disk/scsi.c

   1 /* scsi.c - scsi support.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2008  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/disk.h>
  21 #include <grub/dl.h>
  22 #include <grub/kernel.h>
  23 #include <grub/misc.h>
  24 #include <grub/mm.h>
  25 #include <grub/types.h>
  26 #include <grub/machine/kernel.h>
  27 #include <grub/scsi.h>
  28 #include <grub/scsicmd.h>
  29
  30 \f
  31 static grub_scsi_dev_t grub_scsi_dev_list;
  32
  33 void
  34 grub_scsi_dev_register (grub_scsi_dev_t dev)
  35 {
  36   dev->next = grub_scsi_dev_list;
  37   grub_scsi_dev_list = dev;
  38 }
  39
  40 void
  41 grub_scsi_dev_unregister (grub_scsi_dev_t dev)
  42 {
  43   grub_scsi_dev_t *p, q;
  44
  45   for (p = &grub_scsi_dev_list, q = *p; q; p = &(q->next), q = q->next)
  46     if (q == dev)
  47       {
  48         *p = q->next;
  49         break;
  50       }
  51 }
  52
  53 \f
  54 /* Determine the the device is removable and the type of the device
  55    SCSI.  */
  56 static grub_err_t
  57 grub_scsi_inquiry (grub_scsi_t scsi)
  58 {
  59   struct grub_scsi_inquiry iq;
  60   struct grub_scsi_inquiry_data iqd;
  61   grub_err_t err;
  62
  63   iq.opcode = grub_scsi_cmd_inquiry;
  64   iq.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
  65   iq.reserved = 0;
  66   iq.alloc_length = 0x24; /* XXX: Hardcoded for now */
  67   iq.reserved2 = 0;
  68
  69   err = scsi->dev->read (scsi, sizeof (iq), (char *) &iq,
  70                          sizeof (iqd), (char *) &iqd);
  71   if (err)
  72     return err;
  73
  74   scsi->devtype = iqd.devtype & GRUB_SCSI_DEVTYPE_MASK;
  75   scsi->removable = iqd.rmb >> GRUB_SCSI_REMOVABLE_BIT;
  76
  77   return GRUB_ERR_NONE;
  78 }
  79
  80 /* Read the capacity and block size of SCSI.  */
  81 static grub_err_t
  82 grub_scsi_read_capacity (grub_scsi_t scsi)
  83 {
  84   struct grub_scsi_read_capacity rc;
  85   struct grub_scsi_read_capacity_data rcd;
  86   grub_err_t err;
  87
  88   rc.opcode = grub_scsi_cmd_read_capacity;
  89   rc.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
  90   grub_memset (rc.reserved, 0, sizeof (rc.reserved));
  91
  92   err = scsi->dev->read (scsi, sizeof (rc), (char *) &rc,
  93                          sizeof (rcd), (char *) &rcd);
  94   if (err)
  95     return err;
  96
  97   scsi->size = grub_be_to_cpu32 (rcd.size);
  98   scsi->blocksize = grub_be_to_cpu32 (rcd.blocksize);
  99
 100   return GRUB_ERR_NONE;
 101 }
 102
 103 /* Send a SCSI request for DISK: read SIZE sectors starting with
 104    sector SECTOR to BUF.  */
 105 static grub_err_t
 106 grub_scsi_read10 (grub_disk_t disk, grub_disk_addr_t sector,
 107                   grub_size_t size, char *buf)
 108 {
 109   grub_scsi_t scsi;
 110   struct grub_scsi_read10 rd;
 111
 112   scsi = disk->data;
 113
 114   rd.opcode = grub_scsi_cmd_read10;
 115   rd.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
 116   rd.lba = grub_cpu_to_be32 (sector);
 117   rd.reserved = 0;
 118   rd.size = grub_cpu_to_be16 (size);
 119   rd.reserved2 = 0;
 120   rd.pad = 0;
 121
 122   return scsi->dev->read (scsi, sizeof (rd), (char *) &rd, size * scsi->blocksize, buf);
 123 }
 124
 125 /* Send a SCSI request for DISK: read SIZE sectors starting with
 126    sector SECTOR to BUF.  */
 127 static grub_err_t
 128 grub_scsi_read12 (grub_disk_t disk, grub_disk_addr_t sector,
 129                   grub_size_t size, char *buf)
 130 {
 131   grub_scsi_t scsi;
 132   struct grub_scsi_read12 rd;
 133
 134   scsi = disk->data;
 135
 136   rd.opcode = grub_scsi_cmd_read12;
 137   rd.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
 138   rd.lba = grub_cpu_to_be32 (sector);
 139   rd.size = grub_cpu_to_be32 (size);
 140   rd.reserved = 0;
 141   rd.control = 0;
 142
 143   return scsi->dev->read (scsi, sizeof (rd), (char *) &rd, size * scsi->blocksize, buf);
