block/partitions/acorn.c

   1 /*
   2  *  linux/fs/partitions/acorn.c
   3  *
   4  *  Copyright (c) 1996-2000 Russell King.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Scan ADFS partitions on hard disk drives.  Unfortunately, there
  11  *  isn't a standard for partitioning drives on Acorn machines, so
  12  *  every single manufacturer of SCSI and IDE cards created their own
  13  *  method.
  14  */
  15 #include <linux/buffer_head.h>
  16 #include <linux/adfs_fs.h>
  17
  18 #include "check.h"
  19 #include "acorn.h"
  20
  21 /*
  22  * Partition types. (Oh for reusability)
  23  */
  24 #define PARTITION_RISCIX_MFM    1
  25 #define PARTITION_RISCIX_SCSI   2
  26 #define PARTITION_LINUX         9
  27
  28 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
  29         defined(CONFIG_ACORN_PARTITION_ADFS)
  30 static struct adfs_discrecord *
  31 adfs_partition(struct parsed_partitions *state, char *name, char *data,
  32                unsigned long first_sector, int slot)
  33 {
  34         struct adfs_discrecord *dr;
  35         unsigned int nr_sects;
  36
  37         if (adfs_checkbblk(data))
  38                 return NULL;
  39
  40         dr = (struct adfs_discrecord *)(data + 0x1c0);
  41
  42         if (dr->disc_size == 0 && dr->disc_size_high == 0)
  43                 return NULL;
  44
  45         nr_sects = (le32_to_cpu(dr->disc_size_high) << 23) |
  46                    (le32_to_cpu(dr->disc_size) >> 9);
  47
  48         if (name) {
  49                 strlcat(state->pp_buf, " [", PAGE_SIZE);
  50                 strlcat(state->pp_buf, name, PAGE_SIZE);
  51                 strlcat(state->pp_buf, "]", PAGE_SIZE);
  52         }
  53         put_partition(state, slot, first_sector, nr_sects);
  54         return dr;
  55 }
  56 #endif
  57
  58 #ifdef CONFIG_ACORN_PARTITION_RISCIX
  59
  60 struct riscix_part {
  61         __le32  start;
  62         __le32  length;
  63         __le32  one;
  64         char    name[16];
  65 };
  66
  67 struct riscix_record {
  68         __le32  magic;
  69 #define RISCIX_MAGIC    cpu_to_le32(0x4a657320)
  70         __le32  date;
  71         struct riscix_part part[8];
  72 };
  73
  74 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
  75         defined(CONFIG_ACORN_PARTITION_ADFS)
  76 static int riscix_partition(struct parsed_partitions *state,
  77                             unsigned long first_sect, int slot,
  78                             unsigned long nr_sects)
  79 {
  80         Sector sect;
  81         struct riscix_record *rr;
  82
  83         rr = read_part_sector(state, first_sect, &sect);
  84         if (!rr)
  85                 return -1;
  86
  87         strlcat(state->pp_buf, " [RISCiX]", PAGE_SIZE);
  88
  89
  90         if (rr->magic == RISCIX_MAGIC) {
  91                 unsigned long size = nr_sects > 2 ? 2 : nr_sects;
  92                 int part;
  93
  94                 strlcat(state->pp_buf, " <", PAGE_SIZE);
  95
  96                 put_partition(state, slot++, first_sect, size);
  97                 for (part = 0; part < 8; part++) {
  98                         if (rr->part[part].one &&
  99                             memcmp(rr->part[part].name, "All\0", 4)) {
 100                                 put_partition(state, slot++,
 101                                         le32_to_cpu(rr->part[part].start),
 102                                         le32_to_cpu(rr->part[part].length));
 103                                 strlcat(state->pp_buf, "(", PAGE_SIZE);
 104                                 strlcat(state->pp_buf, rr->part[part].name, PAGE_SIZE);
 105                                 strlcat(state->pp_buf, ")", PAGE_SIZE);
 106                         }
 107                 }
 108
 109                 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
 110         } else {
 111                 put_partition(state, slot++, first_sect, nr_sects);
 112         }
 113
 114         put_dev_sector(sect);
 115         return slot;
 116 }
 117 #endif
 118 #endif
 119
 120 #define LINUX_NATIVE_MAGIC 0xdeafa1de
 121 #define LINUX_SWAP_MAGIC   0xdeafab1e
 122
 123 struct linux_part {
 124         __le32 magic;
 125         __le32 start_sect;
 126         __le32 nr_sects;
 127 };
 128
 129 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
 130         defined(CONFIG_ACORN_PARTITION_ADFS)
 131 static int linux_partition(struct parsed_partitions *state,
 132                            unsigned long first_sect, int slot,
