xref: /freebsd/sys/geom/part/g_part_apm.c (revision 7d99ab9fd0cc2c1ce2ecef0ed6d0672c2a50b0cb)
1 /*-
2  * Copyright (c) 2006-2008 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/apm.h>
32 #include <sys/bio.h>
33 #include <sys/diskmbr.h>
34 #include <sys/endian.h>
35 #include <sys/kernel.h>
36 #include <sys/kobj.h>
37 #include <sys/limits.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
41 #include <sys/queue.h>
42 #include <sys/sbuf.h>
43 #include <sys/systm.h>
44 #include <sys/sysctl.h>
45 #include <geom/geom.h>
46 #include <geom/part/g_part.h>
47 
48 #include "g_part_if.h"
49 
50 FEATURE(geom_part_apm, "GEOM partitioning class for Apple-style partitions");
51 
52 struct g_part_apm_table {
53 	struct g_part_table	base;
54 	struct apm_ddr		ddr;
55 	struct apm_ent		self;
56 	int			tivo_series1;
57 };
58 
59 struct g_part_apm_entry {
60 	struct g_part_entry	base;
61 	struct apm_ent		ent;
62 };
63 
64 static int g_part_apm_add(struct g_part_table *, struct g_part_entry *,
65     struct g_part_parms *);
66 static int g_part_apm_create(struct g_part_table *, struct g_part_parms *);
67 static int g_part_apm_destroy(struct g_part_table *, struct g_part_parms *);
68 static void g_part_apm_dumpconf(struct g_part_table *, struct g_part_entry *,
69     struct sbuf *, const char *);
70 static int g_part_apm_dumpto(struct g_part_table *, struct g_part_entry *);
71 static int g_part_apm_modify(struct g_part_table *, struct g_part_entry *,
72     struct g_part_parms *);
73 static const char *g_part_apm_name(struct g_part_table *, struct g_part_entry *,
74     char *, size_t);
75 static int g_part_apm_probe(struct g_part_table *, struct g_consumer *);
76 static int g_part_apm_read(struct g_part_table *, struct g_consumer *);
77 static const char *g_part_apm_type(struct g_part_table *, struct g_part_entry *,
78     char *, size_t);
79 static int g_part_apm_write(struct g_part_table *, struct g_consumer *);
80 static int g_part_apm_resize(struct g_part_table *, struct g_part_entry *,
81     struct g_part_parms *);
82 
83 static kobj_method_t g_part_apm_methods[] = {
84 	KOBJMETHOD(g_part_add,		g_part_apm_add),
85 	KOBJMETHOD(g_part_create,	g_part_apm_create),
86 	KOBJMETHOD(g_part_destroy,	g_part_apm_destroy),
87 	KOBJMETHOD(g_part_dumpconf,	g_part_apm_dumpconf),
88 	KOBJMETHOD(g_part_dumpto,	g_part_apm_dumpto),
89 	KOBJMETHOD(g_part_modify,	g_part_apm_modify),
90 	KOBJMETHOD(g_part_resize,	g_part_apm_resize),
91 	KOBJMETHOD(g_part_name,		g_part_apm_name),
92 	KOBJMETHOD(g_part_probe,	g_part_apm_probe),
93 	KOBJMETHOD(g_part_read,		g_part_apm_read),
94 	KOBJMETHOD(g_part_type,		g_part_apm_type),
95 	KOBJMETHOD(g_part_write,	g_part_apm_write),
96 	{ 0, 0 }
97 };
98 
99 static struct g_part_scheme g_part_apm_scheme = {
100 	"APM",
101 	g_part_apm_methods,
102 	sizeof(struct g_part_apm_table),
103 	.gps_entrysz = sizeof(struct g_part_apm_entry),
104 	.gps_minent = 16,
105 	.gps_maxent = 4096,
106 };
107 G_PART_SCHEME_DECLARE(g_part_apm);
108 
109 static void
110 swab(char *buf, size_t bufsz)
111 {
112 	int i;
113 	char ch;
114 
115 	for (i = 0; i < bufsz; i += 2) {
116 		ch = buf[i];
117 		buf[i] = buf[i + 1];
118 		buf[i + 1] = ch;
119 	}
120 }
