fd.c revision 1.81
1 /* $NetBSD: fd.c,v 1.81 2009/03/18 16:00:09 cegger 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 1.81 2009/03/18 16:00:09 cegger 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 <uvm/uvm_extern.h> 55 56 #include <machine/cpu.h> 57 #include <amiga/amiga/device.h> 58 #include <amiga/amiga/custom.h> 59 #include <amiga/amiga/cia.h> 60 #include <amiga/amiga/cc.h> 61 62 #include "locators.h" 63 64 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY }; 65 /* 66 * partitions in fd represent different format floppies 67 * partition a is 0 etc.. 68 */ 69 enum fd_parttypes { 70 FDAMIGAPART = 0, 71 FDMSDOSPART, 72 FDMAXPARTS 73 }; 74 75 #define FDBBSIZE (8192) 76 #define FDSBSIZE (8192) 77 78 #define FDUNIT(dev) DISKUNIT(dev) 79 #define FDPART(dev) DISKPART(dev) 80 #define FDMAKEDEV(m, u, p) MAKEDISKDEV((m), (u), (p)) 81 82 /* that's nice, but we don't want to always use this as an amiga drive 83 bunghole :-) */ 84 #define FDNHEADS (2) /* amiga drives always have 2 heads */ 85 #define FDSECSIZE (512) /* amiga drives always have 512 byte sectors */ 86 #define FDSECLWORDS (128) 87 88 #define FDSETTLEDELAY (18000) /* usec delay after seeking after switch dir */ 89 #define FDSTEPDELAY (3500) /* usec delay after steping */ 90 #define FDPRESIDEDELAY (1000) /* usec delay before writing can occur */ 91 #define FDWRITEDELAY (1300) /* usec delay after write */ 92 93 #define FDSTEPOUT (1) /* decrease track step */ 94 #define FDSTEPIN (0) /* increase track step */ 95 96 #define FDCUNITMASK (0x78) /* mask for all units (bits 6-3) */ 97 98 #define FDRETRIES (2) /* default number of retries */ 99 #define FDMAXUNITS (4) /* maximum number of supported units */ 100 101 #define DISKLEN_READ (0) /* fake mask for reading */ 102 #define DISKLEN_WRITE (1 << 14) /* bit for writing */ 103 #define DISKLEN_DMAEN (1 << 15) /* DMA go */ 104 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2) /* largest DMA possible */ 105 106 #define FDMFMSYNC (0x4489) 107 #define FDMFMID (0x5554) 108 #define FDMFMDATA (0x5545) 109 #define FDMFMGAP1 (0x9254) 110 #define FDMFMGAP2 (0xAAAA) 111 #define FDMFMGAP3 (0x9254) 112 #define CRC16POLY (0x1021) /* (x^16) + x^12 + x^5 + x^0 */ 113 114 /* 115 * Msdos-type MFM encode/decode 116 */ 117 static u_char msdecode[128]; 118 static u_char msencode[16] = 119 { 120 0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15, 121 0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55 122 }; 123 static u_short mscrctab[256]; 124 125 /* 126 5554 aaaa aaaa aaa5 2aa4 4452 aa51 127 00 00 03 02 ac 0d 128 */ 129 130 /* 131 * floppy device type 132 */ 133 struct fdtype { 134 u_int driveid; /* drive identification (from drive) */ 135 u_int ncylinders; /* number of cylinders on drive */ 136 u_int amiga_nsectors; /* number of sectors per amiga track */ 137 u_int msdos_nsectors; /* number of sectors per msdos track */ 138 u_int nreadw; /* number of words (short) read per track */ 139 u_int nwritew; /* number of words (short) written per track */ 140 u_int gap; /* track gap size in long words */ 141 const u_int precomp[2]; /* 1st and 2nd precomp values */ 142 const char *desc; /* description of drive type (useq) */ 143 }; 144 145 /* 146 * floppy disk device data 147 */ 148 struct fd_softc { 149 struct device sc_dv; /* generic device info; must come first */ 150 struct disk dkdev; /* generic disk info */ 151 struct bufq_state *bufq;/* queue pending I/O operations */ 152 struct buf curbuf; /* state of current I/O operation */ 153 struct callout calibrate_ch; 154 struct callout motor_ch; 155 struct fdtype *type; 156 void *cachep; /* cached track data (write through) */ 157 int cachetrk; /* cahced track -1 for none */ 158 int hwunit; /* unit for amiga controlling hw */ 159 int unitmask; /* mask for cia select deslect */ 160 int pstepdir; /* previous step direction */ 161 int curcyl; /* current curcyl head positioned on */ 162 int flags; /* misc flags */ 163 int wlabel; 164 int stepdelay; /* useq to delay after seek user setable */ 165 int nsectors; /* number of sectors per track */ 166 int openpart; /* which partition [ab] == [12] is open */ 167 short retries; /* number of times to retry failed io */ 168 short retried; /* number of times current io retried */ 169 int bytespersec; /* number of bytes per sector */ 170 }; 171 172 /* fd_softc->flags */ 173 #define FDF_MOTORON (0x01) /* motor is running */ 174 #define FDF_MOTOROFF (0x02) /* motor is waiting to be turned off */ 175 #define FDF_WMOTOROFF (0x04) /* unit wants a wakeup after off */ 176 #define FDF_DIRTY (0x08) /* track cache needs write */ 177 #define FDF_WRITEWAIT (0x10) /* need to head select delay on next setpos */ 178 #define FDF_HAVELABEL (0x20) /* label is valid */ 179 #define FDF_JUSTFLUSH (0x40) /* don't bother caching track. */ 180 #define FDF_NOTRACK0 (0x80) /* was not able to recalibrate drive */ 181 182 int fdc_wantwakeup; 183 int fdc_side; 184 void *fdc_dmap; 185 struct fd_softc *fdc_indma; 186 int fdc_dmalen; 187 int fdc_dmawrite; 188 189 struct fdcargs { 190 struct fdtype *type; 191 int unit; 192 }; 193 194 int fdcmatch(struct device *, struct cfdata *, void *); 195 void fdcattach(struct device *, struct device *, void *); 196 int fdcprint(void *, const char *); 197 int fdmatch(struct device *, struct cfdata *, void *); 198 void fdattach(struct device *, struct device *, void *); 199 200 void fdintr(int); 201 void fdidxintr(void); 202 int fdloaddisk(struct fd_softc *); 203 void fdgetdefaultlabel(struct fd_softc *, struct disklabel *, int); 204 int fdgetdisklabel(struct fd_softc *, dev_t); 205 int fdsetdisklabel(struct fd_softc *, struct disklabel *); 206 int fdputdisklabel(struct fd_softc *, dev_t); 207 struct fdtype * fdcgetfdtype(int); 208 void fdmotoroff(void *); 209 void fdsetpos(struct fd_softc *, int, int); 210 void fdselunit(struct fd_softc *); 211 void fdstart(struct fd_softc *); 212 void fdcont(struct fd_softc *); 213 void fddmastart(struct fd_softc *, int); 214 void fdcalibrate(void *); 215 void fddmadone(struct fd_softc *, int); 216 void fddone(struct fd_softc *); 217 void fdfindwork(int); 218 void fdminphys(struct buf *); 219 void fdcachetoraw(struct fd_softc *); 220 void amcachetoraw(struct fd_softc *); 221 int