xref: /freebsd/usr.sbin/efibootmgr/efibootmgr.c (revision 47dd1d1b619cc035b82b49a91a25544309ff95ae)
1 /*-
2  * Copyright (c) 2017 Netflix, Inc.
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  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
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/stat.h>
31 #include <sys/vtoc.h>
32 #include <sys/param.h>
33 #include <assert.h>
34 #include <ctype.h>
35 #include <err.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <libgeom.h>
39 #include <paths.h>
40 #include <signal.h>
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <getopt.h>
45 #include <limits.h>
46 #include <inttypes.h>
47 #include <stdbool.h>
48 #include <string.h>
49 #include <strings.h>
50 #include <unistd.h>
51 #include <libgeom.h>
52 #include <geom/geom.h>
53 #include <geom/geom_ctl.h>
54 #include <geom/geom_int.h>
55 
56 #include <efivar.h>
57 #include <efiutil.h>
58 #include <efichar.h>
59 #include <efivar-dp.h>
60 
61 #ifndef LOAD_OPTION_ACTIVE
62 #define LOAD_OPTION_ACTIVE 0x00000001
63 #endif
64 
65 #ifndef LOAD_OPTION_CATEGORY_BOOT
66 #define LOAD_OPTION_CATEGORY_BOOT 0x00000000
67 #endif
68 
69 #define BAD_LENGTH	((size_t)-1)
70 
71 typedef struct _bmgr_opts {
72 	char	*env;
73 	char	*loader;
74 	char	*label;
75 	char	*kernel;
76 	char	*name;
77 	char	*order;
78 	int     bootnum;
79 	bool	copy;
80 	bool    create;
81 	bool    delete;
82 	bool    delete_bootnext;
83 	bool    del_timeout;
84 	bool    dry_run;
85 	bool    once;
86 	int	cp_src;
87 	bool    set_active;
88 	bool    set_bootnext;
89 	bool    set_inactive;
90 	bool    set_timeout;
91 	int     timeout;
92 	bool    verbose;
93 } bmgr_opts_t;
94 
95 static struct option lopts[] = {
96 	{"activate", required_argument, NULL, 'a'},
97 	{"bootnext", required_argument, NULL, 'n'}, /* set bootnext */
98 	{"bootorder", required_argument, NULL, 'o'}, /* set order */
99 	{"copy", required_argument, NULL, 'C'},		/* Copy boot method */
100 	{"create", no_argument, NULL, 'c'},
101 	{"deactivate", required_argument, NULL, 'A'},
102 	{"del-timout", no_argument, NULL, 'T'},
103 	{"delete", required_argument, NULL, 'B'},
104 	{"delete-bootnext", required_argument, NULL, 'N'},
105 	{"dry-run", no_argument, NULL, 'D'},
106 	{"env", required_argument, NULL, 'e'},
107 	{"help", no_argument, NULL, 'h'},
108 	{"kernel", required_argument, NULL, 'k'},
109 	{"label", required_argument, NULL, 'L'},
110 	{"loader", required_argument, NULL, 'l'},
111 	{"once", no_argument, NULL, 'O'},
112 	{"set-timeout", required_argument, NULL, 't'},
113 	{"verbose", no_argument, NULL, 'v'},
114 	{ NULL, 0, NULL, 0}
115 };
116 
117 /* global efibootmgr opts */
118 static bmgr_opts_t opts;
119 
120 static LIST_HEAD(efivars_head, entry) efivars =
121 	LIST_HEAD_INITIALIZER(efivars);
122 
123 struct entry {
124 	efi_guid_t	guid;
125 	uint32_t	attrs;
126 	uint8_t		*data;
127 	size_t		size;
128 	char		*name;
129 	char		*label;
130 	int		idx;
131 	int		flags;
132 #define SEEN	1
133 
134 	LIST_ENTRY(entry) entries;
135 };
136 
137 #define MAX_DP_LEN	4096
138 #define MAX_LOADOPT_LEN	8192
139 
140 
141 static char *
142 mangle_loader(char *loader)
143 {
144 	char *c;
145 
146 	for (c = loader; *c; c++)
147 		if (*c == '/')
148 			*c = '\\';
149 
150 	return loader;
151 }
152 
153 
154 #define COMMON_ATTRS EFI_VARIABLE_NON_VOLATILE | \
155 	EFI_VARIABLE_BOOTSERVICE_ACCESS | \
156 	EFI_VARIABLE_RUNTIME_ACCESS
157 
158 /*
159  * We use global guid, and common var attrs and
160  * find it better to just delete and re-create a var.
