biosdisk.c revision 176654
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 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/boot/pc98/libpc98/biosdisk.c 176654 2008-02-29 04:56:51Z nyan $"); 29 30/* 31 * BIOS disk device handling. 32 * 33 * Ideas and algorithms from: 34 * 35 * - NetBSD libi386/biosdisk.c 36 * - FreeBSD biosboot/disk.c 37 * 38 */ 39 40#include <stand.h> 41 42#include <sys/disklabel.h> 43#include <sys/diskpc98.h> 44#include <machine/bootinfo.h> 45 46#include <stdarg.h> 47 48#include <bootstrap.h> 49#include <btxv86.h> 50#include "libi386.h" 51 52#define BIOS_NUMDRIVES 0x475 53#define BIOSDISK_SECSIZE 512 54#define BUFSIZE (1 * BIOSDISK_SECSIZE) 55#define MAXBDDEV MAXDEV 56 57#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */ 58#define WDMAJOR 0 /* major numbers for devices we frontend for */ 59#define WFDMAJOR 1 60#define FDMAJOR 2 61#define DAMAJOR 4 62 63#ifdef DISK_DEBUG 64# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 65#else 66# define DEBUG(fmt, args...) 67#endif 68 69struct open_disk { 70 int od_dkunit; /* disk unit number */ 71 int od_unit; /* BIOS unit number */ 72 int od_cyl; /* BIOS geometry */ 73 int od_hds; 74 int od_sec; 75 int od_boff; /* block offset from beginning of BIOS disk */ 76 int od_flags; 77#define BD_MODEINT13 0x0000 78#define BD_MODEEDD1 0x0001 79#define BD_MODEEDD3 0x0002 80#define BD_MODEMASK 0x0003 81#define BD_FLOPPY 0x0004 82#define BD_LABELOK 0x0008 83#define BD_PARTTABOK 0x0010 84#define BD_OPTICAL 0x0020 85 struct disklabel od_disklabel; 86 int od_nslices; /* slice count */ 87 struct pc98_partition od_slicetab[NDOSPART]; 88}; 89 90/* 91 * List of BIOS devices, translation from disk unit number to 92 * BIOS unit number. 93 */ 94static struct bdinfo 95{ 96 int bd_unit; /* BIOS unit number */ 97 int bd_flags; 98 int bd_type; /* BIOS 'drive type' (floppy only) */ 99 int bd_da_unit; /* kernel unit number for da */ 100} bdinfo [MAXBDDEV]; 101static int nbdinfo = 0; 102 103static int bd_getgeom(struct open_disk *od); 104static int bd_read(struct open_disk *od, daddr_t dblk, int blks, 105 caddr_t dest); 106static int bd_write(struct open_disk *od, daddr_t dblk, int blks, 107 caddr_t dest); 108 109static int bd_int13probe(struct bdinfo *bd); 110 111static void bd_printslice(struct open_disk *od, struct pc98_partition *dp, 112 char *prefix, int verbose); 113static void bd_printbsdslice(struct open_disk *od, daddr_t offset, 114 char *prefix, int verbose); 115 116static int bd_init(void); 117static int bd_strategy(void *devdata, int flag, daddr_t dblk, 118 size_t size, char *buf, size_t *rsize); 119static int bd_realstrategy(void *devdata, int flag, daddr_t dblk, 120 size_t size, char *buf, size_t *rsize); 121static int bd_open(struct open_file *f, ...); 122static int bd_close(struct open_file *f); 123static void bd_print(int verbose); 124 125struct devsw biosdisk = { 126 "disk", 127 DEVT_DISK, 128 bd_init, 129 bd_strategy, 130 bd_open, 131 bd_close, 132 noioctl, 133 bd_print, 134 NULL 135}; 136 137static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev); 138static void bd_closedisk(struct open_disk *od); 139static int bd_open_pc98(struct open_disk *od, struct i386_devdesc *dev); 140static int bd_bestslice(struct open_disk *od); 141static void bd_checkextended(struct open_disk *od, int slicenum); 142 143/* 144 * Translate between BIOS device numbers and our private unit numbers. 