amrawtocache(struct fd_softc *); 222 u_long *fdfindsync(u_long *, u_long *); 223 int fdrawtocache(struct fd_softc *); 224 void mscachetoraw(struct fd_softc *); 225 int msrawtocache(struct fd_softc *); 226 u_long *mfmblkencode(u_long *, u_long *, u_long *, int); 227 u_long *mfmblkdecode(u_long *, u_long *, u_long *, int); 228 u_short *msblkdecode(u_short *, u_char *, int); 229 u_short *msblkencode(u_short *, u_char *, int, u_short *); 230 231 /* 232 * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts 233 * write size is nsectors * mfm secsize + gap bytes + 3 shorts 234 * the extra shorts are to deal with a DMA hw bug in the controller 235 * they are probably too much (I belive the bug is 1 short on write and 236 * 3 bits on read) but there is no need to be cheap here. 237 */ 238 #define MAXTRKSZ (22 * FDSECSIZE) 239 struct fdtype fdtype[] = { 240 { 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" }, 241 { 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" }, 242 { 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" } 243 }; 244 int nfdtype = sizeof(fdtype) / sizeof(*fdtype); 245 246 CFATTACH_DECL(fd, sizeof(struct fd_softc), 247 fdmatch, fdattach, NULL, NULL); 248 249 extern struct cfdriver fd_cd; 250 251 dev_type_open(fdopen); 252 dev_type_close(fdclose); 253 dev_type_read(fdread); 254 dev_type_write(fdwrite); 255 dev_type_ioctl(fdioctl); 256 dev_type_strategy(fdstrategy); 257 258 const struct bdevsw fd_bdevsw = { 259 fdopen, fdclose, fdstrategy, fdioctl, nodump, nosize, D_DISK 260 }; 261 262 const struct cdevsw fd_cdevsw = { 263 fdopen, fdclose, fdread, fdwrite, fdioctl, 264 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 265 }; 266 267 struct dkdriver fddkdriver = { fdstrategy }; 268 269 CFATTACH_DECL(fdc, sizeof(struct device), 270 fdcmatch, fdcattach, NULL, NULL); 271 272 /* 273 * all hw access through macros, this helps to hide the active low 274 * properties 275 */ 276 277 #define FDUNITMASK(unit) (1 << (3 + (unit))) 278 279 /* 280 * select units using mask 281 */ 282 #define FDSELECT(um) do { ciab.prb &= ~(um); } while (0) 283 284 /* 285 * deselect units using mask 286 */ 287 #define FDDESELECT(um) do { ciab.prb |= (um); delay(1); } while (0) 288 289 /* 290 * test hw condition bits 291 */ 292 #define FDTESTC(bit) ((ciaa.pra & (1 << (bit))) == 0) 293 294 /* 295 * set motor for select units, true motor on else off 296 */ 297 #define FDSETMOTOR(on) do { \ 298 if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \ 299 } while (0) 300 301 /* 302 * set head for select units 303 */ 304 #define FDSETHEAD(head) do { \ 305 if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \ 306 delay(1); } while (0) 307 308 /* 309 * select direction, true towards spindle else outwards 310 */ 311 #define FDSETDIR(in) do { \ 312 if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \ 313 delay(1); } while (0) 314 315 /* 316 * step the selected units 317 */ 318 #define FDSTEP do { \ 319 ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \ 320 } while (0) 321 322 #define FDDMASTART(len, towrite) do { \ 323 int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \ 324 custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0) 325 326 #define FDDMASTOP do { custom.dsklen = 0; } while (0) 327 328 329 int 330 fdcmatch(struct device *pdp, struct cfdata *cfp, void *auxp) 331 { 332 static int fdc_matched = 0; 333 334 /* Allow only once instance. */ 335 if (matchname("fdc", auxp) == 0 || fdc_matched) 336 return(0); 337 if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) { 338 printf("fdc: unable to allocate DMA buffer\n"); 339 return(0); 340 } 341 342 fdc_matched = 1; 343 return(1); 344 } 345 346 void 347 fdcattach(struct device *pdp, struct device *dp, void *auxp) 348 { 349 struct fdcargs args; 350 351 printf(": dmabuf pa 0x%x", (unsigned)kvtop(fdc_dmap)); 352 printf(": dmabuf ka %p\n", fdc_dmap); 353 args.unit = 0; 354 args.type = fdcgetfdtype(args.unit); 355 356 fdc_side = -1; 357 config_found(dp, &args, fdcprint); 358 for (args.unit++; args.unit < FDMAXUNITS; args.unit++) { 359 if ((args.type = fdcgetfdtype(args.unit)) == NULL) 360 continue; 361 config_found(dp, &args, fdcprint); 362 } 363 } 364 365 int 366 fdcprint(void *auxp, const char *pnp) 367 { 368 struct fdcargs *fcp; 369 370 fcp = auxp; 371 if (pnp) 372 aprint_normal("fd%d at %s unit %d:", fcp->unit, pnp, 373 fcp->type->driveid); 374 return(UNCONF); 375 } 376 377 /*ARGSUSED*/ 378 int 379 fdmatch(struct device *pdp, struct cfdata *cfp, void *auxp) 380 { 381 struct fdcargs *fdap; 382 383 fdap = auxp; 384 if (cfp->cf_loc[FDCCF_UNIT] == fdap->unit || 385 cfp->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT) 386 return(1); 387 388 return(0); 389 } 390 391 void 392 fdattach(struct device *pdp, struct device *dp, void *auxp) 393 { 394 struct fdcargs *ap; 395 struct fd_softc *sc; 396 int i; 397 398 ap = auxp; 399 sc = device_private(dp); 400 401 bufq_alloc(&sc->bufq, "disksort", BUFQ_SORT_CYLINDER); 402 callout_init(&sc->calibrate_ch, 0); 403 callout_init(&sc->motor_ch, 0); 404 405 sc->curcyl = sc->cachetrk = -1; 406 sc->openpart = -1; 407 sc->type = ap->type; 408 sc->hwunit = ap->unit; 409 sc->unitmask = 1 << (3 + ap->unit); 410 sc->retries = FDRETRIES; 411 sc->stepdelay = FDSTEPDELAY; 412 sc->bytespersec = 512; 413 printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n", 414 sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS, 415 sc->type->amiga_nsectors, sc->type->msdos_nsectors); 416 417 /* 418 * Initialize and attach the disk structure. 