121 
122 static int
123 apm_parse_type(const char *type, char *buf, size_t bufsz)
124 {
125 	const char *alias;
126 
127 	if (type[0] == '!') {
128 		type++;
129 		if (strlen(type) > bufsz)
130 			return (EINVAL);
131 		if (!strcmp(type, APM_ENT_TYPE_SELF) ||
132 		    !strcmp(type, APM_ENT_TYPE_UNUSED))
133 			return (EINVAL);
134 		strncpy(buf, type, bufsz);
135 		return (0);
136 	}
137 	alias = g_part_alias_name(G_PART_ALIAS_APPLE_BOOT);
138 	if (!strcasecmp(type, alias)) {
139 		strcpy(buf, APM_ENT_TYPE_APPLE_BOOT);
140 		return (0);
141 	}
142 	alias = g_part_alias_name(G_PART_ALIAS_APPLE_HFS);
143 	if (!strcasecmp(type, alias)) {
144 		strcpy(buf, APM_ENT_TYPE_APPLE_HFS);
145 		return (0);
146 	}
147 	alias = g_part_alias_name(G_PART_ALIAS_APPLE_UFS);
148 	if (!strcasecmp(type, alias)) {
149 		strcpy(buf, APM_ENT_TYPE_APPLE_UFS);
150 		return (0);
151 	}
152 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_BOOT);
153 	if (!strcasecmp(type, alias)) {
154 		strcpy(buf, APM_ENT_TYPE_APPLE_BOOT);
155 		return (0);
156 	}
157 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD);
158 	if (!strcasecmp(type, alias)) {
159 		strcpy(buf, APM_ENT_TYPE_FREEBSD);
160 		return (0);
161 	}
162 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_NANDFS);
163 	if (!strcasecmp(type, alias)) {
164 		strcpy(buf, APM_ENT_TYPE_FREEBSD_NANDFS);
165 		return (0);
166 	}
167 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_SWAP);
168 	if (!strcasecmp(type, alias)) {
169 		strcpy(buf, APM_ENT_TYPE_FREEBSD_SWAP);
170 		return (0);
171 	}
172 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_UFS);
173 	if (!strcasecmp(type, alias)) {
174 		strcpy(buf, APM_ENT_TYPE_FREEBSD_UFS);
175 		return (0);
176 	}
177 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_VINUM);
178 	if (!strcasecmp(type, alias)) {
179 		strcpy(buf, APM_ENT_TYPE_FREEBSD_VINUM);
180 		return (0);
181 	}
182 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_ZFS);
183 	if (!strcasecmp(type, alias)) {
184 		strcpy(buf, APM_ENT_TYPE_FREEBSD_ZFS);
185 		return (0);
186 	}
187 	return (EINVAL);
188 }
189 
190 static int
191 apm_read_ent(struct g_consumer *cp, uint32_t blk, struct apm_ent *ent,
192     int tivo_series1)
193 {
194 	struct g_provider *pp;
195 	char *buf;
196 	int error;
197 
198 	pp = cp->provider;
199 	buf = g_read_data(cp, pp->sectorsize * blk, pp->sectorsize, &error);
200 	if (buf == NULL)
201 		return (error);
202 	if (tivo_series1)
203 		swab(buf, pp->sectorsize);
204 	ent->ent_sig = be16dec(buf);
205 	ent->ent_pmblkcnt = be32dec(buf + 4);
206 	ent->ent_start = be32dec(buf + 8);
207 	ent->ent_size = be32dec(buf + 12);
208 	bcopy(buf + 16, ent->ent_name, sizeof(ent->ent_name));
209 	bcopy(buf + 48, ent->ent_type, sizeof(ent->ent_type));
210 	g_free(buf);
211 	return (0);
212 }
213 
214 static int
215 g_part_apm_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
216     struct g_part_parms *gpp)
217 {
218 	struct g_part_apm_entry *entry;
219 	struct g_part_apm_table *table;
220 	int error;
221 
222 	entry = (struct g_part_apm_entry *)baseentry;
223 	table = (struct g_part_apm_table *)basetable;
224 	entry->ent.ent_sig = APM_ENT_SIG;