 144 }
 145
 146 #if 0
 147 /* Send a SCSI request for DISK: write the data stored in BUF to SIZE
 148    sectors starting with SECTOR.  */
 149 static grub_err_t
 150 grub_scsi_write10 (grub_disk_t disk, grub_disk_addr_t sector,
 151                    grub_size_t size, char *buf)
 152 {
 153   grub_scsi_t scsi;
 154   struct grub_scsi_write10 wr;
 155
 156   scsi = disk->data;
 157
 158   wr.opcode = grub_scsi_cmd_write10;
 159   wr.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
 160   wr.lba = grub_cpu_to_be32 (sector);
 161   wr.reserved = 0;
 162   wr.size = grub_cpu_to_be16 (size);
 163   wr.reserved2 = 0;
 164   wr.pad = 0;
 165
 166   return scsi->dev->write (scsi, sizeof (wr), (char *) &wr, size * scsi->blocksize, buf);
 167 }
 168
 169 /* Send a SCSI request for DISK: write the data stored in BUF to SIZE
 170    sectors starting with SECTOR.  */
 171 static grub_err_t
 172 grub_scsi_write12 (grub_disk_t disk, grub_disk_addr_t sector,
 173                    grub_size_t size, char *buf)
 174 {
 175   grub_scsi_t scsi;
 176   struct grub_scsi_write10 wr;
 177
 178   scsi = disk->data;
 179
 180   wr.opcode = grub_scsi_cmd_write12;
 181   wr.lun = scsi->lun << GRUB_SCSI_LUN_SHIFT;
 182   wr.lba = grub_cpu_to_be32 (sector);
 183   wr.size = grub_cpu_to_be32 (size);
 184   wr.reserved = 0;
 185   wr.pad = 0;
 186
 187   return scsi->dev->write (scsi, sizeof (wr), (char *) &wr, size * scsi->blocksize, buf);
 188 }
 189 #endif
 190
 191 \f
 192 static int
 193 grub_scsi_iterate (int (*hook) (const char *name))
 194 {
 195   grub_scsi_dev_t p;
 196
 197   auto int scsi_iterate (const char *name, int luns);
 198
 199   int scsi_iterate (const char *name, int luns)
 200     {
 201       char sname[40];
 202       int i;
 203
 204       /* In case of a single LUN, just return `usbX'.  */
 205       if (luns == 1)
 206         return hook (name);
 207
 208       /* In case of multiple LUNs, every LUN will get a prefix to
 209          distinguish it.  */
 210       for (i = 0; i < luns; i++)
 211         {
 212           grub_sprintf (sname, "%s%c", name, 'a' + i);
 213           if (hook (sname))
 214             return 1;
 215         }
 216       return 0;
 217     }
 218
 219   for (p = grub_scsi_dev_list; p; p = p->next)
 220     if (p->iterate && (p->iterate) (scsi_iterate))
 221       return 1;
 222
 223   return 0;
 224 }
 225
 226 static grub_err_t
 227 grub_scsi_open (const char *name, grub_disk_t disk)
 228 {
 229   grub_scsi_dev_t p;
 230   grub_scsi_t scsi;
 231   grub_err_t err;
 232   int len;
 233   int lun;
 234
 235   scsi = grub_malloc (sizeof (*scsi));
 236   if (! scsi)
 237     return grub_errno;
 238
 239   len = grub_strlen (name);
 240   lun = name[len - 1] - 'a';
 241
 242   /* Try to detect a LUN ('a'-'z'), otherwise just use the first
 243      LUN.  */
 244   if (lun < 0 || lun > 26)
 245     lun = 0;
 246
 247   for (p = grub_scsi_dev_list; p; p = p->next)
 248     {
 249       if (p->open (name, scsi))
 250         continue;
 251
 252       disk->id = (unsigned long) "scsi"; /* XXX */
 253       disk->data = scsi;
 254       scsi->dev = p;
 255       scsi->lun = lun;
 256       scsi->name = grub_strdup (name);
 257       if (! scsi->name)
 258         {
 259           grub_free (scsi);
 260           return grub_errno;
 261         }
 262
 263       grub_dprintf ("scsi", "dev opened\n");
 264
 265       err = grub_scsi_inquiry (scsi);
 266       if (err)
 267         {
 268           grub_free (scsi);
 269           grub_dprintf ("scsi", "inquiry failed\n");
 270           return err;
 271         }
 272
 273       grub_dprintf ("scsi", "inquiry: devtype=0x%02x removable=%d\n",
 274                     scsi->devtype, scsi->removable);
 275
 276       /* Try to be conservative about the device types
 277          supported.  */
 278       if (scsi->devtype != grub_scsi_devtype_direct