161  */
162 static int
163 set_bootvar(const char *name, uint8_t *data, size_t size)
164 {
165 
166 	return efi_set_variable(EFI_GLOBAL_GUID, name, data, size,
167 	    COMMON_ATTRS);
168 }
169 
170 
171 #define USAGE \
172 	"   [-aAnNB Bootvar] [-t timeout] [-T] [-o bootorder] [-O] [--verbose] [--help] \n\
173   [-c -l loader [-k kernel ] [-L label] [--dry-run]]"
174 
175 #define CREATE_USAGE \
176 	"       efibootmgr -c -l loader [-k kernel] [-L label] [--dry-run]"
177 #define ORDER_USAGE \
178 	"       efibootmgr -o bootvarnum1,bootvarnum2,..."
179 #define TIMEOUT_USAGE \
180 	"       efibootmgr -t seconds"
181 #define DELETE_USAGE \
182 	"       efibootmgr -B bootvarnum"
183 #define ACTIVE_USAGE \
184 	"       efibootmgr [-a | -A] bootvarnum"
185 #define BOOTNEXT_USAGE \
186 	"       efibootmgr [-n | -N] bootvarnum"
187 
188 static void
189 parse_args(int argc, char *argv[])
190 {
191 	int ch;
192 
193 	while ((ch = getopt_long(argc, argv, "A:a:B:C:cDe:hk:L:l:Nn:Oo:Tt:v",
194 		    lopts, NULL)) != -1) {
195 		switch (ch) {
196 		case 'A':
197 			opts.set_inactive = true;
198 			opts.bootnum = strtoul(optarg, NULL, 16);
199 			break;
200 		case 'a':
201 			opts.set_active = true;
202 			opts.bootnum = strtoul(optarg, NULL, 16);
203 			break;
204 		case 'B':
205 			opts.delete = true;
206 			opts.bootnum = strtoul(optarg, NULL, 16);
207 			break;
208 		case 'C':
209 			opts.copy = true;
210 			opts.cp_src = strtoul(optarg, NULL, 16);
211 		case 'c':
212 			opts.create = true;
213 			break;
214 		case 'D': /* should be remove dups XXX */
215 			opts.dry_run = true;
216 			break;
217 		case 'e':
218 			free(opts.env);
219 			opts.env = strdup(optarg);
220 			break;
221 		case 'h':
222 		default:
223 			errx(1, "%s", USAGE);
224 			break;
225 		case 'k':
226 			free(opts.kernel);
227 			opts.kernel = strdup(optarg);
228 			break;
229 		case 'L':
230 			free(opts.label);
231 			opts.label = strdup(optarg);
232 			break;
233 		case 'l':
234 			free(opts.loader);
235 			opts.loader = strdup(optarg);
236 			opts.loader = mangle_loader(opts.loader);
237 			break;
238 		case 'N':
239 			opts.delete_bootnext = true;
240 			break;
241 		case 'n':
242 			opts.set_bootnext = true;
243 			opts.bootnum = strtoul(optarg, NULL, 16);
244 			break;
245 		case 'O':
246 			opts.once = true;
247 			break;
248 		case 'o':
249 			free(opts.order);
250 			opts.order = strdup(optarg);
251 			break;
252 		case 'T':
253 			opts.del_timeout = true;
254 			break;
255 		case 't':
256 			opts.set_timeout = true;
257 			opts.timeout = strtoul(optarg, NULL, 10);
258 			break;
259 		case 'v':
260 			opts.verbose = true;
261 			break;
262 		}
263 	}
264 	if (opts.create) {
265 		if (!opts.loader)
266 			errx(1, "%s",CREATE_USAGE);
267 		return;
268 	}