225 	entry->ent.ent_pmblkcnt = table->self.ent_pmblkcnt;
226 	entry->ent.ent_start = gpp->gpp_start;
227 	entry->ent.ent_size = gpp->gpp_size;
228 	if (baseentry->gpe_deleted) {
229 		bzero(entry->ent.ent_type, sizeof(entry->ent.ent_type));
230 		bzero(entry->ent.ent_name, sizeof(entry->ent.ent_name));
231 	}
232 	error = apm_parse_type(gpp->gpp_type, entry->ent.ent_type,
233 	    sizeof(entry->ent.ent_type));
234 	if (error)
235 		return (error);
236 	if (gpp->gpp_parms & G_PART_PARM_LABEL) {
237 		if (strlen(gpp->gpp_label) > sizeof(entry->ent.ent_name))
238 			return (EINVAL);
239 		strncpy(entry->ent.ent_name, gpp->gpp_label,
240 		    sizeof(entry->ent.ent_name));
241 	}
242 	if (baseentry->gpe_index >= table->self.ent_pmblkcnt)
243 		table->self.ent_pmblkcnt = baseentry->gpe_index + 1;
244 	KASSERT(table->self.ent_size >= table->self.ent_pmblkcnt,
245 	    ("%s", __func__));
246 	KASSERT(table->self.ent_size > baseentry->gpe_index,
247 	    ("%s", __func__));
248 	return (0);
249 }
250 
251 static int
252 g_part_apm_create(struct g_part_table *basetable, struct g_part_parms *gpp)
253 {
254 	struct g_provider *pp;
255 	struct g_part_apm_table *table;
256 	uint32_t last;
257 
258 	/* We don't nest, which means that our depth should be 0. */
259 	if (basetable->gpt_depth != 0)
260 		return (ENXIO);
261 
262 	table = (struct g_part_apm_table *)basetable;
263 	pp = gpp->gpp_provider;
264 	if (pp->sectorsize != 512 ||
265 	    pp->mediasize < (2 + 2 * basetable->gpt_entries) * pp->sectorsize)
266 		return (ENOSPC);
267 
268 	/* APM uses 32-bit LBAs. */
269 	last = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX) - 1;
270 
271 	basetable->gpt_first = 2 + basetable->gpt_entries;
272 	basetable->gpt_last = last;
273 
274 	table->ddr.ddr_sig = APM_DDR_SIG;
275 	table->ddr.ddr_blksize = pp->sectorsize;
276 	table->ddr.ddr_blkcount = last + 1;
277 
278 	table->self.ent_sig = APM_ENT_SIG;
279 	table->self.ent_pmblkcnt = basetable->gpt_entries + 1;
280 	table->self.ent_start = 1;
281 	table->self.ent_size = table->self.ent_pmblkcnt;
282 	strcpy(table->self.ent_name, "Apple");
283 	strcpy(table->self.ent_type, APM_ENT_TYPE_SELF);
284 	return (0);
285 }
286 
287 static int
288 g_part_apm_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
289 {
290 
291 	/* Wipe the first 2 sectors to clear the partitioning. */
292 	basetable->gpt_smhead |= 3;
293 	return (0);
294 }
295 
296 static void
297 g_part_apm_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
298     struct sbuf *sb, const char *indent)
299 {
300 	union {
301 		char name[APM_ENT_NAMELEN + 1];
302 		char type[APM_ENT_TYPELEN + 1];
303 	} u;
304 	struct g_part_apm_entry *entry;
305 
306 	entry = (struct g_part_apm_entry *)baseentry;
307 	if (indent == NULL) {
308 		/* conftxt: libdisk compatibility */
309 		sbuf_printf(sb, " xs APPLE xt %s", entry->ent.ent_type);
310 	} else if (entry != NULL) {
311 		/* confxml: partition entry information */
312 		strncpy(u.name, entry->ent.ent_name, APM_ENT_NAMELEN);
313 		u.name[APM_ENT_NAMELEN] = '\0';
314 		sbuf_printf(sb, "%s<label>%s</label>\n", indent, u.name);
315 		strncpy(u.type, entry->ent.ent_type, APM_ENT_TYPELEN);
316 		u.type[APM_ENT_TYPELEN] = '\0';
