biosdisk.c revision 53207
1/*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/boot/pc98/libpc98/biosdisk.c 53207 1999-11-16 00:42:18Z nyan $ 27 */ 28 29/* 30 * BIOS disk device handling. 31 * 32 * Ideas and algorithms from: 33 * 34 * - NetBSD libi386/biosdisk.c 35 * - FreeBSD biosboot/disk.c 36 * 37 * XXX Todo: add bad144 support. 38 */ 39 40#include <stand.h> 41 42#include <sys/disklabel.h> 43#include <sys/diskslice.h> 44#include <sys/reboot.h> 45 46#include <stdarg.h> 47 48#include <bootstrap.h> 49#include <btxv86.h> 50#include "libi386.h" 51 52#define BIOSDISK_SECSIZE 512 53#define BUFSIZE (1 * BIOSDISK_SECSIZE) 54#define MAXBDDEV MAXDEV 55 56#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */ 57#define WDMAJOR 0 /* major numbers for devices we frontend for */ 58#define WFDMAJOR 1 59#define FDMAJOR 2 60#define DAMAJOR 4 61 62#ifdef DISK_DEBUG 63# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args) 64#else 65# define DEBUG(fmt, args...) 66#endif 67 68struct open_disk { 69 int od_dkunit; /* disk unit number */ 70 int od_unit; /* BIOS unit number */ 71 int od_cyl; /* BIOS geometry */ 72 int od_hds; 73 int od_sec; 74 int od_boff; /* block offset from beginning of BIOS disk */ 75 int od_flags; 76#define BD_MODEMASK 0x3 77#define BD_MODEINT13 0x0 78#define BD_MODEEDD1 0x1 79#define BD_MODEEDD3 0x2 80#define BD_FLOPPY (1<<2) 81 struct disklabel od_disklabel; 82 struct dos_partition od_parttab[NDOSPART]; /* XXX needs to grow for extended partitions */ 83#define BD_LABELOK (1<<3) 84#define BD_PARTTABOK (1<<4) 85}; 86 87/* 88 * List of BIOS devices, translation from disk unit number to 89 * BIOS unit number. 90 */ 91static struct bdinfo 92{ 93 int bd_unit; /* BIOS unit number */ 94 int bd_flags; 95 int bd_type; /* BIOS 'drive type' (floppy only) */ 96#ifdef PC98 97 int bd_da_unit; /* kernel unit number for da */ 98#endif 99} bdinfo [MAXBDDEV]; 100static int nbdinfo = 0; 101 102static int bd_getgeom(struct open_disk *od); 103static int bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest); 104 105static int bd_int13probe(struct bdinfo *bd); 106 107static void bd_printslice(struct open_disk *od, int offset, char *prefix); 108 109static int bd_init(void); 110static int bd_strategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize); 111static int bd_realstrategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize); 112static int bd_open(struct open_file *f, ...); 113static int bd_close(struct open_file *f); 114static void bd_print(int verbose); 115 116struct devsw biosdisk = { 117 "disk", 118 DEVT_DISK, 119 bd_init, 120 bd_strategy, 121 bd_open, 122 bd_close, 123 noioctl, 124 bd_print 125}; 126 127static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev); 128static void bd_closedisk(struct open_disk *od); 129static int bd_bestslice(struct dos_partition *dptr); 130 131/* 132 * Translate between BIOS device numbers and our private unit numbers. 133 */ 134int 135bd_bios2unit(int biosdev) 136{ 137 int i; 138 139 DEBUG("looking for bios device 0x%x", biosdev); 140 for (i = 0; i < nbdinfo; i++) { 141 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit); 142 if (bdinfo[i].bd_unit == biosdev) 143 return(i); 144 } 145 return(-1); 146} 147 148int 149bd_unit2bios(int unit) 150{ 151 if ((unit >= 0) && (unit < nbdinfo)) 152 return(bdinfo[unit].bd_unit); 153 return(-1); 154} 155 156/* 157 * Quiz the BIOS for disk devices, save a little info about them. 158 * 159 * XXX should we be consulting the BIOS equipment list, specifically 160 * the value at 0x475? 