xref: /linux/block/partitions/amiga.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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
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)
27 {
28 	Sector sect;
29 	unsigned char *data;
30 	struct RigidDiskBlock *rdb;
31 	struct PartitionBlock *pb;
32 	int start_sect, nr_sects, blk, part, res = 0;
33 	int blksize = 1;	/* Multiplier for disk block size */
34 	int slot = 1;
35 	char b[BDEVNAME_SIZE];
36 
37 	for (blk = 0; ; blk++, put_dev_sector(sect)) {
38 		if (blk == RDB_ALLOCATION_LIMIT)
39 			goto rdb_done;
40 		data = read_part_sector(state, blk, &sect);
41 		if (!data) {
42 			if (warn_no_part)
43 				printk("Dev %s: unable to read RDB block %d\n",
44 				       bdevname(state->bdev, b), blk);
45 			res = -1;
46 			goto rdb_done;
47 		}
48 		if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
49 			continue;
50 
51 		rdb = (struct RigidDiskBlock *)data;
52 		if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
53 			break;
54 		/* Try again with 0xdc..0xdf zeroed, Windows might have
55 		 * trashed it.
56 		 */
57 		*(__be32 *)(data+0xdc) = 0;
58 		if (checksum_block((__be32 *)data,
59 				be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
60 			printk("Warning: Trashed word at 0xd0 in block %d "
61 				"ignored in checksum calculation\n",blk);
62 			break;
63 		}
64 
65 		printk("Dev %s: RDB in block %d has bad checksum\n",
66 		       bdevname(state->bdev, b), blk);
67 	}
68 
69 	/* blksize is blocks per 512 byte standard block */
70 	blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
71 
72 	{
73 		char tmp[7 + 10 + 1 + 1];
74 
75 		/* Be more informative */
76 		snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
77 		strlcat(state->pp_buf, tmp, PAGE_SIZE);
78 	}
79 	blk = be32_to_cpu(rdb->rdb_PartitionList);
80 	put_dev_sector(sect);
81 	for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
82 		blk *= blksize;	/* Read in terms partition table understands */
83 		data = read_part_sector(state, blk, &sect);
84 		if (!data) {
85 			if (warn_no_part)
86 				printk("Dev %s: unable to read partition block %d\n",
87 				       bdevname(state->bdev, b), blk);
88 			res = -1;
89 			goto rdb_done;
90 		}
91 		pb  = (struct PartitionBlock *)data;
92 		blk = be32_to_cpu(pb->pb_Next);
93 		if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
94 			continue;
95 		if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
96 			continue;
97 
98 		/* Tell Kernel about it */
99 
100 		nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
101 			    be32_to_cpu(pb->pb_Environment[9])) *
102 			   be32_to_cpu(pb->pb_Environment[3]) *
103 			   be32_to_cpu(pb->pb_Environment[5]) *
104 			   blksize;
105 		if (!nr_sects)
106 			continue;
107 		start_sect = be32_to_cpu(pb->pb_Environment[9]) *
108 			     be32_to_cpu(pb->pb_Environment[3]) *
109 			     be32_to_cpu(pb->pb_Environment[5]) *
110 			     blksize;
111 		put_partition(state,slot++,start_sect,nr_sects);
112 		{
113 			/* Be even more informative to aid mounting */
114 			char dostype[4];
115 			char tmp[42];
116 
117 			__be32 *dt = (__be32 *)dostype;
118 			*dt = pb->pb_Environment[16];
119 			if (dostype[3] < ' ')
120 				snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
121 					dostype[0], dostype[1],
122 					dostype[2], dostype[3] + '@' );
123 			else
124 				snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
125 					dostype[0], dostype[1],
126 					dostype[2], dostype[3]);
127 			strlcat(state->pp_buf, tmp, PAGE_SIZE);
128 			snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
129 				be32_to_cpu(pb->pb_Environment[6]),
130 				be32_to_cpu(pb->pb_Environment[4]));
131 			strlcat(state->pp_buf, tmp, PAGE_SIZE);
132 		}
133 		res = 1;
134 	}
135 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
136 
137 rdb_done:
138 	return res;
139 }
140