269 	if (opts.set_bootnext && !(opts.bootnum))
270 		errx(1, "%s", BOOTNEXT_USAGE);
271 
272 	if ((opts.set_active ||  opts.set_inactive) && !(opts.bootnum))
273 		errx(1, "%s", ACTIVE_USAGE);
274 
275 	if (opts.order && !(opts.order))
276 		errx(1, "%s", ORDER_USAGE);
277 }
278 
279 
280 static void
281 read_vars(void)
282 {
283 
284 	efi_guid_t *guid;
285 	char *next_name = NULL;
286 	int ret = 0;
287 
288 	struct entry *nent;
289 
290 	LIST_INIT(&efivars);
291 	while ((ret = efi_get_next_variable_name(&guid, &next_name)) > 0) {
292 		/*
293 		 * Only pay attention to EFI:BootXXXX variables to get the list.
294 		 */
295 		if (efi_guid_cmp(guid, &EFI_GLOBAL_GUID) != 0 ||
296 		    strlen(next_name) != 8 ||
297 		    strncmp(next_name, "Boot", 4) != 0 ||
298 		    !isxdigit(next_name[4]) ||
299 		    !isxdigit(next_name[5]) ||
300 		    !isxdigit(next_name[6]) ||
301 		    !isxdigit(next_name[7]))
302 			continue;
303 		nent = malloc(sizeof(struct entry));
304 		nent->name = strdup(next_name);
305 
306 		ret = efi_get_variable(*guid, next_name, &nent->data,
307 		    &nent->size, &nent->attrs);
308 		if (ret < 0)
309 			err(1, "efi_get_variable");
310 		nent->guid = *guid;
311 		nent->idx = strtoul(&next_name[4], NULL, 16);
312 		LIST_INSERT_HEAD(&efivars, nent, entries);
313 	}
314 }
315 
316 
317 static void
318 set_boot_order(char *order)
319 {
320 	uint16_t *new_data;
321 	size_t size;
322 	char *next, *cp;
323 	int cnt;
324 	int i;
325 
326 	cp = order;
327 	cnt = 1;
328 	while (*cp) {
329 		if (*cp++ == ',')
330 			cnt++;
331 	}
332 	size = sizeof(uint16_t) * cnt;
333 	new_data = malloc(size);
334 
335 	i = 0;
336 	cp = strdup(order);
337 	while ((next = strsep(&cp, ",")) != NULL) {
338 		new_data[i] = strtoul(next, NULL, 16);
339 		if (new_data[i] == 0 && errno == EINVAL) {
340 			warnx("can't parse %s as a numb", next);
341 			errx(1, "%s", ORDER_USAGE);
342 		}
343 		i++;
344 	}
345 	free(cp);
346 	if (set_bootvar("BootOrder", (uint8_t*)new_data, size) < 0)
347 		err(1, "Unabke to set BootOrder to %s", order);
348 	free(new_data);
349 }
350 
351 static void
352 handle_activity(int bootnum, bool active)
353 {
354 	uint32_t attrs, load_attrs;
355 	uint8_t *data;
356 	size_t size;
357 	char *name;
358 
359 	asprintf(&name, "%s%04X", "Boot", bootnum);
360 	if (name == NULL)
361 		err(1, "asprintf");
362 	if (efi_get_variable(EFI_GLOBAL_GUID, name, &data, &size, &attrs) < 0)
363 		err(1, "No such bootvar %s\n", name);
364 
365 	load_attrs = le32dec(data);
366 
367 	if (active)
368 		load_attrs |= LOAD_OPTION_ACTIVE;
369 	else
370 		load_attrs &= ~LOAD_OPTION_ACTIVE;
371 
372 	le32enc(data, load_attrs);
373 
374 	if (set_bootvar(name, data, size) < 0)
375 		err(1, "handle activity efi_set_variable");
376 }
377 
378 
379 /*
380  * add boot var to boot order.
