xref: /freebsd/stand/i386/zfsboot/zfsboot.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * Copyright (c) 1998 Robert Nordier
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are freely
6  * permitted provided that the above copyright notice and this
7  * paragraph and the following disclaimer are duplicated in all
8  * such forms.
9  *
10  * This software is provided "AS IS" and without any express or
11  * implied warranties, including, without limitation, the implied
12  * warranties of merchantability and fitness for a particular
13  * purpose.
14  */
15 
16 #include <stand.h>
17 
18 #include <sys/param.h>
19 #include <sys/errno.h>
20 #include <sys/diskmbr.h>
21 #ifdef GPT
22 #include <sys/gpt.h>
23 #endif
24 #include <sys/reboot.h>
25 #include <sys/queue.h>
26 #ifdef LOADER_ZFS_SUPPORT
27 #include <sys/zfs_bootenv.h>
28 #endif
29 
30 #include <machine/bootinfo.h>
31 #include <machine/elf.h>
32 #include <machine/pc/bios.h>
33 
34 #include <stdarg.h>
35 #include <stddef.h>
36 
37 #include <a.out.h>
38 #include "bootstrap.h"
39 #include "libi386.h"
40 #include <btxv86.h>
41 
42 #include "lib.h"
43 #include "rbx.h"
44 #include "cons.h"
45 #include "bootargs.h"
46 #include "disk.h"
47 #include "part.h"
48 #include "paths.h"
49 
50 #include "libzfs.h"
51 
52 #define	ARGS			0x900
53 #define	NOPT			14
54 #define	NDEV			3
55 
56 #define	BIOS_NUMDRIVES		0x475
57 #define	DRV_HARD		0x80
58 #define	DRV_MASK		0x7f
59 
60 #define	TYPE_AD			0
61 #define	TYPE_DA			1
62 #define	TYPE_MAXHARD		TYPE_DA
63 #define	TYPE_FD			2
64 
65 extern uint32_t _end;
66 
67 static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
68 static const unsigned char flags[NOPT] = {
69     RBX_DUAL,
70     RBX_SERIAL,
71     RBX_ASKNAME,
72     RBX_CDROM,
73     RBX_CONFIG,
74     RBX_KDB,
75     RBX_GDB,
76     RBX_MUTE,
77     RBX_NOINTR,
78     RBX_PAUSE,
79     RBX_QUIET,
80     RBX_DFLTROOT,
81     RBX_SINGLE,
82     RBX_VERBOSE
83 };
84 uint32_t opts;
85 
86 /*
87  * Paths to try loading before falling back to the boot2 prompt.
88  *
89  * /boot/zfsloader must be tried before /boot/loader in order to remain
90  * backward compatible with ZFS boot environments where /boot/loader exists
91  * but does not have ZFS support, which was the case before FreeBSD 12.
92  *
93  * If no loader is found, try to load a kernel directly instead.
94  */
95 static const struct string {
96 	const char *p;
97 	size_t len;
98 } loadpath[] = {
99 	{ PATH_LOADER_ZFS, sizeof(PATH_LOADER_ZFS) },
100 	{ PATH_LOADER, sizeof(PATH_LOADER) },
101 	{ PATH_KERNEL, sizeof(PATH_KERNEL) },
102 };
103 
104 static const unsigned char dev_maj[NDEV] = {30, 4, 2};
105 
106 static struct i386_devdesc *bdev;
107 static char cmd[512];
108 static char cmddup[512];
109 static char kname[1024];
110 static int comspeed = SIOSPD;
111 static struct bootinfo bootinfo;
112 static uint32_t bootdev;
113 static struct zfs_boot_args zfsargs;
114 #ifdef LOADER_GELI_SUPPORT
115 static struct geli_boot_args geliargs;
116 #endif
117 
118 extern vm_offset_t high_heap_base;
119 extern uint32_t	bios_basemem, bios_extmem, high_heap_size;
120 
121 static char *heap_top;
122 static char *heap_bottom;