 279           && scsi->devtype != grub_scsi_devtype_cdrom)
 280         {
 281           grub_free (scsi);
 282           return grub_error (GRUB_ERR_UNKNOWN_DEVICE,
 283                              "unknown SCSI device");
 284         }
 285
 286       if (scsi->devtype == grub_scsi_devtype_cdrom)
 287         disk->has_partitions = 0;
 288       else
 289         disk->has_partitions = 1;
 290
 291       err = grub_scsi_read_capacity (scsi);
 292       if (err)
 293         {
 294           grub_free (scsi);
 295           grub_dprintf ("scsi", "READ CAPACITY failed\n");
 296           return err;
 297         }
 298
 299       /* SCSI blocks can be something else than 512, although GRUB
 300          wants 512 byte blocks.  */
 301       disk->total_sectors = ((scsi->size * scsi->blocksize)
 302                              << GRUB_DISK_SECTOR_BITS);
 303
 304       grub_dprintf ("scsi", "capacity=%llu, blksize=%d\n",
 305                     (unsigned long long) disk->total_sectors,
 306                     scsi->blocksize);
 307
 308       return GRUB_ERR_NONE;
 309     }
 310
 311   grub_free (scsi);
 312
 313   return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a SCSI disk");
 314 }
 315
 316 static void
 317 grub_scsi_close (grub_disk_t disk)
 318 {
 319   grub_scsi_t scsi;
 320
 321   scsi = disk->data;
 322   scsi->dev->close (scsi);
 323   grub_free (scsi);
 324 }
 325
 326 static grub_err_t
 327 grub_scsi_read (grub_disk_t disk, grub_disk_addr_t sector,
 328                 grub_size_t size, char *buf)
 329 {
 330   grub_scsi_t scsi;
 331
 332   /* SCSI sectors are variable in size.  GRUB uses 512 byte
 333      sectors.  */
 334   if (scsi->blocksize != GRUB_DISK_SECTOR_SIZE)
 335     {
 336       unsigned spb = scsi->blocksize >> GRUB_DISK_SECTOR_BITS;
 337       grub_uint32_t sector_mod;
 338
 339       if (! (spb != 0 && (scsi->blocksize & GRUB_DISK_SECTOR_SIZE) == 0))
 340         return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 341                            "Unsupported SCSI block size");
 342
 343       sector_mod = 0;
 344       sector = grub_divmod64 (sector, spb, &sector_mod);
 345
 346       if (! (sector_mod == 0 && size % spb == 0))
 347         return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 348                            "Unaligned SCSI read not supported");
 349
 350       size /= spb;
 351     }
 352
 353   scsi = disk->data;
 354
 355   /* Depending on the type, select a read function.  */
 356   switch (scsi->devtype)
 357     {
 358     case grub_scsi_devtype_direct:
 359       return grub_scsi_read10 (disk, sector, size, buf);
 360
 361     case grub_scsi_devtype_cdrom:
 362       return grub_scsi_read12 (disk, sector, size, buf);
 363     }
 364
 365   /* XXX: Never reached.  */
 366   return GRUB_ERR_NONE;
 367 }
 368
 369 static grub_err_t
 370 grub_scsi_write (grub_disk_t disk __attribute((unused)),
 371                  grub_disk_addr_t sector __attribute((unused)),
 372                  grub_size_t size __attribute((unused)),
 373                  const char *buf __attribute((unused)))
 374 {
 375 #if 0
 376   /* XXX: Not tested yet!  */
 377
 378   /* XXX: This should depend on the device type?  */
 379   return grub_scsi_write10 (disk, sector, size, buf);
 380 #endif
 381   return GRUB_ERR_NOT_IMPLEMENTED_YET;
 382 }
 383
 384
 385 static struct grub_disk_dev grub_scsi_dev =
 386   {
 387     .name = "scsi",
 388     .id = GRUB_DISK_DEVICE_SCSI_ID,
 389     .iterate = grub_scsi_iterate,
 390     .open = grub_scsi_open,
 391     .close = grub_scsi_close,
 392     .read = grub_scsi_read,
 393     .write = grub_scsi_write,
 394     .next = 0
 395   };
 396
 397 GRUB_MOD_INIT(scsi)
 398 {
 399   grub_disk_dev_register (&grub_scsi_dev);
 400 }
 401
 402 GRUB_MOD_FINI(scsi)
 403 {
 404   grub_disk_dev_unregister (&grub_scsi_dev);
 405 }