381  * called by create boot var. There is no option
382  * to add one independent of create.
383  *
384  * Note: we currently don't support where it goes
385  * so it goes on the front, inactive.
386  * use -o 2,3,7 etc to affect order, -a to activate.
387  */
388 static void
389 add_to_boot_order(char *bootvar)
390 {
391 	size_t size;
392 	uint32_t attrs;
393 	uint16_t val;
394 	uint8_t *data, *new;
395 
396 	val = strtoul(&bootvar[4], NULL, 16);
397 
398 	if (efi_get_variable(EFI_GLOBAL_GUID, "BootOrder", &data, &size, &attrs) < 0) {
399 		if (errno == ENOENT) { /* create it and set this bootvar to active */
400 			size = 0;
401 			data = NULL;
402 		} else
403 			err(1, "efi_get_variable BootOrder");
404 	}
405 
406 	/*
407 	 * We have BootOrder with the current order
408 	 * so grow the array by one, add the value
409 	 * and write the new variable value.
410 	 */
411 	size += sizeof(uint16_t);
412 	new = malloc(size);
413 	if (!new)
414 		err(1, "malloc");
415 
416 	le16enc(new, val);
417 	if (size > sizeof(uint16_t))
418 		memcpy(new + sizeof(uint16_t), data, size - sizeof(uint16_t));
419 
420 	if (set_bootvar("BootOrder", new, size) < 0)
421 		err(1, "set_bootvar");
422 	free(new);
423 }
424 
425 
426 static void
427 remove_from_order(uint16_t bootnum)
428 {
429 	uint32_t attrs;
430 	size_t size, i, j;
431 	uint8_t *new, *data;
432 
433 	if (efi_get_variable(EFI_GLOBAL_GUID, "BootOrder", &data, &size, &attrs) < 0)
434 		return;
435 
436 	new = malloc(size);
437 	if (new == NULL)
438 		err(1, "malloc");
439 
440 	for (j = i = 0; i < size; i += sizeof(uint16_t)) {
441 		if (le16dec(data + i) == bootnum)
442 			continue;
443 		memcpy(new + j, data + i, sizeof(uint16_t));
444 		j += sizeof(uint16_t);
445 	}
446 	if (i == j)
447 		warnx("Boot variable %04x not in BootOrder", bootnum);
448 	else if (set_bootvar("BootOrder", new, j) < 0)
449 		err(1, "Unable to update BootOrder with new value");
450 	free(new);
451 }
452 
453 
454 static void
455 delete_bootvar(int bootnum)
456 {
457 	char *name;
458 	int defer = 0;
459 
460 	/*
461 	 * Try to delete the boot variable and remocve it
462 	 * from the boot order. We always do both actions
463 	 * to make it easy to clean up from oopses.