317 		sbuf_printf(sb, "%s<rawtype>%s</rawtype>\n", indent, u.type);
318 	} else {
319 		/* confxml: scheme information */
320 	}
321 }
322 
323 static int
324 g_part_apm_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
325 {
326 	struct g_part_apm_entry *entry;
327 
328 	entry = (struct g_part_apm_entry *)baseentry;
329 	return ((!strcmp(entry->ent.ent_type, APM_ENT_TYPE_FREEBSD_SWAP))
330 	    ? 1 : 0);
331 }
332 
333 static int
334 g_part_apm_modify(struct g_part_table *basetable,
335     struct g_part_entry *baseentry, struct g_part_parms *gpp)
336 {
337 	struct g_part_apm_entry *entry;
338 	int error;
339 
340 	entry = (struct g_part_apm_entry *)baseentry;
341 	if (gpp->gpp_parms & G_PART_PARM_LABEL) {
342 		if (strlen(gpp->gpp_label) > sizeof(entry->ent.ent_name))
343 			return (EINVAL);
344 	}
345 	if (gpp->gpp_parms & G_PART_PARM_TYPE) {
346 		error = apm_parse_type(gpp->gpp_type, entry->ent.ent_type,
347 		    sizeof(entry->ent.ent_type));
348 		if (error)
349 			return (error);
350 	}
351 	if (gpp->gpp_parms & G_PART_PARM_LABEL) {
352 		strncpy(entry->ent.ent_name, gpp->gpp_label,
353 		    sizeof(entry->ent.ent_name));
354 	}
355 	return (0);
356 }
357 
358 static int
359 g_part_apm_resize(struct g_part_table *basetable,
360     struct g_part_entry *baseentry, struct g_part_parms *gpp)
361 {
362 	struct g_part_apm_entry *entry;
363 
364 	entry = (struct g_part_apm_entry *)baseentry;
365 	baseentry->gpe_end = baseentry->gpe_start + gpp->gpp_size - 1;
366 	entry->ent.ent_size = gpp->gpp_size;
367 
368 	return (0);
369 }
370 
371 static const char *
372 g_part_apm_name(struct g_part_table *table, struct g_part_entry *baseentry,
373     char *buf, size_t bufsz)
374 {
375 
376 	snprintf(buf, bufsz, "s%d", baseentry->gpe_index + 1);
377 	return (buf);
378 }
379 
380 static int
381 g_part_apm_probe(struct g_part_table *basetable, struct g_consumer *cp)
382 {
383 	struct g_provider *pp;
384 	struct g_part_apm_table *table;
385 	char *buf;
386 	int error;
387 
388 	/* We don't nest, which means that our depth should be 0. */
389 	if (basetable->gpt_depth != 0)
390 		return (ENXIO);
391 
392 	table = (struct g_part_apm_table *)basetable;
393 	table->tivo_series1 = 0;
394 	pp = cp->provider;
395 
396 	/* Sanity-check the provider. */
397 	if (pp->mediasize < 4 * pp->sectorsize)
398 		return (ENOSPC);
399 
400 	/* Check that there's a Driver Descriptor Record (DDR). */
401 	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
402 	if (buf == NULL)
403 		return (error);
404 	if (be16dec(buf) == APM_DDR_SIG) {
405 		/* Normal Apple DDR */
406 		table->ddr.ddr_sig = be16dec(buf);
407 		table->ddr.ddr_blksize = be16dec(buf + 2);
408 		table->ddr.ddr_blkcount = be32dec(buf + 4);
409 		g_free(buf);
410 		if (table->ddr.ddr_blksize != pp->sectorsize)
411 			return (ENXIO);
412 		if (table->ddr.ddr_blkcount > pp->mediasize / pp->sectorsize)
413 			return (ENXIO);
414 	} else {
415 		/*
416 		 * Check for Tivo drives, which have no DDR and a different
417 		 * signature.  Those whose first two bytes are 14 92 are
418 		 * Series 2 drives, and aren't supported.  Those that start
419 		 * with 92 14 are series 1 drives and are supported.
