fs/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/fs.h>
  11 #include <linux/genhd.h>
  12 #include <linux/kernel.h>
  13 #include <linux/major.h>
  14 #include <linux/string.h>
  15 #include <linux/blk.h>
  16 #include <linux/ctype.h>
  17
  18 #include <asm/byteorder.h>
  19 #include <asm/system.h>
  20
  21 #include "check.h"
  22 #include "atari.h"
  23
  24 /* ++guenther: this should be settable by the user ("make config")?.
  25  */
  26 #define ICD_PARTS
  27
  28 /* check if a partition entry looks valid -- Atari format is assumed if at
  29    least one of the primary entries is ok this way */
  30 #define VALID_PARTITION(pi,hdsiz)                                            \
  31     (((pi)->flg & 1) &&                                                      \
  32      isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
  33      be32_to_cpu((pi)->st) <= (hdsiz) &&                                     \
  34      be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
  35
  36 static inline int OK_id(char *s)
  37 {
  38         return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
  39                 memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
  40                 memcmp (s, "RAW", 3) == 0 ;
  41 }
  42
  43 int atari_partition (struct gendisk *hd, struct block_device *bdev,
  44                      unsigned long first_sector, int minor)
  45 {
  46         int m_lim = minor + hd->max_p;
  47         Sector sect;
  48         struct rootsector *rs;
  49         struct partition_info *pi;
  50         u32 extensect;
  51         u32 hd_size;
  52 #ifdef ICD_PARTS
  53         int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
  54 #endif
  55
  56         rs = (struct rootsector *) read_dev_sector(bdev, 0, &sect);
  57         if (!rs)
  58                 return -1;
  59
  60         /* Verify this is an Atari rootsector: */
  61         hd_size = hd->part[minor - 1].nr_sects;
  62         if (!VALID_PARTITION(&rs->part[0], hd_size) &&
  63             !VALID_PARTITION(&rs->part[1], hd_size) &&
  64             !VALID_PARTITION(&rs->part[2], hd_size) &&
  65             !VALID_PARTITION(&rs->part[3], hd_size)) {
  66                 /*
  67                  * if there's no valid primary partition, assume that no Atari
  68                  * format partition table (there's no reliable magic or the like
  69                  * :-()
  70                  */
  71                 put_dev_sector(sect);
  72                 return 0;
  73         }
  74
  75         pi = &rs->part[0];
  76         printk (" AHDI");
  77         for (; pi < &rs->part[4] && minor < m_lim; minor++, pi++) {
  78                 struct rootsector *xrs;
  79                 Sector sect2;
  80                 ulong partsect;
  81
  82                 if ( !(pi->flg & 1) )
  83                         continue;
  84                 /* active partition */
  85                 if (memcmp (pi->id, "XGM", 3) != 0) {
  86                         /* we don't care about other id's */
  87                         add_gd_partition (hd, minor, be32_to_cpu(pi->st),
  88                                         be32_to_cpu(pi->siz));
  89                         continue;
  90                 }
  91                 /* extension partition */
  92 #ifdef ICD_PARTS
  93                 part_fmt = 1;
  94 #endif
  95                 printk(" XGM<");
  96                 partsect = extensect = be32_to_cpu(pi->st);
  97                 while (1) {
  98                         xrs = (struct rootsector *)read_dev_sector(bdev, partsect, &sect2);
  99                         if (!xrs) {
 100                                 printk (" block %ld read failed\n", partsect);
 101                                 put_dev_sector(sect);
 102                                 return 0;
 103                         }
 104
 105                         /* ++roman: sanity check: bit 0 of flg field must be set */
 106                         if (!(xrs->part[0].flg & 1)) {
 107                                 printk( "\nFirst sub-partition in extended partition is not valid!\n" );
 108                                 put_dev_sector(sect2);
 109                                 break;
 110                         }
 111
 112                         add_gd_partition(hd, minor,
 113                                    partsect + be32_to_cpu(xrs->part[0].st),
 114                                    be32_to_cpu(xrs->part[0].siz));
 115
 116                         if (!(xrs->part[1].flg & 1)) {
 117                                 /* end of linked partition list */
 118                                 put_dev_sector(sect2);
 119                                 break;
 120                         }
 121                         if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
 122                                 printk("\nID of extended partition is not XGM!\n");
 123                                 put_dev_sector(sect2);
 124                                 break;
 125                         }
 126
 127                         partsect = be32_to_cpu(xrs->part[1].st) + extensect;
 128                         put_dev_sector(sect2);
 129                         minor++;
 130                         if (minor >= m_lim) {
 131                                 printk( "\nMaximum number of partitions reached!\n" );
 132                                 break;
 133                         }
 134                 }
 135                 printk(" >");
 136         }
 137 #ifdef ICD_PARTS
 138         if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
 139                 pi = &rs->icdpart[0];
 140                 /* sanity check: no ICD format if first partition invalid */
 141                 if (OK_id(pi->id)) {
 142                         printk(" ICD<");
 143                         for (; pi < &rs->icdpart[8] && minor < m_lim; minor++, pi++) {
 144                                 /* accept only GEM,BGM,RAW,LNX,SWP partitions */
 145                                 if (!((pi->flg & 1) && OK_id(pi->id)))
 146                                         continue;
 147                                 part_fmt = 2;
 148                                 add_gd_partition (hd, minor,
 149                                                 be32_to_cpu(pi->st),
 150                                                 be32_to_cpu(pi->siz));
 151                         }
 152                         printk(" >");
 153                 }
 154         }
 155 #endif
 156         put_dev_sector(sect);
 157
 158         printk ("\n");
 159
 160         return 1;
 161 }
 162