161 */ 162static int 163bd_init(void) 164{ 165 int base, unit; 166 167#ifdef PC98 168 int da_drive=0, n=-0x10; 169 /* sequence 0x90, 0x80, 0xa0 */ 170 for (base = 0x90; base <= 0xa0; base += n, n += 0x30) { 171 for (unit = base; (nbdinfo < MAXBDDEV) || ((unit & 0x0f) < 4); unit++) { 172 bdinfo[nbdinfo].bd_unit = unit; 173 bdinfo[nbdinfo].bd_flags = (unit & 0xf0) == 0x90 ? BD_FLOPPY : 0; 174 175 /* XXX add EDD probes */ 176 if (!bd_int13probe(&bdinfo[nbdinfo])){ 177 if (((unit & 0xf0) == 0x90 && (unit & 0x0f) < 4) || 178 ((unit & 0xf0) == 0xa0 && (unit & 0x0f) < 6)) 179 continue; /* Target IDs are not contiguous. */ 180 else 181 break; 182 } 183 184 if (bdinfo[nbdinfo].bd_flags & BD_FLOPPY){ 185 /* available 1.44MB access? */ 186 if (*(u_char *)PTOV(0xA15AE) & (1<<(unit & 0xf))){ 187 /* boot media 1.2MB FD? */ 188 if ((*(u_char *)PTOV(0xA1584) & 0xf0) != 0x90) 189 bdinfo[nbdinfo].bd_unit = 0x30 + (unit & 0xf); 190 } 191 } 192 else { 193 if ((unit & 0xa0) == 0xa0) 194 bdinfo[nbdinfo].bd_da_unit = da_drive++; 195 } 196 /* XXX we need "disk aliases" to make this simpler */ 197 printf("BIOS drive %c: is disk%d\n", 198 'A' + nbdinfo, nbdinfo); 199 nbdinfo++; 200 } 201 } 202#else 203 /* sequence 0, 0x80 */ 204 for (base = 0; base <= 0x80; base += 0x80) { 205 for (unit = base; (nbdinfo < MAXBDDEV); unit++) { 206 bdinfo[nbdinfo].bd_unit = unit; 207 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0; 208 209 /* XXX add EDD probes */ 210 if (!bd_int13probe(&bdinfo[nbdinfo])) 211 break; 212 213 /* XXX we need "disk aliases" to make this simpler */ 214 printf("BIOS drive %c: is disk%d\n", 215 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo); 216 nbdinfo++; 217 } 218 } 219#endif 220 return(0); 221} 222 223/* 224 * Try to detect a device supported by the legacy int13 BIOS 225 */ 226 227static int 228bd_int13probe(struct bdinfo *bd) 229{ 230 231#ifdef PC98 232 int addr; 233 if (bd->bd_flags & BD_FLOPPY){ 234 addr = 0xa155c; 235 } 236 else { 237 if ((bd->bd_unit & 0xf0) == 0x80) 238 addr = 0xa155d; 239 else 240 addr = 0xa1482; 241 } 242 if ( *(u_char *)PTOV(addr) & (1<<(bd->bd_unit & 0x0f))) { 243 bd->bd_flags |= BD_MODEINT13; 244 return(1); 245 } 246 return(0); 247#else 248 v86.ctl = V86_FLAGS; 249 v86.addr = 0x13; 250 v86.eax = 0x800; 251 v86.edx = bd->bd_unit; 252 v86int(); 253 254 if (!(v86.efl & 0x1) && /* carry clear */ 255 ((v86.edx & 0xff) > (bd->bd_unit & 0x7f))) { /* unit # OK */ 256 bd->bd_flags |= BD_MODEINT13; 257 bd->bd_type = v86.ebx & 0xff; 258 return(1); 259 } 260#endif 261 return(0); 262} 263 264/* 265 * Print information about disks 266 */ 267static void 268bd_print(int verbose) 269{ 270 int i, j; 271 char line[80]; 272 struct i386_devdesc dev; 273 struct open_disk *od; 274 struct dos_partition *dptr; 275 276 for (i = 0; i < nbdinfo; i++) { 277#ifdef PC98 278 sprintf(line, " disk%d: BIOS drive %c:\n", i, 'A' + i); 279#else 280 sprintf(line, " disk%d: BIOS drive %c:\n", i, 281 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80)); 282#endif 283 pager_output(line); 284 285 /* try to open the whole disk */ 286 dev.d_kind.biosdisk.unit = i; 287 dev.d_kind.biosdisk.slice = -1; 288 dev.d_kind.biosdisk.partition = -1; 289 290 if (!bd_opendisk(&od, &dev)) { 291 292 /* Do we have a partition table? */ 293 if (od->od_flags & BD_PARTTABOK) { 294 dptr = &od->od_parttab[0]; 295 296 /* Check for a "truly dedicated" disk */ 297#ifdef PC98 298 for (j = 