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