464 	 */
465 	if (bootnum < 0 || bootnum > 0xffff)
466 		errx(1, "Bad boot variable %#x", bootnum);
467 	asprintf(&name, "%s%04X", "Boot", bootnum);
468 	if (name == NULL)
469 		err(1, "asprintf");
470 	printf("Removing boot variable '%s'\n", name);
471 	if (efi_del_variable(EFI_GLOBAL_GUID, name) < 0) {
472 		defer = 1;
473 		warn("cannot delete variable %s", name);
474 	}
475 	printf("Removing 0x%x from BootOrder\n", bootnum);
476 	remove_from_order(bootnum);
477 	free(name);
478 	if (defer)
479 		exit(defer);
480 }
481 
482 
483 static void
484 del_bootnext(void)
485 {
486 
487 	if (efi_del_variable(EFI_GLOBAL_GUID, "BootNext") < 0)
488 		err(1, "efi_del_variable");
489 }
490 
491 static void
492 handle_bootnext(uint16_t bootnum)
493 {
494 	uint16_t num;
495 
496 	le16enc(&num, bootnum);
497 	if (set_bootvar("BootNext", (uint8_t*)&bootnum, sizeof(uint16_t)) < 0)
498 		err(1, "set_bootvar");
499 }
500 
501 
502 static int
503 compare(const void *a, const void *b)
504 {
505 	uint16_t c;
506 	uint16_t d;
507 
508 	memcpy(&c, a, sizeof(uint16_t));
509 	memcpy(&d, b, sizeof(uint16_t));
510 
511 	if (c < d)
512 		return -1;
513 	if (c == d)
514 		return  0;
515 	return  1;
516 }
517 
518 static char *
519 make_next_boot_var_name(void)
520 {
521 	struct entry *v;
522 	uint16_t *vals, next_free = 0;
523 	char *name;
524 	int cnt = 0;
525 	int i;
526 
527 	LIST_FOREACH(v, &efivars, entries) {
528 		cnt++;
529 	}
530 
531 	vals = malloc(sizeof(uint16_t) * cnt);
532 	if (!vals)
533 		return NULL;
534 
535 	i = 0;
536 	LIST_FOREACH(v, &efivars, entries) {
537 		vals[i++] = v->idx;
538 	}
539 	qsort(vals, cnt, sizeof(uint16_t), compare);
540 	/* if the hole is at the beginning, just return zero */
541 	if (vals[0] > 0) {
542 		next_free = 0;
543 	} else {
544 		/* now just run the list looking for the first hole */
545 		for (i = 0; i < cnt - 1 && next_free == 0; i++)
546 			if (vals[i] + 1 != vals[i + 1])
547 				next_free = vals[i] + 1;
548 		if (next_free == 0)
549 			next_free = vals[cnt - 1] + 1;
550 		/* In theory we could have used all 65k slots -- what to do? */
551 	}
552 	free(vals);
553 
554 	asprintf(&name, "%s%04X", "Boot", next_free);
555 	if (name == NULL)
556 		err(1, "asprintf");
557 	return name;
558 }
559 
560 
561 static size_t
562 create_loadopt(uint8_t *buf, size_t bufmax, uint32_t attributes, efidp dp, size_t dp_size,
563     const char *description, const uint8_t *optional_data, size_t optional_data_size)
564 {
565 	efi_char *bbuf = NULL;
566 	uint8_t *pos = buf;
567 	size_t desc_len = 0;
568 	size_t len;
569 
570 	if (optional_data == NULL && optional_data_size != 0)
571 		return BAD_LENGTH;
572 	if (dp == NULL && dp_size != 0)
573 		return BAD_LENGTH;
574 
575 	/*
576 	 * Compute the length to make sure the passed in buffer is long enough.