420 		 */
421 		if (be16dec(buf) != 0x9214) {
422 			/* If this is 0x1492 it could be a series 2 drive */
423 			g_free(buf);
424 			return (ENXIO);
425 		}
426 		table->ddr.ddr_sig = APM_DDR_SIG;		/* XXX */
427 		table->ddr.ddr_blksize = pp->sectorsize;	/* XXX */
428 		table->ddr.ddr_blkcount =
429 		    MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
430 		table->tivo_series1 = 1;
431 		g_free(buf);
432 	}
433 
434 	/* Check that there's a Partition Map. */
435 	error = apm_read_ent(cp, 1, &table->self, table->tivo_series1);
436 	if (error)
437 		return (error);
438 	if (table->self.ent_sig != APM_ENT_SIG)
439 		return (ENXIO);
440 	if (strcmp(table->self.ent_type, APM_ENT_TYPE_SELF))
441 		return (ENXIO);
442 	if (table->self.ent_pmblkcnt >= table->ddr.ddr_blkcount)
443 		return (ENXIO);
444 	return (G_PART_PROBE_PRI_NORM);
445 }
446 
447 static int
448 g_part_apm_read(struct g_part_table *basetable, struct g_consumer *cp)
449 {
450 	struct apm_ent ent;
451 	struct g_part_apm_entry *entry;
452 	struct g_part_apm_table *table;
453 	int error, index;
454 
455 	table = (struct g_part_apm_table *)basetable;
456 
457 	basetable->gpt_first = table->self.ent_size + 1;
458 	basetable->gpt_last = table->ddr.ddr_blkcount - 1;
459 	basetable->gpt_entries = table->self.ent_size - 1;
460 
461 	for (index = table->self.ent_pmblkcnt - 1; index > 0; index--) {
462 		error = apm_read_ent(cp, index + 1, &ent, table->tivo_series1);
463 		if (error)
464 			continue;
465 		if (!strcmp(ent.ent_type, APM_ENT_TYPE_UNUSED))
466 			continue;
467 		entry = (struct g_part_apm_entry *)g_part_new_entry(basetable,
468 		    index, ent.ent_start, ent.ent_start + ent.ent_size - 1);
469 		entry->ent = ent;
470 	}
471 
472 	return (0);
473 }
474 
475 static const char *
476 g_part_apm_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
477     char *buf, size_t bufsz)
478 {
479 	struct g_part_apm_entry *entry;
480 	const char *type;
481 	size_t len;
482 
483 	entry = (struct g_part_apm_entry *)baseentry;
484 	type = entry->ent.ent_type;
485 	if (!strcmp(type, APM_ENT_TYPE_APPLE_BOOT))
486 		return (g_part_alias_name(G_PART_ALIAS_APPLE_BOOT));
487 	if (!strcmp(type, APM_ENT_TYPE_APPLE_HFS))
488 		return (g_part_alias_name(G_PART_ALIAS_APPLE_HFS));
489 	if (!strcmp(type, APM_ENT_TYPE_APPLE_UFS))
490 		return (g_part_alias_name(G_PART_ALIAS_APPLE_UFS));
491 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD))
492 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD));
493 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD_NANDFS))
494 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_NANDFS));
495 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD_SWAP))
496 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_SWAP));
497 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD_UFS))
498 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_UFS));
499 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD_VINUM))
500 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_VINUM));
501 	if (!strcmp(type, APM_ENT_TYPE_FREEBSD_ZFS))
502 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_ZFS));
503 	buf[0] = '!';
504 	len = MIN(sizeof(entry->ent.ent_type), bufsz - 2);
505 	bcopy(type, buf + 1, len);
506 	buf[len + 1] = '\0';
507 	return (buf);
508 }
509 
510 static int
511 g_part_apm_write(struct g_part_table *basetable, struct g_consumer *cp)
512 {
513 	struct g_provider *pp;
514 	struct g_part_entry *baseentry;
515 	struct g_part_apm_entry *entry;
516 	struct g_part_apm_table *table;
517 	char *buf, *ptr;
518 	uint32_t index;
519 	int error;
520 	size_t tblsz;
521 
522 	pp = cp->provider;
523 	table = (struct g_part_apm_table *)basetable;
524 	/*
525 	 * Tivo Series 1 disk partitions are currently read-only.