145 */ 146int 147bd_bios2unit(int biosdev) 148{ 149 int i; 150 151 DEBUG("looking for bios device 0x%x", biosdev); 152 for (i = 0; i < nbdinfo; i++) { 153 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit); 154 if (bdinfo[i].bd_unit == biosdev) 155 return(i); 156 } 157 return(-1); 158} 159 160int 161bd_unit2bios(int unit) 162{ 163 if ((unit >= 0) && (unit < nbdinfo)) 164 return(bdinfo[unit].bd_unit); 165 return(-1); 166} 167 168/* 169 * Quiz the BIOS for disk devices, save a little info about them. 170 */ 171static int 172bd_init(void) 173{ 174 int base, unit; 175 int da_drive=0, n=-0x10; 176 177 /* sequence 0x90, 0x80, 0xa0 */ 178 for (base = 0x90; base <= 0xa0; base += n, n += 0x30) { 179 for (unit = base; (nbdinfo < MAXBDDEV) || ((unit & 0x0f) < 4); unit++) { 180 bdinfo[nbdinfo].bd_unit = unit; 181 bdinfo[nbdinfo].bd_flags = (unit & 0xf0) == 0x90 ? BD_FLOPPY : 0; 182 183 if (!bd_int13probe(&bdinfo[nbdinfo])){ 184 if (((unit & 0xf0) == 0x90 && (unit & 0x0f) < 4) || 185 ((unit & 0xf0) == 0xa0 && (unit & 0x0f) < 6)) 186 continue; /* Target IDs are not contiguous. */ 187 else 188 break; 189 } 190 191 if (bdinfo[nbdinfo].bd_flags & BD_FLOPPY){ 192 /* available 1.44MB access? */ 193 if (*(u_char *)PTOV(0xA15AE) & (1<<(unit & 0xf))) { 194 /* boot media 1.2MB FD? */ 195 if ((*(u_char *)PTOV(0xA1584) & 0xf0) != 0x90) 196 bdinfo[nbdinfo].bd_unit = 0x30 + (unit & 0xf); 197 } 198 } 199 else { 200 if ((unit & 0xF0) == 0xA0) /* SCSI HD or MO */ 201 bdinfo[nbdinfo].bd_da_unit = da_drive++; 202 } 203 /* XXX we need "disk aliases" to make this simpler */ 204 printf("BIOS drive %c: is disk%d\n", 205 'A' + nbdinfo, nbdinfo); 206 nbdinfo++; 207 } 208 } 209 return(0); 210} 211 212/* 213 * Try to detect a device supported by the legacy int13 BIOS 214 */ 215static int 216bd_int13probe(struct bdinfo *bd) 217{ 218 int addr; 219 220 if (bd->bd_flags & BD_FLOPPY) { 221 addr = 0xa155c; 222 } else { 223 if ((bd->bd_unit & 0xf0) == 0x80) 224 addr = 0xa155d; 225 else 226 addr = 0xa1482; 227 } 228 if ( *(u_char *)PTOV(addr) & (1<<(bd->bd_unit & 0x0f))) { 229 bd->bd_flags |= BD_MODEINT13; 230 return(1); 231 } 232 if ((bd->bd_unit & 0xF0) == 0xA0) { 233 int media = ((unsigned *)PTOV(0xA1460))[bd->bd_unit & 0x0F] & 0x1F; 234 235 if (media == 7) { /* MO */ 236 bd->bd_flags |= BD_MODEINT13 | BD_OPTICAL; 237 return(1); 238 } 239 } 240 return(0); 241} 242 243/* 244 * Print information about disks 245 */ 246static void 247bd_print(int verbose) 248{ 249 int i, j; 250 char line[80]; 251 struct i386_devdesc dev; 252 struct open_disk *od; 253 struct pc98_partition *dptr; 254 255 for (i = 0; i < nbdinfo; i++) { 256 sprintf(line, " disk%d: BIOS drive %c:\n", i, 'A' + i); 257 pager_output(line); 258 259 /* try to open the whole disk */ 260 dev.d_unit = i; 261 dev.d_kind.biosdisk.slice = -1; 262 dev.d_kind.biosdisk.partition = -1; 263 264 if (!bd_opendisk(&od, &dev)) { 265 266 /* Do we have a partition table? */ 267 if (od->od_flags & BD_PARTTABOK) { 268 dptr = &od->od_slicetab[0]; 269 270 /* Check for a "dedicated" disk */ 271 for (j = 0; j < od->od_nslices; j++) { 272 switch(dptr[j].dp_mid) { 273 case DOSMID_386BSD: 274 sprintf(line, " disk%ds%d", i, j + 1); 275 bd_printbsdslice(od, 276 dptr[j].dp_scyl * od->od_hds * od->od_sec + 277 dptr[j].dp_shd * od->od_sec + dptr[j].dp_ssect, 