1 /* $NetBSD: boot1.c,v 1.22 2023/06/29 14:18:58 manu Exp $ */
2
3 /*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by David Laight.
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 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: boot1.c,v 1.22 2023/06/29 14:18:58 manu Exp $");
34
35 #include <lib/libsa/stand.h>
36 #include <lib/libkern/libkern.h>
37 #include <biosdisk_ll.h>
38
39 #include <sys/param.h>
40 #include <sys/uuid.h>
41 #include <sys/bootblock.h>
42 #include <sys/disklabel.h>
43 #include <sys/disklabel_gpt.h>
44 #include <dev/raidframe/raidframevar.h> /* For RF_PROTECTED_SECTORS */
45
46 #define XSTR(x) #x
47 #define STR(x) XSTR(x)
48
49 static daddr_t bios_sector;
50
51 static struct biosdisk_ll d;
52
53 const char *boot1(uint32_t, uint64_t *);
54 #ifndef NO_GPT
55 static daddr_t gpt_lookup(daddr_t);
56 #endif
57 extern void putstr(const char *);
58
59 extern struct disklabel ptn_disklabel;
60
61 static int
ob(void)62 ob(void)
63 {
64 return open("boot", 0);
65 }
66
67 const char *
boot1(uint32_t biosdev,uint64_t * sector)68 boot1(uint32_t biosdev, uint64_t *sector)
69 {
70 struct stat sb;
71 int fd;
72
73 bios_sector = *sector;
74 d.dev = biosdev;
75
76 putstr("\r\nNetBSD/x86 " STR(FS) " Primary Bootstrap\r\n");
77
78 if (set_geometry(&d, NULL))
79 return "set_geometry\r\n";
80
81 /*
82 * We default to the filesystem at the start of the
83 * MBR partition
84 */
85 fd = ob();
86 if (fd != -1)
87 goto done;
88 /*
89 * Maybe the filesystem is enclosed in a raid set.
90 * add in size of raidframe header and try again.
91 * (Maybe this should only be done if the filesystem
92 * magic number is absent.)
93 */
94 bios_sector += RF_PROTECTED_SECTORS;
95 fd = ob();
96 if (fd != -1)
97 goto done;
98
99 #ifndef NO_GPT
100 /*
101 * Test for a GPT inside the RAID
102 */
103 bios_sector += gpt_lookup(bios_sector);
104 fd = ob();
105 if (fd != -1)
106 goto done;
107 #endif
108
109 /*
110 * Nothing at the start of the MBR partition, fallback on
111 * partition 'a' from the disklabel in this MBR partition.
112 */
113 if (ptn_disklabel.d_magic != DISKMAGIC ||
114 ptn_disklabel.d_magic2 != DISKMAGIC ||
115 ptn_disklabel.d_partitions[0].p_fstype == FS_UNUSED)
116 goto done;
117 bios_sector = ptn_disklabel.d_partitions[0].p_offset;
118 *sector = bios_sector;
119 if (ptn_disklabel.d_partitions[0].p_fstype == FS_RAID)
120 bios_sector += RF_PROTECTED_SECTORS;
121
122 fd = ob();
123
124 done:
125 if (fd == -1 || fstat(fd, &sb) == -1)
126 return "Can't open /boot\r\n";
127
128 biosdev = (uint32_t)sb.st_size;
129 #if 0
130 if (biosdev > SECONDARY_MAX_LOAD)
131 return "/boot too large\r\n";
132 #endif
133
134 if (read(fd, (void *)SECONDARY_LOAD_ADDRESS, biosdev) != biosdev)
135 return "/boot load failed\r\n";
136
137 if (*(uint32_t *)(SECONDARY_LOAD_ADDRESS + 4) != X86_BOOT_MAGIC_2)
138 return "Invalid /boot file format\r\n";
139
140 /* We need to jump to the secondary bootstrap in realmode */
141 return 0;
142 }
143
144 int
blkdevstrategy(void * devdata,int flag,daddr_t dblk,size_t size,void * buf,size_t * rsize)145 blkdevstrategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
146 {
147 if (flag != F_READ)
148 return EROFS;
149
150 if (size & (BIOSDISK_DEFAULT_SECSIZE - 1))
151 return EINVAL;
152
153 if (rsize)
154 *rsize = size;
155
156 if (size != 0 && readsects(&d, bios_sector + dblk,
157 size / BIOSDISK_DEFAULT_SECSIZE,
158 buf, 1) != 0)
159 return EIO;
160
161 return 0;
162 }
163
164 #ifndef NO_GPT
165 static int