419 */ 420 disk_init(&sc->dkdev, sc->sc_dv.dv_xname, &fddkdriver); 421 disk_attach(&sc->dkdev); 422 423 /* 424 * calibrate the drive 425 */ 426 fdsetpos(sc, 0, 0); 427 fdsetpos(sc, sc->type->ncylinders, 0); 428 fdsetpos(sc, 0, 0); 429 fdmotoroff(sc); 430 431 /* 432 * precalc msdos MFM and CRC 433 */ 434 for (i = 0; i < 128; i++) 435 msdecode[i] = 0xff; 436 for (i = 0; i < 16; i++) 437 msdecode[msencode[i]] = i; 438 for (i = 0; i < 256; i++) { 439 mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^ 440 (0x1021 * (i >> 4)); 441 } 442 443 /* 444 * enable disk related interrupts 445 */ 446 custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK; 447 custom.intena = INTF_SETCLR | INTF_DSKBLK; 448 ciab.icr = CIA_ICR_FLG; 449 } 450 451 /*ARGSUSED*/ 452 int 453 fdopen(dev_t dev, int flags, int devtype, struct lwp *l) 454 { 455 struct fd_softc *sc; 456 int wasopen, fwork, error, s; 457 458 error = 0; 459 460 if (FDPART(dev) >= FDMAXPARTS) 461 return(ENXIO); 462 463 if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL) 464 return(ENXIO); 465 if (sc->flags & FDF_NOTRACK0) 466 return(ENXIO); 467 if (sc->cachep == NULL) 468 sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK); 469 470 s = splbio(); 471 /* 472 * if we are sleeping in fdclose(); waiting for a chance to 473 * shut the motor off, do a sleep here also. 474 */ 475 while (sc->flags & FDF_WMOTOROFF) 476 tsleep(fdmotoroff, PRIBIO, "fdopen", 0); 477 478 fwork = 0; 479 /* 480 * if not open let user open request type, otherwise 481 * ensure they are trying to open same type. 482 */ 483 if (sc->openpart == FDPART(dev)) 484 wasopen = 1; 485 else if (sc->openpart == -1) { 486 sc->openpart = FDPART(dev); 487 wasopen = 0; 488 } else { 489 wasopen = 1; 490 error = EPERM; 491 goto done; 492 } 493 494 /* 495 * wait for current io to complete if any 496 */ 497 if (fdc_indma) { 498 fwork = 1; 499 fdc_wantwakeup++; 500 tsleep(fdopen, PRIBIO, "fdopen", 0); 501 } 502 if ((error = fdloaddisk(sc)) != 0) 503 goto done; 504 if ((error = fdgetdisklabel(sc, dev)) != 0) 505 goto done; 506 #ifdef FDDEBUG 507 printf(" open successful\n"); 508 #endif 509 done: 510 /* 511 * if we requested that fddone()->fdfindwork() wake us, allow it to 512 * complete its job now 513 */ 514 if (fwork) 515 fdfindwork(FDUNIT(dev)); 516 splx(s); 517 518 /* 519 * if we were not open and we marked us so reverse that. 520 */ 521 if (error && wasopen == 0) 522 sc->openpart = -1; 523 return(error); 524 } 525 526 /*ARGSUSED*/ 527 int 528 fdclose(dev_t dev, int flags, int devtype, struct lwp *l) 529 { 530 struct fd_softc *sc; 531 int s; 532 533 #ifdef FDDEBUG 534 printf("fdclose()\n"); 535 #endif 536 sc = getsoftc(fd_cd, FDUNIT(dev)); 537 s = splbio(); 538 if (sc->flags & FDF_MOTORON) { 539 sc->flags |= FDF_WMOTOROFF; 540 tsleep(fdmotoroff, PRIBIO, "fdclose", 0); 541 sc->flags &= ~FDF_WMOTOROFF; 542 wakeup(fdmotoroff); 543 } 544 sc->openpart = -1; 545 splx(s); 546 return(0); 547 } 548 549 int 550 fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) 551 { 552 struct fd_softc *sc; 553 int error, wlab; 554 555 sc = getsoftc(fd_cd, FDUNIT(dev)); 556 557 if ((sc->flags & FDF_HAVELABEL) == 0) 558 return(EBADF); 559 560 switch (cmd) { 561 case DIOCSBAD: 562 return(EINVAL); 563 case DIOCSRETRIES: 564 if (*(int *)addr < 0) 565 return(EINVAL); 566 sc->retries = *(int *)addr; 567 return(0); 568 case DIOCSSTEP: 569 if (*(int *)addr < FDSTEPDELAY) 570 return(EINVAL); 571 sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr; 572 return(0); 573 case DIOCGDINFO: 574 *(struct disklabel *)addr = *(sc->dkdev.dk_label); 575 return(0); 576 case DIOCGPART: 577 ((struct partinfo *)addr)->disklab = sc->dkdev.dk_label; 578 ((struct partinfo *)addr)->part = 579 &sc->dkdev.dk_label->d_partitions[FDPART(dev)]; 580 return(0); 581 case DIOCSDINFO: 582 if ((flag & FWRITE) == 0) 583 return(EBADF); 584 return(fdsetdisklabel(sc, (struct disklabel *)addr)); 585 case DIOCWDINFO: 586 if ((flag & FWRITE) == 0) 587 return(EBADF); 588 if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0) 589 return(error); 590 wlab = sc->wlabel; 591 sc->wlabel = 1; 592 error = fdputdisklabel(sc, dev); 593 sc->wlabel = wlab; 594 return(error); 595 case DIOCWLABEL: 596 if ((flag & FWRITE) == 0) 597 return(EBADF); 598 sc->wlabel = *(int *)addr; 599 return(0); 600 case DIOCGDEFLABEL: 601 fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev)); 602 return(0); 603 default: 604 return(ENOTTY); 605 } 606 } 607 608 int 609 fdread(dev_t dev, struct uio *uio, int flags) 610 { 611 return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio)); 612 } 613 614 int 615 fdwrite(dev_t dev, struct uio *uio, int flags) 616 { 617 return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio)); 618 } 619 620 621 void 622 fdintr(int flag) 623 { 624 int s; 625 626 s = splbio(); 627 if (fdc_indma) 628 fddmadone(fdc_indma, 0); 629 splx(s); 630 } 631 632 void 633 fdidxintr(void) 634 { 635 if (fdc_indma && fdc_dmalen) { 636 /* 637 * turn off intr and start actual dma 638 */ 639 ciab.icr = CIA_ICR_FLG; 640 FDDMASTART(fdc_dmalen, fdc_dmawrite); 641 fdc_dmalen = 0; 642 } 643 } 644 645 void 646 fdstrategy(struct buf *bp) 647 { 648 struct disklabel *lp; 649 struct fd_softc *sc; 650 int unit, part, s; 651 652 unit = FDUNIT(bp->b_dev); 653 part = FDPART(bp->b_dev); 654 sc = getsoftc(fd_cd, unit); 655 656 #ifdef FDDEBUG 657 printf("fdstrategy: %p\n", bp); 658 #endif 659 /* 660 * check for valid partition and bounds 661 */ 662 lp = sc->dkdev.dk_label; 663 if ((sc->flags & FDF_HAVELABEL) == 0) { 664 bp->b_error = EIO; 665 goto done; 666 } 667 if (bounds_check_with_label(&sc->dkdev, bp, sc->wlabel) <= 0) 668 goto done; 669 670 /* 671 * trans count of zero or bounds check indicates io is done 672 * we are done. 673 */ 674 if (bp->b_bcount == 0) 675 goto done; 676 677 bp->b_rawblkno = bp->b_blkno; 678 679 /* 680 * queue the buf and kick the low level code 681 */ 682 s = splbio(); 683 bufq_put(sc->bufq, bp); 684 fdstart(sc); 685 splx(s); 686 return; 687 done: 688 bp->b_resid = bp->b_bcount; 689 biodone(bp); 690 } 691 692 /* 693 * make sure disk is loaded and label is up-to-date. 694 */ 695 int 696 fdloaddisk(struct fd_softc *sc) 697 { 698 /* 699 * if diskchange is low step drive to 0 then up one then to zero. 700 */ 701 fdselunit(sc); /* make sure the unit is selected */ 702 if (FDTESTC(FDB_CHANGED)) { 703 fdsetpos(sc, 0, 0); 704 sc->cachetrk = -1; /* invalidate the cache */ 705 sc->flags &= ~FDF_HAVELABEL; 706 fdsetpos(sc, FDNHEADS, 0); 707 fdsetpos(sc, 0, 0); 708 if (FDTESTC(FDB_CHANGED)) { 709 fdmotoroff(sc); 710 FDDESELECT(sc->unitmask); 711 return(ENXIO); 712 } 713 } 714 FDDESELECT(sc->unitmask); 715 fdmotoroff(sc); 716 sc->type = fdcgetfdtype(sc->hwunit); 717 if (sc->type == NULL) 718 return(ENXIO); 719 if (sc->openpart == FDMSDOSPART) 720 sc->nsectors = sc->type->msdos_nsectors; 721 else 722 sc->nsectors = sc->type->amiga_nsectors; 723 return(0); 724 } 725 