278 line, verbose); 279 break; 280 default: 281 break; 282 } 283 } 284 } 285 bd_closedisk(od); 286 } 287 } 288} 289 290/* Given a size in 512 byte sectors, convert it to a human-readable number. */ 291static char * 292display_size(uint64_t size) 293{ 294 static char buf[80]; 295 char unit; 296 297 size /= 2; 298 unit = 'K'; 299 if (size >= 10485760000LL) { 300 size /= 1073741824; 301 unit = 'T'; 302 } else if (size >= 10240000) { 303 size /= 1048576; 304 unit = 'G'; 305 } else if (size >= 10000) { 306 size /= 1024; 307 unit = 'M'; 308 } 309 sprintf(buf, "%.6ld%cB", (long)size, unit); 310 return (buf); 311} 312 313/* 314 * Print out each valid partition in the disklabel of a FreeBSD slice. 315 * For size calculations, we assume a 512 byte sector size. 316 */ 317static void 318bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix, 319 int verbose) 320{ 321 char line[80]; 322 char buf[BIOSDISK_SECSIZE]; 323 struct disklabel *lp; 324 int i; 325 326 /* read disklabel */ 327 if (bd_read(od, offset + LABELSECTOR, 1, buf)) 328 return; 329 lp =(struct disklabel *)(&buf[0]); 330 if (lp->d_magic != DISKMAGIC) { 331 sprintf(line, "%s: FFS bad disklabel\n", prefix); 332 pager_output(line); 333 return; 334 } 335 336 /* Print partitions */ 337 for (i = 0; i < lp->d_npartitions; i++) { 338 /* 339 * For each partition, make sure we know what type of fs it is. If 340 * not, then skip it. However, since floppies often have bogus 341 * fstypes, print the 'a' partition on a floppy even if it is marked 342 * unused. 343 */ 344 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) || 345 (lp->d_partitions[i].p_fstype == FS_SWAP) || 346 (lp->d_partitions[i].p_fstype == FS_VINUM) || 347 ((lp->d_partitions[i].p_fstype == FS_UNUSED) && 348 (od->od_flags & BD_FLOPPY) && (i == 0))) { 349 350 /* Only print out statistics in verbose mode */ 351 if (verbose) 352 sprintf(line, " %s%c: %s %s (%d - %d)\n", prefix, 'a' + i, 353 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap " : 354 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" : 355 "FFS ", 356 display_size(lp->d_partitions[i].p_size), 357 lp->d_partitions[i].p_offset, 358 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size); 359 else 360 sprintf(line, " %s%c: %s\n", prefix, 'a' + i, 361 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" : 362 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" : 363 "FFS"); 364 pager_output(line); 365 } 366 } 367} 368 369 370/* 371 * Attempt to open the disk described by (dev) for use by (f). 372 * 373 * Note that the philosophy here is "give them exactly what 374 * they ask for". This is necessary because being too "smart" 375 * about what the user might want leads to complications. 376 * (eg. given no slice or partition value, with a disk that is 377 * sliced - are they after the first BSD slice, or the DOS 378 * slice before it?) 379 */ 380static int 381bd_open(struct open_file *f, ...) 