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 #ifdef CONFIG_BLK_DEV_MFM
 279         if (MAJOR(bdev->bd_dev) == MFM_ACORN_MAJOR) {
 280                 extern void xd_set_geometry(struct block_device *,
 281                         unsigned char, unsigned char, unsigned int);
 282                 xd_set_geometry(bdev, dr->secspertrack, heads, 1);
 283                 invalidate_bh_lrus();
 284                 truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
 285         }
 286 #endif
 287
 288         /*
 289          * Work out start of non-adfs partition.
 290          */
 291         nr_sects = (bdev->bd_inode->i_size >> 9) - start_sect;
 292
 293         if (start_sect) {
 294                 switch (id) {
 295 #ifdef CONFIG_ACORN_PARTITION_RISCIX
 296                 case PARTITION_RISCIX_SCSI:
 297                 case PARTITION_RISCIX_MFM:
 298                         slot = riscix_partition(state, bdev, start_sect,
 299                                                  slot, nr_sects);
 300                         break;
 301 #endif
 302
 303                 case PARTITION_LINUX:
 304                         slot = linux_partition(state, bdev, start_sect,
 305                                                 slot, nr_sects);
 306                         break;
 307                 }
 308         }
 309         printk("\n");
 310         return 1;
 311 }
 312 #endif
 313
 314 #ifdef CONFIG_ACORN_PARTITION_ICS
 315
 316 struct ics_part {
 317         __le32 start;
 318         __le32 size;
 319 };
 320
 321 static int adfspart_check_ICSLinux(struct block_device *bdev, unsigned long block)
 322 {
 323         Sector sect;
 324         unsigned char *data = read_dev_sector(bdev, block, &sect);
 325         int result = 0;
 326
 327         if (data) {
 328                 if (memcmp(data, "LinuxPart", 9) == 0)
 329                         result = 1;
 330                 put_dev_sector(sect);
 331         }
 332
 333         return result;
 334 }
 335
 336 /*
 337  * Check for a valid ICS partition using the checksum.
 338  */
 339 static inline int valid_ics_sector(const unsigned char *data)
 340 {
 341         unsigned long sum;
 342         int i;
 343
 344         for (i = 0, sum = 0x50617274; i < 508; i++)
 345                 sum += data[i];
 346
 347         sum -= le32_to_cpu(*(__le32 *)(&data[508]));
 348
 349         return sum == 0;
 350 }
 351
 352 /*
 353  * Purpose: allocate ICS partitions.
 354  * Params : hd          - pointer to gendisk structure to store partition info.
 355  *          dev         - device number to access.
 356  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 357  * Alloc  : hda  = whole drive
 358  *          hda1 = ADFS partition 0 on first drive.
 359  *          hda2 = ADFS partition 1 on first drive.
 360  *              ..etc..
 361  */
 362 int
 363 adfspart_check_ICS(struct parsed_partitions *state, struct block_device *bdev)
 364 {
 365         const unsigned char *data;
 366         const struct ics_part *p;
 367         int slot;
 368         Sector sect;
 369
 370         /*
 371          * Try ICS style partitions - sector 0 contains partition info.
 372          */
 373         data = read_dev_sector(bdev, 0, &sect);
 374         if (!data)
 375                 return -1;
 376
 377         if (!valid_ics_sector(data)) {
 378                 put_dev_sector(sect);
 379                 return 0;
 380         }
 381
 382         printk(" [ICS]");
 383
 384         for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
 385                 u32 start = le32_to_cpu(p->start);
 386                 s32 size = le32_to_cpu(p->size); /* yes, it's signed. */
 387
 388                 if (slot == state->limit)
 389                         break;
 390
 391                 /*
 392                  * Negative sizes tell the RISC OS ICS driver to ignore
 393                  * this partition - in effect it says that this does not
 394                  * contain an ADFS filesystem.
 395                  */
 396                 if (size < 0) {
 397                         size = -size;
 398
 399                         /*
 400                          * Our own extension - We use the first sector
 401                          * of the partition to identify what type this
 402                          * partition is.  We must not make this visible
 403                          * to the filesystem.
