fd.c revision 1.92.4.1
1 /* $NetBSD: fd.c,v 1.92.4.1 2015/04/06 15:17:51 skrll 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 1.92.4.1 2015/04/06 15:17:51 skrll 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 .d_open = fdopen, 258 .d_close = fdclose, 259 .d_strategy = fdstrategy, 260 .d_ioctl = fdioctl, 261 .d_dump = nodump, 262 .d_psize = nosize, 263 .d_discard = nodiscard, 264 .d_flag = D_DISK 265 }; 266 267 const struct cdevsw fd_cdevsw = { 268 .d_open = fdopen, 269 .d_close = fdclose, 270 .d_read = fdread, 271 .d_write = fdwrite, 272 .d_ioctl = fdioctl, 273 .d_stop = nostop, 274 .d_tty = notty, 275 .d_poll = nopoll, 276 .d_mmap = nommap, 277 .d_kqfilter = nokqfilter, 278 .d_discard = nodiscard, 279 .d_flag = D_DISK 280 }; 281 282 struct dkdriver fddkdriver = { fdstrategy }; 283 284 CFATTACH_DECL_NEW(fdc, 0, 285 fdcmatch, fdcattach, NULL, NULL); 286 287 /* 288 * all hw access through macros, this helps to hide the active low 289 * properties 290 */ 291 292 #define FDUNITMASK(unit) (1 << (3 + (unit))) 293 294 /* 295 * select units using mask 296 */ 297 #define FDSELECT(um) do { ciab.prb &= ~(um); } while (0) 298 299 /* 300 * deselect units using mask 301 */ 302 #define FDDESELECT(um) do { ciab.prb |= (um); delay(1); } while (0) 303 304 /* 305 * test hw condition bits 306 */ 307 #define FDTESTC(bit) ((ciaa.pra & (1 << (bit))) == 0) 308 309 /* 310 * set motor for select units, true motor on else off 311 */ 312 #define FDSETMOTOR(on) do { \ 313 if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \ 314 } while (0) 315 316 /* 317 * set head for select units 318 */ 319 #define FDSETHEAD(head) do { \ 320 if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \ 321 delay(1); } while (0) 322 323 /* 324 * select direction, true towards spindle else outwards 325 */ 326 #define FDSETDIR(in) do { \ 327 if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \ 328 delay(1); } while (0) 329 330 /* 331 * step the selected units 332 */ 333 #define FDSTEP do { \ 334 ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \ 335 } while (0) 336 337 #define FDDMASTART(len, towrite) do { \ 338 int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \ 339 custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0) 340 341 #define FDDMASTOP do { custom.dsklen = 0; } while (0) 342 343 344 int 345 fdcmatch(device_t parent, cfdata_t cf, void *aux) 346 { 347 static int fdc_matched = 0; 348 349 /* Allow only once instance. */ 350 if (matchname("fdc", aux) == 0 || fdc_matched) 351 return(0); 352 if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) { 353 printf("fdc: unable to allocate DMA buffer\n"); 354 return(0); 355 } 356 357 fdc_matched = 1; 358 return(1); 359 } 360 361 void 362 fdcattach(device_t parent, device_t self, void *aux) 363 { 364 struct fdcargs args; 365 366 printf(": dmabuf pa 0x%x", (unsigned)kvtop(fdc_dmap)); 367 printf(": dmabuf ka %p\n", fdc_dmap); 368 args.unit = 0; 369 args.type = fdcgetfdtype(args.unit); 370 371 fdc_side = -1; 372 config_found(self, &args, fdcprint); 373 for (args.unit++; args.unit < FDMAXUNITS; args.unit++) { 374 if ((args.type = fdcgetfdtype(args.unit)) == NULL) 375 continue; 376 config_found(self, &args, fdcprint); 377 } 378 } 379 380 int 381 fdcprint(void *aux, const char *pnp) 382 { 383 struct fdcargs *fcp; 384 385 fcp = aux; 386 if (pnp) 387 aprint_normal("fd%d at %s unit %d:", fcp->unit, pnp, 388 fcp->type->driveid); 389 return(UNCONF); 390 } 391 392 /*ARGSUSED*/ 393 int 394 fdmatch(device_t parent, cfdata_t cf, void *aux) 395 { 396 struct fdcargs *fdap; 397 398 fdap = aux; 399 if (cf->cf_loc[FDCCF_UNIT] == fdap->unit || 400 cf->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT) 401 return(1); 402 403 return(0); 404 } 405 406 void 407 fdattach(device_t parent, device_t self, void *aux) 408 { 409 struct fdcargs *ap; 410 struct fd_softc *sc; 411 int i; 412 413 ap = aux; 414 sc = device_private(self); 415 sc->sc_dev = self; 416 417 bufq_alloc(&sc->bufq, "disksort", BUFQ_SORT_CYLINDER); 418 callout_init(&sc->calibrate_ch, 0); 419 callout_init(&sc->motor_ch, 0); 420 421 sc->curcyl = sc->cachetrk = -1; 422 sc->openpart = -1; 423 sc->type = ap->type; 424 sc->hwunit = ap->unit; 425 sc->unitmask = 1 << (3 + ap->unit); 426 sc->retries = FDRETRIES; 427 sc->stepdelay = FDSTEPDELAY; 428 sc->bytespersec = 512; 429 printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n", 430 sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS, 431 sc->type->amiga_nsectors, sc->type->msdos_nsectors); 432 433 /* 434 * Initialize and attach the disk structure. 435 */ 436 disk_init(&sc->dkdev, device_xname(sc->sc_dev), &fddkdriver); 437 disk_attach(&sc->dkdev); 438 439 /* 440 * calibrate the drive 441 */ 442 fdsetpos(sc, 0, 0); 443 fdsetpos(sc, sc->type->ncylinders, 0); 444 fdsetpos(sc, 0, 0); 445 fdmotoroff(sc); 446 447 /* 448 * precalc msdos MFM and CRC 449 */ 450 for (i = 0; i < 128; i++) 451 msdecode[i] = 0xff; 452 for (i = 0; i < 16; i++) 453 msdecode[msencode[i]] = i; 454 for (i = 0; i < 256; i++) { 455 mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^ 456 (0x1021 * (i >> 4)); 457 } 458 459 /* 460 * enable disk related interrupts 461 */ 462 custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK; 463 custom.intena = INTF_SETCLR | INTF_DSKBLK; 464 ciab.icr = CIA_ICR_FLG; 465 } 466 467 /*ARGSUSED*/ 468 int 469 fdopen(dev_t dev, int flags, int devtype, struct lwp *l) 470 { 471 struct fd_softc *sc; 472 int wasopen, fwork, error, s; 473 474 error = 0; 475 476 if (FDPART(dev) >= FDMAXPARTS) 477 return(ENXIO); 478 479 if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL) 480 return(ENXIO); 481 if (sc->flags & FDF_NOTRACK0) 482 return(ENXIO); 