382{ 383 va_list ap; 384 struct i386_devdesc *dev; 385 struct open_disk *od; 386 int error; 387 388 va_start(ap, f); 389 dev = va_arg(ap, struct i386_devdesc *); 390 va_end(ap); 391 if ((error = bd_opendisk(&od, dev))) 392 return(error); 393 394 /* 395 * Save our context 396 */ 397 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od; 398 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff); 399 return(0); 400} 401 402static int 403bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev) 404{ 405 struct open_disk *od; 406 int error; 407 408 if (dev->d_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_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 %d", 426 i386_fmtdev(dev), dev->d_unit, 427 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition); 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 /* Determine disk layout. */ 437 error = bd_open_pc98(od, dev); 438 439 out: 440 if (error) { 441 free(od); 442 } else { 443 *odp = od; /* return the open disk */ 444 } 445 return(error); 446} 447 448static int 449bd_open_pc98(struct open_disk *od, struct i386_devdesc *dev) 450{ 451 struct pc98_partition *dptr; 452 struct disklabel *lp; 453 int sector, slice, i; 454 char buf[BUFSIZE]; 455 456 /* 457 * Following calculations attempt to determine the correct value 458 * for d->od_boff by looking for the slice and partition specified, 459 * or searching for reasonable defaults. 460 */ 461 462 /* 463 * Find the slice in the DOS slice table. 464 */ 465 od->od_nslices = 0; 466 if (od->od_flags & BD_FLOPPY) { 467 sector = 0; 468 goto unsliced; 469 } 470 if (bd_read(od, 0, 1, buf)) { 471 DEBUG("error reading MBR"); 472 return (EIO); 473 } 474 475 /* 476 * Check the slice table magic. 477 */ 478 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) { 479 /* If a slice number was explicitly supplied, this is an error */ 480 if (dev->d_kind.biosdisk.slice > 0) { 481 DEBUG("no slice table/MBR (no magic)"); 482 return (ENOENT); 483 } 484 sector = 0; 485 goto unsliced; /* may be a floppy */ 486 } 487 if (bd_read(od, 1, 1, buf)) { 488 DEBUG("error reading MBR"); 489 return (EIO); 490 } 491 492 /* 493 * copy the partition table, then pick up any extended partitions. 494 */ 495 bcopy(buf + DOSPARTOFF, &od->od_slicetab, 496 sizeof(struct pc98_partition) * NDOSPART); 497 od->od_nslices = NDOSPART; /* extended slices start here */ 498 od->od_flags |= BD_PARTTABOK; 499 dptr = &od->od_slicetab[0]; 500 501 /* Is this a request for the whole disk? */ 502 if (dev->d_kind.biosdisk.slice == -1) { 503 sector = 0; 504 goto unsliced; 505 } 506 507 /* 508 * if a slice number was supplied but not found, this is an error. 509 */ 510 if (dev->d_kind.biosdisk.slice > 0) { 511 slice = dev->d_kind.biosdisk.slice - 1; 512 if (slice >= od->od_nslices) { 513 DEBUG("slice %d not found", slice); 514 return (ENOENT); 515 } 516 } 517 518 /* Try to auto-detect the best slice; this should always give a slice number */ 519 if (dev->d_kind.biosdisk.slice == 0) { 520 slice = bd_bestslice(od); 521 if (slice == -1) { 522 return (ENOENT); 523 } 524 dev->d_kind.biosdisk.slice = slice; 525 } 526 527 dptr = &od->od_slicetab[0]; 528 /* 529 * Accept the supplied slice number unequivocally (we may be looking 530 * at a DOS partition). 531 */ 532 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */ 533 sector = dptr->dp_scyl * od->od_hds * od->od_sec + 534 dptr->dp_shd * od->od_sec + dptr->dp_ssect; 535 { 536 int end = dptr->dp_ecyl * od->od_hds * od->od_sec + 537 dptr->dp_ehd * od->od_sec + dptr->dp_esect; 538 DEBUG("slice entry %d at %d, %d sectors", 539 dev->d_kind.biosdisk.slice - 1, sector, end-sector); 540 } 541 542 /* 543 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition 544 */ 545 if ((dptr->dp_mid == DOSMID_386BSD) && (dev->d_kind.biosdisk.partition < 0)) 546 dev->d_kind.biosdisk.partition = 0; 547 548 unsliced: 549 /* 550 * Now we have the slice offset, look for the partition in the disklabel if we have 551 * a partition to start with. 552 * 553 * XXX we might want to check the label checksum. 