726 void 727 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part) 728 /* (variable part) XXX ick */ 729 { 730 731 memset(lp, 0, sizeof(struct disklabel)); 732 lp->d_secsize = FDSECSIZE; 733 lp->d_ntracks = FDNHEADS; 734 lp->d_ncylinders = sc->type->ncylinders; 735 lp->d_nsectors = sc->nsectors; 736 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 737 lp->d_type = DTYPE_FLOPPY; 738 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 739 lp->d_rpm = 300; /* good guess I suppose. */ 740 lp->d_interleave = 1; /* should change when adding msdos */ 741 sc->stepdelay = lp->d_trkseek = FDSTEPDELAY; 742 lp->d_bbsize = 0; 743 lp->d_sbsize = 0; 744 lp->d_partitions[part].p_size = lp->d_secperunit; 745 lp->d_partitions[part].p_fstype = FS_UNUSED; 746 lp->d_partitions[part].p_fsize = 1024; 747 lp->d_partitions[part].p_frag = 8; 748 lp->d_partitions[part].p_cpg = 2; /* adosfs: reserved blocks */ 749 lp->d_npartitions = part + 1; 750 lp->d_magic = lp->d_magic2 = DISKMAGIC; 751 lp->d_checksum = dkcksum(lp); 752 } 753 754 /* 755 * read disk label, if present otherwise create one 756 * return a new label if raw part and none found, otherwise err. 757 */ 758 int 759 fdgetdisklabel(struct fd_softc *sc, dev_t dev) 760 { 761 struct disklabel *lp, *dlp; 762 struct cpu_disklabel *clp; 763 struct buf *bp; 764 int error, part; 765 766 if (sc->flags & FDF_HAVELABEL && 767 sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1)) 768 return(0); 769 #ifdef FDDEBUG 770 printf("fdgetdisklabel()\n"); 771 #endif 772 part = FDPART(dev); 773 lp = sc->dkdev.dk_label; 774 clp = sc->dkdev.dk_cpulabel; 775 memset(lp, 0, sizeof(struct disklabel)); 776 memset(clp, 0, sizeof(struct cpu_disklabel)); 777 778 lp->d_secsize = FDSECSIZE; 779 lp->d_ntracks = FDNHEADS; 780 lp->d_ncylinders = sc->type->ncylinders; 781 lp->d_nsectors = sc->nsectors; 782 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 783 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 784 lp->d_npartitions = part + 1; 785 lp->d_partitions[part].p_size = lp->d_secperunit; 786 lp->d_partitions[part].p_fstype = FS_UNUSED; 787 lp->d_partitions[part].p_fsize = 1024; 788 lp->d_partitions[part].p_frag = 8; 789 lp->d_partitions[part].p_cpg = 2; /* for adosfs: reserved blks */ 790 791 sc->flags |= FDF_HAVELABEL; 792 793 bp = (void *)geteblk((int)lp->d_secsize); 794 bp->b_dev = dev; 795 bp->b_blkno = 0; 796 bp->b_cylinder = 0; 797 bp->b_bcount = FDSECSIZE; 798 bp->b_flags |= B_READ; 799 fdstrategy(bp); 800 if ((error = biowait(bp)) != 0) 801 goto nolabel; 802 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 803 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC || 804 dkcksum(dlp)) { 805 error = EINVAL; 806 goto nolabel; 807 } 808 bcopy(dlp, lp, sizeof(struct disklabel)); 809 if (lp->d_trkseek > FDSTEPDELAY) 810 sc->stepdelay = lp->d_trkseek; 811 brelse(bp, 0); 812 return(0); 813 nolabel: 814 fdgetdefaultlabel(sc, lp, part); 815 brelse(bp, 0); 816 return(0); 817 } 818 819 /* 820 * set the incore copy of this units disklabel 821 */ 822 int 823 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp) 824 { 825 struct disklabel *clp; 826 struct partition *pp; 827 828 /* 829 * must have at least opened raw unit to fetch the 830 * raw_part stuff. 831 */ 832 if ((sc->flags & FDF_HAVELABEL) == 0) 833 return(EINVAL); 834 clp = sc->dkdev.dk_label; 835 /* 836 * make sure things check out and we only have one valid 837 * partition 838 */ 839 #ifdef FDDEBUG 840 printf("fdsetdisklabel\n"); 841 #endif 842 if (lp->d_secsize != FDSECSIZE || 843 lp->d_nsectors != clp->d_nsectors || 844 lp->d_ntracks != FDNHEADS || 845 lp->d_ncylinders != clp->d_ncylinders || 846 lp->d_secpercyl != clp->d_secpercyl || 847 lp->d_secperunit != clp->d_secperunit || 848 lp->d_magic != DISKMAGIC || 849 lp->d_magic2 != DISKMAGIC || 850 lp->d_npartitions == 0 || 851 lp->d_npartitions > FDMAXPARTS || 852 (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) || 853 dkcksum(lp)) 854 return(EINVAL); 855 /* 856 * if any partitions are present make sure they 857 * represent the currently open type 858 */ 859 if ((pp = &lp->d_partitions[0])->p_size) { 860 if ((pp = &lp->d_partitions[1])->p_size == 0) 861 goto done; 862 else if (sc->openpart != 1) 863 return(EINVAL); 864 } else if (sc->openpart != 0) 865 return(EINVAL); 866 /* 867 * make sure selected partition is within bounds 868 * XXX on the second check, its to handle a bug in 869 * XXX the cluster routines as they require mutliples 870 * XXX of PAGE_SIZE currently 871 */ 872 if ((pp->p_offset + pp->p_size >= lp->d_secperunit) || 873 (pp->p_frag * pp->p_fsize % PAGE_SIZE)) 874 return(EINVAL); 875 done: 876 bcopy(lp, clp, sizeof(struct disklabel)); 877 return(0); 878 } 879 880 /* 881 * write out the incore copy of this units disklabel 882 */ 883 int 884 fdputdisklabel(struct fd_softc *sc, dev_t dev) 885 { 886 struct disklabel *lp, *dlp; 887 struct buf *bp; 888 int error; 889 890 if ((sc->flags & FDF_HAVELABEL) == 0) 891 return(EBADF); 892 #ifdef FDDEBUG 893 printf("fdputdisklabel\n"); 894 #endif 895 /* 896 * get buf and read in sector 0 897 */ 898 lp = sc->dkdev.dk_label; 899 bp = geteblk((int)lp->d_secsize); 900 bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART); 901 bp->b_blkno = 0; 902 bp->b_cylinder = 0; 903 bp->b_bcount = FDSECSIZE; 904 bp->b_flags |= B_READ; 905 fdstrategy(bp); 906 if ((error = biowait(bp)) != 0) 907 goto done; 908 /* 909 * copy disklabel to buf and write it out synchronous 910 */ 911 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 912 bcopy(lp, dlp, sizeof(struct disklabel)); 913 bp->b_blkno = 0; 914 bp->b_cylinder = 0; 915 bp->b_flags &= ~(B_READ); 916 bp->b_oflags &= ~(BO_DONE); 917 bp->b_flags |= B_WRITE; 918 fdstrategy(bp); 919 error = biowait(bp); 920 done: 921 brelse(bp, 0); 922 return(error); 923 } 924 925 /* 926 * figure out drive type or NULL if none. 927 */ 928 struct fdtype * 929 fdcgetfdtype(int unit) 930 { 931 struct fdtype *ftp; 932 u_long id, idb; 933 int cnt, umask; 934 935 id = 0; 936 umask = 1 << (3 + unit); 937 938 FDDESELECT(FDCUNITMASK); 939 940 FDSETMOTOR(1); 941 delay(1); 942 FDSELECT(umask); 943 delay(1); 944 FDDESELECT(umask); 945 946 FDSETMOTOR(0); 947 delay(1); 948 FDSELECT(umask); 949 delay(1); 950 FDDESELECT(umask); 951 952 for (idb = 0x80000000; idb; idb >>= 1) { 953 FDSELECT(umask); 954 delay(1); 955 if (FDTESTC(FDB_READY) == 0) 956 id |= idb; 957 FDDESELECT(umask); 958 delay(1); 959 } 960 #ifdef FDDEBUG 961 printf("fdcgettype unit %d id 0x%lx\n", unit, id); 962 #endif 963 964 for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++) 965 if (ftp->driveid == id) 966 return(ftp); 967 /* 968 * 3.5dd's at unit 0 do not always return id. 969 */ 970 if (unit == 0) 971 return(fdtype); 972 return(NULL); 973 } 974 975 /* 976 * turn motor off if possible otherwise mark as needed and will be done 977 * later. 