xref: /linux/block/partitions/sysv68.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  fs/partitions/sysv68.c
4  *
5  *  Copyright (C) 2007 Philippe De Muyter <phdm@macqel.be>
6  */
7 
8 #include "check.h"
9 
10 /*
11  *	Volume ID structure: on first 256-bytes sector of disk
12  */
13 
14 struct volumeid {
15 	u8	vid_unused[248];
16 	u8	vid_mac[8];	/* ASCII string "MOTOROLA" */
17 };
18 
19 /*
20  *	config block: second 256-bytes sector on disk
21  */
22 
23 struct dkconfig {
24 	u8	ios_unused0[128];
25 	__be32	ios_slcblk;	/* Slice table block number */
26 	__be16	ios_slccnt;	/* Number of entries in slice table */
27 	u8	ios_unused1[122];
28 };
29 
30 /*
31  *	combined volumeid and dkconfig block
32  */
33 
34 struct dkblk0 {
35 	struct volumeid dk_vid;
36 	struct dkconfig dk_ios;
37 };
38 
39 /*
40  *	Slice Table Structure
41  */
42 
43 struct slice {
44 	__be32	nblocks;		/* slice size (in blocks) */
45 	__be32	blkoff;			/* block offset of slice */
46 };
47 
48 
49 int sysv68_partition(struct parsed_partitions *state)
50 {
51 	int i, slices;
52 	int slot = 1;
53 	Sector sect;
54 	unsigned char *data;
55 	struct dkblk0 *b;
56 	struct slice *slice;
57 	char tmp[64];
58 
59 	data = read_part_sector(state, 0, &sect);
60 	if (!data)
61 		return -1;
62 
63 	b = (struct dkblk0 *)data;
64 	if (memcmp(b->dk_vid.vid_mac, "MOTOROLA", sizeof(b->dk_vid.vid_mac))) {
65 		put_dev_sector(sect);
66 		return 0;
67 	}
68 	slices = be16_to_cpu(b->dk_ios.ios_slccnt);
69 	i = be32_to_cpu(b->dk_ios.ios_slcblk);
70 	put_dev_sector(sect);
71 
72 	data = read_part_sector(state, i, &sect);
73 	if (!data)
74 		return -1;
75 
76 	slices -= 1; /* last slice is the whole disk */
77 	snprintf(tmp, sizeof(tmp), "sysV68: %s(s%u)", state->name, slices);
78 	strlcat(state->pp_buf, tmp, PAGE_SIZE);
79 	slice = (struct slice *)data;
80 	for (i = 0; i < slices; i++, slice++) {
81 		if (slot == state->limit)
82 			break;
83 		if (be32_to_cpu(slice->nblocks)) {
84 			put_partition(state, slot,
85 				be32_to_cpu(slice->blkoff),
86 				be32_to_cpu(slice->nblocks));
87 			snprintf(tmp, sizeof(tmp), "(s%u)", i);
88 			strlcat(state->pp_buf, tmp, PAGE_SIZE);
89 		}
90 		slot++;
91 	}
92 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
93 	put_dev_sector(sect);
94 	return 1;
95 }
96