577 	 */
578 	utf8_to_ucs2(description, &bbuf, &desc_len);
579 	len = sizeof(uint32_t) + sizeof(uint16_t) + desc_len + dp_size + optional_data_size;
580 	if (len > bufmax) {
581 		free(bbuf);
582 		return BAD_LENGTH;
583 	}
584 
585 	le32enc(pos, attributes);
586 	pos += sizeof (attributes);
587 
588 	le16enc(pos, dp_size);
589 	pos += sizeof (uint16_t);
590 
591 	memcpy(pos, bbuf, desc_len);	/* NB:desc_len includes strailing NUL */
592 	pos += desc_len;
593 	free(bbuf);
594 
595 	memcpy(pos, dp, dp_size);
596 	pos += dp_size;
597 
598 	if (optional_data && optional_data_size > 0) {
599 		memcpy(pos, optional_data, optional_data_size);
600 		pos += optional_data_size;
601 	}
602 
603 	return pos - buf;
604 }
605 
606 
607 static int
608 make_boot_var(const char *label, const char *loader, const char *kernel, const char *env, bool dry_run)
609 {
610 	struct entry *new_ent;
611 	uint32_t load_attrs = 0;
612 	uint8_t *load_opt_buf;
613 	size_t lopt_size, llen, klen;
614 	efidp dp, loaderdp, kerneldp;
615 	char *bootvar = NULL;
616 	int ret;
617 
618 	assert(label != NULL);
619 
620 	bootvar = make_next_boot_var_name();
621 	if (bootvar == NULL)
622 		err(1, "bootvar creation");
623 	if (loader == NULL)
624 		errx(1, "Must specify boot loader");
625 	if (efivar_unix_path_to_device_path(loader, &loaderdp) != 0)
626 		err(1, "Cannot translate unix loader path '%s' to UEFI", loader);
627 	if (kernel != NULL) {
628 		if (efivar_unix_path_to_device_path(kernel, &kerneldp) != 0)
629 			err(1, "Cannot translate unix kernel path '%s' to UEFI", kernel);
630 	} else {
631 		kerneldp = NULL;
632 	}
633 	llen = efidp_size(loaderdp);
634 	if (llen > MAX_DP_LEN)
635 		errx(1, "Loader path too long.");
636 	klen = efidp_size(kerneldp);
637 	if (klen > MAX_DP_LEN)
638 		errx(1, "Kernel path too long.");
639 	dp = malloc(llen + klen);
640 	if (dp == NULL)
641 		errx(1, "Can't allocate memory for new device paths");
642 	memcpy(dp, loaderdp, llen);
643 	if (kerneldp != NULL)
644 		memcpy((char *)dp + llen, kerneldp, klen);
645 
646 	/* don't make the new bootvar active by default, use the -a option later */
647 	load_attrs = LOAD_OPTION_CATEGORY_BOOT;
648 	load_opt_buf = malloc(MAX_LOADOPT_LEN);
649 	if (load_opt_buf == NULL)
650 		err(1, "malloc");
651 
652 	lopt_size = create_loadopt(load_opt_buf, MAX_LOADOPT_LEN, load_attrs,
653 	    dp, llen + klen, label, env, env ? strlen(env) + 1 : 0);
654 	if (lopt_size == BAD_LENGTH)
655 		errx(1, "Can't crate loadopt");
656 
657 	ret = 0;
658 	if (!dry_run) {
659 		ret = efi_set_variable(EFI_GLOBAL_GUID, bootvar,
660 		    (uint8_t*)load_opt_buf, lopt_size, COMMON_ATTRS);
661 	}
662 
663 	if (ret)
664 		err(1, "efi_set_variable");
665 
666 	add_to_boot_order(bootvar); /* first, still not active */
667 	new_ent = malloc(sizeof(struct entry));
668 	if (new_ent == NULL)
669 		err(1, "malloc");
670 	memset(new_ent, 0, sizeof(struct entry));
671 	new_ent->name = bootvar;
672 	new_ent->guid = EFI_GLOBAL_GUID;