978 */ 979 void 980 fdmotoroff(void *arg) 981 { 982 struct fd_softc *sc; 983 int s; 984 985 sc = arg; 986 s = splbio(); 987 988 #ifdef FDDEBUG 989 printf("fdmotoroff: unit %d\n", sc->hwunit); 990 #endif 991 if ((sc->flags & FDF_MOTORON) == 0) 992 goto done; 993 /* 994 * if we have a timeout on a DMA operation let fddmadone() 995 * deal with it. 996 */ 997 if (fdc_indma == sc) { 998 fddmadone(sc, 1); 999 goto done; 1000 } 1001 #ifdef FDDEBUG 1002 printf(" motor was on, turning off\n"); 1003 #endif 1004 1005 /* 1006 * flush cache if needed 1007 */ 1008 if (sc->flags & FDF_DIRTY) { 1009 sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF; 1010 #ifdef FDDEBUG 1011 printf(" flushing dirty buffer first\n"); 1012 #endif 1013 /* 1014 * if DMA'ing done for now, fddone() will call us again 1015 */ 1016 if (fdc_indma) 1017 goto done; 1018 fddmastart(sc, sc->cachetrk); 1019 goto done; 1020 } 1021 1022 /* 1023 * if controller is busy just schedule us to be called back 1024 */ 1025 if (fdc_indma) { 1026 /* 1027 * someone else has the controller now 1028 * just set flag and let fddone() call us again. 1029 */ 1030 sc->flags |= FDF_MOTOROFF; 1031 goto done; 1032 } 1033 1034 #ifdef FDDEBUG 1035 printf(" hw turning unit off\n"); 1036 #endif 1037 1038 sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF); 1039 FDDESELECT(FDCUNITMASK); 1040 FDSETMOTOR(0); 1041 delay(1); 1042 FDSELECT(sc->unitmask); 1043 delay(4); 1044 FDDESELECT(sc->unitmask); 1045 delay(1); 1046 if (sc->flags & FDF_WMOTOROFF) 1047 wakeup(fdmotoroff); 1048 done: 1049 splx(s); 1050 } 1051 1052 /* 1053 * select drive seek to track exit with motor on. 1054 * fdsetpos(x, 0, 0) does calibrates the drive. 1055 */ 1056 void 1057 fdsetpos(struct fd_softc *sc, int trk, int towrite) 1058 { 1059 int nstep, sdir, ondly, ncyl, nside; 1060 1061 FDDESELECT(FDCUNITMASK); 1062 FDSETMOTOR(1); 1063 delay(1); 1064 FDSELECT(sc->unitmask); 1065 delay(1); 1066 if ((sc->flags & FDF_MOTORON) == 0) { 1067 ondly = 0; 1068 while (FDTESTC(FDB_READY) == 0) { 1069 delay(1000); 1070 if (++ondly >= 1000) 1071 break; 1072 } 1073 } 1074 sc->flags |= FDF_MOTORON; 1075 1076 ncyl = trk / FDNHEADS; 1077 nside = trk % FDNHEADS; 1078 1079 if (sc->curcyl == ncyl && fdc_side == nside) 1080 return; 1081 1082 if (towrite) 1083 sc->flags |= FDF_WRITEWAIT; 1084 1085 #ifdef FDDEBUG 1086 printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS, 1087 trk % FDNHEADS, towrite); 1088 #endif 1089 nstep = ncyl - sc->curcyl; 1090 if (nstep) { 1091 /* 1092 * figure direction 1093 */ 1094 if (nstep > 0 && ncyl != 0) { 1095 sdir = FDSTEPIN; 1096 FDSETDIR(1); 1097 } else { 1098 nstep = -nstep; 1099 sdir = FDSTEPOUT; 1100 FDSETDIR(0); 1101 } 1102 if (ncyl == 0) { 1103 /* 1104 * either just want cylinder 0 or doing 1105 * a calibrate. 1106 */ 1107 nstep = 256; 1108 while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) { 1109 FDSTEP; 1110 delay(sc->stepdelay); 1111 } 1112 if (nstep < 0) 1113 sc->flags |= FDF_NOTRACK0; 1114 } else { 1115 /* 1116 * step the needed amount amount. 1117 */ 1118 while (nstep--) { 1119 FDSTEP; 1120 delay(sc->stepdelay); 1121 } 1122 } 1123 /* 1124 * if switched directions 1125 * allow drive to settle. 1126 */ 1127 if (sc->pstepdir != sdir) 1128 delay(FDSETTLEDELAY); 1129 sc->pstepdir = sdir; 1130 sc->curcyl = ncyl; 1131 } 1132 if (nside == fdc_side) 1133 return; 1134 /* 1135 * select side 1136 */ 1137 fdc_side = nside; 1138 FDSETHEAD(nside); 1139 delay(FDPRESIDEDELAY); 1140 } 1141 1142 void 1143 fdselunit(struct fd_softc *sc) 1144 { 1145 FDDESELECT(FDCUNITMASK); /* deselect all */ 1146 FDSETMOTOR(sc->flags & FDF_MOTORON); /* set motor to unit's state */ 1147 delay(1); 1148 FDSELECT(sc->unitmask); /* select unit */ 1149 delay(1); 1150 } 1151 1152 /* 1153 * process next buf on device queue. 1154 * normall sequence of events: 1155 * fdstart() -> fddmastart(); 1156 * fdidxintr(); 1157 * fdintr() -> fddmadone() -> fddone(); 1158 * if the track is in the cache then fdstart() will short-circuit 1159 * to fddone() else if the track cache is dirty it will flush. If 1160 * the buf is not an entire track it will cache the requested track. 1161 */ 1162 void 1163 fdstart(struct fd_softc *sc) 1164 { 1165 int trk, error, write; 1166 struct buf *bp, *dp; 1167 int changed; 1168 1169 #ifdef FDDEBUG 1170 printf("fdstart: unit %d\n", sc->hwunit); 1171 #endif 1172 1173 /* 1174 * if DMA'ing just return. we must have been called from fdstartegy. 1175 */ 1176 if (fdc_indma) 1177 return; 1178 1179 /* 1180 * get next buf if there. 1181 */ 1182 dp = &sc->curbuf; 1183 if ((bp = bufq_peek(sc->bufq)) == NULL) { 1184 #ifdef FDDEBUG 1185 printf(" nothing to do\n"); 1186 #endif 1187 return; 1188 } 1189 1190 /* 1191 * Mark us as busy now, in case fddone() gets called in one 1192 * of the cases below. 1193 */ 1194 disk_busy(&sc->dkdev); 1195 1196 /* 1197 * make sure same disk is loaded 1198 */ 1199 fdselunit(sc); 1200 changed = FDTESTC(FDB_CHANGED); 1201 FDDESELECT(sc->unitmask); 1202 if (changed) { 1203 /* 1204 * disk missing, invalidate all future io on 1205 * this unit until re-open()'ed also invalidate 1206 * all current io 1207 */ 1208 printf("fdstart: disk changed\n"); 1209 #ifdef FDDEBUG 1210 printf(" disk was removed invalidating all io\n"); 1211 #endif 1212 sc->flags &= ~FDF_HAVELABEL; 1213 for (;;) { 1214 bp = bufq_get(sc->bufq); 1215 bp->b_error = EIO; 1216 if (bufq_peek(sc->bufq) == NULL) 1217 break; 1218 biodone(bp); 1219 } 1220 /* 1221 * do fddone() on last buf to allow other units to start. 