root/arch/m68k/amiga/amipart.c

/* */

DEFINITIONS

1. checksum
2. amiga_check_partition

   1 /*
   2  * linux/amiga/amipart.c
   3  *
   4  * Amiga partition checking driver for 680x0 Linux
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file README.legal in the main directory of this archive
   8  * for more details.
   9  */
  10 
  11 #include <linux/fs.h>
  12 #include <linux/genhd.h>
  13 #include <linux/kernel.h>
  14 
  15 #include <asm/amigardb.h>
  16 #include <asm/machdep.h>
  17 
  18 extern int current_minor;
  19 
  20 static ulong checksum (ulong *ptr, int len)
     /*  */
  21 {
  22         ulong sum;
  23         int cnt;
  24 
  25         for (sum = 0, cnt = 0; cnt < len; cnt++)
  26                 sum += ptr[cnt];
  27 
  28         return sum;
  29 }
  30 
  31 /* XXX */
  32 /* int current_minor = 0; */
  33 
  34 void amiga_check_partition(struct gendisk *hd, kdev_t dev)
     /*  */
  35 {
  36         int i, minor = current_minor, m_lim = current_minor + hd->max_p;
  37         struct buffer_head *bh;
  38         struct RigidDiskBlock *rdb;
  39         struct PartitionBlock *pb;
  40         ulong bnum, partsect;
  41 
  42         for (bnum = 0; bnum < RDB_LOCATION_LIMIT/2; bnum++) {
  43                 if (!(bh = bread(dev,bnum,1024))) {
  44                         printk (" unable to read block %ld\n", bnum);
  45                         return;
  46                 }
  47 #ifdef DEBUG
  48                 printk ("block read, press mousebutton to continue\n");
  49                 waitbut();
  50 #endif
  51                 rdb = (struct RigidDiskBlock *)bh->b_data;
  52                 if (rdb->rdb_ID == IDNAME_RIGIDDISK)
  53                         break;
  54                 rdb = (struct RigidDiskBlock *)&bh->b_data[512];
  55                 if (rdb->rdb_ID == IDNAME_RIGIDDISK)
  56                         break;
  57                 brelse (bh);
  58         }
  59         if (bnum == RDB_LOCATION_LIMIT/2) {
  60                 /* no RDB on the disk! */
  61                 printk (" unable to find RigidDiskBlock\n");
  62                 return;
  63         }
  64 
  65         /* checksum the RigidDiskBlock */
  66         if (checksum ((ulong *)rdb, rdb->rdb_SummedLongs) != 0) {
  67                 printk (" RDB checksum bad\n");
  68                 return;
  69         }
  70 
  71         printk("  %s%c:", hd->major_name, 'a'+(minor >> hd->minor_shift));
  72 
  73         partsect = rdb->rdb_PartitionList;
  74         brelse (bh);
  75 
  76         for (i = 1; minor < m_lim && partsect != 0xffffffff; minor++, i++)
  77         {
  78                 ulong *env;
  79 
  80                 if (!(bh = bread(dev,partsect/2,1024))) {
  81                         printk (" block %ld read failed\n", partsect);
  82                         return;
  83                 }
  84 #ifdef DEBUG
  85                 printk ("block read, press mousebutton to continue\n");
  86                 waitbut();
  87 #endif
  88                 pb = (struct PartitionBlock *)bh->b_data;
  89                 if (partsect & 1)
  90                         pb = (struct PartitionBlock *)&bh->b_data[512];
  91                 if (pb->pb_ID != IDNAME_PARTITION) {
  92                         printk (" block %ld Not a partition block (%#lx)\n",
  93                                 partsect, pb->pb_ID);
  94                         brelse (bh);
  95                         return;
  96                 }
  97                 if (checksum ((ulong *)pb, pb->pb_SummedLongs) != 0) {
  98                         printk (" block %ld checksum bad\n", partsect);
  99                         brelse (bh);
 100                         return;
 101                 }
 102 
 103                 env = pb->pb_Environment;
 104 
 105                 hd->part[minor].start_sect = env[DE_LOWCYL]
 106                         * env[DE_NUMHEADS] * env[DE_BLKSPERTRACK];
 107                 hd->part[minor].nr_sects = (env[DE_UPPERCYL]
 108                                             - env[DE_LOWCYL] + 1)
 109                         * env[DE_NUMHEADS] * env[DE_BLKSPERTRACK];
 110 
 111                 printk(" %s%c%d", hd->major_name,
 112                        'a'+(minor >> hd->minor_shift), i);
 113 
 114                 partsect = pb->pb_Next;
 115                 brelse (bh);
 116         }
 117 
 118         printk ("\n");
 119 }

/* */