xref: /linux/block/partitions/atari.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
1 /*
2  *  fs/partitions/atari.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/ctype.h>
11 #include "check.h"
12 #include "atari.h"
13 
14 /* ++guenther: this should be settable by the user ("make config")?.
15  */
16 #define ICD_PARTS
17 
18 /* check if a partition entry looks valid -- Atari format is assumed if at
19    least one of the primary entries is ok this way */
20 #define	VALID_PARTITION(pi,hdsiz)					     \
21     (((pi)->flg & 1) &&							     \
22      isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
23      be32_to_cpu((pi)->st) <= (hdsiz) &&				     \
24      be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
25 
26 static inline int OK_id(char *s)
27 {
28 	return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
29 		memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
30 		memcmp (s, "RAW", 3) == 0 ;
31 }
32 
33 int atari_partition(struct parsed_partitions *state)
34 {
35 	Sector sect;
36 	struct rootsector *rs;
37 	struct partition_info *pi;
38 	u32 extensect;
39 	u32 hd_size;
40 	int slot;
41 #ifdef ICD_PARTS
42 	int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
43 #endif
44 
45 	rs = read_part_sector(state, 0, &sect);
46 	if (!rs)
47 		return -1;
48 
49 	/* Verify this is an Atari rootsector: */
50 	hd_size = state->bdev->bd_inode->i_size >> 9;
51 	if (!VALID_PARTITION(&rs->part[0], hd_size) &&
52 	    !VALID_PARTITION(&rs->part[1], hd_size) &&
53 	    !VALID_PARTITION(&rs->part[2], hd_size) &&
54 	    !VALID_PARTITION(&rs->part[3], hd_size)) {
55 		/*
56 		 * if there's no valid primary partition, assume that no Atari
57 		 * format partition table (there's no reliable magic or the like
58 	         * :-()
59 		 */
60 		put_dev_sector(sect);
61 		return 0;
62 	}
63 
64 	pi = &rs->part[0];
65 	strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
66 	for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
67 		struct rootsector *xrs;
68 		Sector sect2;
69 		ulong partsect;
70 
71 		if ( !(pi->flg & 1) )
72 			continue;
73 		/* active partition */
74 		if (memcmp (pi->id, "XGM", 3) != 0) {
75 			/* we don't care about other id's */
76 			put_partition (state, slot, be32_to_cpu(pi->st),
77 					be32_to_cpu(pi->siz));
78 			continue;
79 		}
80 		/* extension partition */
81 #ifdef ICD_PARTS
82 		part_fmt = 1;
83 #endif
84 		strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
85 		partsect = extensect = be32_to_cpu(pi->st);
86 		while (1) {
87 			xrs = read_part_sector(state, partsect, &sect2);
88 			if (!xrs) {
89 				printk (" block %ld read failed\n", partsect);
90 				put_dev_sector(sect);
91 				return -1;
92 			}
93 
94 			/* ++roman: sanity check: bit 0 of flg field must be set */
95 			if (!(xrs->part[0].flg & 1)) {
96 				printk( "\nFirst sub-partition in extended partition is not valid!\n" );
97 				put_dev_sector(sect2);
98 				break;
99 			}
100 
101 			put_partition(state, slot,
102 				   partsect + be32_to_cpu(xrs->part[0].st),
103 				   be32_to_cpu(xrs->part[0].siz));
104 
105 			if (!(xrs->part[1].flg & 1)) {
106 				/* end of linked partition list */
107 				put_dev_sector(sect2);
108 				break;
109 			}
110 			if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
111 				printk("\nID of extended partition is not XGM!\n");
112 				put_dev_sector(sect2);
113 				break;
114 			}
115 
116 			partsect = be32_to_cpu(xrs->part[1].st) + extensect;
117 			put_dev_sector(sect2);
118 			if (++slot == state->limit) {
119 				printk( "\nMaximum number of partitions reached!\n" );
120 				break;
121 			}
122 		}
123 		strlcat(state->pp_buf, " >", PAGE_SIZE);
124 	}
125 #ifdef ICD_PARTS
126 	if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
127 		pi = &rs->icdpart[0];
128 		/* sanity check: no ICD format if first partition invalid */
129 		if (OK_id(pi->id)) {
130 			strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
131 			for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
132 				/* accept only GEM,BGM,RAW,LNX,SWP partitions */
133 				if (!((pi->flg & 1) && OK_id(pi->id)))
134 					continue;
135 				part_fmt = 2;
136 				put_partition (state, slot,
137 						be32_to_cpu(pi->st),
138 						be32_to_cpu(pi->siz));
139 			}
140 			strlcat(state->pp_buf, " >", PAGE_SIZE);
141 		}
142 	}
143 #endif
144 	put_dev_sector(sect);
145 
146 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
147 
148 	return 1;
149 }
150