123 
124 void exit(int);
125 static void i386_zfs_probe(void);
126 static void load(void);
127 static int parse_cmd(void);
128 
129 #ifdef LOADER_GELI_SUPPORT
130 #include "geliboot.h"
131 static char gelipw[GELI_PW_MAXLEN];
132 #endif
133 
134 struct arch_switch archsw;	/* MI/MD interface boundary */
135 static char boot_devname[2 * ZFS_MAXNAMELEN + 8]; /* disk or pool:dataset */
136 
137 struct devsw *devsw[] = {
138 	&bioshd,
139 #if defined(LOADER_ZFS_SUPPORT)
140 	&zfs_dev,
141 #endif
142 	NULL
143 };
144 
145 struct fs_ops *file_system[] = {
146 #if defined(LOADER_ZFS_SUPPORT)
147 	&zfs_fsops,
148 #endif
149 #if defined(LOADER_UFS_SUPPORT)
150 	&ufs_fsops,
151 #endif
152 	NULL
153 };
154 
155 caddr_t
156 ptov(uintptr_t x)
157 {
158 	return (PTOV(x));
159 }
160 
161 int main(void);
162 
163 int
164 main(void)
165 {
166 	unsigned i;
167 	int auto_boot, fd, nextboot = 0;
168 	struct disk_devdesc *devdesc;
169 
170 	bios_getmem();
171 
172 	if (high_heap_size > 0) {
173 		heap_top = PTOV(high_heap_base + high_heap_size);
174 		heap_bottom = PTOV(high_heap_base);
175 	} else {
176 		heap_bottom = (char *)
177 		    (roundup2(__base + (int32_t)&_end, 0x10000) - __base);
178 		heap_top = (char *)PTOV(bios_basemem);
179 	}
180 	setheap(heap_bottom, heap_top);
181 
182 	/*
183 	 * Initialise the block cache. Set the upper limit.
184 	 */
185 	bcache_init(32768, 512);
186 
187 	archsw.arch_autoload = NULL;
188 	archsw.arch_getdev = i386_getdev;
189 	archsw.arch_copyin = NULL;
190 	archsw.arch_copyout = NULL;
191 	archsw.arch_readin = NULL;
192 	archsw.arch_isainb = NULL;
193 	archsw.arch_isaoutb = NULL;
194 	archsw.arch_zfs_probe = i386_zfs_probe;
195 
196 	bootinfo.bi_version = BOOTINFO_VERSION;
197 	bootinfo.bi_size = sizeof(bootinfo);
198 	bootinfo.bi_basemem = bios_basemem / 1024;
199 	bootinfo.bi_extmem = bios_extmem / 1024;
200 	bootinfo.bi_memsizes_valid++;
201 	bootinfo.bi_bios_dev = *(uint8_t *)PTOV(ARGS);
202 
203 	/* Set up fall back device name. */
204 	snprintf(boot_devname, sizeof (boot_devname), "disk%d:",
205 	    bd_bios2unit(bootinfo.bi_bios_dev));
206 
207 	/* Set up currdev variable to have hooks in place. */
208 	env_setenv("currdev", EV_VOLATILE, "", gen_setcurrdev,
209 	    env_nounset);
210 
211 	devinit();
212 
213 	/* XXX assumes this will be a disk, but it looks likely give above */
214 	disk_parsedev((struct devdesc **)&devdesc, boot_devname, NULL);
215 
216 	bootdev = MAKEBOOTDEV(dev_maj[DEVT_DISK], devdesc->d_slice + 1,
217 	    devdesc->dd.d_unit,
218 	    devdesc->d_partition >= 0 ? devdesc->d_partition : 0xff);
219 	free(devdesc);
220 
221 	/*
222 	 * devformat() can be called only after dv_init
223 	 */
224 	if (bdev != NULL && bdev->dd.d_dev->dv_type == DEVT_ZFS) {
225 		/* set up proper device name string for ZFS */
226 		strncpy(boot_devname, devformat(&bdev->dd), sizeof (boot_devname));
227 		if (zfs_get_bootonce(bdev, OS_BOOTONCE, cmd,
228 		    sizeof(cmd)) == 0) {
229 			nvlist_t *benv;
230 
231 			nextboot = 1;
232 			memcpy(cmddup, cmd, sizeof(cmd));
233 			if (parse_cmd()) {
234 				if (!OPT_CHECK(RBX_QUIET))
235 					printf("failed to parse bootonce "
236 					    "command\n");