0; j < NDOSPART; j++) { 299 switch(dptr[j].dp_mid) { 300 case DOSMID_386BSD: 301 sprintf(line, " disk%ds%d", i, j + 1); 302 bd_printslice(od, dptr[j].dp_scyl * od->od_hds * od->od_sec + dptr[j].dp_shd * od->od_sec + dptr[j].dp_ssect, line); 303 break; 304 default: 305 } 306 } 307#else 308 if ((dptr[3].dp_typ == DOSPTYP_386BSD) && 309 (dptr[3].dp_start == 0) && 310 (dptr[3].dp_size == 50000)) { 311 sprintf(line, " disk%d", i); 312 bd_printslice(od, 0, line); 313 } else { 314 for (j = 0; j < NDOSPART; j++) { 315 switch(dptr[j].dp_typ) { 316 case DOSPTYP_386BSD: 317 sprintf(line, " disk%ds%d", i, j + 1); 318 bd_printslice(od, dptr[j].dp_start, line); 319 break; 320 default: 321 } 322 } 323 324 } 325#endif 326 } 327 bd_closedisk(od); 328 } 329 } 330} 331 332static void 333bd_printslice(struct open_disk *od, int offset, char *prefix) 334{ 335 char line[80]; 336 u_char buf[BIOSDISK_SECSIZE]; 337 struct disklabel *lp; 338 int i; 339 340 /* read disklabel */ 341 if (bd_read(od, offset + LABELSECTOR, 1, buf)) 342 return; 343 lp =(struct disklabel *)(&buf[0]); 344 if (lp->d_magic != DISKMAGIC) { 345 sprintf(line, "bad disklabel\n"); 346 pager_output(line); 347 return; 348 } 349 350 /* Print partitions */ 351 for (i = 0; i < lp->d_npartitions; i++) { 352 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) || (lp->d_partitions[i].p_fstype == FS_SWAP) || 353 ((lp->d_partitions[i].p_fstype == FS_UNUSED) && 354 (od->od_flags & BD_FLOPPY) && (i == 0))) { /* Floppies often have bogus fstype, print 'a' */ 355 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i, 356 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" : "FFS", 357 lp->d_partitions[i].p_size / 2048, /* 512-byte sector assumption */ 358 lp->d_partitions[i].p_offset, lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size); 359 pager_output(line); 360 } 361 } 362} 363 364 365/* 366 * Attempt to open the disk described by (dev) for use by (f). 367 * 368 * Note that the philosophy here is "give them exactly what 369 * they ask for". This is necessary because being too "smart" 370 * about what the user might want leads to complications. 371 * (eg. given no slice or partition value, with a disk that is 372 * sliced - are they after the first BSD slice, or the DOS 373 * slice before it?) 374 */ 375static int 376bd_open(struct open_file *f, ...) 377{ 378 va_list ap; 379 struct i386_devdesc *dev; 380 struct open_disk *od; 381 int error; 382 383 va_start(ap, f); 384 dev = va_arg(ap, struct i386_devdesc *); 385 va_end(ap); 386 if ((error = bd_opendisk(&od, dev))) 387 return(error); 388 389 /* 390 * Save our context 391 */ 392 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od; 393 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff); 394 return(0); 395} 396 397static int 398bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev) 399{ 400 struct dos_partition *dptr; 401 struct disklabel *lp; 402 struct open_disk *od; 403 int sector, slice, i; 404 int error; 405 u_char buf[BUFSIZE]; 406 daddr_t pref_slice[4]; 407 408 if (dev->d_kind.biosdisk.unit >= nbdinfo) { 409 DEBUG("attempt to open nonexistent disk"); 410 return(ENXIO); 411 } 412 413 od = (struct open_disk *)malloc(sizeof(struct open_disk)); 414 if (!od) { 415 DEBUG("no memory"); 416 return (ENOMEM); 417 } 418 419 /* Look up BIOS unit number, intialise open_disk structure */ 420 od->od_dkunit = dev->d_kind.biosdisk.unit; 421 od->od_unit = bdinfo[od->od_dkunit].bd_unit; 422 od->od_flags = bdinfo[od->od_dkunit].bd_flags; 423 od->od_boff = 0; 424 error = 0; 425 DEBUG("open '%s', unit 0x%x slice %d partition %c", 426 i386_fmtdev(dev), dev->d_kind.biosdisk.unit, 427 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a'); 428 429 /* Get geometry for this open (removable device may have changed) */ 430 if (bd_getgeom(od)) { 431 DEBUG("can't get geometry"); 432 error = ENXIO; 433 goto out; 434 } 435 436 /* 437 * Following calculations attempt to determine the correct value 438 * for d->od_boff by looking for the slice and partition specified, 439 * or searching for reasonable defaults. 440 */ 441 442 /* 443 * Find the slice in the DOS slice table. 444 */ 445#ifdef PC98 446 if (od->od_flags & BD_FLOPPY) { 447 sector = 0; 448 goto unsliced; 449 } 450#endif 451 if (bd_read(od, 0, 1, buf)) { 452 DEBUG("error reading MBR"); 453 error = EIO; 454 goto out; 455 } 456 457 /* 458 * Check the slice table magic. 459 */ 460 if ((buf[0x1fe] != 0x55) || (buf[0x1ff] != 0xaa)) { 461 /* If a slice number was explicitly supplied, this is an error */ 462 if (dev->d_kind.biosdisk.slice > 0) { 463 DEBUG("no slice table/MBR (no magic)"); 464 error = ENOENT; 465 goto out; 466 } 467 sector = 0; 468 goto unsliced; /* may be a floppy */ 469 } 470#ifdef PC98 471 if (bd_read(od, 1, 1, buf)) { 472 DEBUG("error reading MBR"); 473 error = EIO; 474 goto out; 475 } 476#endif 477 bcopy(buf + DOSPARTOFF, &od->od_parttab, sizeof(struct dos_partition) * NDOSPART); 478 dptr = &od->od_parttab[0]; 479 od->od_flags |= BD_PARTTABOK; 480 481 /* Is this a request for the whole disk? */ 482 if (dev->d_kind.biosdisk.slice == -1) { 483 sector = 0; 484 goto unsliced; 485 } 486 487 /* Try to auto-detect the best slice; this should always give a slice number */ 488 if (dev->d_kind.biosdisk.slice == 0) 489 dev->d_kind.biosdisk.slice = bd_bestslice(dptr); 490 491 switch (dev->d_kind.biosdisk.slice) { 492 case -1: 493 error = ENOENT; 494 goto out; 495 case 0: 496 sector = 0; 497 goto unsliced; 498 default: 499 break; 500 } 501 502 /* 503 * Accept the supplied slice number unequivocally (we may be looking 504 * at a DOS partition). 505 */ 506 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */ 507#ifdef PC98 508 sector = dptr->dp_scyl * od->od_hds * od->od_sec + dptr->dp_shd * od->od_sec + dptr->dp_ssect; 509 { 510 int end = dptr->dp_ecyl * od->od_hds * od->od_sec + dptr->dp_ehd * od->od_sec + dptr->dp_esect; 511 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, end-sector); 512 } 513#else 514 sector = dptr->dp_start; 515 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size); 516#endif 517 518 /* 519 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition 520 */ 521#ifdef PC98 522 if ((dptr->dp_mid == DOSMID_386BSD) && (dev->d_kind.biosdisk.partition < 0)) 523#else 524 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0)) 525#endif 526 dev->d_kind.biosdisk.partition = 0; 527 528 unsliced: 529 /* 530 * Now we have the slice offset, look for the partition in the disklabel if we have 531 * a partition to start with. 532 * 533 * XXX we might want to check the label checksum. 