483 if (sc->cachep == NULL) 484 sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK); 485 486 s = splbio(); 487 /* 488 * if we are sleeping in fdclose(); waiting for a chance to 489 * shut the motor off, do a sleep here also. 490 */ 491 while (sc->flags & FDF_WMOTOROFF) 492 tsleep(fdmotoroff, PRIBIO, "fdopen", 0); 493 494 fwork = 0; 495 /* 496 * if not open let user open request type, otherwise 497 * ensure they are trying to open same type. 498 */ 499 if (sc->openpart == FDPART(dev)) 500 wasopen = 1; 501 else if (sc->openpart == -1) { 502 sc->openpart = FDPART(dev); 503 wasopen = 0; 504 } else { 505 wasopen = 1; 506 error = EPERM; 507 goto done; 508 } 509 510 /* 511 * wait for current io to complete if any 512 */ 513 if (fdc_indma) { 514 fwork = 1; 515 fdc_wantwakeup++; 516 tsleep(fdopen, PRIBIO, "fdopen", 0); 517 } 518 if ((error = fdloaddisk(sc)) != 0) 519 goto done; 520 if ((error = fdgetdisklabel(sc, dev)) != 0) 521 goto done; 522 #ifdef FDDEBUG 523 printf(" open successful\n"); 524 #endif 525 done: 526 /* 527 * if we requested that fddone()->fdfindwork() wake us, allow it to 528 * complete its job now 529 */ 530 if (fwork) 531 fdfindwork(FDUNIT(dev)); 532 splx(s); 533 534 /* 535 * if we were not open and we marked us so reverse that. 536 */ 537 if (error && wasopen == 0) 538 sc->openpart = -1; 539 return(error); 540 } 541 542 /*ARGSUSED*/ 543 int 544 fdclose(dev_t dev, int flags, int devtype, struct lwp *l) 545 { 546 struct fd_softc *sc; 547 int s; 548 549 #ifdef FDDEBUG 550 printf("fdclose()\n"); 551 #endif 552 sc = getsoftc(fd_cd, FDUNIT(dev)); 553 s = splbio(); 554 if (sc->flags & FDF_MOTORON) { 555 sc->flags |= FDF_WMOTOROFF; 556 tsleep(fdmotoroff, PRIBIO, "fdclose", 0); 557 sc->flags &= ~FDF_WMOTOROFF; 558 wakeup(fdmotoroff); 559 } 560 sc->openpart = -1; 561 splx(s); 562 return(0); 563 } 564 565 int 566 fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) 567 { 568 struct fd_softc *sc; 569 int error, wlab; 570 571 sc = getsoftc(fd_cd, FDUNIT(dev)); 572 573 if ((sc->flags & FDF_HAVELABEL) == 0) 574 return(EBADF); 575 576 error = disk_ioctl(&sc->dkdev, dev, cmd, addr, flag, l); 577 if (error != EPASSTHROUGH) 578 return error; 579 580 switch (cmd) { 581 case DIOCSBAD: 582 return(EINVAL); 583 case DIOCSRETRIES: 584 if (*(int *)addr < 0) 585 return(EINVAL); 586 sc->retries = *(int *)addr; 587 return(0); 588 case DIOCSSTEP: 589 if (*(int *)addr < FDSTEPDELAY) 590 return(EINVAL); 591 sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr; 592 return(0); 593 case DIOCSDINFO: 594 if ((flag & FWRITE) == 0) 595 return(EBADF); 596 return(fdsetdisklabel(sc, (struct disklabel *)addr)); 597 case DIOCWDINFO: 598 if ((flag & FWRITE) == 0) 599 return(EBADF); 600 if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0) 601 return(error); 602 wlab = sc->wlabel; 603 sc->wlabel = 1; 604 error = fdputdisklabel(sc, dev); 605 sc->wlabel = wlab; 606 return(error); 607 case DIOCWLABEL: 608 if ((flag & FWRITE) == 0) 609 return(EBADF); 610 sc->wlabel = *(int *)addr; 611 return(0); 612 case DIOCGDEFLABEL: 613 fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev)); 614 return(0); 615 default: 616 return(ENOTTY); 617 } 618 } 619 620 int 621 fdread(dev_t dev, struct uio *uio, int flags) 622 { 623 return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio)); 624 } 625 626 int 627 fdwrite(dev_t dev, struct uio *uio, int flags) 628 { 629 return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio)); 630 } 631 632 633 void 634 fdintr(int flag) 635 { 636 int s; 637 638 s = splbio(); 639 if (fdc_indma) 640 fddmadone(fdc_indma, 0); 641 splx(s); 642 } 643 644 void 645 fdidxintr(void) 646 { 647 if (fdc_indma && fdc_dmalen) { 648 /* 649 * turn off intr and start actual dma 650 */ 651 ciab.icr = CIA_ICR_FLG; 652 FDDMASTART(fdc_dmalen, fdc_dmawrite); 653 fdc_dmalen = 0; 654 } 655 } 656 657 void 658 fdstrategy(struct buf *bp) 659 { 660 struct fd_softc *sc; 661 int unit, s; 662 663 unit = FDUNIT(bp->b_dev); 664 sc = getsoftc(fd_cd, unit); 665 666 #ifdef FDDEBUG 667 printf("fdstrategy: %p\n", bp); 668 #endif 669 /* 670 * check for valid partition and bounds 671 */ 672 if ((sc->flags & FDF_HAVELABEL) == 0) { 673 bp->b_error = EIO; 674 goto done; 675 } 676 if (bounds_check_with_label(&sc->dkdev, bp, sc->wlabel) <= 0) 677 goto done; 678 679 /* 680 * trans count of zero or bounds check indicates io is done 681 * we are done. 682 */ 683 if (bp->b_bcount == 0) 684 goto done; 685 686 bp->b_rawblkno = bp->b_blkno; 687 688 /* 689 * queue the buf and kick the low level code 690 */ 691 s = splbio(); 692 bufq_put(sc->bufq, bp); 693 fdstart(sc); 694 splx(s); 695 return; 696 done: 697 bp->b_resid = bp->b_bcount; 698 biodone(bp); 699 } 700 701 /* 702 * make sure disk is loaded and label is up-to-date. 703 */ 704 int 705 fdloaddisk(struct fd_softc *sc) 706 { 707 /* 708 * if diskchange is low step drive to 0 then up one then to zero. 709 */ 710 fdselunit(sc); /* make sure the unit is selected */ 711 if (FDTESTC(FDB_CHANGED)) { 712 fdsetpos(sc, 0, 0); 713 sc->cachetrk = -1; /* invalidate the cache */ 714 sc->flags &= ~FDF_HAVELABEL; 715 fdsetpos(sc, FDNHEADS, 0); 716 fdsetpos(sc, 0, 0); 717 if (FDTESTC(FDB_CHANGED)) { 718 fdmotoroff(sc); 719 FDDESELECT(sc->unitmask); 720 return(ENXIO); 721 } 722 } 723 FDDESELECT(sc->unitmask); 724 fdmotoroff(sc); 725 sc->type = fdcgetfdtype(sc->hwunit); 726 if (sc->type == NULL) 727 return(ENXIO); 728 if (sc->openpart == FDMSDOSPART) 729 sc->nsectors = sc->type->msdos_nsectors; 730 else 731 sc->nsectors = sc->type->amiga_nsectors; 732 return(0); 733 } 734 735 void 736 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part) 737 /* (variable part) XXX ick */ 738 { 