ((u_long *)sp < ep) 1775 return((u_long *)sp); 1776 return(NULL); 1777 } 1778 1779 int 1780 amrawtocache(struct fd_softc *sc) 1781 { 1782 u_long mfmnull[4]; 1783 u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp; 1784 int cnt, doagain; 1785 1786 doagain = 1; 1787 srp = rp = fdc_dmap; 1788 erp = (u_long *)((u_short *)rp + sc->type->nreadw); 1789 cnt = 0; 1790 again: 1791 if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) { 1792 #ifdef DIAGNOSTIC 1793 aprint_error_dev(sc->sc_dev, "corrupted track (%d) data.\n", 1794 sc->cachetrk); 1795 #endif 1796 return(-1); 1797 } 1798 1799 /* 1800 * process sectors 1801 */ 1802 for (; cnt < sc->nsectors; cnt++) { 1803 hcksum = dcksum = 0; 1804 rp = mfmblkdecode(rp, &info, &hcksum, 1); 1805 rp = mfmblkdecode(rp, mfmnull, &hcksum, 4); 1806 rp = mfmblkdecode(rp, &cktmp, NULL, 1); 1807 if (cktmp != hcksum) { 1808 #ifdef FDDEBUG 1809 printf(" info 0x%lx hchksum 0x%lx trkhcksum 0x%lx\n", 1810 info, hcksum, cktmp); 1811 #endif 1812 goto again; 1813 } 1814 if (((info >> 16) & 0xff) != sc->cachetrk) { 1815 #ifdef DEBUG 1816 aprint_debug_dev(sc->sc_dev, 1817 "incorrect track found: 0x%lx %d\n", 1818 info, sc->cachetrk); 1819 #endif 1820 goto again; 1821 } 1822 #ifdef FDDEBUG 1823 printf(" info 0x%lx\n", info); 1824 #endif 1825 1826 rp = mfmblkdecode(rp, &cktmp, NULL, 1); 1827 dp = sc->cachep; 1828 dp += FDSECLWORDS * ((info >> 8) & 0xff); 1829 crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS); 1830 if (cktmp != dcksum) { 1831 #ifdef FDDEBUG 1832 printf(" info 0x%lx dchksum 0x%lx trkdcksum 0x%lx\n", 1833 info, dcksum, cktmp); 1834 #endif 1835 goto again; 1836 } 1837 1838 /* 1839 * if we are at gap then we can no longer be sure 1840 * of correct sync marks 1841 */ 1842 if ((info && 0xff) == 1) 1843 doagain = 1; 1844 else 1845 doagain = 0; 1846 srp = rp = fdfindsync(crp, erp); 1847 } 1848 return(0); 1849 } 1850 1851 void 1852 mscachetoraw(struct fd_softc *sc) 1853 { 1854 u_short *rp, *erp, crc; 1855 u_char *cp, tb[5]; 1856 int sec, i; 1857 1858 rp = (u_short *)fdc_dmap; 1859 erp = rp + sc->type->nwritew; 1860 cp = sc->cachep; 1861 1862 /* 1863 * initial track filler (828 * GAP1) 1864 */ 1865 for (i = 0; i < sc->type->gap; i++) { 1866 *rp++ = FDMFMGAP1; 1867 *rp++ = FDMFMGAP1; 1868 } 1869 1870 for (sec = 0; sec < sc->nsectors; sec++) { 1871 1872 /* 1873 * leading sector gap 1874 * (12 * GAP2) + (3 * SYNC) 1875 */ 1876 for (i = 0; i < 12; i++) 1877 *rp++ = FDMFMGAP2; 1878 *rp++ = FDMFMSYNC; 1879 *rp++ = FDMFMSYNC; 1880 *rp++ = FDMFMSYNC; 1881 1882 /* 1883 * sector information 1884 * (ID) + track + side + sector + sector size + CRC16 1885 */ 1886 *rp++ = FDMFMID; 1887 tb[0] = sc->cachetrk / FDNHEADS; 1888 tb[1] = sc->cachetrk % FDNHEADS; 1889 tb[2] = sec + 1; 1890 i = sc->bytespersec; 1891 tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3)); 1892 rp = msblkencode(rp, tb, 4, &crc); 1893 tb[0] = crc >> 8; 1894 tb[1] = crc & 0xff; 1895 tb[2] = 0x4e; /* GAP1 decoded */ 1896 rp = msblkencode(rp, tb, 3, 0); 1897 1898 /* 1899 * sector info/data gap 1900 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC) 1901 */ 1902 for (i = 0; i < 21; i++) 1903 *rp++ = FDMFMGAP1; 1904 for (i = 0; i < 12; i++) 1905 *rp++ = FDMFMGAP2; 1906 *rp++ = FDMFMSYNC; 1907 *rp++ = FDMFMSYNC; 1908 *rp++ = FDMFMSYNC; 1909 1910 /* 1911 * sector data 1912 * (DATA) + ...data... + CRC16 1913 */ 1914 *rp++ = FDMFMDATA; 1915 rp = msblkencode(rp, cp, sc->bytespersec, &crc); 1916 cp += sc->bytespersec; 1917 tb[0] = crc >> 8; 1918 tb[1] = crc & 0xff; 1919 tb[2] = 0x4e; /* GAP3 decoded */ 1920 rp = msblkencode(rp, tb, 3, 0); 1921 1922 /* 1923 * trailing sector gap 1924 * (80 * GAP3) 1925 */ 1926 for (i = 0; i < 79; i++) 1927 *rp++ = FDMFMGAP3; 1928 } 1929 1930 /* 1931 * fill rest of track with GAP3 1932 */ 1933 while (rp != erp) 1934 *rp++ = FDMFMGAP3; 1935 1936 } 1937 1938 int 1939 msrawtocache(struct fd_softc *sc) 1940 { 1941 u_short *rp, *srp, *erp; 1942 u_char tb[5], *cp; 1943 int ct, sec, retry; 1944 1945 srp = rp = (u_short *)fdc_dmap; 1946 erp = rp + sc->type->nreadw; 1947 cp = sc->cachep; 1948 1949 for (ct = 0; ct < sc->nsectors; ct++) { 1950 retry = 1; 1951 do { 1952 /* 1953 * skip leading gap to sync 1954 */ 1955 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) { 1956 #ifdef DIAGNOSTIC 1957 aprint_normal_dev(sc->sc_dev, 1958 "corrupted track (%d) data.\n", 1959 sc->cachetrk); 1960 #endif 1961 return(-1); 1962 } 1963 1964 /* 1965 * Grab sector info 1966 */ 1967 if (*rp++ != FDMFMID) 1968 continue; 1969 rp = msblkdecode(rp, tb, 4); 1970 #ifdef FDDEBUG 1971 printf("sector id: sector %d, track %d, side %d," 1972 "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]); 1973 #endif 1974 if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk || 1975 tb[2] > sc->nsectors) 1976 continue; 1977 1978 sec = tb[2]; 1979 sc->bytespersec = 128 << tb[3]; 1980 rp += 2; /* skip CRC-16 */ 1981 1982 /* 1983 * skip gap and read in data 1984 */ 1985 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) 1986 return(-1); 1987 if (*rp++ != FDMFMDATA) 1988 continue; 1989 rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec), 1990 sc->bytespersec); 1991 rp += 2; /* skip CRC-16 */ 1992 1993 retry = 0; 1994 } while (retry); 1995 } 1996 return(0); 1997 } 1998 1999 /* 2000 * encode len longwords of `dp' data in amiga mfm block format (`rp') 2001 * this format specified that the odd bits are at current pos and even 2002 * bits at len + current pos 2003 */ 2004 u_long * 2005 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len) 2006 { 2007 u_long *sdp, *edp, d, dtmp, correct; 2008 2009 sdp = dp; 2010 edp = dp + len; 2011 2012 if (*(rp - 1) & 0x1) 2013 correct = 1; 2014 else 2015 correct = 0; 2016 /* 2017 * do odd bits 2018 */ 2019 while (dp < edp) { 2020 d = (*dp >> 1) & 0x55555555; /* remove clock bits */ 2021 dtmp = d ^ 0x55555555; 2022 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2023 /* 2024 * correct upper clock bit if needed 2025 */ 2026 if (correct) 2027 d &= 0x7fffffff; 2028 if (d & 0x1) 2029 correct = 1; 2030 else 2031 correct = 0; 2032 /* 2033 * do checksums and store in raw buffer 2034 */ 2035 if (cp) 2036 *cp ^= d; 2037 *rp++ = d; 2038 dp++; 2039 } 2040 /* 2041 * do even bits 2042 */ 2043 dp = sdp; 2044 while (dp < edp) { 2045 d = *dp & 0x55555555; /* remove clock bits */ 2046 dtmp = d ^ 0x55555555; 2047 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2048 /* 2049 * correct upper clock bit if needed 2050 */ 2051 if (correct) 2052 d &= 0x7fffffff; 2053 if (d & 0x1) 2054 correct = 1; 2055 else 2056 correct = 0; 2057 /* 2058 * do checksums and store in raw buffer 2059 */ 2060 if (cp) 2061 *cp ^= d; 2062 *rp++ = d; 2063 dp++; 2064 } 2065 if (cp) 2066 *cp &= 0x55555555; 2067 return(rp); 2068 } 2069 2070 /* 2071 * decode len longwords of `dp' data in amiga mfm block format (`rp') 2072 * this format specified that the odd bits are at current pos and even 2073 * bits at len + current pos 2074 */ 2075 u_long * 2076 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len) 2077 { 2078 u_long o, e; 2079 int cnt; 2080 2081 cnt = len; 2082 while (cnt--) { 2083 o = *rp; 2084 e = *(rp + len); 2085 if (cp) { 2086 *cp ^= o; 2087 *cp ^= e; 2088 } 2089 o &= 0x55555555; 2090 e &= 0x55555555; 2091 *dp++ = (o << 1) | e; 2092 rp++; 2093 } 2094 if (cp) 2095 *cp &= 0x55555555; 2096 return(rp + len); 2097 } 2098 2099 /* 2100 * decode len words in standard MFM format to len bytes 2101 * of data. 2102 */ 2103 u_short * 2104 msblkdecode(u_short *rp, u_char *cp, int len) 2105 { 2106 while (len--) { 2107 *cp++ = msdecode[*rp & 0x7f] | 2108 (msdecode[(*rp >> 8) & 0x7f] << 4); 2109 rp++; 2110 } 2111 2112 return(rp); 2113 } 2114 2115 /* 2116 * encode len bytes of data into len words in standard MFM format. 2117 * If a pointer is supplied for crc, calculate the CRC-16 of the data 2118 * as well. 2119 */ 2120 u_short * 2121 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc) 2122 { 2123 u_short td; 2124 u_short mycrc; 2125 2126 /* preload crc for header (4 bytes) 2127 * or data (anything else) 2128 */ 2129 mycrc = (len == 4) ? 0xb230 : 0xe295; 2130 2131 while (len--) { 2132 td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f]; 2133 2134 /* Check for zeros in top bit of encode and bottom 2135 * bit of previous encode. if so, slap a one in betweem 2136 * them. 2137 */ 2138 if ((td & 0x140) == 0) 2139 td |= 0x80; 2140 if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0) 2141 td |= 0x8000; 2142 2143 *rp++ = td; 2144 2145 /* 2146 * calc crc if requested 2147 */ 2148 if (crc) 2149 mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)]; 2150 2151 cp++; 2152 } 2153 2154 if (crc) 2155 *crc = mycrc; 2156 2157 return(rp); 2158 } 2159
Indexes created Thu Oct 02 14:10:14 GMT 2025