526 	 */
527 	if (table->tivo_series1)
528 		return (EOPNOTSUPP);
529 
530 	/* Write the DDR only when we're newly created. */
531 	if (basetable->gpt_created) {
532 		buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
533 		be16enc(buf, table->ddr.ddr_sig);
534 		be16enc(buf + 2, table->ddr.ddr_blksize);
535 		be32enc(buf + 4, table->ddr.ddr_blkcount);
536 		error = g_write_data(cp, 0, buf, pp->sectorsize);
537 		g_free(buf);
538 		if (error)
539 			return (error);
540 	}
541 
542 	/* Allocate the buffer for all entries */
543 	tblsz = table->self.ent_pmblkcnt;
544 	buf = g_malloc(tblsz * pp->sectorsize, M_WAITOK | M_ZERO);
545 
546 	/* Fill the self entry */
547 	be16enc(buf, APM_ENT_SIG);
548 	be32enc(buf + 4, table->self.ent_pmblkcnt);
549 	be32enc(buf + 8, table->self.ent_start);
550 	be32enc(buf + 12, table->self.ent_size);
551 	bcopy(table->self.ent_name, buf + 16, sizeof(table->self.ent_name));
552 	bcopy(table->self.ent_type, buf + 48, sizeof(table->self.ent_type));
553 
554 	baseentry = LIST_FIRST(&basetable->gpt_entry);
555 	for (index = 1; index < tblsz; index++) {
556 		entry = (baseentry != NULL && index == baseentry->gpe_index)
557 		    ? (struct g_part_apm_entry *)baseentry : NULL;
558 		ptr = buf + index * pp->sectorsize;
559 		be16enc(ptr, APM_ENT_SIG);
560 		be32enc(ptr + 4, table->self.ent_pmblkcnt);
561 		if (entry != NULL && !baseentry->gpe_deleted) {
562 			be32enc(ptr + 8, entry->ent.ent_start);
563 			be32enc(ptr + 12, entry->ent.ent_size);
564 			bcopy(entry->ent.ent_name, ptr + 16,
565 			    sizeof(entry->ent.ent_name));
566 			bcopy(entry->ent.ent_type, ptr + 48,
567 			    sizeof(entry->ent.ent_type));
568 		} else {
569 			strcpy(ptr + 48, APM_ENT_TYPE_UNUSED);
570 		}
571 		if (entry != NULL)
572 			baseentry = LIST_NEXT(baseentry, gpe_entry);
573 	}
574 
575 	for (index = 0; index < tblsz; index += MAXPHYS / pp->sectorsize) {
576 		error = g_write_data(cp, (1 + index) * pp->sectorsize,
577 		    buf + index * pp->sectorsize,
578 		    (tblsz - index > MAXPHYS / pp->sectorsize) ? MAXPHYS:
579 		    (tblsz - index) * pp->sectorsize);
580 		if (error) {
581 			g_free(buf);
582 			return (error);
583 		}
584 	}
585 	g_free(buf);
586 	return (0);
587 }
588