739 740 memset(lp, 0, sizeof(struct disklabel)); 741 lp->d_secsize = FDSECSIZE; 742 lp->d_ntracks = FDNHEADS; 743 lp->d_ncylinders = sc->type->ncylinders; 744 lp->d_nsectors = sc->nsectors; 745 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 746 lp->d_type = DKTYPE_FLOPPY; 747 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 748 lp->d_rpm = 300; /* good guess I suppose. */ 749 lp->d_interleave = 1; /* should change when adding msdos */ 750 sc->stepdelay = lp->d_trkseek = FDSTEPDELAY; 751 lp->d_bbsize = 0; 752 lp->d_sbsize = 0; 753 lp->d_partitions[part].p_size = lp->d_secperunit; 754 lp->d_partitions[part].p_fstype = FS_UNUSED; 755 lp->d_partitions[part].p_fsize = 1024; 756 lp->d_partitions[part].p_frag = 8; 757 lp->d_partitions[part].p_cpg = 2; /* adosfs: reserved blocks */ 758 lp->d_npartitions = part + 1; 759 lp->d_magic = lp->d_magic2 = DISKMAGIC; 760 lp->d_checksum = dkcksum(lp); 761 } 762 763 /* 764 * read disk label, if present otherwise create one 765 * return a new label if raw part and none found, otherwise err. 766 */ 767 int 768 fdgetdisklabel(struct fd_softc *sc, dev_t dev) 769 { 770 struct disklabel *lp, *dlp; 771 struct cpu_disklabel *clp; 772 struct buf *bp; 773 int error, part; 774 775 if (sc->flags & FDF_HAVELABEL && 776 sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1)) 777 return(0); 778 #ifdef FDDEBUG 779 printf("fdgetdisklabel()\n"); 780 #endif 781 part = FDPART(dev); 782 lp = sc->dkdev.dk_label; 783 clp = sc->dkdev.dk_cpulabel; 784 memset(lp, 0, sizeof(struct disklabel)); 785 memset(clp, 0, sizeof(struct cpu_disklabel)); 786 787 lp->d_secsize = FDSECSIZE; 788 lp->d_ntracks = FDNHEADS; 789 lp->d_ncylinders = sc->type->ncylinders; 790 lp->d_nsectors = sc->nsectors; 791 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 792 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders; 793 lp->d_npartitions = part + 1; 794 lp->d_partitions[part].p_size = lp->d_secperunit; 795 lp->d_partitions[part].p_fstype = FS_UNUSED; 796 lp->d_partitions[part].p_fsize = 1024; 797 lp->d_partitions[part].p_frag = 8; 798 lp->d_partitions[part].p_cpg = 2; /* for adosfs: reserved blks */ 799 800 sc->flags |= FDF_HAVELABEL; 801 802 bp = (void *)geteblk((int)lp->d_secsize); 803 bp->b_dev = dev; 804 bp->b_blkno = 0; 805 bp->b_cylinder = 0; 806 bp->b_bcount = FDSECSIZE; 807 bp->b_flags |= B_READ; 808 fdstrategy(bp); 809 if ((error = biowait(bp)) != 0) 810 goto nolabel; 811 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 812 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC || 813 dkcksum(dlp)) { 814 error = EINVAL; 815 goto nolabel; 816 } 817 memcpy(lp, dlp, sizeof(struct disklabel)); 818 if (lp->d_trkseek > FDSTEPDELAY) 819 sc->stepdelay = lp->d_trkseek; 820 brelse(bp, 0); 821 return(0); 822 nolabel: 823 fdgetdefaultlabel(sc, lp, part); 824 brelse(bp, 0); 825 return(0); 826 } 827 828 /* 829 * set the incore copy of this units disklabel 830 */ 831 int 832 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp) 833 { 834 struct disklabel *clp; 835 struct partition *pp; 836 837 /* 838 * must have at least opened raw unit to fetch the 839 * raw_part stuff. 840 */ 841 if ((sc->flags & FDF_HAVELABEL) == 0) 842 return(EINVAL); 843 clp = sc->dkdev.dk_label; 844 /* 845 * make sure things check out and we only have one valid 846 * partition 847 */ 848 #ifdef FDDEBUG 849 printf("fdsetdisklabel\n"); 850 #endif 851 if (lp->d_secsize != FDSECSIZE || 852 lp->d_nsectors != clp->d_nsectors || 853 lp->d_ntracks != FDNHEADS || 854 lp->d_ncylinders != clp->d_ncylinders || 855 lp->d_secpercyl != clp->d_secpercyl || 856 lp->d_secperunit != clp->d_secperunit || 857 lp->d_magic != DISKMAGIC || 858 lp->d_magic2 != DISKMAGIC || 859 lp->d_npartitions == 0 || 860 lp->d_npartitions > FDMAXPARTS || 861 (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) || 862 dkcksum(lp)) 863 return(EINVAL); 864 /* 865 * if any partitions are present make sure they 866 * represent the currently open type 867 */ 868 if ((pp = &lp->d_partitions[0])->p_size) { 869 if ((pp = &lp->d_partitions[1])->p_size == 0) 870 goto done; 871 else if (sc->openpart != 1) 872 return(EINVAL); 873 } else if (sc->openpart != 0) 874 return(EINVAL); 875 /* 876 * make sure selected partition is within bounds 877 * XXX on the second check, its to handle a bug in 878 * XXX the cluster routines as they require mutliples 879 * XXX of PAGE_SIZE currently 880 */ 881 if ((pp->p_offset + pp->p_size >= lp->d_secperunit) || 882 (pp->p_frag * pp->p_fsize % PAGE_SIZE)) 883 return(EINVAL); 884 done: 885 memcpy(clp, lp, sizeof(struct disklabel)); 886 return(0); 887 } 888 889 /* 890 * write out the incore copy of this units disklabel 891 */ 892 int 893 fdputdisklabel(struct fd_softc *sc, dev_t dev) 894 { 895 struct disklabel *lp, *dlp; 896 struct buf *bp; 897 int error; 898 899 if ((sc->flags & FDF_HAVELABEL) == 0) 900 return(EBADF); 901 #ifdef FDDEBUG 902 printf("fdputdisklabel\n"); 903 #endif 904 /* 905 * get buf and read in sector 0 906 */ 907 lp = sc->dkdev.dk_label; 908 bp = geteblk((int)lp->d_secsize); 909 bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART); 910 bp->b_blkno = 0; 911 bp->b_cylinder = 0; 912 bp->b_bcount = FDSECSIZE; 913 bp->b_flags |= B_READ; 914 fdstrategy(bp); 915 if ((error = biowait(bp)) != 0) 916 goto done; 917 /* 918 * copy disklabel to buf and write it out synchronous 919 */ 920 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET); 921 memcpy(dlp, lp, sizeof(struct disklabel)); 922 bp->b_blkno = 0; 923 bp->b_cylinder = 0; 924 bp->b_flags &= ~(B_READ); 925 bp->b_oflags &= ~(BO_DONE); 926 bp->b_flags |= B_WRITE; 927 fdstrategy(bp); 928 error = biowait(bp); 929 done: 930 brelse(bp, 