237 				exit(0);
238 			}
239 			if (!OPT_CHECK(RBX_QUIET))
240 				printf("zfs bootonce: %s\n", cmddup);
241 
242 			if (zfs_get_bootenv(bdev, &benv) == 0) {
243 				nvlist_add_string(benv, OS_BOOTONCE_USED,
244 				    cmddup);
245 				zfs_set_bootenv(bdev, benv);
246 			}
247 			/* Do not process this command twice */
248 			*cmd = 0;
249 		}
250 	}
251 
252 	/* now make sure we have bdev on all cases */
253 	free(bdev);
254 	i386_getdev((void **)&bdev, boot_devname, NULL);
255 
256 	env_setenv("currdev", EV_VOLATILE, boot_devname, gen_setcurrdev,
257 	    env_nounset);
258 
259 	/* Process configuration file */
260 	auto_boot = 1;
261 
262 	fd = open(PATH_CONFIG, O_RDONLY);
263 	if (fd == -1)
264 		fd = open(PATH_DOTCONFIG, O_RDONLY);
265 
266 	if (fd != -1) {
267 		ssize_t cmdlen;
268 
269 		if ((cmdlen = read(fd, cmd, sizeof(cmd))) > 0)
270 			cmd[cmdlen] = '\0';
271 		else
272 			*cmd = '\0';
273 		close(fd);
274 	}
275 
276 	if (*cmd) {
277 		/*
278 		 * Note that parse_cmd() is destructive to cmd[] and we also
279 		 * want to honor RBX_QUIET option that could be present in
280 		 * cmd[].
281 		 */
282 		memcpy(cmddup, cmd, sizeof(cmd));
283 		if (parse_cmd())
284 			auto_boot = 0;
285 		if (!OPT_CHECK(RBX_QUIET))
286 			printf("%s: %s\n", PATH_CONFIG, cmddup);
287 		/* Do not process this command twice */
288 		*cmd = 0;
289 	}
290 
291 	/* Do not risk waiting at the prompt forever. */
292 	if (nextboot && !auto_boot)
293 		exit(0);
294 
295 	if (auto_boot && !*kname) {
296 		/*
297 		 * Iterate through the list of loader and kernel paths,
298 		 * trying to load. If interrupted by a keypress, or in case of
299 		 * failure, drop the user to the boot2 prompt.
300 		 */
301 		for (i = 0; i < nitems(loadpath); i++) {
302 			memcpy(kname, loadpath[i].p, loadpath[i].len);
303 			if (keyhit(3))
304 				break;
305 			load();
306 		}
307 	}
308 
309 	/* Present the user with the boot2 prompt. */
310 
311 	for (;;) {
312 		if (!auto_boot || !OPT_CHECK(RBX_QUIET)) {
313 			printf("\nFreeBSD/x86 boot\n");
314 			printf("Default: %s%s\nboot: ", boot_devname, kname);
315 		}
316 		if (ioctrl & IO_SERIAL)
317 			sio_flush();
318 		if (!auto_boot || keyhit(5))
319 			getstr(cmd, sizeof(cmd));
320 		else if (!auto_boot || !OPT_CHECK(RBX_QUIET))
321 			putchar('\n');
322 		auto_boot = 0;
323 		if (parse_cmd())
324 			putchar('\a');
325 		else
326 			load();
327 	}
328 }
329 
330 /* XXX - Needed for btxld to link the boot2 binary; do not remove. */
331 void
332 exit(int x)
333 {
334 	__exit(x);
335 }
336 
337 static void
338 load(void)
339 {
340 	union {
341 		struct exec ex;
342 		Elf32_Ehdr eh;
343 	} hdr;
344 	static Elf32_Phdr ep[2];
345 	static Elf32_Shdr es[2];
346 	caddr_t p;
347 	uint32_t addr, x;
348 	int fd, fmt, i, j;
349 	ssize_t size;
350 
351 	if ((fd = open(kname, O_RDONLY)) == -1) {
352 		printf("\nCan't find %s\n", kname);
353 		return;
354 	}
355 
356 	size = sizeof(hdr);
357 	if (read(fd, &hdr, sizeof (hdr)) != size) {
358 		close(fd);
359 		return;
360 	}
361 	if (N_GETMAGIC(hdr.ex) == ZMAGIC) {
362 		fmt = 0;
363 	} else if (IS_ELF(hdr.eh)) {
364 		fmt = 1;
365 	} else {
366 		printf("Invalid %s\n", "format");