 404                          */
 405                         if (size > 1 && adfspart_check_ICSLinux(bdev, start)) {
 406                                 start += 1;
 407                                 size -= 1;
 408                         }
 409                 }
 410
 411                 if (size)
 412                         put_partition(state, slot++, start, size);
 413         }
 414
 415         put_dev_sector(sect);
 416         printk("\n");
 417         return 1;
 418 }
 419 #endif
 420
 421 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
 422 struct ptec_part {
 423         __le32 unused1;
 424         __le32 unused2;
 425         __le32 start;
 426         __le32 size;
 427         __le32 unused5;
 428         char type[8];
 429 };
 430
 431 static inline int valid_ptec_sector(const unsigned char *data)
 432 {
 433         unsigned char checksum = 0x2a;
 434         int i;
 435
 436         /*
 437          * If it looks like a PC/BIOS partition, then it
 438          * probably isn't PowerTec.
 439          */
 440         if (data[510] == 0x55 && data[511] == 0xaa)
 441                 return 0;
 442
 443         for (i = 0; i < 511; i++)
 444                 checksum += data[i];
 445
 446         return checksum == data[511];
 447 }
 448
 449 /*
 450  * Purpose: allocate ICS partitions.
 451  * Params : hd          - pointer to gendisk structure to store partition info.
 452  *          dev         - device number to access.
 453  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 454  * Alloc  : hda  = whole drive
 455  *          hda1 = ADFS partition 0 on first drive.
 456  *          hda2 = ADFS partition 1 on first drive.
 457  *              ..etc..
 458  */
 459 int
 460 adfspart_check_POWERTEC(struct parsed_partitions *state, struct block_device *bdev)
 461 {
 462         Sector sect;
 463         const unsigned char *data;
 464         const struct ptec_part *p;
 465         int slot = 1;
 466         int i;
 467
 468         data = read_dev_sector(bdev, 0, &sect);
 469         if (!data)
 470                 return -1;
 471
 472         if (!valid_ptec_sector(data)) {
 473                 put_dev_sector(sect);
 474                 return 0;
 475         }
 476
 477         printk(" [POWERTEC]");
 478
 479         for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
 480                 u32 start = le32_to_cpu(p->start);
 481                 u32 size = le32_to_cpu(p->size);
 482
 483                 if (size)
 484                         put_partition(state, slot++, start, size);
 485         }
 486
 487         put_dev_sector(sect);
 488         printk("\n");
 489         return 1;
 490 }
 491 #endif
 492
 493 #ifdef CONFIG_ACORN_PARTITION_EESOX
 494 struct eesox_part {
 495         char    magic[6];
 496         char    name[10];
 497         __le32  start;
 498         __le32  unused6;
 499         __le32  unused7;
 500         __le32  unused8;
 501 };
 502
 503 /*
 504  * Guess who created this format?
 505  */
 506 static const char eesox_name[] = {
 507         'N', 'e', 'i', 'l', ' ',
 508         'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
 509 };
 510
 511 /*
 512  * EESOX SCSI partition format.
 513  *
 514  * This is a goddamned awful partition format.  We don't seem to store
 515  * the size of the partition in this table, only the start addresses.
 516  *
 517  * There are two possibilities where the size comes from:
 518  *  1. The individual ADFS boot block entries that are placed on the disk.
 519  *  2. The start address of the next entry.
 520  */
 521 int
 522 adfspart_check_EESOX(struct parsed_partitions *state, struct block_device *bdev)
 523 {
 524         Sector sect;
 525         const unsigned char *data;
 526         unsigned char buffer[256];
 527         struct eesox_part *p;
 528         sector_t start = 0;
 529         int i, slot = 1;
 530
 531         data = read_dev_sector(bdev, 7, &sect);
 532         if (!data)
 533                 return -1;
 534
 535         /*
 536          * "Decrypt" the partition table.  God knows why...
 537          */
 538         for (i = 0; i < 256; i++)
 539                 buffer[i] = data[i] ^ eesox_name[i & 15];
 540
 541         put_dev_sector(sect);
 542
 543         for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
 544                 sector_t next;
 545
 546                 if (memcmp(p->magic, "Eesox", 6))
 547                         break;
 548
 549                 next = le32_to_cpu(p->start);
 550                 if (i)
 551                         put_partition(state, slot++, start, next - start);
 552                 start = next;
 553         }
 554
 555         if (i != 0) {
 556                 sector_t size;
 557
 558                 size = get_capacity(bdev->bd_disk);
 559                 put_partition(state, slot++, start, size - start);
 560                 printk("\n");
 561         }
 562
 563         return i ? 1 : 0;
 564 }
 565 #endif