534 */ 535 if (dev->d_kind.biosdisk.partition < 0) { 536 od->od_boff = sector; /* no partition, must be after the slice */ 537 DEBUG("opening raw slice"); 538 } else { 539 540 if (bd_read(od, sector + LABELSECTOR, 1, buf)) { 541 DEBUG("error reading disklabel"); 542 error = EIO; 543 goto out; 544 } 545 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel); 546 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel)); 547 lp = &od->od_disklabel; 548 od->od_flags |= BD_LABELOK; 549 550 if (lp->d_magic != DISKMAGIC) { 551 DEBUG("no disklabel"); 552 error = ENOENT; 553 goto out; 554 } 555 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) { 556 DEBUG("partition '%c' exceeds partitions in table (a-'%c')", 557 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions); 558 error = EPART; 559 goto out; 560 561 } 562 563 /* Complain if the partition type is wrong */ 564 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) && 565 !(od->od_flags & BD_FLOPPY)) /* Floppies often have bogus fstype */ 566 DEBUG("warning, partition marked as unused"); 567 568 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset; 569 } 570 571 out: 572 if (error) { 573 free(od); 574 } else { 575 *odp = od; /* return the open disk */ 576 } 577 return(error); 578} 579 580 581/* 582 * Search for a slice with the following preferences: 583 * 584 * 1: Active FreeBSD slice 585 * 2: Non-active FreeBSD slice 586 * 3: Active FAT/FAT32 slice 587 * 4: non-active FAT/FAT32 slice 588 */ 589#define PREF_FBSD_ACT 0 590#define PREF_FBSD 1 591#define PREF_DOS_ACT 2 592#define PREF_DOS 3 593#define PREF_NONE 4 594 595static int 596bd_bestslice(struct dos_partition *dptr) 597{ 598 int i; 599 int preflevel, pref; 600 601 602#ifndef PC98 603 /* 604 * Check for the historically bogus MBR found on true dedicated disks 605 */ 606 if ((dptr[3].dp_typ == DOSPTYP_386BSD) && 607 (dptr[3].dp_start == 0) && 608 (dptr[3].dp_size == 50000)) 609 return(0); 610#endif 611 612 preflevel = PREF_NONE; 613 pref = -1; 614 615 /* 616 * XXX No support here for 'extended' slices 617 */ 618 for (i = 0; i < NDOSPART; i++) { 619#ifdef PC98 620 switch(dptr[i].dp_mid & 0x7f) { 621 case DOSMID_386BSD & 0x7f: /* FreeBSD */ 622 if ((dptr[i].dp_mid & 0x80) && (preflevel > PREF_FBSD_ACT)) { 623 pref = i; 624 preflevel = PREF_FBSD_ACT; 625 } else if (preflevel > PREF_FBSD) { 626 pref = i; 627 preflevel = PREF_FBSD; 628 } 629 break; 630 631 case 0x11: /* DOS/Windows */ 632 case 0x20: 633 case 0x21: 634 case 0x22: 635 case 0x23: 636 case 0x63: 637 if ((dptr[i].dp_mid & 0x80) && (preflevel > PREF_DOS_ACT)) { 638 pref = i; 639 preflevel = PREF_DOS_ACT; 640 } else if (preflevel > PREF_DOS) { 641 pref = i; 642 preflevel = PREF_DOS; 643 } 644 break; 645 } 646#else 647 switch(dptr[i].dp_typ) { 648 case DOSPTYP_386BSD: /* FreeBSD */ 649 if ((dptr[i].dp_flag & 0x80) && (preflevel > PREF_FBSD_ACT)) { 650 pref = i; 651 preflevel = PREF_FBSD_ACT; 652 } else if (preflevel > PREF_FBSD) { 653 pref = i; 654 preflevel = PREF_FBSD; 655 } 656 break; 657 658 case 0x04: /* DOS/Windows */ 659 case 0x06: 660 case 0x0b: 661 case 0x0c: 662 case 0x0e: 663 case 0x63: 664 if ((dptr[i].dp_flag & 0x80) && (preflevel > PREF_DOS_ACT)) { 665 pref = i; 666 preflevel = PREF_DOS_ACT; 667 } else if (preflevel > PREF_DOS) { 668 pref = i; 669 preflevel = PREF_DOS; 670 } 671 break; 672 } 673#endif 674 } 675 return(pref + 1); /* slices numbered 1-4 */ 676} 677 678 679static int 680bd_close(struct open_file *f) 681{ 682 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data); 683 684 bd_closedisk(od); 685 return(0); 686} 687 688static void 689bd_closedisk(struct open_disk *od) 690{ 691 DEBUG("open_disk %p", od); 692#if 0 693 /* XXX is this required? (especially if disk already open...) */ 694 if (od->od_flags & BD_FLOPPY) 695 delay(3000000); 696#endif 697 free(od); 698} 699 700static int 701bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, void *buf, size_t *rsize) 702{ 703 struct bcache_devdata bcd; 704 705 bcd.dv_strategy = bd_realstrategy; 706 bcd.dv_devdata = devdata; 707 return(bcache_strategy(&bcd, rw, dblk, size, buf, rsize)); 708} 709 710static int 711bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, void *buf, size_t *rsize) 712{ 713 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data); 714 int blks; 715#ifdef BD_SUPPORT_FRAGS 716 char fragbuf[BIOSDISK_SECSIZE]; 717 size_t fragsize; 718 719 fragsize = size % BIOSDISK_SECSIZE; 720#else 721 if (size % BIOSDISK_SECSIZE) 722 panic("bd_strategy: %d bytes I/O not multiple of block size", size); 723#endif 724 725 DEBUG("open_disk %p", od); 726 727 if (rw != F_READ) 728 return(EROFS); 729 730 731 blks = size / BIOSDISK_SECSIZE; 732 DEBUG("read %d from %d+%d to %p", blks, od->od_boff, dblk, buf); 733 734 if (rsize) 735 *rsize = 0; 736 if (blks && bd_read(od, dblk + od->od_boff, blks, buf)) { 737 DEBUG("read error"); 738 return (EIO); 739 } 740#ifdef BD_SUPPORT_FRAGS 741 DEBUG("bd_strategy: frag read %d from %d+%d+d to %p", 742 fragsize, od->od_boff, dblk, blks, buf + (blks * BIOSDISK_SECSIZE)); 743 if (fragsize && bd_read(od, dblk + od->od_boff + blks, 1, fragsize)) { 744 DEBUG("frag read error"); 745 return(EIO); 746 } 747 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize); 748#endif 749 if (rsize) 750 *rsize = size; 751 return (0); 752} 753 754/* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */ 755#define FLOPPY_BOUNCEBUF 18 756 757static int 758bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest) 759{ 760 int x, bpc, cyl, hd, sec, result, resid, cnt, retry, maxfer; 761 caddr_t p, xp, bbuf, breg; 762 763 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */ 764 resid = blks; 765 p = dest; 766 767 /* Decide whether we have to bounce */ 768#ifdef PC98 769 if ( 770#else 771 if ((od->od_unit < 0x80) && 772#endif 773 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) { 774 775 /* 776 * There is a 64k physical boundary somewhere in the destination buffer, so we have 777 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we 778 * need to. Use the bottom half unless there is a break there, in which case we 779 * use the top half. 780 */ 781#ifdef PC98 782 x = min(od->od_sec, blks); 783#else 784 x = min(FLOPPY_BOUNCEBUF, blks); 785#endif 786 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE); 787 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) { 788 breg = bbuf; 789 } else { 790 breg = bbuf + x * BIOSDISK_SECSIZE; 791 } 792 maxfer = x; /* limit transfers to bounce region size */ 793 } else { 794 bbuf = NULL; 795 maxfer = 0; 796 } 797 798 while (resid > 0) { 799 x = dblk; 800 cyl = x / bpc; /* block # / blocks per cylinder */ 801 x %= bpc; /* block offset into cylinder */ 802 hd = x / od->od_sec; /* offset / blocks per track */ 803 sec = x % od->od_sec; /* offset into track */ 804 805 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */ 806 x = min(od->od_sec - sec, resid); 807 if (maxfer > 0) 808 x = min(x, maxfer); /* fit bounce buffer */ 809 810 /* where do we transfer to? */ 811 xp = bbuf == NULL ? p : breg; 812 813 /* correct sector number for 1-based BIOS numbering */ 814#ifdef PC98 815 if ((od->od_unit & 0xf0) == 0x30 || (od->od_unit & 0xf0) == 0x90) 816 sec++; 817#else 818 sec++; 819#endif 820 821 /* Loop retrying the operation a couple of times. The BIOS may also retry. */ 822 for (retry = 0; retry < 3; retry++) { 823 /* if retrying, reset the drive */ 824 if (retry > 0) { 825#ifdef PC98 826 v86.ctl = V86_FLAGS; 827 v86.addr = 0x1b; 828 v86.eax = 0x0300 | od->od_unit; 829#else 830 v86.ctl = V86_FLAGS; 831 v86.addr = 0x13; 832 v86.eax = 0; 833 v86.edx = od->od_unit; 834#endif 835 v86int(); 836 } 837 838 /* build request XXX support EDD requests too */ 839 v86.ctl = V86_FLAGS; 840#ifdef PC98 841 v86.addr = 0x1b; 842 if (od->od_flags & BD_FLOPPY) { 843 v86.eax = 0xd600 | od->od_unit; 844 v86.ecx = 0x0200 | (cyl & 0xff); 845 } 846 else { 847 v86.eax = 0x0600 | od->od_unit; 848 v86.ecx = cyl; 849 } 850 v86.edx = (hd << 8) | sec; 851 v86.ebx = x * BIOSDISK_SECSIZE; 852 v86.es = VTOPSEG(xp); 853 v86.ebp = VTOPOFF(xp); 854#else 855 v86.addr = 0x13; 856 v86.eax = 0x200 | x; 857 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec; 858 v86.edx = (hd << 8) | od->od_unit; 859 v86.es = VTOPSEG(xp); 860 v86.ebx = VTOPOFF(xp); 861#endif 862 v86int(); 863 result = (v86.efl & 0x1); 864 if (result == 0) 865 break; 866 } 867 868#ifdef PC98 869 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, od->od_flags & BD_FLOPPY ? sec - 1 : sec, p, VTOP(p), result ? "failed" : "ok"); 870 /* BUG here, cannot use v86 in printf because putchar uses it too */ 871 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x", 872 od->od_flags & BD_FLOPPY ? 0xd600 | od->od_unit : 0x0600 | od->od_unit, 873 od->od_flags & BD_FLOPPY ? 0x0200 | cyl : cyl, (hd << 8) | sec, 874 (v86.eax >> 8) & 0xff); 875#else 876 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok"); 877 /* BUG here, cannot use v86 in printf because putchar uses it too */ 878 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x", 879 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff); 880#endif 881 if (result) { 882 if (bbuf != NULL) 883 free(bbuf); 884 return(-1); 885 } 886 if (bbuf != NULL) 887 bcopy(breg, p, x * BIOSDISK_SECSIZE); 888 p += (x * BIOSDISK_SECSIZE); 889 dblk += x; 890 resid -= x; 891 } 892 893/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */ 894 if (bbuf != NULL) 895 free(bbuf); 896 return(0); 897} 898 899static int 900bd_getgeom(struct open_disk *od) 901{ 902 903#ifdef PC98 904 if (od->od_flags & BD_FLOPPY) { 905 od->od_cyl = 79; 906 od->od_hds = 2; 907 od->od_sec = (od->od_unit & 0xf0) == 0x30 ? 18 : 15; 908 } 909 else { 910 v86.ctl = V86_FLAGS; 911 v86.addr = 0x1b; 912 v86.eax = 0x8400 | od->od_unit; 913 v86int(); 914 915 od->od_cyl = v86.ecx; 916 od->od_hds = (v86.edx >> 8) & 0xff; 917 od->od_sec = v86.edx & 0xff; 918 if (v86.efl & 0x1) 919 return(1); 920 } 921#else 922 v86.ctl = V86_FLAGS; 923 v86.addr = 0x13; 924 v86.eax = 0x800; 925 v86.edx = od->od_unit; 926 v86int(); 927 928 if ((v86.efl & 0x1) || /* carry set */ 929 ((v86.edx & 0xff) <= (od->od_unit & 0x7f))) /* unit # bad */ 930 return(1); 931 932 /* convert max cyl # -> # of cylinders */ 933 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1; 934 /* convert max head # -> # of heads */ 935 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1; 936 od->od_sec = v86.ecx & 0x3f; 937#endif 938 939 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec); 940 return(0); 941} 942 943#ifndef PC98 944/* 945 * Return the BIOS geometry of a given "fixed drive" in a format 946 * suitable for the legacy bootinfo structure. Since the kernel is 947 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we 948 * prefer to get the information directly, rather than rely on being 949 * able to put it together from information already maintained for 950 * different purposes and for a probably different number of drives. 