1222 */ 1223 bufq_put(sc->bufq, bp); 1224 fddone(sc); 1225 return; 1226 } 1227 1228 /* 1229 * we have a valid buf, setup our local version 1230 * we use this count to allow reading over multiple tracks. 1231 * into a single buffer 1232 */ 1233 dp->b_bcount = bp->b_bcount; 1234 dp->b_blkno = bp->b_blkno; 1235 dp->b_data = bp->b_data; 1236 dp->b_flags = bp->b_flags; 1237 dp->b_resid = 0; 1238 1239 if (bp->b_flags & B_READ) 1240 write = 0; 1241 else if (FDTESTC(FDB_PROTECT) == 0) 1242 write = 1; 1243 else { 1244 error = EPERM; 1245 goto done; 1246 } 1247 1248 /* 1249 * figure trk given blkno 1250 */ 1251 trk = bp->b_blkno / sc->nsectors; 1252 1253 /* 1254 * check to see if same as currently cached track 1255 * if so we need to do no DMA read. 1256 */ 1257 if (trk == sc->cachetrk) { 1258 fddone(sc); 1259 return; 1260 } 1261 1262 /* 1263 * if we will be overwriting the entire cache, don't bother to 1264 * fetch it. 1265 */ 1266 if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write && 1267 bp->b_blkno % sc->nsectors == 0) { 1268 if (sc->flags & FDF_DIRTY) 1269 sc->flags |= FDF_JUSTFLUSH; 1270 else { 1271 sc->cachetrk = trk; 1272 fddone(sc); 1273 return; 1274 } 1275 } 1276 1277 /* 1278 * start DMA read of `trk' 1279 */ 1280 fddmastart(sc, trk); 1281 return; 1282 done: 1283 bp->b_error = error; 1284 fddone(sc); 1285 } 1286 1287 /* 1288 * continue a started operation on next track. always begin at 1289 * sector 0 on the next track. 1290 */ 1291 void 1292 fdcont(struct fd_softc *sc) 1293 { 1294 struct buf *dp, *bp; 1295 int trk, write; 1296 1297 dp = &sc->curbuf; 1298 bp = bufq_peek(sc->bufq); 1299 dp->b_data = (char*)dp->b_data + (dp->b_bcount - bp->b_resid); 1300 dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE; 1301 dp->b_bcount = bp->b_resid; 1302 1303 /* 1304 * figure trk given blkno 1305 */ 1306 trk = dp->b_blkno / sc->nsectors; 1307 #ifdef DEBUG 1308 if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0) 1309 panic("fdcont: confused"); 1310 #endif 1311 if (dp->b_flags & B_READ) 1312 write = 0; 1313 else 1314 write = 1; 1315 /* 1316 * if we will be overwriting the entire cache, don't bother to 1317 * fetch it. 1318 */ 1319 if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) { 1320 if (sc->flags & FDF_DIRTY) 1321 sc->flags |= FDF_JUSTFLUSH; 1322 else { 1323 sc->cachetrk = trk; 1324 fddone(sc); 1325 return; 1326 } 1327 } 1328 /* 1329 * start DMA read of `trk' 1330 */ 1331 fddmastart(sc, trk); 1332 return; 1333 } 1334 1335 void 1336 fddmastart(struct fd_softc *sc, int trk) 1337 { 1338 int adkmask, ndmaw, write, dmatrk; 1339 1340 #ifdef FDDEBUG 1341 printf("fddmastart: unit %d cyl %d head %d", sc->hwunit, 1342 trk / FDNHEADS, trk % FDNHEADS); 1343 #endif 1344 /* 1345 * flush the cached track if dirty else read requested track. 1346 */ 1347 if (sc->flags & FDF_DIRTY) { 1348 fdcachetoraw(sc); 1349 ndmaw = sc->type->nwritew; 1350 dmatrk = sc->cachetrk; 1351 write = 1; 1352 } else { 1353 ndmaw = sc->type->nreadw; 1354 dmatrk = trk; 1355 write = 0; 1356 } 1357 1358 #ifdef FDDEBUG 1359 printf(" %s", write ? " flushing cache\n" : " loading cache\n"); 1360 #endif 1361 sc->cachetrk = trk; 1362 fdc_indma = sc; 1363 fdsetpos(sc, dmatrk, write); 1364 1365 /* 1366 * setup dma stuff 1367 */ 1368 if (write == 0) { 1369 custom.adkcon = ADKF_MSBSYNC; 1370 custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST; 1371 custom.dsksync = FDMFMSYNC; 1372 } else { 1373 custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC | 1374 ADKF_MSBSYNC; 1375 adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC; 1376 if (dmatrk >= sc->type->precomp[0]) 1377 adkmask |= ADKF_PRECOMP0; 1378 if (dmatrk >= sc->type->precomp[1]) 1379 adkmask |= ADKF_PRECOMP1; 1380 custom.adkcon = adkmask; 1381 } 1382 custom.dskpt = (u_char *)kvtop(fdc_dmap); 1383 1384 /* 1385 * If writing an MSDOS track, activate disk index pulse 1386 * interrupt, DMA will be started in the intr routine fdidxintr() 1387 * Otherwise, start the DMA here. 1388 */ 1389 if (write && sc->openpart == FDMSDOSPART) { 1390 fdc_dmalen = ndmaw; 1391 fdc_dmawrite = write; 1392 ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG; 1393 } else { 1394 FDDMASTART(ndmaw, write); 1395 fdc_dmalen = 0; 1396 } 1397 1398 #ifdef FDDEBUG 1399 printf(" DMA started\n"); 1400 #endif 1401 } 1402 1403 /* 1404 * recalibrate the drive 1405 */ 1406 void 1407 fdcalibrate(void *arg) 1408 { 1409 struct fd_softc *sc; 1410 static int loopcnt; 1411 1412 sc = arg; 1413 1414 if (loopcnt == 0) { 1415 /* 1416 * seek cyl 0 1417 */ 1418 fdc_indma = sc; 1419 sc->stepdelay += 900; 1420 if (sc->cachetrk > 1) 1421 fdsetpos(sc, sc->cachetrk % FDNHEADS, 0); 1422 sc->stepdelay -= 900; 1423 } 1424 if (loopcnt++ & 1) 1425 fdsetpos(sc, sc->cachetrk, 0); 1426 else 1427 fdsetpos(sc, sc->cachetrk + FDNHEADS, 0); 1428 /* 1429 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and DMA 1430 */ 1431 if (loopcnt < 8) 1432 callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc); 1433 else { 1434 loopcnt = 0; 1435 fdc_indma = NULL; 1436 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1437 fddmastart(sc, sc->cachetrk); 1438 } 1439 } 1440 1441 void 1442 fddmadone(struct fd_softc *sc, int timeo) 1443 { 1444 #ifdef FDDEBUG 1445 printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo); 1446 #endif 1447 fdc_indma = NULL; 1448 callout_stop(&sc->motor_ch); 1449 FDDMASTOP; 1450 1451 /* 1452 * guarantee the drive has been at current head and cyl 1453 * for at least FDWRITEDELAY after a write. 1454 */ 1455 if (sc->flags & FDF_WRITEWAIT) { 1456 delay(FDWRITEDELAY); 1457 sc->flags &= ~FDF_WRITEWAIT; 1458 } 1459 1460 if ((sc->flags & FDF_MOTOROFF) == 0) { 1461 /* 1462 * motor runs for 1.5 seconds after last DMA 1463 */ 1464 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1465 } 1466 if (sc->flags & FDF_DIRTY) { 1467 /* 1468 * if buffer dirty, the last DMA cleaned it 1469 */ 1470 sc->flags &= ~FDF_DIRTY; 1471 if (timeo) 1472 printf("%s: write of track cache timed out.\n", 1473 sc->sc_dv.dv_xname); 1474 if (sc->flags & FDF_JUSTFLUSH) { 1475 sc->flags &= ~FDF_JUSTFLUSH; 1476 /* 1477 * we are done DMA'ing 1478 */ 1479 fddone(sc); 1480 return; 1481 } 1482 /* 1483 * load the cache 1484 */ 1485 fddmastart(sc, sc->cachetrk); 1486 return; 1487 } 1488 #ifdef FDDEBUG 1489 else if (sc->flags & FDF_MOTOROFF) 1490 panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY"); 1491 #endif 1492 1493 /* 1494 * cache loaded decode it into cache buffer 1495 */ 1496 if (timeo == 0 && fdrawtocache(sc) == 0) 1497 sc->retried = 0; 1498 else { 1499 #ifdef FDDEBUG 1500 if (timeo) 1501 printf("%s: fddmadone: cache load timed out.