0); 931 return(error); 932 } 933 934 /* 935 * figure out drive type or NULL if none. 936 */ 937 struct fdtype * 938 fdcgetfdtype(int unit) 939 { 940 struct fdtype *ftp; 941 u_long id, idb; 942 int cnt, umask; 943 944 id = 0; 945 umask = 1 << (3 + unit); 946 947 FDDESELECT(FDCUNITMASK); 948 949 FDSETMOTOR(1); 950 delay(1); 951 FDSELECT(umask); 952 delay(1); 953 FDDESELECT(umask); 954 955 FDSETMOTOR(0); 956 delay(1); 957 FDSELECT(umask); 958 delay(1); 959 FDDESELECT(umask); 960 961 for (idb = 0x80000000; idb; idb >>= 1) { 962 FDSELECT(umask); 963 delay(1); 964 if (FDTESTC(FDB_READY) == 0) 965 id |= idb; 966 FDDESELECT(umask); 967 delay(1); 968 } 969 #ifdef FDDEBUG 970 printf("fdcgettype unit %d id 0x%lx\n", unit, id); 971 #endif 972 973 for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++) 974 if (ftp->driveid == id) 975 return(ftp); 976 /* 977 * 3.5dd's at unit 0 do not always return id. 978 */ 979 if (unit == 0) 980 return(fdtype); 981 return(NULL); 982 } 983 984 /* 985 * turn motor off if possible otherwise mark as needed and will be done 986 * later. 987 */ 988 void 989 fdmotoroff(void *arg) 990 { 991 struct fd_softc *sc; 992 int s; 993 994 sc = arg; 995 s = splbio(); 996 997 #ifdef FDDEBUG 998 printf("fdmotoroff: unit %d\n", sc->hwunit); 999 #endif 1000 if ((sc->flags & FDF_MOTORON) == 0) 1001 goto done; 1002 /* 1003 * if we have a timeout on a DMA operation let fddmadone() 1004 * deal with it. 1005 */ 1006 if (fdc_indma == sc) { 1007 fddmadone(sc, 1); 1008 goto done; 1009 } 1010 #ifdef FDDEBUG 1011 printf(" motor was on, turning off\n"); 1012 #endif 1013 1014 /* 1015 * flush cache if needed 1016 */ 1017 if (sc->flags & FDF_DIRTY) { 1018 sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF; 1019 #ifdef FDDEBUG 1020 printf(" flushing dirty buffer first\n"); 1021 #endif 1022 /* 1023 * if DMA'ing done for now, fddone() will call us again 1024 */ 1025 if (fdc_indma) 1026 goto done; 1027 fddmastart(sc, sc->cachetrk); 1028 goto done; 1029 } 1030 1031 /* 1032 * if controller is busy just schedule us to be called back 1033 */ 1034 if (fdc_indma) { 1035 /* 1036 * someone else has the controller now 1037 * just set flag and let fddone() call us again. 1038 */ 1039 sc->flags |= FDF_MOTOROFF; 1040 goto done; 1041 } 1042 1043 #ifdef FDDEBUG 1044 printf(" hw turning unit off\n"); 1045 #endif 1046 1047 sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF); 1048 FDDESELECT(FDCUNITMASK); 1049 FDSETMOTOR(0); 1050 delay(1); 1051 FDSELECT(sc->unitmask); 1052 delay(4); 1053 FDDESELECT(sc->unitmask); 1054 delay(1); 1055 if (sc->flags & FDF_WMOTOROFF) 1056 wakeup(fdmotoroff); 1057 done: 1058 splx(s); 1059 } 1060 1061 /* 1062 * select drive seek to track exit with motor on. 1063 * fdsetpos(x, 0, 0) does calibrates the drive. 1064 */ 1065 void 1066 fdsetpos(struct fd_softc *sc, int trk, int towrite) 1067 { 1068 int nstep, sdir, ondly, ncyl, nside; 1069 1070 FDDESELECT(FDCUNITMASK); 1071 FDSETMOTOR(1); 1072 delay(1); 1073 FDSELECT(sc->unitmask); 1074 delay(1); 1075 if ((sc->flags & FDF_MOTORON) == 0) { 1076 ondly = 0; 1077 while (FDTESTC(FDB_READY) == 0) { 1078 delay(1000); 1079 if (++ondly >= 1000) 1080 break; 1081 } 1082 } 1083 sc->flags |= FDF_MOTORON; 1084 1085 ncyl = trk / FDNHEADS; 1086 nside = trk % FDNHEADS; 1087 1088 if (sc->curcyl == ncyl && fdc_side == nside) 1089 return; 1090 1091 if (towrite) 1092 sc->flags |= FDF_WRITEWAIT; 1093 1094 #ifdef FDDEBUG 1095 printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS, 1096 trk % FDNHEADS, towrite); 1097 #endif 1098 nstep = ncyl - sc->curcyl; 1099 if (nstep) { 1100 /* 1101 * figure direction 1102 */ 1103 if (nstep > 0 && ncyl != 0) { 1104 sdir = FDSTEPIN; 1105 FDSETDIR(1); 1106 } else { 1107 nstep = -nstep; 1108 sdir = FDSTEPOUT; 1109 FDSETDIR(0); 1110 } 1111 if (ncyl == 0) { 1112 /* 1113 * either just want cylinder 0 or doing 1114 * a calibrate. 1115 */ 1116 nstep = 256; 1117 while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) { 1118 FDSTEP; 1119 delay(sc->stepdelay); 1120 } 1121 if (nstep < 0) 1122 sc->flags |= FDF_NOTRACK0; 1123 } else { 1124 /* 1125 * step the needed amount amount. 1126 */ 1127 while (nstep--) { 1128 FDSTEP; 1129 delay(sc->stepdelay); 1130 } 1131 } 1132 /* 1133 * if switched directions 1134 * allow drive to settle. 1135 */ 1136 if (sc->pstepdir != sdir) 1137 delay(FDSETTLEDELAY); 1138 sc->pstepdir = sdir; 1139 sc->curcyl = ncyl; 1140 } 1141 if (nside == fdc_side) 1142 return; 1143 /* 1144 * select side 1145 */ 1146 fdc_side = nside; 1147 FDSETHEAD(nside); 1148 delay(FDPRESIDEDELAY); 1149 } 1150 1151 void 1152 fdselunit(struct fd_softc *sc) 1153 { 1154 FDDESELECT(FDCUNITMASK); /* deselect all */ 1155 FDSETMOTOR(sc->flags & FDF_MOTORON); /* set motor to unit's state */ 1156 delay(1); 1157 FDSELECT(sc->unitmask); /* select unit */ 1158 delay(1); 1159 } 1160 1161 /* 1162 * process next buf on device queue. 1163 * normall sequence of events: 1164 * fdstart() -> fddmastart(); 1165 * fdidxintr(); 1166 * fdintr() -> fddmadone() -> fddone(); 1167 * if the track is in the cache then fdstart() will short-circuit 1168 * to fddone() else if the track cache is dirty it will flush. If 1169 * the buf is not an entire track it will cache the requested track. 1170 */ 1171 void 1172 fdstart(struct fd_softc *sc) 1173 { 1174 int trk, error, write; 1175 struct buf *bp, *dp; 1176 int changed; 1177 1178 #ifdef FDDEBUG 1179 printf("fdstart: unit %d\n", sc->hwunit); 1180 #endif 1181 1182 /* 1183 * if DMA'ing just return. we must have been called from fdstartegy. 1184 */ 1185 if (fdc_indma) 1186 return; 1187 1188 /* 1189 * get next buf if there. 