554 */ 555 if (dev->d_kind.biosdisk.partition < 0) { 556 od->od_boff = sector; /* no partition, must be after the slice */ 557 DEBUG("opening raw slice"); 558 } else { 559 560 if (bd_read(od, sector + LABELSECTOR, 1, buf)) { 561 DEBUG("error reading disklabel"); 562 return (EIO); 563 } 564 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel); 565 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel)); 566 lp = &od->od_disklabel; 567 od->od_flags |= BD_LABELOK; 568 569 if (lp->d_magic != DISKMAGIC) { 570 DEBUG("no disklabel"); 571 return (ENOENT); 572 } 573 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) { 574 DEBUG("partition '%c' exceeds partitions in table (a-'%c')", 575 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions); 576 return (EPART); 577 } 578 579#ifdef DISK_DEBUG 580 /* Complain if the partition is unused unless this is a floppy. */ 581 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) && 582 !(od->od_flags & BD_FLOPPY)) 583 DEBUG("warning, partition marked as unused"); 584#endif 585 586 od->od_boff = 587 lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset - 588 lp->d_partitions[RAW_PART].p_offset + 589 sector; 590 } 591 return (0); 592} 593 594/* 595 * Search for a slice with the following preferences: 596 * 597 * 1: Active FreeBSD slice 598 * 2: Non-active FreeBSD slice 599 * 3: Active Linux slice 600 * 4: non-active Linux slice 601 * 5: Active FAT/FAT32 slice 602 * 6: non-active FAT/FAT32 slice 603 */ 604#define PREF_RAWDISK 0 605#define PREF_FBSD_ACT 1 606#define PREF_FBSD 2 607#define PREF_LINUX_ACT 3 608#define PREF_LINUX 4 609#define PREF_DOS_ACT 5 610#define PREF_DOS 6 611#define PREF_NONE 7 612 613/* 614 * slicelimit is in the range 0 .. NDOSPART 615 */ 616static int 617bd_bestslice(struct open_disk *od) 618{ 619 struct pc98_partition *dp; 620 int pref, preflevel; 621 int i, prefslice; 622 623 prefslice = 0; 624 preflevel = PREF_NONE; 625 626 dp = &od->od_slicetab[0]; 627 for (i = 0; i < od->od_nslices; i++, dp++) { 628 switch(dp->dp_mid & 0x7f) { 629 case DOSMID_386BSD & 0x7f: /* FreeBSD */ 630 if ((dp->dp_mid & 0x80) && 631 (preflevel > PREF_FBSD_ACT)) { 632 pref = i; 633 preflevel = PREF_FBSD_ACT; 634 } else if (preflevel > PREF_FBSD) { 635 pref = i; 636 preflevel = PREF_FBSD; 637 } 638 break; 639 640 case 0x11: /* DOS/Windows */ 641 case 0x20: 642 case 0x21: 643 case 0x22: 644 case 0x23: 645 case 0x63: 646 if ((dp->dp_mid & 0x80) && 647 (preflevel > PREF_DOS_ACT)) { 648 pref = i; 649 preflevel = PREF_DOS_ACT; 650 } else if (preflevel > PREF_DOS) { 651 pref = i; 652 preflevel = PREF_DOS; 653 } 654 break; 655 } 656 } 657 return (prefslice); 658} 659 660static int 661bd_close(struct open_file *f) 662{ 663 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data); 664 665 bd_closedisk(od); 666 return(0); 667} 668 669static void 670bd_closedisk(struct open_disk *od) 671{ 672 DEBUG("open_disk %p", od); 673#if 0 674 /* XXX is this required? (especially if disk already open...) */ 675 if (od->od_flags & BD_FLOPPY) 676 delay(3000000); 677#endif 678 free(od); 679} 680 681static int 682bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize) 683{ 684 struct bcache_devdata bcd; 685 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data); 686 687 bcd.dv_strategy = bd_realstrategy; 688 bcd.dv_devdata = devdata; 689 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize)); 690} 691 692static int 693bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize) 694{ 695 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data); 696 int blks; 697#ifdef BD_SUPPORT_FRAGS 698 char fragbuf[BIOSDISK_SECSIZE]; 699 size_t fragsize; 700 701 fragsize = size % BIOSDISK_SECSIZE; 702#else 703 if (size % BIOSDISK_SECSIZE) 704 panic("bd_strategy: %d bytes I/O not multiple of block size", size); 705#endif 706 707 DEBUG("open_disk %p", od); 708 blks = size / BIOSDISK_SECSIZE; 709 if (rsize) 710 *rsize = 0; 711 712 switch(rw){ 713 case F_READ: 714 DEBUG("read %d from %d to %p", blks, dblk, buf); 715 716 if (blks && bd_read(od, dblk, blks, buf)) { 717 DEBUG("read error"); 718 return (EIO); 719 } 720#ifdef BD_SUPPORT_FRAGS 721 DEBUG("bd_strategy: frag read %d from %d+%d to %p", 722 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE)); 723 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) { 724 DEBUG("frag read error"); 725 return(EIO); 726 } 727 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize); 728#endif 729 break; 730 case F_WRITE : 731 DEBUG("write %d from %d to %p", blks, dblk, buf); 732 733 if (blks && bd_write(od, dblk, blks, buf)) { 734 DEBUG("write error"); 735 return (EIO); 736 } 737#ifdef BD_SUPPORT_FRAGS 738 if(fragsize) { 739 DEBUG("Attempted to write a frag"); 740 return (EIO); 741 } 742#endif 743 break; 744 default: 745 /* DO NOTHING */ 746 return (EROFS); 747 } 748 749 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_chs_io(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest, int write) 759{ 760 u_int x, bpc, cyl, hd, sec; 761 762 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */ 763 x = dblk; 764 cyl = x / bpc; /* block # / blocks per cylinder */ 765 x %= bpc; /* block offset into cylinder */ 766 hd = x / od->od_sec; /* offset / blocks per track */ 767 sec = x % od->od_sec; /* offset into track */ 768 769 v86.ctl = V86_FLAGS; 770 v86.addr = 0x1b; 771 if (write) 772 v86.eax = 0x0500 | od->od_unit; 773 else 774 v86.eax = 0x0600 | od->od_unit; 775 if (od->od_flags & BD_FLOPPY) { 776 v86.eax |= 0xd000; 777 v86.ecx = 0x0200 | (cyl & 0xff); 778 v86.edx = (hd << 8) | (sec + 1); 779 } else if (od->od_flags & BD_OPTICAL) { 780 v86.eax &= 0xFF7F; 781 v86.ecx = dblk & 0xFFFF; 782 v86.edx = dblk >> 16; 783 } else { 784 v86.ecx = cyl; 785 v86.edx = (hd << 8) | sec; 786 } 787 v86.ebx = blks * BIOSDISK_SECSIZE; 788 v86.es = VTOPSEG(dest); 789 v86.ebp = VTOPOFF(dest); 790 v86int(); 791 return (v86.efl & 0x1); 792} 793 794static int 795bd_io(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest, int write) 796{ 797 u_int x, sec, result, resid, retry, maxfer; 798 caddr_t p, xp, bbuf, breg; 799 800 /* Just in case some idiot actually tries to read/write -1 blocks... */ 801 if (blks < 0) 802 return (-1); 803 804 resid = blks; 805 p = dest; 806 807 /* Decide whether we have to bounce */ 808 if (VTOP(dest) >> 20 != 0 || 809 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) { 810 811 /* 812 * There is a 64k physical boundary somewhere in the 813 * destination buffer, or