xref: /linux/block/partitions/mac.c (revision c21614d5c0e76cf1d7a864f15d495fd3e5876acc)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  fs/partitions/mac.c
4  *
5  *  Code extracted from drivers/block/genhd.c
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 "mac.h"
13 
14 #ifdef CONFIG_PPC_PMAC
15 #include <asm/machdep.h>
16 extern void note_bootable_part(dev_t dev, int part, int goodness);
17 #endif
18 
19 /*
20  * Code to understand MacOS partition tables.
21  */
22 
23 #ifdef CONFIG_PPC_PMAC
24 static inline void mac_fix_string(char *stg, int len)
25 {
26 	int i;
27 
28 	for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
29 		stg[i] = 0;
30 }
31 #endif
32 
33 int mac_partition(struct parsed_partitions *state)
34 {
35 	Sector sect;
36 	unsigned char *data;
37 	int slot, blocks_in_map;
38 	unsigned secsize, datasize, partoffset;
39 #ifdef CONFIG_PPC_PMAC
40 	int found_root = 0;
41 	int found_root_goodness = 0;
42 #endif
43 	struct mac_partition *part;
44 	struct mac_driver_desc *md;
45 
46 	/* Get 0th block and look at the first partition map entry. */
47 	md = read_part_sector(state, 0, &sect);
48 	if (!md)
49 		return -1;
50 	if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
51 		put_dev_sector(sect);
52 		return 0;
53 	}
54 	secsize = be16_to_cpu(md->block_size);
55 	put_dev_sector(sect);
56 	datasize = round_down(secsize, 512);
57 	data = read_part_sector(state, datasize / 512, &sect);
58 	if (!data)
59 		return -1;
60 	partoffset = secsize % 512;
61 	if (partoffset + sizeof(*part) > datasize)
62 		return -1;
63 	part = (struct mac_partition *) (data + partoffset);
64 	if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
65 		put_dev_sector(sect);
66 		return 0;		/* not a MacOS disk */
67 	}
68 	blocks_in_map = be32_to_cpu(part->map_count);
69 	if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
70 		put_dev_sector(sect);
71 		return 0;
72 	}
73 
74 	if (blocks_in_map >= state->limit)
75 		blocks_in_map = state->limit - 1;
76 
77 	strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
78 	for (slot = 1; slot <= blocks_in_map; ++slot) {
79 		int pos = slot * secsize;
80 		put_dev_sector(sect);
81 		data = read_part_sector(state, pos/512, &sect);
82 		if (!data)
83 			return -1;
84 		part = (struct mac_partition *) (data + pos%512);
85 		if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
86 			break;
87 		put_partition(state, slot,
88 			be32_to_cpu(part->start_block) * (secsize/512),
89 			be32_to_cpu(part->block_count) * (secsize/512));
90 
91 		if (!strncasecmp(part->type, "Linux_RAID", 10))
92 			state->parts[slot].flags = ADDPART_FLAG_RAID;
93 #ifdef CONFIG_PPC_PMAC
94 		/*
95 		 * If this is the first bootable partition, tell the
96 		 * setup code, in case it wants to make this the root.
97 		 */
98 		if (machine_is(powermac)) {
99 			int goodness = 0;
100 
101 			mac_fix_string(part->processor, 16);
102 			mac_fix_string(part->name, 32);
103 			mac_fix_string(part->type, 32);
104 
105 			if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
106 			    && strcasecmp(part->processor, "powerpc") == 0)
107 				goodness++;
108 
109 			if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
110 			    || (strncasecmp(part->type, "Linux", 5) == 0
111 			        && strcasecmp(part->type, "Linux_swap") != 0)) {
112 				int i, l;
113 
114 				goodness++;
115 				l = strlen(part->name);
116 				if (strcmp(part->name, "/") == 0)
117 					goodness++;
118 				for (i = 0; i <= l - 4; ++i) {
119 					if (strncasecmp(part->name + i, "root",
120 						     4) == 0) {
121 						goodness += 2;
122 						break;
123 					}
124 				}
125 				if (strncasecmp(part->name, "swap", 4) == 0)
126 					goodness--;
127 			}
128 
129 			if (goodness > found_root_goodness) {
130 				found_root = slot;
131 				found_root_goodness = goodness;
132 			}
133 		}
134 #endif /* CONFIG_PPC_PMAC */
135 	}
136 #ifdef CONFIG_PPC_PMAC
137 	if (found_root_goodness)
138 		note_bootable_part(state->disk->part0->bd_dev, found_root,
139 				   found_root_goodness);
140 #endif
141 
142 	put_dev_sector(sect);
143 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
144 	return 1;
145 }
146