 133                            unsigned long nr_sects)
 134 {
 135         Sector sect;
 136         struct linux_part *linuxp;
 137         unsigned long size = nr_sects > 2 ? 2 : nr_sects;
 138
 139         strlcat(state->pp_buf, " [Linux]", PAGE_SIZE);
 140
 141         put_partition(state, slot++, first_sect, size);
 142
 143         linuxp = read_part_sector(state, first_sect, &sect);
 144         if (!linuxp)
 145                 return -1;
 146
 147         strlcat(state->pp_buf, " <", PAGE_SIZE);
 148         while (linuxp->magic == cpu_to_le32(LINUX_NATIVE_MAGIC) ||
 149                linuxp->magic == cpu_to_le32(LINUX_SWAP_MAGIC)) {
 150                 if (slot == state->limit)
 151                         break;
 152                 put_partition(state, slot++, first_sect +
 153                                  le32_to_cpu(linuxp->start_sect),
 154                                  le32_to_cpu(linuxp->nr_sects));
 155                 linuxp ++;
 156         }
 157         strlcat(state->pp_buf, " >", PAGE_SIZE);
 158
 159         put_dev_sector(sect);
 160         return slot;
 161 }
 162 #endif
 163
 164 #ifdef CONFIG_ACORN_PARTITION_CUMANA
 165 int adfspart_check_CUMANA(struct parsed_partitions *state)
 166 {
 167         unsigned long first_sector = 0;
 168         unsigned int start_blk = 0;
 169         Sector sect;
 170         unsigned char *data;
 171         char *name = "CUMANA/ADFS";
 172         int first = 1;
 173         int slot = 1;
 174
 175         /*
 176          * Try Cumana style partitions - sector 6 contains ADFS boot block
 177          * with pointer to next 'drive'.
 178          *
 179          * There are unknowns in this code - is the 'cylinder number' of the
 180          * next partition relative to the start of this one - I'm assuming
 181          * it is.
 182          *
 183          * Also, which ID did Cumana use?
 184          *
 185          * This is totally unfinished, and will require more work to get it
 186          * going. Hence it is totally untested.
 187          */
 188         do {
 189                 struct adfs_discrecord *dr;
 190                 unsigned int nr_sects;
 191
 192                 data = read_part_sector(state, start_blk * 2 + 6, &sect);
 193                 if (!data)
 194                         return -1;
 195
 196                 if (slot == state->limit)
 197                         break;
 198
 199                 dr = adfs_partition(state, name, data, first_sector, slot++);
 200                 if (!dr)
 201                         break;
 202
 203                 name = NULL;
 204
 205                 nr_sects = (data[0x1fd] + (data[0x1fe] << 8)) *
 206                            (dr->heads + (dr->lowsector & 0x40 ? 1 : 0)) *
 207                            dr->secspertrack;
 208
 209                 if (!nr_sects)
 210                         break;
 211
 212                 first = 0;
 213                 first_sector += nr_sects;
 214                 start_blk += nr_sects >> (BLOCK_SIZE_BITS - 9);
 215                 nr_sects = 0; /* hmm - should be partition size */
 216
 217                 switch (data[0x1fc] & 15) {
 218                 case 0: /* No partition / ADFS? */
 219                         break;
 220
 221 #ifdef CONFIG_ACORN_PARTITION_RISCIX
 222                 case PARTITION_RISCIX_SCSI:
 223                         /* RISCiX - we don't know how to find the next one. */
 224                         slot = riscix_partition(state, first_sector, slot,
 225                                                 nr_sects);
 226                         break;
 227 #endif
 228
 229                 case PARTITION_LINUX:
 230                         slot = linux_partition(state, first_sector, slot,
 231                                                nr_sects);
 232                         break;
 233                 }
 234                 put_dev_sector(sect);
 235                 if (slot == -1)
 236                         return -1;
 237         } while (1);
 238         put_dev_sector(sect);
 239         return first ? 0 : 1;
 240 }
 241 #endif
 242
 243 #ifdef CONFIG_ACORN_PARTITION_ADFS
 244 /*
 245  * Purpose: allocate ADFS partitions.
 246  *
 247  * Params : hd          - pointer to gendisk structure to store partition info.
 248  *          dev         - device number to access.
 249  *
 250  * Returns: -1 on error, 0 for no ADFS boot sector, 1 for ok.
 251  *
 252  * Alloc  : hda  = whole drive
 253  *          hda1 = ADFS partition on first drive.
 254  *          hda2 = non-ADFS partition.