is_unused(struct gpt_ent * ent)166 is_unused(struct gpt_ent *ent)
167 {
168 const struct uuid unused = GPT_ENT_TYPE_UNUSED;
169
170 return (memcmp(ent->ent_type, &unused, sizeof(unused)) == 0);
171 }
172
173 static int
is_bootable(struct gpt_ent * ent)174 is_bootable(struct gpt_ent *ent)
175 {
176 /* GPT_ENT_TYPE_NETBSD_RAID omitted as we are already in a RAID */
177 const struct uuid bootable[] = {
178 GPT_ENT_TYPE_NETBSD_FFS,
179 GPT_ENT_TYPE_NETBSD_LFS,
180 GPT_ENT_TYPE_NETBSD_CCD,
181 GPT_ENT_TYPE_NETBSD_CGD,
182 };
183 int i;
184
185 for (i = 0; i < sizeof(bootable) / sizeof(*bootable); i++) {
186 if (memcmp(ent->ent_type, &bootable[i],
187 sizeof(struct uuid)) == 0)
188 return 1;
189 }
190
191 return 0;
192 }
193
194 static daddr_t
gpt_lookup(daddr_t sector)195 gpt_lookup(daddr_t sector)
196 {
197 char buf[BIOSDISK_DEFAULT_SECSIZE];
198 struct mbr_sector *pmbr;
199 const char gpt_hdr_sig[] = GPT_HDR_SIG;
200 struct gpt_hdr *hdr;
201 struct gpt_ent *ent;
202 uint32_t nents;
203 uint32_t entsz;
204 uint32_t entries_per_sector;
205 uint32_t sectors_per_entry;
206 uint64_t firstpart_lba = 0;
207 uint64_t bootable_lba = 0;
208 uint64_t bootme_lba = 0;
209 int i, j;
210
211 /*
212 * Look for a PMBR
213 */
214 if (readsects(&d, sector, 1, buf, 1) != 0)
215 return 0;
216
217 pmbr = (struct mbr_sector *)buf;
218
219 if (pmbr->mbr_magic != htole16(MBR_MAGIC))
220 return 0;
221
222 if (pmbr->mbr_parts[0].mbrp_type != MBR_PTYPE_PMBR)
223 return 0;
224
225 sector++; /* skip PMBR */
226
227 /*
228 * Look for a GPT header
229 * Space is scarce, we do not check CRC.
230 */
231 if (readsects(&d, sector, 1, buf, 1) != 0)
232 return 0;
233
234 hdr = (struct gpt_hdr *)buf;
235
236 if (memcmp(gpt_hdr_sig, hdr->hdr_sig, sizeof(hdr->hdr_sig)) != 0)
237 return 0;
238
239 if (hdr->hdr_revision != htole32(GPT_HDR_REVISION))
240 return 0;
241
242 if (le32toh(hdr->hdr_size) > BIOSDISK_DEFAULT_SECSIZE)
243 return 0;
244
245 nents = le32toh(hdr->hdr_entries);
246 entsz = le32toh(hdr->hdr_entsz);
247
248 sector++; /* skip GPT header */
249
250 /*
251 * Read partition table
252 *
253 * According to UEFI specification section 5.3.2, entries
254 * are 128 * (2^n) bytes long. The most common scenario is
255 * 128 bytes (n = 0) where there are 4 entries per sector.
256 * If n > 2, then entries spans multiple sectors, but they
257 * remain sector-aligned.
258 */
259 entries_per_sector = BIOSDISK_DEFAULT_SECSIZE / entsz;
260 if (entries_per_sector == 0)
261 entries_per_sector = 1;
262
263 sectors_per_entry = entsz / BIOSDISK_DEFAULT_SECSIZE;
264 if (sectors_per_entry == 0)
265 sectors_per_entry = 1;
266
267 for (i = 0; i < nents; i += entries_per_sector) {
268 if (readsects(&d, sector, 1, buf, 1) != 0)
269 return 0;
270
271 sector += sectors_per_entry;
272
273 for (j = 0; j < entries_per_sector; j++) {
274 ent = (struct gpt_ent *)&buf[j * entsz];
275
276 if (is_unused(ent))
277 continue;
278
279 /* First bootme wins, we can stop there */
280 if (ent->ent_attr & GPT_ENT_ATTR_BOOTME) {
281 bootme_lba = le64toh(ent->ent_lba_start);
282 goto out;
283 }
284
285 if (firstpart_lba == 0)
286 firstpart_lba = le64toh(ent->ent_lba_start);
287
288 if (is_bootable(ent) && bootable_lba == 0)
289 bootable_lba = le64toh(ent->ent_lba_start);
290 }
291 }
292
293 out:
294 if (bootme_lba)
295 return bootme_lba;
296
297 if (bootable_lba)
298 return bootable_lba;
299
300 if (firstpart_lba)
301 return firstpart_lba;
302
303 return 0;
304 }
305 #endif /* ! NO_GPT */
306