367 		close(fd);
368 		return;
369 	}
370 	if (fmt == 0) {
371 		addr = hdr.ex.a_entry & 0xffffff;
372 		p = PTOV(addr);
373 		lseek(fd, PAGE_SIZE, SEEK_SET);
374 		size = hdr.ex.a_text;
375 		if (read(fd, p, hdr.ex.a_text) != size) {
376 			close(fd);
377 			return;
378 		}
379 		p += roundup2(hdr.ex.a_text, PAGE_SIZE);
380 		size = hdr.ex.a_data;
381 		if (read(fd, p, hdr.ex.a_data) != size) {
382 			close(fd);
383 			return;
384 		}
385 		p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
386 		bootinfo.bi_symtab = VTOP(p);
387 		memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
388 		p += sizeof(hdr.ex.a_syms);
389 		if (hdr.ex.a_syms) {
390 			size = hdr.ex.a_syms;
391 			if (read(fd, p, hdr.ex.a_syms) != size) {
392 				close(fd);
393 				return;
394 			}
395 			p += hdr.ex.a_syms;
396 			size = sizeof (int);
397 			if (read(fd, p, sizeof (int)) != size) {
398 				close(fd);
399 				return;
400 			}
401 			x = *(uint32_t *)p;
402 			p += sizeof(int);
403 			x -= sizeof(int);
404 			size = x;
405 			if (read(fd, p, x) != size) {
406 				close(fd);
407 				return;
408 			}
409 			p += x;
410 		}
411 	} else {
412 		lseek(fd, hdr.eh.e_phoff, SEEK_SET);
413 		for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
414 			size = sizeof (ep[0]);
415 			if (read(fd, ep + j, sizeof (ep[0])) != size) {
416 				close(fd);
417 				return;
418 			}
419 			if (ep[j].p_type == PT_LOAD)
420 				j++;
421 		}
422 		for (i = 0; i < 2; i++) {
423 			p = PTOV(ep[i].p_paddr & 0xffffff);
424 			lseek(fd, ep[i].p_offset, SEEK_SET);
425 			size = ep[i].p_filesz;
426 			if (read(fd, p, ep[i].p_filesz) != size) {
427 				close(fd);
428 				return;
429 			}
430 		}
431 		p += roundup2(ep[1].p_memsz, PAGE_SIZE);
432 		bootinfo.bi_symtab = VTOP(p);
433 		if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
434 			lseek(fd, hdr.eh.e_shoff +
435 			    sizeof (es[0]) * (hdr.eh.e_shstrndx + 1),
436 			    SEEK_SET);
437 			size = sizeof(es);
438 			if (read(fd, &es, sizeof (es)) != size) {
439 				close(fd);
440 				return;
441 			}
442 			for (i = 0; i < 2; i++) {
443 				memcpy(p, &es[i].sh_size,
444 				    sizeof(es[i].sh_size));
445 				p += sizeof(es[i].sh_size);
446 				lseek(fd, es[i].sh_offset, SEEK_SET);
447 				size = es[i].sh_size;
448 				if (read(fd, p, es[i].sh_size) != size) {
449 					close(fd);
450 					return;
451 				}
452 				p += es[i].sh_size;
453 			}
454 		}
455 		addr = hdr.eh.e_entry & 0xffffff;
456 	}
457 	close(fd);
458 
459 	bootinfo.bi_esymtab = VTOP(p);
460 	bootinfo.bi_kernelname = VTOP(kname);
461 #ifdef LOADER_GELI_SUPPORT
462 	explicit_bzero(gelipw, sizeof(gelipw));
463 #endif
464 
465 	if (bdev->dd.d_dev->dv_type == DEVT_ZFS) {
466 		zfsargs.size = sizeof(zfsargs);
467 		zfsargs.pool = bdev->zfs.pool_guid;
468 		zfsargs.root = bdev->zfs.root_guid;
469 #ifdef LOADER_GELI_SUPPORT
470 		export_geli_boot_data(&zfsargs.gelidata);
471 #endif
472 		/*
473 		 * Note that the zfsargs struct is passed by value, not by
474 		 * pointer. Code in btxldr.S copies the values from the entry
475 		 * stack to a fixed location within loader(8) at startup due
476 		 * to the presence of KARGS_FLAGS_EXTARG.
