1 /* $NetBSD: dkwedge_tos.c,v 1.2 2024/04/06 09:51:34 hannken Exp $ */
2
3 /*
4 * Copyright (c) 2024 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charlotte Koch.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * dk(4) support for Atari "TOS" partition schemes.
34 *
35 * Technical details taken from:
36 *
37 * - "Atari Hard Disk File Systems Reference Guide" v1.2b by Jean
38 * Louis-Guerin (DrCoolZic) (September 2014)
39 *
40 * https://info-coach.fr/atari/documents/_mydoc/Atari_HD_File_Sytem_Reference_Guide.pdf
41 */
42
43 #include <sys/buf.h>
44 #include <sys/disk.h>
45 #include <sys/endian.h>
46 #include <sys/vnode.h>
47
48 #define TOS_PART_TYPE_LEN 3
49 #define TOS_GEM_PARTITION "GEM"
50 #define TOS_BGM_PARTITION "BGM"
51 #define TOS_XGM_PARTITION "XGM"
52
53 #define TOS_CXNMETHOD_SASI 0x00
54 #define TOS_CXNMETHOD_SCSI 0xFF
55
56 #define TOS_MAX_PART_COUNT 4
57 #define TOS_SECTOR_SIZE 512
58
59 struct tos_partition {
60 uint8_t status;
61 char type[TOS_PART_TYPE_LEN];
62 uint32_t offset;
63 uint32_t size;
64 } __packed;
65 __CTASSERT(sizeof(struct tos_partition) == 12);
66
67 struct tos_root_sector {
68 uint8_t unused1[441];
69 uint8_t connection_method;
70 uint8_t unused2[8];
71 uint32_t size;
72 struct tos_partition parts[TOS_MAX_PART_COUNT];
73 uint8_t unused3[10];
74 } __packed;
75 __CTASSERT(sizeof(struct tos_root_sector) == TOS_SECTOR_SIZE);
76
77 static int dkwedge_discover_tos(struct disk *pdk, struct vnode *vp);
78
79 static int
dkwedge_discover_tos(struct disk * pdk,struct vnode * vp)80 dkwedge_discover_tos(struct disk *pdk, struct vnode *vp)
81 {
82 struct dkwedge_info dkw;
83 int error = 0;
84 size_t i;
85 char safe_type[4];
86
87 /* Get ourselves a fistful of memory. */
88 buf_t *bp = geteblk(TOS_SECTOR_SIZE);
89
90 error = dkwedge_read(pdk, vp, 0L, bp->b_data, TOS_SECTOR_SIZE);
91 if (error) {
92 aprint_error("unable to read TOS Root Sector: error = %d",
93 error);
94 goto out;
95 }
96
97 struct tos_root_sector *trs = bp->b_data;
98
99 /*
100 * If the "connection method" isn't recognized, then this is
101 * probably NOT an Atari-style partition, so get outta here. Note
102 * that there really isn't a magic number we can rely on; this check
103 * is somewhat made up. But at least it's better than nothing.
104 */
105 switch (trs->connection_method) {
106 case TOS_CXNMETHOD_SASI: /* FALLTHROUGH */
107 case TOS_CXNMETHOD_SCSI:
108 ; /* OK */
109 break;
110 default:
111 error = ESRCH;
112 goto out;
113 }
114
115 /*
116 * Make a wedge for each partition that exists (i.e., has the "exist"
117 * bit set).
118 */
119 for (i = 0; i < TOS_MAX_PART_COUNT; i++) {
120 struct tos_partition part = trs->parts[i];
121
122 if (!(part.status & 0x01))
123 continue;
124
125 /* Ignore if we see it's an extended "XGM" partition. */
126 if (!strncmp(part.type, TOS_XGM_PARTITION, TOS_PART_TYPE_LEN)) {
127 aprint_normal(
128 "WARNING: XGM partitions are not yet supported\n");
129 continue;
130 }
131
132 /*
133 * Otherwise, get outta here if it's not the partition-types
134 * we *do* support.
135 */
136 if (strncmp(part.type, TOS_GEM_PARTITION, TOS_PART_TYPE_LEN) &&
137 strncmp(part.type, TOS_BGM_PARTITION, TOS_PART_TYPE_LEN)) {
138 error = ESRCH;
139 goto out;
140 }
141
142 memset(&dkw, 0, sizeof(dkw));
143 memset(safe_type, 0, sizeof(safe_type));
144
145 /*
146 * The partition type string is NOT NUL-terminated, so let's
147 * play it safe.
148 */
149 memcpy(safe_type, part.type, TOS_PART_TYPE_LEN);
150 safe_type[TOS_PART_TYPE_LEN] = '\0';
151
152 /* Finally, make the wedge. */
153 snprintf(dkw.dkw_wname, sizeof(dkw.dkw_wname), "ATARI_%s_%02zu",
154 safe_type, i);
155 dkw.dkw_offset = be32toh(trs->parts[i].offset);
156 dkw.dkw_size = be32toh(trs->parts[i].size);
157 strlcpy(dkw.dkw_ptype, DKW_PTYPE_FAT, sizeof(dkw.dkw_ptype));
158 strlcpy(dkw.dkw_parent, pdk->dk_name, sizeof(dkw.dkw_parent));
159 error = dkwedge_add(&dkw);
160
161 if (error == EEXIST) {
162 aprint_error("partition named \"%s\" already exists",
163 dkw.dkw_wname);
164 goto out;
165 }
166 }
167
168 error = 0;
169
170 out:
171 brelse(bp, 0);
172 return error;
173 }
174
175 DKWEDGE_DISCOVERY_METHOD_DECL(TOS, 10, dkwedge_discover_tos);
176