951 * 952 * For valid drives, the geometry is expected in the format (31..0) 953 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are 954 * indicated by returning the geometry of a "1.2M" PC-format floppy 955 * disk. And, incidentally, what is returned is not the geometry as 956 * such but the highest valid cylinder, head, and sector numbers. 957 */ 958u_int32_t 959bd_getbigeom(int bunit) 960{ 961 962 v86.ctl = V86_FLAGS; 963 v86.addr = 0x13; 964 v86.eax = 0x800; 965 v86.edx = 0x80 + bunit; 966 v86int(); 967 if (v86.efl & 0x1) 968 return 0x4f010f; 969 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) | 970 (v86.edx & 0xff00) | (v86.ecx & 0x3f); 971} 972#endif 973 974/* 975 * Return a suitable dev_t value for (dev). 976 * 977 * In the case where it looks like (dev) is a SCSI disk, we allow the number of 978 * IDE disks to be specified in $num_ide_disks. There should be a Better Way. 979 */ 980int 981bd_getdev(struct i386_devdesc *dev) 982{ 983 struct open_disk *od; 984 int biosdev; 985 int major; 986 int rootdev; 987 char *nip, *cp; 988 int unitofs = 0, i, unit; 989 990 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit); 991 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev); 992 if (biosdev == -1) /* not a BIOS device */ 993 return(-1); 994 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */ 995 return(-1); 996 997#ifdef PC98 998 if ((biosdev & 0xf0) == 0x90 || (biosdev & 0xf0) == 0x30) { 999#else 1000 if (biosdev < 0x80) { 1001#endif 1002 /* floppy (or emulated floppy) or ATAPI device */ 1003 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) { 1004 /* is an ATAPI disk */ 1005 major = WFDMAJOR; 1006 } else { 1007 /* is a floppy disk */ 1008 major = FDMAJOR; 1009 } 1010 } else { 1011 /* harddisk */ 1012 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) { 1013 /* label OK, disk labelled as SCSI */ 1014 major = DAMAJOR; 1015 /* check for unit number correction hint, now deprecated */ 1016 if ((nip = getenv("num_ide_disks")) != NULL) { 1017 i = strtol(nip, &cp, 0); 1018 /* check for parse error */ 1019 if ((cp != nip) && (*cp == 0)) 1020 unitofs = i; 1021 } 1022 } else { 1023 /* assume an IDE disk */ 1024 major = WDMAJOR; 1025 } 1026 } 1027 /* XXX a better kludge to set the root disk unit number */ 1028 if ((nip = getenv("root_disk_unit")) != NULL) { 1029 i = strtol(nip, &cp, 0); 1030 /* check for parse error */ 1031 if ((cp != nip) && (*cp == 0)) 1032 unit = i; 1033 } else { 1034#ifdef PC98 1035 if ((biosdev & 0xf0) == 0xa0) 1036 unit = bdinfo[dev->d_kind.biosdisk.unit].bd_da_unit; 1037 else 1038 unit = biosdev & 0xf; 1039#else 1040 unit = (biosdev & 0x7f) - unitofs; /* allow for #wd compenstation in da case */ 1041#endif 1042 } 1043 1044 rootdev = MAKEBOOTDEV(major, 1045 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */ 1046 (dev->d_kind.biosdisk.slice + 1) & 0xf, 1047 unit, 1048 dev->d_kind.biosdisk.partition); 1049 DEBUG("dev is 0x%x\n", rootdev); 1050 return(rootdev); 1051} 1052 1053/* 1054 * Fix (dev) so that it refers to the 'real' disk/slice/partition that it implies. 1055 */ 1056int 1057bd_fixupdev(struct i386_devdesc *dev) 1058{ 1059 struct open_disk *od; 1060 1061 /* 1062 * Open the disk. This will fix up the slice and partition fields. 1063 */ 1064 if (bd_opendisk(&od, dev) != 0) 1065 return(ENOENT); 1066 1067 bd_closedisk(od); 1068} 1069