1190 */ 1191 dp = &sc->curbuf; 1192 if ((bp = bufq_peek(sc->bufq)) == NULL) { 1193 #ifdef FDDEBUG 1194 printf(" nothing to do\n"); 1195 #endif 1196 return; 1197 } 1198 1199 /* 1200 * Mark us as busy now, in case fddone() gets called in one 1201 * of the cases below. 1202 */ 1203 disk_busy(&sc->dkdev); 1204 1205 /* 1206 * make sure same disk is loaded 1207 */ 1208 fdselunit(sc); 1209 changed = FDTESTC(FDB_CHANGED); 1210 FDDESELECT(sc->unitmask); 1211 if (changed) { 1212 /* 1213 * disk missing, invalidate all future io on 1214 * this unit until re-open()'ed also invalidate 1215 * all current io 1216 */ 1217 printf("fdstart: disk changed\n"); 1218 #ifdef FDDEBUG 1219 printf(" disk was removed invalidating all io\n"); 1220 #endif 1221 sc->flags &= ~FDF_HAVELABEL; 1222 for (;;) { 1223 bp = bufq_get(sc->bufq); 1224 bp->b_error = EIO; 1225 if (bufq_peek(sc->bufq) == NULL) 1226 break; 1227 biodone(bp); 1228 } 1229 /* 1230 * do fddone() on last buf to allow other units to start. 1231 */ 1232 bufq_put(sc->bufq, bp); 1233 fddone(sc); 1234 return; 1235 } 1236 1237 /* 1238 * we have a valid buf, setup our local version 1239 * we use this count to allow reading over multiple tracks. 1240 * into a single buffer 1241 */ 1242 dp->b_bcount = bp->b_bcount; 1243 dp->b_blkno = bp->b_blkno; 1244 dp->b_data = bp->b_data; 1245 dp->b_flags = bp->b_flags; 1246 dp->b_resid = 0; 1247 1248 if (bp->b_flags & B_READ) 1249 write = 0; 1250 else if (FDTESTC(FDB_PROTECT) == 0) 1251 write = 1; 1252 else { 1253 error = EPERM; 1254 goto done; 1255 } 1256 1257 /* 1258 * figure trk given blkno 1259 */ 1260 trk = bp->b_blkno / sc->nsectors; 1261 1262 /* 1263 * check to see if same as currently cached track 1264 * if so we need to do no DMA read. 1265 */ 1266 if (trk == sc->cachetrk) { 1267 fddone(sc); 1268 return; 1269 } 1270 1271 /* 1272 * if we will be overwriting the entire cache, don't bother to 1273 * fetch it. 1274 */ 1275 if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write && 1276 bp->b_blkno % sc->nsectors == 0) { 1277 if (sc->flags & FDF_DIRTY) 1278 sc->flags |= FDF_JUSTFLUSH; 1279 else { 1280 sc->cachetrk = trk; 1281 fddone(sc); 1282 return; 1283 } 1284 } 1285 1286 /* 1287 * start DMA read of `trk' 1288 */ 1289 fddmastart(sc, trk); 1290 return; 1291 done: 1292 bp->b_error = error; 1293 fddone(sc); 1294 } 1295 1296 /* 1297 * continue a started operation on next track. always begin at 1298 * sector 0 on the next track. 1299 */ 1300 void 1301 fdcont(struct fd_softc *sc) 1302 { 1303 struct buf *dp, *bp; 1304 int trk, write; 1305 1306 dp = &sc->curbuf; 1307 bp = bufq_peek(sc->bufq); 1308 dp->b_data = (char*)dp->b_data + (dp->b_bcount - bp->b_resid); 1309 dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE; 1310 dp->b_bcount = bp->b_resid; 1311 1312 /* 1313 * figure trk given blkno 1314 */ 1315 trk = dp->b_blkno / sc->nsectors; 1316 #ifdef DEBUG 1317 if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0) 1318 panic("fdcont: confused"); 1319 #endif 1320 if (dp->b_flags & B_READ) 1321 write = 0; 1322 else 1323 write = 1; 1324 /* 1325 * if we will be overwriting the entire cache, don't bother to 1326 * fetch it. 1327 */ 1328 if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) { 1329 if (sc->flags & FDF_DIRTY) 1330 sc->flags |= FDF_JUSTFLUSH; 1331 else { 1332 sc->cachetrk = trk; 1333 fddone(sc); 1334 return; 1335 } 1336 } 1337 /* 1338 * start DMA read of `trk' 1339 */ 1340 fddmastart(sc, trk); 1341 return; 1342 } 1343 1344 void 1345 fddmastart(struct fd_softc *sc, int trk) 1346 { 1347 int adkmask, ndmaw, write, dmatrk; 1348 1349 #ifdef FDDEBUG 1350 printf("fddmastart: unit %d cyl %d head %d", sc->hwunit, 1351 trk / FDNHEADS, trk % FDNHEADS); 1352 #endif 1353 /* 1354 * flush the cached track if dirty else read requested track. 1355 */ 1356 if (sc->flags & FDF_DIRTY) { 1357 fdcachetoraw(sc); 1358 ndmaw = sc->type->nwritew; 1359 dmatrk = sc->cachetrk; 1360 write = 1; 1361 } else { 1362 ndmaw = sc->type->nreadw; 1363 dmatrk = trk; 1364 write = 0; 1365 } 1366 1367 #ifdef FDDEBUG 1368 printf(" %s", write ? " flushing cache\n" : " loading cache\n"); 1369 #endif 1370 sc->cachetrk = trk; 1371 fdc_indma = sc; 1372 fdsetpos(sc, dmatrk, write); 1373 1374 /* 1375 * setup dma stuff 1376 */ 1377 if (write == 0) { 1378 custom.adkcon = ADKF_MSBSYNC; 1379 custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST; 1380 custom.dsksync = FDMFMSYNC; 1381 } else { 1382 custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC | 1383 ADKF_MSBSYNC; 1384 adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC; 1385 if (dmatrk >= sc->type->precomp[0]) 1386 adkmask |= ADKF_PRECOMP0; 1387 if (dmatrk >= sc->type->precomp[1]) 1388 adkmask |= ADKF_PRECOMP1; 1389 custom.adkcon = adkmask; 1390 } 1391 custom.dskpt = (u_char *)kvtop(fdc_dmap); 1392 1393 /* 1394 * If writing an MSDOS track, activate disk index pulse 1395 * interrupt, DMA will be started in the intr routine fdidxintr() 1396 * Otherwise, start the DMA here. 1397 */ 1398 if (write && sc->openpart == FDMSDOSPART) { 1399 fdc_dmalen = ndmaw; 1400 fdc_dmawrite = write; 1401 ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG; 1402 } else { 1403 FDDMASTART(ndmaw, write); 1404 fdc_dmalen = 0; 1405 } 1406 1407 #ifdef FDDEBUG 1408 printf(" DMA started\n"); 1409 #endif 1410 } 1411 1412 /* 1413 * recalibrate the drive 1414 */ 1415 void 1416 fdcalibrate(void *arg) 1417 { 1418 struct fd_softc *sc; 1419 static int loopcnt; 1420 1421 sc = arg; 1422 1423 if (loopcnt == 0) { 1424 /* 1425 * seek cyl 0 1426 */ 1427 fdc_indma = sc; 1428 sc->stepdelay += 900; 1429 if (sc->cachetrk > 1) 1430 fdsetpos(sc, sc->cachetrk % FDNHEADS, 0); 1431 sc->stepdelay -= 900; 1432 } 1433 if (loopcnt++ & 1) 1434 fdsetpos(sc, sc->cachetrk, 0); 1435 else 1436 fdsetpos(sc, sc->cachetrk + FDNHEADS, 0); 1437 /* 1438 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and DMA 1439 */ 1440 if (loopcnt < 8) 1441 callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc); 1442 else { 1443 loopcnt = 0; 1444 fdc_indma = NULL; 1445 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1446 fddmastart(sc, sc->cachetrk); 1447 } 1448 } 1449 1450 void 1451 fddmadone(struct fd_softc *sc, int timeo) 1452 { 1453 #ifdef FDDEBUG 1454 printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo); 1455 #endif 1456 fdc_indma = NULL; 1457 callout_stop(&sc->motor_ch); 1458 FDDMASTOP; 1459 1460 /* 1461 * guarantee the drive has been at current head and cyl 1462 * for at least FDWRITEDELAY after a write. 