477 		 */
478 		__exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
479 		    bootdev,
480 		    KARGS_FLAGS_ZFS | KARGS_FLAGS_EXTARG,
481 		    (uint32_t)bdev->zfs.pool_guid,
482 		    (uint32_t)(bdev->zfs.pool_guid >> 32),
483 		    VTOP(&bootinfo),
484 		    zfsargs);
485 	} else {
486 #ifdef LOADER_GELI_SUPPORT
487 		geliargs.size = sizeof(geliargs);
488 		export_geli_boot_data(&geliargs.gelidata);
489 #endif
490 
491 		/*
492 		 * Note that the geliargs struct is passed by value, not by
493 		 * pointer. Code in btxldr.S copies the values from the entry
494 		 * stack to a fixed location within loader(8) at startup due
495 		 * to the presence of the KARGS_FLAGS_EXTARG flag.
496 		 */
497 		__exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
498 		    bootdev,
499 #ifdef LOADER_GELI_SUPPORT
500 		    KARGS_FLAGS_GELI | KARGS_FLAGS_EXTARG, 0, 0,
501 		    VTOP(&bootinfo), geliargs
502 #else
503 		    0, 0, 0, VTOP(&bootinfo)
504 #endif
505 		    );
506 	}
507 }
508 
509 static int
510 mount_root(char *arg)
511 {
512 	char *root;
513 	struct i386_devdesc *ddesc;
514 	uint8_t part;
515 
516 	if (asprintf(&root, "%s:", arg) < 0)
517 		return (1);
518 
519 	if (i386_getdev((void **)&ddesc, root, NULL)) {
520 		free(root);
521 		return (1);
522 	}
523 
524 	/* we should have new device descriptor, free old and replace it. */
525 	free(bdev);
526 	bdev = ddesc;
527 	if (bdev->dd.d_dev->dv_type == DEVT_DISK) {
528 		if (bdev->disk.d_partition == -1)
529 			part = 0xff;
530 		else
531 			part = bdev->disk.d_partition;
532 		bootdev = MAKEBOOTDEV(dev_maj[bdev->dd.d_dev->dv_type],
533 		    bdev->disk.d_slice + 1, bdev->dd.d_unit, part);
534 		bootinfo.bi_bios_dev = bd_unit2bios(bdev);
535 	}
536 	strncpy(boot_devname, root, sizeof (boot_devname));
537 	setenv("currdev", root, 1);
538 	free(root);
539 	return (0);
540 }
541 
542 static void
543 fs_list(char *arg)
544 {
545 	int fd;
546 	struct dirent *d;
547 	char line[80];
548 
549 	fd = open(arg, O_RDONLY);
550 	if (fd < 0)
551 		return;
552 	pager_open();
553 	while ((d = readdirfd(fd)) != NULL) {
554 		sprintf(line, "%s\n", d->d_name);
555 		if (pager_output(line))
556 			break;
557 	}
558 	pager_close();
559 	close(fd);
560 }
561 
562 static int
563 parse_cmd(void)
564 {
565 	char *arg = cmd;
566 	char *ep, *p, *q;
567 	const char *cp;
568 	char line[80];
569 	int c, i, j;
570 
571 	while ((c = *arg++)) {
572 		if (c == ' ' || c == '\t' || c == '\n')
573 			continue;
574 		for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++)
575 			;
576 		ep = p;
577 		if (*p)
578 			*p++ = 0;
579 		if (c == '-') {
580 			while ((c = *arg++)) {
581 				if (c == 'P') {
582 					if (*(uint8_t *)PTOV(0x496) & 0x10) {
583 						cp = "yes";
584 					} else {
585 						opts |= OPT_SET(RBX_DUAL);
586 						opts |= OPT_SET(RBX_SERIAL);
587 						cp = "no";
588 					}
589 					printf("Keyboard: %s\n", cp);
590 					continue;
591 				} else if (c == 'S') {
592 					j = 0;
593 					while ((unsigned int)
594 					    (i = *arg++ - '0') <= 9)
595 						j = j * 10 + i;
596 					if (j > 0 && i == -'0') {
597 						comspeed = j;
598 						break;
599 					}
600 					/*
601 					 * Fall through to error below
602 					 * ('S' not in optstr[]).
