fs/partitions/mac.c

   1 /*
   2  *  fs/partitions/mac.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *  Copyright (C) 1991-1998  Linus Torvalds
   6  *  Re-organised Feb 1998 Russell King
   7  */
   8
   9 #include <linux/config.h>
  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/system.h>
  19
  20 #include "check.h"
  21 #include "mac.h"
  22
  23 #ifdef CONFIG_PPC
  24 extern void note_bootable_part(kdev_t dev, int part);
  25 #endif
  26
  27 /*
  28  * Code to understand MacOS partition tables.
  29  */
  30
  31 static inline void mac_fix_string(char *stg, int len)
  32 {
  33         int i;
  34
  35         for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
  36                 stg[i] = 0;
  37 }
  38
  39 int mac_partition(struct gendisk *hd, kdev_t dev, unsigned long fsec, int first_part_minor)
  40 {
  41         struct buffer_head *bh;
  42         int blk, blocks_in_map;
  43         int dev_bsize, dev_pos, pos;
  44         unsigned secsize;
  45 #ifdef CONFIG_PPC
  46         int found_root = 0;
  47         int found_root_goodness = 0;
  48 #endif
  49         struct mac_partition *part;
  50         struct mac_driver_desc *md;
  51
  52         dev_bsize = get_ptable_blocksize(dev);
  53         dev_pos = 0;
  54         /* Get 0th block and look at the first partition map entry. */
  55         if ((bh = bread(dev, 0, dev_bsize)) == 0) {
  56             printk("%s: error reading partition table\n",
  57                    kdevname(dev));
  58             return -1;
  59         }
  60         md = (struct mac_driver_desc *) bh->b_data;
  61         if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
  62                 brelse(bh);
  63                 return 0;
  64         }
  65         secsize = be16_to_cpu(md->block_size);
  66         if (secsize >= dev_bsize) {
  67                 brelse(bh);
  68                 dev_pos = secsize;
  69                 if ((bh = bread(dev, secsize/dev_bsize, dev_bsize)) == 0) {
  70                         printk("%s: error reading partition table\n",
  71                                kdevname(dev));
  72                         return -1;
  73                 }
  74         }
  75         part = (struct mac_partition *) (bh->b_data + secsize - dev_pos);
  76         if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
  77                 brelse(bh);
  78                 return 0;               /* not a MacOS disk */
  79         }
  80         blocks_in_map = be32_to_cpu(part->map_count);
  81         for (blk = 1; blk <= blocks_in_map; ++blk) {
  82                 pos = blk * secsize;
  83                 if (pos >= dev_pos + dev_bsize) {
  84                         brelse(bh);
  85                         dev_pos = pos;
  86                         if ((bh = bread(dev, pos/dev_bsize, dev_bsize)) == 0) {
  87                                 printk("%s: error reading partition table\n",
  88                                        kdevname(dev));
  89                                 return -1;
  90                         }
  91                 }
  92                 part = (struct mac_partition *) (bh->b_data + pos - dev_pos);
  93                 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
  94                         break;
  95                 blocks_in_map = be32_to_cpu(part->map_count);
  96                 add_gd_partition(hd, first_part_minor,
  97                         fsec + be32_to_cpu(part->start_block) * (secsize/512),
  98                         be32_to_cpu(part->block_count) * (secsize/512));
  99
 100 #ifdef CONFIG_PPC
 101                 /*
 102                  * If this is the first bootable partition, tell the
 103                  * setup code, in case it wants to make this the root.
 104                  */
 105                 if (_machine == _MACH_Pmac) {
 106                         int goodness = 0;
 107
 108                         mac_fix_string(part->processor, 16);
 109                         mac_fix_string(part->name, 32);
 110                         mac_fix_string(part->type, 32);
 111
 112                         if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
 113                             && strcasecmp(part->processor, "powerpc") == 0)
 114                                 goodness++;
 115
 116                         if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
 117                             || strcasecmp(part->type, "Linux_PPC") == 0) {
 118                                 int i, l;
 119
 120                                 goodness++;
 121                                 l = strlen(part->name);
 122                                 if (strcmp(part->name, "/") == 0)
 123                                         goodness++;
 124                                 for (i = 0; i <= l - 4; ++i) {
 125                                         if (strnicmp(part->name + i, "root",
 126                                                      4) == 0) {
 127                                                 goodness += 2;
 128                                                 break;
 129                                         }
 130                                 }
 131                                 if (strnicmp(part->name, "swap", 4) == 0)
 132                                         goodness--;
 133                         }
 134
 135                         if (goodness > found_root_goodness) {
 136                                 found_root = blk;
 137                                 found_root_goodness = goodness;
 138                         }
 139                 }
 140 #endif /* CONFIG_PPC */
 141
 142                 ++first_part_minor;
 143         }
 144 #ifdef CONFIG_PPC
 145         if (found_root_goodness)
 146                 note_bootable_part(dev, found_root);
 147 #endif
 148         brelse(bh);
 149         printk("\n");
 150         return 1;
 151 }
 152