the destination buffer is above 814 * first 1MB of physical memory so we have to arrange a 815 * suitable bounce buffer. Allocate a buffer twice as large 816 * as we need to. Use the bottom half unless there is a break 817 * there, in which case we use the top half. 818 */ 819 x = min(od->od_sec, (unsigned)blks); 820 bbuf = alloca(x * 2 * BIOSDISK_SECSIZE); 821 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == 822 ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE) & 0xffff0000)) { 823 breg = bbuf; 824 } else { 825 breg = bbuf + x * BIOSDISK_SECSIZE; 826 } 827 maxfer = x; /* limit transfers to bounce region size */ 828 } else { 829 breg = bbuf = NULL; 830 maxfer = 0; 831 } 832 833 while (resid > 0) { 834 /* 835 * Play it safe and don't cross track boundaries. 836 * (XXX this is probably unnecessary) 837 */ 838 sec = dblk % od->od_sec; /* offset into track */ 839 x = min(od->od_sec - sec, resid); 840 if (maxfer > 0) 841 x = min(x, maxfer); /* fit bounce buffer */ 842 843 /* where do we transfer to? */ 844 xp = bbuf == NULL ? p : breg; 845 846 /* 847 * Put your Data In, Put your Data out, 848 * Put your Data In, and shake it all about 849 */ 850 if (write && bbuf != NULL) 851 bcopy(p, breg, x * BIOSDISK_SECSIZE); 852 853 /* 854 * Loop retrying the operation a couple of times. The BIOS 855 * may also retry. 856 */ 857 for (retry = 0; retry < 3; retry++) { 858 /* if retrying, reset the drive */ 859 if (retry > 0) { 860 v86.ctl = V86_FLAGS; 861 v86.addr = 0x1b; 862 v86.eax = 0x0300 | od->od_unit; 863 v86int(); 864 } 865 866 result = bd_chs_io(od, dblk, x, xp, write); 867 if (result == 0) 868 break; 869 } 870 871 if (write) 872 DEBUG("%d sectors from %lld to %p (0x%x) %s", x, dblk, p, VTOP(p), 873 result ? "failed" : "ok"); 874 else 875 DEBUG("%d sectors from %p (0x%x) to %lld %s", x, p, VTOP(p), dblk, 876 result ? "failed" : "ok"); 877 if (result) { 878 return(-1); 879 } 880 if (!write && bbuf != NULL) 881 bcopy(breg, p, x * BIOSDISK_SECSIZE); 882 p += (x * BIOSDISK_SECSIZE); 883 dblk += x; 884 resid -= x; 885 } 886 887/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */ 888 return(0); 889} 890 891static int 892bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest) 893{ 894 895 return (bd_io(od, dblk, blks, dest, 0)); 896} 897 898static int 899bd_write(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest) 900{ 901 902 return (bd_io(od, dblk, blks, dest, 1)); 903} 904 905static int 906bd_getgeom(struct open_disk *od) 907{ 908 909 if (od->od_flags & BD_FLOPPY) { 910 od->od_cyl = 79; 911 od->od_hds = 2; 912 od->od_sec = (od->od_unit & 0xf0) == 0x30 ? 18 : 15; 913 } else if (od->od_flags & BD_OPTICAL) { 914 od->od_cyl = 0xFFFE; 915 od->od_hds = 8; 916 od->od_sec = 32; 917 } else { 918 v86.ctl = V86_FLAGS; 919 v86.addr = 0x1b; 920 v86.eax = 0x8400 | od->od_unit; 921 v86int(); 922 923 od->od_cyl = v86.ecx; 924 od->od_hds = (v86.edx >> 8) & 0xff; 925 od->od_sec = v86.edx & 0xff; 926 if (v86.efl & 0x1) 927 return(1); 928 } 929 930 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec); 931 return(0); 932} 933 934/* 935 * Return the BIOS geometry of a given "fixed drive" in a format 936 * suitable for the legacy bootinfo structure. Since the kernel is 937 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we 938 * prefer to get the information directly, rather than rely on being 939 * able to put it together from information already maintained for 940 * different purposes and for a probably different number of drives. 