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