 255  */
 256 int adfspart_check_ADFS(struct parsed_partitions *state)
 257 {
 258         unsigned long start_sect, nr_sects, sectscyl, heads;
 259         Sector sect;
 260         unsigned char *data;
 261         struct adfs_discrecord *dr;
 262         unsigned char id;
 263         int slot = 1;
 264
 265         data = read_part_sector(state, 6, &sect);
 266         if (!data)
 267                 return -1;
 268
 269         dr = adfs_partition(state, "ADFS", data, 0, slot++);
 270         if (!dr) {
 271                 put_dev_sector(sect);
 272                 return 0;
 273         }
 274
 275         heads = dr->heads + ((dr->lowsector >> 6) & 1);
 276         sectscyl = dr->secspertrack * heads;
 277         start_sect = ((data[0x1fe] << 8) + data[0x1fd]) * sectscyl;
 278         id = data[0x1fc] & 15;
 279         put_dev_sector(sect);
 280
 281         /*
 282          * Work out start of non-adfs partition.
 283          */
 284         nr_sects = (state->bdev->bd_inode->i_size >> 9) - start_sect;
 285
 286         if (start_sect) {
 287                 switch (id) {
 288 #ifdef CONFIG_ACORN_PARTITION_RISCIX
 289                 case PARTITION_RISCIX_SCSI:
 290                 case PARTITION_RISCIX_MFM:
 291                         slot = riscix_partition(state, start_sect, slot,
 292                                                 nr_sects);
 293                         break;
 294 #endif
 295
 296                 case PARTITION_LINUX:
 297                         slot = linux_partition(state, start_sect, slot,
 298                                                nr_sects);
 299                         break;
 300                 }
 301         }
 302         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 303         return 1;
 304 }
 305 #endif
 306
 307 #ifdef CONFIG_ACORN_PARTITION_ICS
 308
 309 struct ics_part {
 310         __le32 start;
 311         __le32 size;
 312 };
 313
 314 static int adfspart_check_ICSLinux(struct parsed_partitions *state,
 315                                    unsigned long block)
 316 {
 317         Sector sect;
 318         unsigned char *data = read_part_sector(state, block, &sect);
 319         int result = 0;
 320
 321         if (data) {
 322                 if (memcmp(data, "LinuxPart", 9) == 0)
 323                         result = 1;
 324                 put_dev_sector(sect);
 325         }
 326
 327         return result;
 328 }
 329
 330 /*
 331  * Check for a valid ICS partition using the checksum.
 332  */
 333 static inline int valid_ics_sector(const unsigned char *data)
 334 {
 335         unsigned long sum;
 336         int i;
 337
 338         for (i = 0, sum = 0x50617274; i < 508; i++)
 339                 sum += data[i];
 340
 341         sum -= le32_to_cpu(*(__le32 *)(&data[508]));
 342
 343         return sum == 0;
 344 }
 345
 346 /*
 347  * Purpose: allocate ICS partitions.
 348  * Params : hd          - pointer to gendisk structure to store partition info.
 349  *          dev         - device number to access.
 350  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 351  * Alloc  : hda  = whole drive
 352  *          hda1 = ADFS partition 0 on first drive.
 353  *          hda2 = ADFS partition 1 on first drive.
 354  *              ..etc..
 355  */
 356 int adfspart_check_ICS(struct parsed_partitions *state)
 357 {
 358         const unsigned char *data;
 359         const struct ics_part *p;
 360         int slot;
 361         Sector sect;
 362
 363         /*
 364          * Try ICS style partitions - sector 0 contains partition info.
 365          */
 366         data = read_part_sector(state, 0, &sect);
 367         if (!data)
 368                 return -1;
 369
 370         if (!valid_ics_sector(data)) {
 371                 put_dev_sector(sect);
 372                 return 0;
 373         }
 374
 375         strlcat(state->pp_buf, " [ICS]", PAGE_SIZE);
 376
 377         for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
 378                 u32 start = le32_to_cpu(p->start);
 379                 s32 size = le32_to_cpu(p->size); /* yes, it's signed. */
 380
 381                 if (slot == state->limit)
 382                         break;
 383
 384                 /*
 385                  * Negative sizes tell the RISC OS ICS driver to ignore
 386                  * this partition - in effect it says that this does not
 387                  * contain an ADFS filesystem.
 388                  */
 389                 if (size < 0) {
 390                         size = -size;
 391
 392                         /*
 393                          * Our own extension - We use the first sector
 394                          * of the partition to identify what type this
 395                          * partition is.  We must not make this visible
 396                          * to the filesystem.