941 * 942 * For valid drives, the geometry is expected in the format (31..0) 943 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are 944 * indicated by returning the geometry of a "1.2M" PC-format floppy 945 * disk. And, incidentally, what is returned is not the geometry as 946 * such but the highest valid cylinder, head, and sector numbers. 947 */ 948u_int32_t 949bd_getbigeom(int bunit) 950{ 951 int hds = 0; 952 int unit = 0x80; /* IDE HDD */ 953 u_int addr = 0xA155d; 954 955 while (unit < 0xa7) { 956 if (*(u_char *)PTOV(addr) & (1 << (unit & 0x0f))) 957 if (hds++ == bunit) 958 break; 959 960 if (unit >= 0xA0) { 961 int media = ((unsigned *)PTOV(0xA1460))[unit & 0x0F] & 0x1F; 962 963 if (media == 7 && hds++ == bunit) /* SCSI MO */ 964 return(0xFFFE0820); /* C:65535 H:8 S:32 */ 965 } 966 if (++unit == 0x84) { 967 unit = 0xA0; /* SCSI HDD */ 968 addr = 0xA1482; 969 } 970 } 971 if (unit == 0xa7) 972 return 0x4F020F; /* 1200KB FD C:80 H:2 S:15 */ 973 v86.ctl = V86_FLAGS; 974 v86.addr = 0x1b; 975 v86.eax = 0x8400 | unit; 976 v86int(); 977 if (v86.efl & 0x1) 978 return 0x4F020F; /* 1200KB FD C:80 H:2 S:15 */ 979 return ((v86.ecx & 0xffff) << 16) | (v86.edx & 0xffff); 980} 981 982/* 983 * Return a suitable dev_t value for (dev). 984 * 985 * In the case where it looks like (dev) is a SCSI disk, we allow the number of 986 * IDE disks to be specified in $num_ide_disks. There should be a Better Way. 987 */ 988int 989bd_getdev(struct i386_devdesc *dev) 990{ 991 struct open_disk *od; 992 int biosdev; 993 int major; 994 int rootdev; 995 char *nip, *cp; 996 int unitofs = 0, i, unit; 997 998 biosdev = bd_unit2bios(dev->d_unit); 999 DEBUG("unit %d BIOS device %d", dev->d_unit, biosdev); 1000 if (biosdev == -1) /* not a BIOS device */ 1001 return(-1); 1002 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */ 1003 return(-1); 1004 1005 if ((biosdev & 0xf0) == 0x90 || (biosdev & 0xf0) == 0x30) { 1006 /* floppy (or emulated floppy) or ATAPI device */ 1007 if (bdinfo[dev->d_unit].bd_type == DT_ATAPI) { 1008 /* is an ATAPI disk */ 1009 major = WFDMAJOR; 1010 } else { 1011 /* is a floppy disk */ 1012 major = FDMAJOR; 1013 } 1014 } else { 1015 /* harddisk */ 1016 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) { 1017 /* label OK, disk labelled as SCSI */ 1018 major = DAMAJOR; 1019 /* check for unit number correction hint, now deprecated */ 1020 if ((nip = getenv("num_ide_disks")) != NULL) { 1021 i = strtol(nip, &cp, 0); 1022 /* check for parse error */ 1023 if ((cp != nip) && (*cp == 0)) 1024 unitofs = i; 1025 } 1026 } else { 1027 /* assume an IDE disk */ 1028 major = WDMAJOR; 1029 } 1030 } 1031 /* default root disk unit number */ 1032 if ((biosdev & 0xf0) == 0xa0) 1033 unit = bdinfo[dev->d_unit].bd_da_unit; 1034 else 1035 unit = biosdev & 0xf; 1036 1037 /* XXX a better kludge to set the root disk unit number */ 1038 if ((nip = getenv("root_disk_unit")) != NULL) { 1039 i = strtol(nip, &cp, 0); 1040 /* check for parse error */ 1041 if ((cp != nip) && (*cp == 0)) 1042 unit = i; 1043 } 1044 1045 rootdev = MAKEBOOTDEV(major, dev->d_kind.biosdisk.slice + 1, unit, 1046 dev->d_kind.biosdisk.partition); 1047 DEBUG("dev is 0x%x\n", rootdev); 1048 return(rootdev); 1049} 1050