603 					 */
604 				}
605 				for (i = 0; c != optstr[i]; i++)
606 					if (i == NOPT - 1)
607 						return (-1);
608 				opts ^= OPT_SET(flags[i]);
609 			}
610 			ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
611 			    OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
612 			if (ioctrl & IO_SERIAL) {
613 				if (sio_init(115200 / comspeed) != 0)
614 					ioctrl &= ~IO_SERIAL;
615 			}
616 		} if (c == '?') {
617 			printf("\n");
618 			if (*arg == '\0')
619 				arg = (char *)"/";
620 			fs_list(arg);
621 			zfs_list(arg);
622 			return (-1);
623 		} else {
624 			char *ptr;
625 			printf("\n");
626 			arg--;
627 
628 			/*
629 			 * Report pool status if the comment is 'status'. Lets
630 			 * hope no-one wants to load /status as a kernel.
631 			 */
632 			if (strcmp(arg, "status") == 0) {
633 				pager_open();
634 				for (i = 0; devsw[i] != NULL; i++) {
635 					if (devsw[i]->dv_print != NULL) {
636 						if (devsw[i]->dv_print(1))
637 							break;
638 					} else {
639 						snprintf(line, sizeof(line),
640 						    "%s: (unknown)\n",
641 						    devsw[i]->dv_name);
642 						if (pager_output(line))
643 							break;
644 					}
645 				}
646 				pager_close();
647 				return (-1);
648 			}
649 
650 			/*
651 			 * If there is "zfs:" prefix simply ignore it.
652 			 */
653 			ptr = arg;
654 			if (strncmp(ptr, "zfs:", 4) == 0)
655 				ptr += 4;
656 
657 			/*
658 			 * If there is a colon, switch pools.
659 			 */
660 			q = strchr(ptr, ':');
661 			if (q) {
662 				*q++ = '\0';
663 				if (mount_root(arg) != 0) {
664 					return (-1);
665 				}
666 				arg = q;
667 			}
668 			if ((i = ep - arg)) {
669 				if ((size_t)i >= sizeof(kname))
670 					return (-1);
671 				memcpy(kname, arg, i + 1);
672 			}
673 		}
674 		arg = p;
675 	}
676 	return (0);
677 }
678 
679 /*
680  * Probe all disks to discover ZFS pools. The idea is to walk all possible
681  * disk devices, however, we also need to identify possible boot pool.
682  * For boot pool detection we have boot disk passed us from BIOS, recorded
683  * in bootinfo.bi_bios_dev.
684  */
685 static void
686 i386_zfs_probe(void)
687 {
688 	char devname[32];
689 	int boot_unit;
690 	struct i386_devdesc dev;
691 	uint64_t pool_guid = 0;
692 
693 	dev.dd.d_dev = &bioshd;
694 	/* Translate bios dev to our unit number. */
695 	boot_unit = bd_bios2unit(bootinfo.bi_bios_dev);
696 
697 	/*
698 	 * Open all the disks we can find and see if we can reconstruct
699 	 * ZFS pools from them.
700 	 */
701 	for (dev.dd.d_unit = 0; bd_unit2bios(&dev) >= 0; dev.dd.d_unit++) {
702 		snprintf(devname, sizeof (devname), "%s%d:", bioshd.dv_name,
703 		    dev.dd.d_unit);
704 		/* If this is not boot disk, use generic probe. */
705 		if (dev.dd.d_unit != boot_unit)
706 			zfs_probe_dev(devname, NULL, true);
707 		else
708 			zfs_probe_dev(devname, &pool_guid, true);
709 
710 		if (pool_guid != 0 && bdev == NULL) {
711 			bdev = malloc(sizeof (struct i386_devdesc));
712 			bzero(bdev, sizeof (struct i386_devdesc));
713 			bdev->zfs.dd.d_dev = &zfs_dev;
714 			bdev->zfs.pool_guid = pool_guid;
715 		}
716 	}
717 }
718