673 	LIST_INSERT_HEAD(&efivars, new_ent, entries);
674 	free(load_opt_buf);
675 	free(dp);
676 
677 	return 0;
678 }
679 
680 
681 static void
682 print_loadopt_str(uint8_t *data, size_t datalen)
683 {
684 	char *dev, *relpath, *abspath;
685 	uint32_t attr;
686 	uint16_t fplen;
687 	efi_char *descr;
688 	uint8_t *ep = data + datalen;
689 	uint8_t *walker = data;
690 	efidp dp, edp;
691 	char buf[1024];
692 	int len;
693 	int rv;
694 	int indent;
695 
696 	if (datalen < sizeof(attr) + sizeof(fplen) + sizeof(efi_char))
697 		return;
698 	// First 4 bytes are attribute flags
699 	attr = le32dec(walker);
700 	walker += sizeof(attr);
701 	// Next two bytes are length of the file paths
702 	fplen = le16dec(walker);
703 	walker += sizeof(fplen);
704 	// Next we have a 0 terminated UCS2 string that we know to be aligned
705 	descr = (efi_char *)(intptr_t)(void *)walker;
706 	len = ucs2len(descr); // XXX need to sanity check that len < (datalen - (ep - walker) / 2)
707 	walker += (len + 1) * sizeof(efi_char);
708 	if (walker > ep)
709 		return;
710 	// Now we have fplen bytes worth of file path stuff
711 	dp = (efidp)walker;
712 	walker += fplen;
713 	if (walker > ep)
714 		return;
715 	edp = (efidp)walker;
716 	/*
717 	 * Everything left is the binary option args
718 	 * opt = walker;
719 	 * optlen = ep - walker;
720 	 */
721 	indent = 1;
722 	while (dp < edp) {
723 		efidp_format_device_path(buf, sizeof(buf), dp,
724 		    (intptr_t)(void *)edp - (intptr_t)(void *)dp);
725 		printf("%*s%s\n", indent, "", buf);
726 		indent = 10 + len + 1;
727 		rv = efivar_device_path_to_unix_path(dp, &dev, &relpath, &abspath);
728 		if (rv == 0) {
729 			printf("%*s%s:%s %s\n", indent + 4, "", dev, relpath, abspath);
730 			free(dev);
731 			free(relpath);
732 			free(abspath);
733 		}
734 		dp = (efidp)((char *)dp + efidp_size(dp));
735 	}
736 }
737 
738 static char *
739 get_descr(uint8_t *data)
740 {
741 	uint8_t *pos = data;
742 	efi_char *desc;
743 	int  len;
744 	char *buf;
745 	int i = 0;
746 
747 	pos += sizeof(uint32_t) + sizeof(uint16_t);
748 	desc = (efi_char*)(intptr_t)(void *)pos;
749 	len = ucs2len(desc);
750 	buf = malloc(len + 1);
751 	memset(buf, 0, len + 1);
752 	while (desc[i]) {
753 		buf[i] = desc[i];
754 		i++;
755 	}
756 	return (char*)buf;
757 }
758 
759 
760 static bool
761 print_boot_var(const char *name, bool verbose, bool curboot)
762 {
763 	size_t size;
764 	uint32_t load_attrs;
765 	uint8_t *data;
766 	int ret;
767 	char *d;
768 
769 	ret = efi_get_variable(EFI_GLOBAL_GUID, name, &data, &size, NULL);
770 	if (ret < 0)
771 		return false;
772 	load_attrs = le32dec(data);
773 	d = get_descr(data);
774 	printf("%c%s%c %s", curboot ? '+' : ' ', name,
775 	    ((load_attrs & LOAD_OPTION_ACTIVE) ? '*': ' '), d);
776 	free(d);
777 	if (verbose)
778 		print_loadopt_str(data, size);
779 	else
780 		printf("\n");
781 	return true;
782 }
783 
784 
785 /* Cmd epilogue, or just the default with no args.
