block/partitions/atari.c

   1 /*
   2  *  fs/partitions/atari.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *
   6  *  Copyright (C) 1991-1998  Linus Torvalds
   7  *  Re-organised Feb 1998 Russell King
   8  */
   9
  10 #include <linux/ctype.h>
  11 #include "check.h"
  12 #include "atari.h"
  13
  14 /* ++guenther: this should be settable by the user ("make config")?.
  15  */
  16 #define ICD_PARTS
  17
  18 /* check if a partition entry looks valid -- Atari format is assumed if at
  19    least one of the primary entries is ok this way */
  20 #define VALID_PARTITION(pi,hdsiz)                                            \
  21     (((pi)->flg & 1) &&                                                      \
  22      isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
  23      be32_to_cpu((pi)->st) <= (hdsiz) &&                                     \
  24      be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
  25
  26 static inline int OK_id(char *s)
  27 {
  28         return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
  29                 memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
  30                 memcmp (s, "RAW", 3) == 0 ;
  31 }
  32
  33 int atari_partition(struct parsed_partitions *state)
  34 {
  35         Sector sect;
  36         struct rootsector *rs;
  37         struct partition_info *pi;
  38         u32 extensect;
  39         u32 hd_size;
  40         int slot;
  41 #ifdef ICD_PARTS
  42         int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
  43 #endif
  44
  45         /*
  46          * ATARI partition scheme supports 512 lba only.  If this is not
  47          * the case, bail early to avoid miscalculating hd_size.
  48          */
  49         if (bdev_logical_block_size(state->bdev) != 512)
  50                 return 0;
  51
  52         rs = read_part_sector(state, 0, &sect);
  53         if (!rs)
  54                 return -1;
  55
  56         /* Verify this is an Atari rootsector: */
  57         hd_size = state->bdev->bd_inode->i_size >> 9;
  58         if (!VALID_PARTITION(&rs->part[0], hd_size) &&
  59             !VALID_PARTITION(&rs->part[1], hd_size) &&
  60             !VALID_PARTITION(&rs->part[2], hd_size) &&
  61             !VALID_PARTITION(&rs->part[3], hd_size)) {
  62                 /*
  63                  * if there's no valid primary partition, assume that no Atari
  64                  * format partition table (there's no reliable magic or the like
  65                  * :-()
  66                  */
  67                 put_dev_sector(sect);
  68                 return 0;
  69         }
  70
  71         pi = &rs->part[0];
  72         strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
  73         for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
  74                 struct rootsector *xrs;
  75                 Sector sect2;
  76                 ulong partsect;
  77
  78                 if ( !(pi->flg & 1) )
  79                         continue;
  80                 /* active partition */
  81                 if (memcmp (pi->id, "XGM", 3) != 0) {
  82                         /* we don't care about other id's */
  83                         put_partition (state, slot, be32_to_cpu(pi->st),
  84                                         be32_to_cpu(pi->siz));
  85                         continue;
  86                 }
  87                 /* extension partition */
  88 #ifdef ICD_PARTS
  89                 part_fmt = 1;
  90 #endif
  91                 strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
  92                 partsect = extensect = be32_to_cpu(pi->st);
  93                 while (1) {
  94                         xrs = read_part_sector(state, partsect, &sect2);
  95                         if (!xrs) {
  96                                 printk (" block %ld read failed\n", partsect);
  97                                 put_dev_sector(sect);
  98                                 return -1;
  99                         }
 100
 101                         /* ++roman: sanity check: bit 0 of flg field must be set */
 102                         if (!(xrs->part[0].flg & 1)) {
 103                                 printk( "\nFirst sub-partition in extended partition is not valid!\n" );
 104                                 put_dev_sector(sect2);
 105                                 break;
 106                         }
 107
 108                         put_partition(state, slot,
 109                                    partsect + be32_to_cpu(xrs->part[0].st),
 110                                    be32_to_cpu(xrs->part[0].siz));
 111
 112                         if (!(xrs->part[1].flg & 1)) {
 113                                 /* end of linked partition list */
 114                                 put_dev_sector(sect2);
 115                                 break;
 116                         }
 117                         if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
 118                                 printk("\nID of extended partition is not XGM!\n");
 119                                 put_dev_sector(sect2);
 120                                 break;
 121                         }
 122
 123                         partsect = be32_to_cpu(xrs->part[1].st) + extensect;
 124                         put_dev_sector(sect2);
 125                         if (++slot == state->limit) {
 126                                 printk( "\nMaximum number of partitions reached!\n" );
 127                                 break;
 128                         }
 129                 }
 130                 strlcat(state->pp_buf, " >", PAGE_SIZE);
 131         }
 132 #ifdef ICD_PARTS
 133         if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
 134                 pi = &rs->icdpart[0];
 135                 /* sanity check: no ICD format if first partition invalid */
 136                 if (OK_id(pi->id)) {
 137                         strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
 138                         for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
 139                                 /* accept only GEM,BGM,RAW,LNX,SWP partitions */
 140                                 if (!((pi->flg & 1) && OK_id(pi->id)))
 141                                         continue;
 142                                 part_fmt = 2;
 143                                 put_partition (state, slot,
 144                                                 be32_to_cpu(pi->st),
 145                                                 be32_to_cpu(pi->siz));
 146                         }
 147                         strlcat(state->pp_buf, " >", PAGE_SIZE);
 148                 }
 149         }
 150 #endif
 151         put_dev_sector(sect);
 152
 153         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 154
 155         return 1;
 156 }