 397                          */
 398                         if (size > 1 && adfspart_check_ICSLinux(state, start)) {
 399                                 start += 1;
 400                                 size -= 1;
 401                         }
 402                 }
 403
 404                 if (size)
 405                         put_partition(state, slot++, start, size);
 406         }
 407
 408         put_dev_sector(sect);
 409         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 410         return 1;
 411 }
 412 #endif
 413
 414 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
 415 struct ptec_part {
 416         __le32 unused1;
 417         __le32 unused2;
 418         __le32 start;
 419         __le32 size;
 420         __le32 unused5;
 421         char type[8];
 422 };
 423
 424 static inline int valid_ptec_sector(const unsigned char *data)
 425 {
 426         unsigned char checksum = 0x2a;
 427         int i;
 428
 429         /*
 430          * If it looks like a PC/BIOS partition, then it
 431          * probably isn't PowerTec.
 432          */
 433         if (data[510] == 0x55 && data[511] == 0xaa)
 434                 return 0;
 435
 436         for (i = 0; i < 511; i++)
 437                 checksum += data[i];
 438
 439         return checksum == data[511];
 440 }
 441
 442 /*
 443  * Purpose: allocate ICS partitions.
 444  * Params : hd          - pointer to gendisk structure to store partition info.
 445  *          dev         - device number to access.
 446  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 447  * Alloc  : hda  = whole drive
 448  *          hda1 = ADFS partition 0 on first drive.
 449  *          hda2 = ADFS partition 1 on first drive.
 450  *              ..etc..
 451  */
 452 int adfspart_check_POWERTEC(struct parsed_partitions *state)
 453 {
 454         Sector sect;
 455         const unsigned char *data;
 456         const struct ptec_part *p;
 457         int slot = 1;
 458         int i;
 459
 460         data = read_part_sector(state, 0, &sect);
 461         if (!data)
 462                 return -1;
 463
 464         if (!valid_ptec_sector(data)) {
 465                 put_dev_sector(sect);
 466                 return 0;
 467         }
 468
 469         strlcat(state->pp_buf, " [POWERTEC]", PAGE_SIZE);
 470
 471         for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
 472                 u32 start = le32_to_cpu(p->start);
 473                 u32 size = le32_to_cpu(p->size);
 474
 475                 if (size)
 476                         put_partition(state, slot++, start, size);
 477         }
 478
 479         put_dev_sector(sect);
 480         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 481         return 1;
 482 }
 483 #endif
 484
 485 #ifdef CONFIG_ACORN_PARTITION_EESOX
 486 struct eesox_part {
 487         char    magic[6];
 488         char    name[10];
 489         __le32  start;
 490         __le32  unused6;
 491         __le32  unused7;
 492         __le32  unused8;
 493 };
 494
 495 /*
 496  * Guess who created this format?
 497  */
 498 static const char eesox_name[] = {
 499         'N', 'e', 'i', 'l', ' ',
 500         'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
 501 };
 502
 503 /*
 504  * EESOX SCSI partition format.
 505  *
 506  * This is a goddamned awful partition format.  We don't seem to store
 507  * the size of the partition in this table, only the start addresses.
 508  *
 509  * There are two possibilities where the size comes from:
 510  *  1. The individual ADFS boot block entries that are placed on the disk.
 511  *  2. The start address of the next entry.
 512  */
 513 int adfspart_check_EESOX(struct parsed_partitions *state)
 514 {
 515         Sector sect;
 516         const unsigned char *data;
 517         unsigned char buffer[256];
 518         struct eesox_part *p;
 519         sector_t start = 0;
 520         int i, slot = 1;
 521
 522         data = read_part_sector(state, 7, &sect);
 523         if (!data)
 524                 return -1;
 525
 526         /*
 527          * "Decrypt" the partition table.  God knows why...
 528          */
 529         for (i = 0; i < 256; i++)
 530                 buffer[i] = data[i] ^ eesox_name[i & 15];
 531
 532         put_dev_sector(sect);
 533
 534         for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
 535                 sector_t next;
 536
 537                 if (memcmp(p->magic, "Eesox", 6))
 538                         break;
 539
 540                 next = le32_to_cpu(p->start);
 541                 if (i)
 542                         put_partition(state, slot++, start, next - start);
 543                 start = next;
 544         }
 545
 546         if (i != 0) {
 547                 sector_t size;
 548
 549                 size = get_capacity(state->bdev->bd_disk);
 550                 put_partition(state, slot++, start, size - start);
 551                 strlcat(state->pp_buf, "\n", PAGE_SIZE);
 552         }
 553
 554         return i ? 1 : 0;
 555 }
 556 #endif