1463 */ 1464 if (sc->flags & FDF_WRITEWAIT) { 1465 delay(FDWRITEDELAY); 1466 sc->flags &= ~FDF_WRITEWAIT; 1467 } 1468 1469 if ((sc->flags & FDF_MOTOROFF) == 0) { 1470 /* 1471 * motor runs for 1.5 seconds after last DMA 1472 */ 1473 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc); 1474 } 1475 if (sc->flags & FDF_DIRTY) { 1476 /* 1477 * if buffer dirty, the last DMA cleaned it 1478 */ 1479 sc->flags &= ~FDF_DIRTY; 1480 if (timeo) 1481 aprint_error_dev(sc->sc_dev, 1482 "write of track cache timed out.\n"); 1483 if (sc->flags & FDF_JUSTFLUSH) { 1484 sc->flags &= ~FDF_JUSTFLUSH; 1485 /* 1486 * we are done DMA'ing 1487 */ 1488 fddone(sc); 1489 return; 1490 } 1491 /* 1492 * load the cache 1493 */ 1494 fddmastart(sc, sc->cachetrk); 1495 return; 1496 } 1497 #ifdef FDDEBUG 1498 else if (sc->flags & FDF_MOTOROFF) 1499 panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY"); 1500 #endif 1501 1502 /* 1503 * cache loaded decode it into cache buffer 1504 */ 1505 if (timeo == 0 && fdrawtocache(sc) == 0) 1506 sc->retried = 0; 1507 else { 1508 #ifdef FDDEBUG 1509 if (timeo) 1510 aprint_debug_dev(sc->sc_dev, 1511 "fddmadone: cache load timed out.\n"); 1512 #endif 1513 if (sc->retried >= sc->retries) { 1514 sc->retried = 0; 1515 sc->cachetrk = -1; 1516 } else { 1517 sc->retried++; 1518 /* 1519 * this will be restarted at end of calibrate loop. 1520 */ 1521 callout_stop(&sc->motor_ch); 1522 fdcalibrate(sc); 1523 return; 1524 } 1525 } 1526 fddone(sc); 1527 } 1528 1529 void 1530 fddone(struct fd_softc *sc) 1531 { 1532 struct buf *dp, *bp; 1533 char *data; 1534 int sz; 1535 1536 #ifdef FDDEBUG 1537 printf("fddone: unit %d\n", sc->hwunit); 1538 #endif 1539 /* 1540 * check to see if unit is just flushing the cache, 1541 * that is we have no io queued. 1542 */ 1543 if (sc->flags & FDF_MOTOROFF) 1544 goto nobuf; 1545 1546 dp = &sc->curbuf; 1547 if ((bp = bufq_peek(sc->bufq)) == NULL) 1548 panic ("fddone"); 1549 /* 1550 * check for an error that may have occurred 1551 * while getting the track. 1552 */ 1553 if (sc->cachetrk == -1) { 1554 sc->retried = 0; 1555 bp->b_error = EIO; 1556 } else if (bp->b_error == 0) { 1557 data = sc->cachep; 1558 /* 1559 * get offset of data in track cache and limit 1560 * the copy size to not exceed the cache's end. 1561 */ 1562 data += (dp->b_blkno % sc->nsectors) * FDSECSIZE; 1563 sz = sc->nsectors - dp->b_blkno % sc->nsectors; 1564 sz *= FDSECSIZE; 1565 sz = min(dp->b_bcount, sz); 1566 if (bp->b_flags & B_READ) 1567 memcpy(dp->b_data, data, sz); 1568 else { 1569 memcpy(data, dp->b_data, sz); 1570 sc->flags |= FDF_DIRTY; 1571 } 1572 bp->b_resid = dp->b_bcount - sz; 1573 if (bp->b_resid == 0) { 1574 bp->b_error = 0; 1575 } else { 1576 /* 1577 * not done yet need to read next track 1578 */ 1579 fdcont(sc); 1580 return; 1581 } 1582 } 1583 /* 1584 * remove from queue. 1585 */ 1586 (void)bufq_get(sc->bufq); 1587 1588 disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid), 1589 (bp->b_flags & B_READ)); 1590 1591 biodone(bp); 1592 nobuf: 1593 fdfindwork(device_unit(sc->sc_dev)); 1594 } 1595 1596 void 1597 fdfindwork(int unit) 1598 { 1599 struct fd_softc *ssc, *sc; 1600 int i, last; 1601 1602 /* 1603 * first see if we have any fdopen()'s waiting 1604 */ 1605 if (fdc_wantwakeup) { 1606 wakeup(fdopen); 1607 fdc_wantwakeup--; 1608 return; 1609 } 1610 1611 /* 1612 * start next available unit, linear search from the next unit 1613 * wrapping and finally this unit. 1614 */ 1615 last = 0; 1616 ssc = NULL; 1617 for (i = unit + 1; last == 0; i++) { 1618 if (i == unit) 1619 last = 1; 1620 if (i >= fd_cd.cd_ndevs) { 1621 i = -1; 1622 continue; 1623 } 1624 if ((sc = device_lookup_private(&fd_cd, i)) == NULL) 1625 continue; 1626 1627 /* 1628 * if unit has requested to be turned off 1629 * and it has no buf's queued do it now 1630 */ 1631 if (sc->flags & FDF_MOTOROFF) { 1632 if (bufq_peek(sc->bufq) == NULL) 1633 fdmotoroff(sc); 1634 else { 1635 /* 1636 * we gained a buf request while 1637 * we waited, forget the motoroff 1638 */ 1639 sc->flags &= ~FDF_MOTOROFF; 1640 } 1641 /* 1642 * if we now have DMA unit must have needed 1643 * flushing, quit 1644 */ 1645 if (fdc_indma) 1646 return; 1647 } 1648 /* 1649 * if we have no start unit and the current unit has 1650 * io waiting choose this unit to start. 1651 */ 1652 if (ssc == NULL && bufq_peek(sc->bufq) != NULL) 1653 ssc = sc; 1654 } 1655 if (ssc) 1656 fdstart(ssc); 1657 } 1658 1659 /* 1660 * min byte count to whats left of the track in question 1661 */ 1662 void 1663 fdminphys(struct buf *bp) 1664 { 1665 struct fd_softc *sc; 1666 int sec, toff, tsz; 1667 1668 if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL) 1669 panic("fdminphys: couldn't get softc"); 1670 1671 sec = bp->b_blkno % sc->nsectors; 1672 1673 toff = sec * FDSECSIZE; 1674 tsz = sc->nsectors * FDSECSIZE; 1675 #ifdef FDDEBUG 1676 printf("fdminphys: before %ld", bp->b_bcount); 1677 #endif 1678 bp->b_bcount = min(bp->b_bcount, tsz - toff); 1679 #ifdef FDDEBUG 1680 printf(" after %ld\n", bp->b_bcount); 1681 #endif 1682 minphys(bp); 1683 } 1684 1685 /* 1686 * encode the track cache into raw MFM ready for DMA 1687 * when we go to multiple disk formats, this will call type dependent 1688 * functions 1689 */ 1690 void fdcachetoraw(struct fd_softc *sc) 1691 { 1692 if (sc->openpart == FDMSDOSPART) 1693 mscachetoraw(sc); 1694 else 1695 amcachetoraw(sc); 1696 } 1697 1698 /* 1699 * decode raw MFM from DMA into units track cache. 