1 /*
2 * fs/partitions/amiga.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/types.h>
11 #include <linux/affs_hardblocks.h>
12
13 #include "check.h"
14 #include "amiga.h"
15
16 static __inline__ u32
checksum_block(__be32 * m,int size)17 checksum_block(__be32 *m, int size)
18 {
19 u32 sum = 0;
20
21 while (size--)
22 sum += be32_to_cpu(*m++);
23 return sum;
24 }
25
26 int
amiga_partition(struct parsed_partitions * state,struct block_device * bdev)27 amiga_partition(struct parsed_partitions *state, struct block_device *bdev)
28 {
29 Sector sect;
30 unsigned char *data;
31 struct RigidDiskBlock *rdb;
32 struct PartitionBlock *pb;
33 int start_sect, nr_sects, blk, part, res = 0;
34 int blksize = 1; /* Multiplier for disk block size */
35 int slot = 1;
36 char b[BDEVNAME_SIZE];
37
38 for (blk = 0; ; blk++, put_dev_sector(sect)) {
39 if (blk == RDB_ALLOCATION_LIMIT)
40 goto rdb_done;
41 data = read_dev_sector(bdev, blk, §);
42 if (!data) {
43 if (warn_no_part)
44 printk("Dev %s: unable to read RDB block %d\n",
45 bdevname(bdev, b), blk);
46 res = -1;
47 goto rdb_done;
48 }
49 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
50 continue;
51
52 rdb = (struct RigidDiskBlock *)data;
53 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
54 break;
55 /* Try again with 0xdc..0xdf zeroed, Windows might have
56 * trashed it.
57 */
58 *(__be32 *)(data+0xdc) = 0;
59 if (checksum_block((__be32 *)data,
60 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
61 printk("Warning: Trashed word at 0xd0 in block %d "
62 "ignored in checksum calculation\n",blk);
63 break;
64 }
65
66 printk("Dev %s: RDB in block %d has bad checksum\n",
67 bdevname(bdev, b), blk);
68 }
69
70 /* blksize is blocks per 512 byte standard block */
71 blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
72
73 printk(" RDSK (%d)", blksize * 512); /* Be more informative */
74 blk = be32_to_cpu(rdb->rdb_PartitionList);
75 put_dev_sector(sect);
76 for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
77 blk *= blksize; /* Read in terms partition table understands */
78 data = read_dev_sector(bdev, blk, §);
79 if (!data) {
80 if (warn_no_part)
81 printk("Dev %s: unable to read partition block %d\n",
82 bdevname(bdev, b), blk);
83 res = -1;
84 goto rdb_done;
85 }
86 pb = (struct PartitionBlock *)data;
87 blk = be32_to_cpu(pb->pb_Next);
88 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
89 continue;
90 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
91 continue;
92
93 /* Tell Kernel about it */
94
95 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
96 be32_to_cpu(pb->pb_Environment[9])) *
97 be32_to_cpu(pb->pb_Environment[3]) *
98 be32_to_cpu(pb->pb_Environment[5]) *
99 blksize;
100 if (!nr_sects)
101 continue;
102 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
103 be32_to_cpu(pb->pb_Environment[3]) *
104 be32_to_cpu(pb->pb_Environment[5]) *
105 blksize;
106 put_partition(state,slot++,start_sect,nr_sects);
107 {
108 /* Be even more informative to aid mounting */
109 char dostype[4];
110 __be32 *dt = (__be32 *)dostype;
111 *dt = pb->pb_Environment[16];
112 if (dostype[3] < ' ')
113 printk(" (%c%c%c^%c)",
114 dostype[0], dostype[1],
115 dostype[2], dostype[3] + '@' );
116 else
117 printk(" (%c%c%c%c)",
118 dostype[0], dostype[1],
119 dostype[2], dostype[3]);
120 printk("(res %d spb %d)",
121 be32_to_cpu(pb->pb_Environment[6]),
122 be32_to_cpu(pb->pb_Environment[4]));
123 }
124 res = 1;
125 }
126 printk("\n");
127
128 rdb_done:
129 return res;
130 }
131