786  * The order is [bootnext] bootcurrent, timeout, order, and the bootvars [-v]
787  */
788 static int
789 print_boot_vars(bool verbose)
790 {
791 	/*
792 	 * just read and print the current values
793 	 * as a command epilogue
794 	 */
795 	struct entry *v;
796 	uint8_t *data;
797 	size_t size;
798 	uint32_t attrs;
799 	int ret, bolen;
800 	uint16_t *boot_order = NULL, current;
801 
802 	ret = efi_get_variable(EFI_GLOBAL_GUID, "BootNext", &data, &size, &attrs);
803 	if (ret > 0) {
804 		printf("BootNext : %04x\n", le16dec(data));
805 	}
806 
807 	ret = efi_get_variable(EFI_GLOBAL_GUID, "BootCurrent", &data, &size,&attrs);
808 	current = le16dec(data);
809 	printf("BootCurrent: %04x\n", current);
810 
811 	ret = efi_get_variable(EFI_GLOBAL_GUID, "Timeout", &data, &size, &attrs);
812 	if (ret > 0) {
813 		printf("Timeout    : %d seconds\n", le16dec(data));
814 	}
815 
816 	if (efi_get_variable(EFI_GLOBAL_GUID, "BootOrder", &data, &size, &attrs) > 0) {
817 		if (size % 2 == 1)
818 			warn("Bad BootOrder variable: odd length %d", (int)size);
819 		boot_order = malloc(size);
820 		bolen = size / 2;
821 		printf("BootOrder  : ");
822 		for (size_t i = 0; i < size; i += 2) {
823 			boot_order[i / 2] = le16dec(data + i);
824 			printf("%04X%s", boot_order[i / 2], i == size - 2 ? "\n" : ", ");
825 		}
826 	}
827 
828 	if (boot_order == NULL) {
829 		/*
830 		 * now we want to fetch 'em all fresh again
831 		 * which possibly includes a newly created bootvar
832 		 */
833 		LIST_FOREACH(v, &efivars, entries) {
834 			print_boot_var(v->name, verbose, v->idx == current);
835 		}
836 	} else {
837 		LIST_FOREACH(v, &efivars, entries) {
838 			v->flags = 0;
839 		}
840 		for (int i = 0; i < bolen; i++) {
841 			char buffer[10];
842 
843 			snprintf(buffer, sizeof(buffer), "Boot%04X", boot_order[i]);
844 			if (!print_boot_var(buffer, verbose, boot_order[i] == current))
845 				printf("%s: MISSING!\n", buffer);
846 			LIST_FOREACH(v, &efivars, entries) {
847 				if (v->idx == boot_order[i]) {
848 					v->flags |= SEEN;
849 					break;
850 				}
851 			}
852 		}
853 		if (verbose) {
854 			printf("\n\nUnreferenced Variables:\n");
855 			LIST_FOREACH(v, &efivars, entries) {
856 				if (v->flags == 0)
857 					print_boot_var(v->name, verbose, v->idx == current);
858 			}
859 		}
860 	}
861 	return 0;
862 }
863 
864 static void
865 delete_timeout(void)
866 {
867 
868 	efi_del_variable(EFI_GLOBAL_GUID,"Timeout");
869 }
870 
871 static void
872 handle_timeout(int to)
873 {
874 	uint16_t timeout;
875 
876 	le16enc(&timeout, to);
877 	if (set_bootvar("Timeout", (uint8_t *)&timeout, sizeof(timeout)) < 0)
878 		errx(1, "Can't set Timeout for booting.");
879 }
880 
881 int
882 main(int argc, char *argv[])
883 {
884 
885 	if (!efi_variables_supported())
886 		errx(1, "efi variables not supported on this system. root? kldload efirt?");
887 
888 	memset(&opts, 0, sizeof (bmgr_opts_t));
889 	parse_args(argc, argv);
890 	read_vars();
891 
892 	if (opts.create)
893 		/*
894 		 * side effect, adds to boot order, but not yet active.
895 		 */
896 		make_boot_var(opts.label ? opts.label : "",
897 		    opts.loader, opts.kernel, opts.env, opts.dry_run);
898 	else if (opts.set_active || opts.set_inactive )
899 		handle_activity(opts.bootnum, opts.set_active);
900 	else if (opts.order != NULL)
901 		set_boot_order(opts.order); /* create a new bootorder with opts.order */
902 	else if (opts.set_bootnext)
903 		handle_bootnext(opts.bootnum);
904 	else if (opts.delete_bootnext)
905 		del_bootnext();
906 	else if (opts.delete)
907 		delete_bootvar(opts.bootnum);
908 	else if (opts.del_timeout)
909 		delete_timeout();
910 	else if (opts.set_timeout)
911 		handle_timeout(opts.timeout);
912 
913 	print_boot_vars(opts.verbose);
914 }
915