1700 * when we go to multiple disk formats, this will call type dependent 1701 * functions 1702 */ 1703 int 1704 fdrawtocache(struct fd_softc *sc) 1705 { 1706 1707 if (sc->openpart == FDMSDOSPART) 1708 return(msrawtocache(sc)); 1709 else 1710 return(amrawtocache(sc)); 1711 } 1712 1713 void 1714 amcachetoraw(struct fd_softc *sc) 1715 { 1716 static u_long mfmnull[4]; 1717 u_long *rp, *crp, *dp, hcksum, dcksum, info; 1718 int sec, i; 1719 1720 rp = fdc_dmap; 1721 1722 /* 1723 * not yet one sector (- 1 long) gap. 1724 * for now use previous drivers values 1725 */ 1726 for (i = 0; i < sc->type->gap; i++) 1727 *rp++ = 0xaaaaaaaa; 1728 /* 1729 * process sectors 1730 */ 1731 dp = sc->cachep; 1732 info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors; 1733 for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) { 1734 hcksum = dcksum = 0; 1735 /* 1736 * sector format 1737 * offset description 1738 *----------------------------------- 1739 * 0 null 1740 * 1 sync 1741 * oddbits evenbits 1742 *---------------------- 1743 * 2 3 [0xff]b [trk]b [sec]b [togap]b 1744 * 4-7 8-11 null 1745 * 12 13 header cksum [2-11] 1746 * 14 15 data cksum [16-271] 1747 * 16-143 144-271 data 1748 */ 1749 *rp = 0xaaaaaaaa; 1750 if (*(rp - 1) & 0x1) 1751 *rp &= 0x7fffffff; /* clock bit correction */ 1752 rp++; 1753 *rp++ = (FDMFMSYNC << 16) | FDMFMSYNC; 1754 rp = mfmblkencode(&info, rp, &hcksum, 1); 1755 rp = mfmblkencode(mfmnull, rp, &hcksum, 4); 1756 rp = mfmblkencode(&hcksum, rp, NULL, 1); 1757 1758 crp = rp; 1759 rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS); 1760 dp += FDSECLWORDS; 1761 crp = mfmblkencode(&dcksum, crp, NULL, 1); 1762 if (*(crp - 1) & 0x1) 1763 *crp &= 0x7fffffff; /* clock bit correction */ 1764 else if ((*crp & 0x40000000) == 0) 1765 *crp |= 0x80000000; 1766 } 1767 *rp = 0xaaa80000; 1768 if (*(rp - 1) & 0x1) 1769 *rp &= 0x7fffffff; 1770 } 1771 1772 u_long * 1773 fdfindsync(u_long *rp, u_long *ep) 1774 { 1775 u_short *sp; 1776 1777 sp = (u_short *)rp; 1778 while ((u_long *)sp < ep && *sp != FDMFMSYNC) 1779 sp++; 1780 while ((u_long *)sp < ep && *sp == FDMFMSYNC) 1781 sp++; 1782 if ((u_long *)sp < ep) 1783 return((u_long *)sp); 1784 return(NULL); 1785 } 1786 1787 int 1788 amrawtocache(struct fd_softc *sc) 1789 { 1790 u_long mfmnull[4]; 1791 u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp; 1792 int cnt, doagain; 1793 1794 doagain = 1; 1795 srp = rp = fdc_dmap; 1796 erp = (u_long *)((u_short *)rp + sc->type->nreadw); 1797 cnt = 0; 1798 again: 1799 if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) { 1800 #ifdef DIAGNOSTIC 1801 aprint_error_dev(sc->sc_dev, "corrupted track (%d) data.\n", 1802 sc->cachetrk); 1803 #endif 1804 return(-1); 1805 } 1806 1807 /* 1808 * process sectors 1809 */ 1810 for (; cnt < sc->nsectors; cnt++) { 1811 hcksum = dcksum = 0; 1812 rp = mfmblkdecode(rp, &info, &hcksum, 1); 1813 rp = mfmblkdecode(rp, mfmnull, &hcksum, 4); 1814 rp = mfmblkdecode(rp, &cktmp, NULL, 1); 1815 if (cktmp != hcksum) { 1816 #ifdef FDDEBUG 1817 printf(" info 0x%lx hchksum 0x%lx trkhcksum 0x%lx\n", 1818 info, hcksum, cktmp); 1819 #endif 1820 goto again; 1821 } 1822 if (((info >> 16) & 0xff) != sc->cachetrk) { 1823 #ifdef DEBUG 1824 aprint_debug_dev(sc->sc_dev, 1825 "incorrect track found: 0x%lx %d\n", 1826 info, sc->cachetrk); 1827 #endif 1828 goto again; 1829 } 1830 #ifdef FDDEBUG 1831 printf(" info 0x%lx\n", info); 1832 #endif 1833 1834 rp = mfmblkdecode(rp, &cktmp, NULL, 1); 1835 dp = sc->cachep; 1836 dp += FDSECLWORDS * ((info >> 8) & 0xff); 1837 crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS); 1838 if (cktmp != dcksum) { 1839 #ifdef FDDEBUG 1840 printf(" info 0x%lx dchksum 0x%lx trkdcksum 0x%lx\n", 1841 info, dcksum, cktmp); 1842 #endif 1843 goto again; 1844 } 1845 1846 /* 1847 * if we are at gap then we can no longer be sure 1848 * of correct sync marks 1849 */ 1850 if ((info & 0xff) == 1) 1851 doagain = 1; 1852 else 1853 doagain = 0; 1854 srp = rp = fdfindsync(crp, erp); 1855 } 1856 return(0); 1857 } 1858 1859 void 1860 mscachetoraw(struct fd_softc *sc) 1861 { 1862 u_short *rp, *erp, crc; 1863 u_char *cp, tb[5]; 1864 int sec, i; 1865 1866 rp = (u_short *)fdc_dmap; 1867 erp = rp + sc->type->nwritew; 1868 cp = sc->cachep; 1869 1870 /* 1871 * initial track filler (828 * GAP1) 1872 */ 1873 for (i = 0; i < sc->type->gap; i++) { 1874 *rp++ = FDMFMGAP1; 1875 *rp++ = FDMFMGAP1; 1876 } 1877 1878 for (sec = 0; sec < sc->nsectors; sec++) { 1879 1880 /* 1881 * leading sector gap 1882 * (12 * GAP2) + (3 * SYNC) 1883 */ 1884 for (i = 0; i < 12; i++) 1885 *rp++ = FDMFMGAP2; 1886 *rp++ = FDMFMSYNC; 1887 *rp++ = FDMFMSYNC; 1888 *rp++ = FDMFMSYNC; 1889 1890 /* 1891 * sector information 1892 * (ID) + track + side + sector + sector size + CRC16 1893 */ 1894 *rp++ = FDMFMID; 1895 tb[0] = sc->cachetrk / FDNHEADS; 1896 tb[1] = sc->cachetrk % FDNHEADS; 1897 tb[2] = sec + 1; 1898 i = sc->bytespersec; 1899 tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3)); 1900 rp = msblkencode(rp, tb, 4, &crc); 1901 tb[0] = crc >> 8; 1902 tb[1] = crc & 0xff; 1903 tb[2] = 0x4e; /* GAP1 decoded */ 1904 rp = msblkencode(rp, tb, 3, 0); 1905 1906 /* 1907 * sector info/data gap 1908 