\n", 1502 sc->sc_dv.dv_xname); 1503 #endif 1504 if (sc->retried >= sc->retries) { 1505 sc->retried = 0; 1506 sc->cachetrk = -1; 1507 } else { 1508 sc->retried++; 1509 /* 1510 * this will be restarted at end of calibrate loop. 1511 */ 1512 callout_stop(&sc->motor_ch); 1513 fdcalibrate(sc); 1514 return; 1515 } 1516 } 1517 fddone(sc); 1518 } 1519 1520 void 1521 fddone(struct fd_softc *sc) 1522 { 1523 struct buf *dp, *bp; 1524 char *data; 1525 int sz; 1526 1527 #ifdef FDDEBUG 1528 printf("fddone: unit %d\n", sc->hwunit); 1529 #endif 1530 /* 1531 * check to see if unit is just flushing the cache, 1532 * that is we have no io queued. 1533 */ 1534 if (sc->flags & FDF_MOTOROFF) 1535 goto nobuf; 1536 1537 dp = &sc->curbuf; 1538 if ((bp = bufq_peek(sc->bufq)) == NULL) 1539 panic ("fddone"); 1540 /* 1541 * check for an error that may have occurred 1542 * while getting the track. 1543 */ 1544 if (sc->cachetrk == -1) { 1545 sc->retried = 0; 1546 bp->b_error = EIO; 1547 } else if (bp->b_error == 0) { 1548 data = sc->cachep; 1549 /* 1550 * get offset of data in track cache and limit 1551 * the copy size to not exceed the cache's end. 1552 */ 1553 data += (dp->b_blkno % sc->nsectors) * FDSECSIZE; 1554 sz = sc->nsectors - dp->b_blkno % sc->nsectors; 1555 sz *= FDSECSIZE; 1556 sz = min(dp->b_bcount, sz); 1557 if (bp->b_flags & B_READ) 1558 bcopy(data, dp->b_data, sz); 1559 else { 1560 bcopy(dp->b_data, data, sz); 1561 sc->flags |= FDF_DIRTY; 1562 } 1563 bp->b_resid = dp->b_bcount - sz; 1564 if (bp->b_resid == 0) { 1565 bp->b_error = 0; 1566 } else { 1567 /* 1568 * not done yet need to read next track 1569 */ 1570 fdcont(sc); 1571 return; 1572 } 1573 } 1574 /* 1575 * remove from queue. 1576 */ 1577 (void)bufq_get(sc->bufq); 1578 1579 disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid), 1580 (bp->b_flags & B_READ)); 1581 1582 biodone(bp); 1583 nobuf: 1584 fdfindwork(device_unit(&sc->sc_dv)); 1585 } 1586 1587 void 1588 fdfindwork(int unit) 1589 { 1590 struct fd_softc *ssc, *sc; 1591 int i, last; 1592 1593 /* 1594 * first see if we have any fdopen()'s waiting 1595 */ 1596 if (fdc_wantwakeup) { 1597 wakeup(fdopen); 1598 fdc_wantwakeup--; 1599 return; 1600 } 1601 1602 /* 1603 * start next available unit, linear search from the next unit 1604 * wrapping and finally this unit. 1605 */ 1606 last = 0; 1607 ssc = NULL; 1608 for (i = unit + 1; last == 0; i++) { 1609 if (i == unit) 1610 last = 1; 1611 if (i >= fd_cd.cd_ndevs) { 1612 i = -1; 1613 continue; 1614 } 1615 if ((sc = device_lookup_private(&fd_cd, i)) == NULL) 1616 continue; 1617 1618 /* 1619 * if unit has requested to be turned off 1620 * and it has no buf's queued do it now 1621 */ 1622 if (sc->flags & FDF_MOTOROFF) { 1623 if (bufq_peek(sc->bufq) == NULL) 1624 fdmotoroff(sc); 1625 else { 1626 /* 1627 * we gained a buf request while 1628 * we waited, forget the motoroff 1629 */ 1630 sc->flags &= ~FDF_MOTOROFF; 1631 } 1632 /* 1633 * if we now have DMA unit must have needed 1634 * flushing, quit 1635 */ 1636 if (fdc_indma) 1637 return; 1638 } 1639 /* 1640 * if we have no start unit and the current unit has 1641 * io waiting choose this unit to start. 1642 */ 1643 if (ssc == NULL && bufq_peek(sc->bufq) != NULL) 1644 ssc = sc; 1645 } 1646 if (ssc) 1647 fdstart(ssc); 1648 } 1649 1650 /* 1651 * min byte count to whats left of the track in question 1652 */ 1653 void 1654 fdminphys(struct buf *bp) 1655 { 1656 struct fd_softc *sc; 1657 int trk, sec, toff, tsz; 1658 1659 if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL) 1660 panic("fdminphys: couldn't get softc"); 1661 1662 trk = bp->b_blkno / sc->nsectors; 1663 sec = bp->b_blkno % sc->nsectors; 1664 1665 toff = sec * FDSECSIZE; 1666 tsz = sc->nsectors * FDSECSIZE; 1667 #ifdef FDDEBUG 1668 printf("fdminphys: before %ld", bp->b_bcount); 1669 #endif 1670 bp->b_bcount = min(bp->b_bcount, tsz - toff); 1671 #ifdef FDDEBUG 1672 printf(" after %ld\n", bp->b_bcount); 1673 #endif 1674 minphys(bp); 1675 } 1676 1677 /* 1678 * encode the track cache into raw MFM ready for DMA 1679 * when we go to multiple disk formats, this will call type dependent 1680 * functions 1681 */ 1682 void fdcachetoraw(struct fd_softc *sc) 1683 { 1684 if (sc->openpart == FDMSDOSPART) 1685 mscachetoraw(sc); 1686 else 1687 amcachetoraw(sc); 1688 } 1689 1690 /* 1691 * decode raw MFM from DMA into units track cache. 1692 * when we go to multiple disk formats, this will call type dependent 1693 * functions 1694 */ 1695 int 1696 fdrawtocache(struct fd_softc *sc) 1697 { 1698 1699 if (sc->openpart == FDMSDOSPART) 1700 return(msrawtocache(sc)); 1701 else 1702 return(amrawtocache(sc)); 1703 } 1704 1705 void 1706 amcachetoraw(struct fd_softc *sc) 1707 { 1708 static u_long mfmnull[4]; 1709 u_long *rp, *crp, *dp, hcksum, dcksum, info, zero; 1710 int sec, i; 1711 1712 rp = fdc_dmap; 1713 1714 /* 1715 * not yet one sector (- 1 long) gap. 1716 * for now use previous drivers values 1717 */ 1718 for (i = 0; i < sc->type->gap; i++) 1719 *rp++ = 0xaaaaaaaa; 1720 /* 1721 * process sectors 1722 */ 1723 dp = sc->cachep; 1724 zero = 0; 1725 info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors; 1726 for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) { 1727 hcksum = dcksum = 0; 1728 /* 1729 * sector format 1730 * offset description 1731 *----------------------------------- 1732 * 0 null 1733 * 1 sync 1734 * oddbits evenbits 1735 *---------------------- 1736 * 2 3 [0xff]b [trk]b [sec]b [togap]b 1737 * 4-7 8-11 null 1738 * 12 13 header cksum [2-11] 1739 * 14 15 data cksum [16-271] 1740 * 16-143 144-271 data 1741 */ 1742 *rp = 0xaaaaaaaa; 1743 if (*(rp - 1) & 0x1) 1744 *rp &= 0x7fffffff; /* clock bit correction */ 1745 rp++; 1746 *rp++ = (FDMFMSYNC << 16) | FDMFMSYNC; 1747 rp = mfmblkencode(&info, rp, &hcksum, 1); 1748 rp = mfmblkencode(mfmnull, rp, &hcksum, 4); 1749 rp = mfmblkencode(&hcksum, rp, NULL, 1); 1750 1751 crp = rp; 1752 rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS); 