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC) 1909 */ 1910 for (i = 0; i < 21; i++) 1911 *rp++ = FDMFMGAP1; 1912 for (i = 0; i < 12; i++) 1913 *rp++ = FDMFMGAP2; 1914 *rp++ = FDMFMSYNC; 1915 *rp++ = FDMFMSYNC; 1916 *rp++ = FDMFMSYNC; 1917 1918 /* 1919 * sector data 1920 * (DATA) + ...data... + CRC16 1921 */ 1922 *rp++ = FDMFMDATA; 1923 rp = msblkencode(rp, cp, sc->bytespersec, &crc); 1924 cp += sc->bytespersec; 1925 tb[0] = crc >> 8; 1926 tb[1] = crc & 0xff; 1927 tb[2] = 0x4e; /* GAP3 decoded */ 1928 rp = msblkencode(rp, tb, 3, 0); 1929 1930 /* 1931 * trailing sector gap 1932 * (80 * GAP3) 1933 */ 1934 for (i = 0; i < 79; i++) 1935 *rp++ = FDMFMGAP3; 1936 } 1937 1938 /* 1939 * fill rest of track with GAP3 1940 */ 1941 while (rp != erp) 1942 *rp++ = FDMFMGAP3; 1943 1944 } 1945 1946 int 1947 msrawtocache(struct fd_softc *sc) 1948 { 1949 u_short *rp, *erp; 1950 u_char tb[5], *cp; 1951 int ct, sec, retry; 1952 1953 rp = (u_short *)fdc_dmap; 1954 erp = rp + sc->type->nreadw; 1955 cp = sc->cachep; 1956 1957 for (ct = 0; ct < sc->nsectors; ct++) { 1958 retry = 1; 1959 do { 1960 /* 1961 * skip leading gap to sync 1962 */ 1963 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) { 1964 #ifdef DIAGNOSTIC 1965 aprint_normal_dev(sc->sc_dev, 1966 "corrupted track (%d) data.\n", 1967 sc->cachetrk); 1968 #endif 1969 return(-1); 1970 } 1971 1972 /* 1973 * Grab sector info 1974 */ 1975 if (*rp++ != FDMFMID) 1976 continue; 1977 rp = msblkdecode(rp, tb, 4); 1978 #ifdef FDDEBUG 1979 printf("sector id: sector %d, track %d, side %d," 1980 "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]); 1981 #endif 1982 if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk || 1983 tb[2] > sc->nsectors) 1984 continue; 1985 1986 sec = tb[2]; 1987 sc->bytespersec = 128 << tb[3]; 1988 rp += 2; /* skip CRC-16 */ 1989 1990 /* 1991 * skip gap and read in data 1992 */ 1993 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) 1994 return(-1); 1995 if (*rp++ != FDMFMDATA) 1996 continue; 1997 rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec), 1998 sc->bytespersec); 1999 rp += 2; /* skip CRC-16 */ 2000 2001 retry = 0; 2002 } while (retry); 2003 } 2004 return(0); 2005 } 2006 2007 /* 2008 * encode len longwords of `dp' data in amiga mfm block format (`rp') 2009 * this format specified that the odd bits are at current pos and even 2010 * bits at len + current pos 2011 */ 2012 u_long * 2013 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len) 2014 { 2015 u_long *sdp, *edp, d, dtmp, correct; 2016 2017 sdp = dp; 2018 edp = dp + len; 2019 2020 if (*(rp - 1) & 0x1) 2021 correct = 1; 2022 else 2023 correct = 0; 2024 /* 2025 * do odd bits 2026 */ 2027 while (dp < edp) { 2028 d = (*dp >> 1) & 0x55555555; /* remove clock bits */ 2029 dtmp = d ^ 0x55555555; 2030 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2031 /* 2032 * correct upper clock bit if needed 2033 */ 2034 if (correct) 2035 d &= 0x7fffffff; 2036 if (d & 0x1) 2037 correct = 1; 2038 else 2039 correct = 0; 2040 /* 2041 * do checksums and store in raw buffer 2042 */ 2043 if (cp) 2044 *cp ^= d; 2045 *rp++ = d; 2046 dp++; 2047 } 2048 /* 2049 * do even bits 2050 */ 2051 dp = sdp; 2052 while (dp < edp) { 2053 d = *dp & 0x55555555; /* remove clock bits */ 2054 dtmp = d ^ 0x55555555; 2055 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1); 2056 /* 2057 * correct upper clock bit if needed 2058 */ 2059 if (correct) 2060 d &= 0x7fffffff; 2061 if (d & 0x1) 2062 correct = 1; 2063 else 2064 correct = 0; 2065 /* 2066 * do checksums and store in raw buffer 2067 */ 2068 if (cp) 2069 *cp ^= d; 2070 *rp++ = d; 2071 dp++; 2072 } 2073 if (cp) 2074 *cp &= 0x55555555; 2075 return(rp); 2076 } 2077 2078 /* 2079 * decode len longwords of `dp' data in amiga mfm block format (`rp') 2080 * this format specified that the odd bits are at current pos and even 2081 * bits at len + current pos 2082 */ 2083 u_long * 2084 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len) 2085 { 2086 u_long o, e; 2087 int cnt; 2088 2089 cnt = len; 2090 while (cnt--) { 2091 o = *rp; 2092 e = *(rp + len); 2093 if (cp) { 2094 *cp ^= o; 2095 *cp ^= e; 2096 } 2097 o &= 0x55555555; 2098 e &= 0x55555555; 2099 *dp++ = (o << 1) | e; 2100 rp++; 2101 } 2102 if (cp) 2103 *cp &= 0x55555555; 2104 return(rp + len); 2105 } 2106 2107 /* 2108 * decode len words in standard MFM format to len bytes 2109 * of data. 2110 */ 2111 u_short * 2112 msblkdecode(u_short *rp, u_char *cp, int len) 2113 { 2114 while (len--) { 2115 *cp++ = msdecode[*rp & 0x7f] | 2116 (msdecode[(*rp >> 8) & 0x7f] << 4); 2117 rp++; 2118 } 2119 2120 return(rp); 2121 } 2122 2123 /* 2124 * encode len bytes of data into len words in standard MFM format. 2125 * If a pointer is supplied for crc, calculate the CRC-16 of the data 2126 * as well. 2127 */ 2128 u_short * 2129 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc) 2130 { 2131 u_short td; 2132 u_short mycrc; 2133 2134 /* preload crc for header (4 bytes) 2135 * or data (anything else) 2136 */ 2137 mycrc = (len == 4) ? 0xb230 : 0xe295; 2138 2139 while (len--) { 2140 td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f]; 2141 2142 /* Check for zeros in top bit of encode and bottom 2143 * bit of previous encode. if so, slap a one in betweem 2144 * them. 2145 */ 2146 if ((td & 0x140) == 0) 2147 td |= 0x80; 2148 if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0) 2149 td |= 0x8000; 2150 2151 *rp++ = td; 2152 2153 /* 2154 * calc crc if requested 2155 */ 2156 if (crc) 2157 mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)]; 2158 2159 cp++; 2160 } 2161 2162 if (crc) 2163 *crc = mycrc; 2164 2165 return(rp); 2166 } 2167
Indexes created Thu Oct 02 14:10:14 GMT 2025