1753 dp += FDSECLWORDS; 1754 crp = mfmblkencode(&dcksum, crp, NULL, 1); 1755 if (*(crp - 1) & 0x1) 1756 *crp &= 0x7fffffff; /* clock bit correction */ 1757 else if ((*crp & 0x40000000) == 0) 1758 *crp |= 0x80000000; 1759 } 1760 *rp = 0xaaa80000; 1761 if (*(rp - 1) & 0x1) 1762 *rp &= 0x7fffffff; 1763 } 1764 1765 u_long * 1766 fdfindsync(u_long *rp, u_long *ep) 1767 { 1768 u_short *sp; 1769 1770 sp = (u_short *)rp; 1771 while ((u_long *)sp < ep && *sp != FDMFMSYNC) 1772 sp++; 1773 while ((u_long *)sp < ep && *sp == FDMFMSYNC) 1774 sp++; 1775 if ((u_long *)sp < ep) 1776 return((u_long *)sp); 1777 return(NULL); 1778 } 1779 1780 int 1781 amrawtocache(struct fd_softc *sc) 1782 { 1783 u_long mfmnull[4]; 1784 u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp; 1785 int cnt, doagain; 1786 1787 doagain = 1; 1788 srp = rp = fdc_dmap; 1789 erp = (u_long *)((u_short *)rp + sc->type->nreadw); 1790 cnt = 0; 1791 again: 1792 if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) { 1793 #ifdef DIAGNOSTIC 1794 printf("%s: corrupted track (%d) data.\n", 1795 sc->sc_dv.dv_xname, sc->cachetrk); 1796 #endif 1797 return(-1); 1798 } 1799 1800 /* 1801 * process sectors 1802 */ 1803 for (; cnt < sc->nsectors; cnt++) { 1804 hcksum = dcksum = 0; 1805 rp = mfmblkdecode(rp, &info, &hcksum, 1); 1806 rp = mfmblkdecode(rp, mfmnull, &hcksum, 4); 1807 rp = mfmblkdecode(rp, &cktmp, NULL, 1); 1808 if (cktmp != hcksum) { 1809 #ifdef FDDEBUG 1810 printf(" info 0x%lx hchksum 0x%lx trkhcksum 0x%lx\n", 1811 info, hcksum, cktmp); 1812 #endif 1813 goto again; 1814 } 1815 if (((info >> 16) & 0xff) != sc->cachetrk) { 1816 #ifdef DEBUG 1817 printf("%s: incorrect track found: 0x%lx %d\n", 1818 sc->sc_dv.dv_xname, 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 printf("%s: corrupted track (%d) data.\n", 1958 sc->sc_dv.dv_xname, sc->cachetrk); 1959 #endif 1960 return(-1); 1961 } 1962 1963 /* 1964 * Grab sector info 1965 */ 1966 if (*rp++ != FDMFMID) 1967 continue; 1968 rp = msblkdecode(rp, tb, 4); 1969 #ifdef FDDEBUG 1970 printf("sector id: sector %d, track %d, side %d," 1971 "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]); 1972 #endif 1973 if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk || 1974 tb[2] > sc->nsectors) 1975 continue; 1976 1977 sec = tb[2]; 1978 sc->bytespersec = 128 << tb[3]; 1979 rp += 2; /* skip CRC-16 */ 1980 1981 /* 1982 * skip gap and read in data 1983 */ 1984 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) 1985 return(-1); 1986 if (*rp++ != FDMFMDATA) 1987 continue; 1988 rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec), 1989 sc->bytespersec); 1990 rp += 2; /* skip CRC-16 */ 1991 1992 retry = 0; 1993 } while (retry); 1994 } 1995 return(0); 1996 } 1997 1998 /* 1999 * encode len longwords of `dp' data in amiga mfm block format (`rp') 2000 * this format specified that the odd bits are at current pos and even 2001 * bits at len + current pos 2002 */ 2003 u_long * 2004 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len) 2005 { 2006 u_long *sdp, *edp, d, dtmp, correct; 2007 2008 sdp = dp; 2009 edp = dp + len; 2010 2011 if (*(rp - 1) & 0x1) 2012 correct = 1; 2013 else 2014 correct = 0; 2015 /* 2016 * do odd bits 2017 */ 2018 while (dp < edp) { 2019 d = (*dp >> 1) & 0x55555555; /* remove clock bits */ 2020 dtmp = d ^ 0x55555555; 2021 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2022 /* 2023 * correct upper clock bit if needed 2024 */ 2025 if (correct) 2026 d &= 0x7fffffff; 2027 if (d & 0x1) 2028 correct = 1; 2029 else 2030 correct = 0; 2031 /* 2032 * do checksums and store in raw buffer 2033 */ 2034 if (cp) 2035 *cp ^= d; 2036 *rp++ = d; 2037 dp++; 2038 } 2039 /* 2040 * do even bits 2041 */ 2042 dp = sdp; 2043 while (dp < edp) { 2044 d = *dp & 0x55555555; /* remove clock bits */ 2045 dtmp = d ^ 0x55555555; 2046 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2047 /* 2048 * correct upper clock bit if needed 2049 */ 2050 if (correct) 2051 d &= 0x7fffffff; 2052 if (d & 0x1) 2053 correct = 1; 2054 else 2055 correct = 0; 2056 /* 2057 * do checksums and store in raw buffer 2058 */ 2059 if (cp) 2060 *cp ^= d; 2061 *rp++ = d; 2062 dp++; 2063 } 2064 if (cp) 2065 *cp &= 0x55555555; 2066 return(rp); 2067 } 2068 2069 /* 2070 * decode len longwords of `dp' data in amiga mfm block format (`rp') 2071 * this format specified that the odd bits are at current pos and even 2072 * bits at len + current pos 2073 */ 2074 u_long * 2075 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len) 2076 { 2077 u_long o, e; 2078 int cnt; 2079 2080 cnt = len; 2081 while (cnt--) { 2082 o = *rp; 2083 e = *(rp + len); 2084 if (cp) { 2085 *cp ^= o; 2086 *cp ^= e; 2087 } 2088 o &= 0x55555555; 2089 e &= 0x55555555; 2090 *dp++ = (o << 1) | e; 2091 rp++; 2092 } 2093 if (cp) 2094 *cp &= 0x55555555; 2095 return(rp + len); 2096 } 2097 2098 /* 2099 * decode len words in standard MFM format to len bytes 2100 * of data. 2101 */ 2102 u_short * 2103 msblkdecode(u_short *rp, u_char *cp, int len) 2104 { 2105 while (len--) { 2106 *cp++ = msdecode[*rp & 0x7f] | 2107 (msdecode[(*rp >> 8) & 0x7f] << 4); 2108 rp++; 2109 } 2110 2111 return(rp); 2112 } 2113 2114 /* 2115 * encode len bytes of data into len words in standard MFM format. 2116 * If a pointer is supplied for crc, calculate the CRC-16 of the data 2117 * as well. 2118 */ 2119 u_short * 2120 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc) 2121 { 2122 u_short td; 2123 u_short mycrc; 2124 2125 /* preload crc for header (4 bytes) 2126 * or data (anything else) 2127 */ 2128 mycrc = (len == 4) ? 0xb230 : 0xe295; 2129 2130 while (len--) { 2131 td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f]; 2132 2133 /* Check for zeros in top bit of encode and bottom 2134 * bit of previous encode. if so, slap a one in betweem 2135 * them. 2136 */ 2137 if ((td & 0x140) == 0) 2138 td |= 0x80; 2139 if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0) 2140 td |= 0x8000; 2141 2142 *rp++ = td; 2143 2144 /* 2145 * calc crc if requested 2146 */ 2147 if (crc) 2148 mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)]; 2149 2150 cp++; 2151 } 2152 2153 if (crc) 2154 *crc = mycrc; 2155 2156 return(rp); 2157 } 2158
Indexes created Thu Oct 02 14:10:14 GMT 2025