xref: /freebsd/stand/uboot/main.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * Copyright (c) 2000 Benno Rice <benno@jeamland.net>
3  * Copyright (c) 2000 Stephane Potvin <sepotvin@videotron.ca>
4  * Copyright (c) 2007-2008 Semihalf, Rafal Jaworowski <raj@semihalf.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 
31 #include <stand.h>
32 
33 #include "api_public.h"
34 #include "bootstrap.h"
35 #include "glue.h"
36 #include "libuboot.h"
37 
38 #ifndef nitems
39 #define	nitems(x)	(sizeof((x)) / sizeof((x)[0]))
40 #endif
41 
42 #ifndef HEAP_SIZE
43 #define	HEAP_SIZE	(2 * 1024 * 1024)
44 #endif
45 
46 struct uboot_devdesc currdev;
47 struct arch_switch archsw;		/* MI/MD interface boundary */
48 int devs_no;
49 
50 uintptr_t uboot_heap_start;
51 uintptr_t uboot_heap_end;
52 
53 struct device_type {
54 	const char *name;
55 	int type;
56 } device_types[] = {
57 	{ "disk", DEV_TYP_STOR },
58 	{ "ide",  DEV_TYP_STOR | DT_STOR_IDE },
59 	{ "mmc",  DEV_TYP_STOR | DT_STOR_MMC },
60 	{ "sata", DEV_TYP_STOR | DT_STOR_SATA },
61 	{ "scsi", DEV_TYP_STOR | DT_STOR_SCSI },
62 	{ "usb",  DEV_TYP_STOR | DT_STOR_USB },
63 	{ "net",  DEV_TYP_NET }
64 };
65 
66 extern char end[];
67 
68 extern unsigned char _etext[];
69 extern unsigned char _edata[];
70 extern unsigned char __bss_start[];
71 extern unsigned char __sbss_start[];
72 extern unsigned char __sbss_end[];
73 extern unsigned char _end[];
74 
75 #ifdef LOADER_FDT_SUPPORT
76 extern int command_fdt_internal(int argc, char *argv[]);
77 #endif
78 
79 static void
80 dump_sig(struct api_signature *sig)
81 {
82 #ifdef DEBUG
83 	printf("signature:\n");
84 	printf("  version\t= %d\n", sig->version);
85 	printf("  checksum\t= 0x%08x\n", sig->checksum);
86 	printf("  sc entry\t= 0x%08x\n", sig->syscall);
87 #endif
88 }
89 
90 static void
91 dump_addr_info(void)
92 {
93 #ifdef DEBUG
94 	printf("\naddresses info:\n");
95 	printf(" _etext (sdata) = 0x%08x\n", (uint32_t)_etext);
96 	printf(" _edata         = 0x%08x\n", (uint32_t)_edata);
97 	printf(" __sbss_start   = 0x%08x\n", (uint32_t)__sbss_start);
98 	printf(" __sbss_end     = 0x%08x\n", (uint32_t)__sbss_end);
99 	printf(" __sbss_start   = 0x%08x\n", (uint32_t)__bss_start);
100 	printf(" _end           = 0x%08x\n", (uint32_t)_end);
101 	printf(" syscall entry  = 0x%08x\n", (uint32_t)syscall_ptr);
102 #endif
103 }
104 
105 static uint64_t
106 memsize(struct sys_info *si, int flags)
107 {
108 	uint64_t size;
109 	int i;
110 
111 	size = 0;
112 	for (i = 0; i < si->mr_no; i++)
113 		if (si->mr[i].flags == flags && si->mr[i].size)
114 			size += (si->mr[i].size);
115 
116 	return (size);
117 }
118 
119 static void
120 meminfo(void)
121 {
122 	uint64_t size;
123 	struct sys_info *si;
124 	int t[3] = { MR_ATTR_DRAM, MR_ATTR_FLASH, MR_ATTR_SRAM };
125 	int i;
126 
127 	if ((si = ub_get_sys_info()) == NULL)
128 		panic("could not retrieve system info");
129 
130 	for (i = 0; i < 3; i++) {
131 		size = memsize(si, t[i]);
132 		if (size > 0)
133 			printf("%s: %juMB\n", ub_mem_type(t[i]),
134 			    (uintmax_t)(size / 1024 / 1024));
135 	}
136 }
137 
138 static const char *
139 get_device_type(const char *devstr, int *devtype)
140 {
141 	int i;
142 	int namelen;
143 	struct device_type *dt;
144 
145 	if (devstr) {
146 		for (i = 0; i < nitems(device_types); i++) {
147 			dt = &device_types[i];
148 			namelen = strlen(dt->name);
149 			if (strncmp(dt->name, devstr, namelen) == 0) {
150 				*devtype = dt->type;
151 				return (devstr + namelen);
152 			}
153 		}
154 		printf("Unknown device type '%s'\n", devstr);
155 	}
156 
157 	*devtype = DEV_TYP_NONE;
158 	return (NULL);
159 }
160 
161 static const char *
162 device_typename(int type)
163 {
164 	int i;
165 
166 	for (i = 0; i < nitems(device_types); i++)
167 		if (device_types[i].type == type)
168 			return (device_types[i].name);
169 
170 	return ("<unknown>");
171 }
172 
173 /*
174  * Parse a device string into type, unit, slice and partition numbers. A
175  * returned value of -1 for type indicates a search should be done for the
176  * first loadable device, otherwise a returned value of -1 for unit
177  * indicates a search should be done for the first loadable device of the
178  * given type.
179  *
180  * The returned values for slice and partition are interpreted by
181  * disk_open().
182  *
183  * The device string can be a standard loader(8) disk specifier:
184  *
185  * disk<unit>s<slice>              disk0s1
186  * disk<unit>s<slice><partition>   disk1s2a
187  * disk<unit>p<partition>          disk0p4
188  *
189  * or one of the following formats:
190  *
191  * Valid device strings:                     For device types:
192  *
193  * <type_name>                               DEV_TYP_STOR, DEV_TYP_NET
194  * <type_name><unit>                         DEV_TYP_STOR, DEV_TYP_NET
195  * <type_name><unit>:                        DEV_TYP_STOR, DEV_TYP_NET
196  * <type_name><unit>:<slice>                 DEV_TYP_STOR
197  * <type_name><unit>:<slice>.                DEV_TYP_STOR
198  * <type_name><unit>:<slice>.<partition>     DEV_TYP_STOR
199  *
200  * For valid type names, see the device_types array, above.
201  *
202  * Slice numbers are 1-based.  0 is a wildcard.
203  */
204 static void
205 get_load_device(int *type, int *unit, int *slice, int *partition)
206 {
207 	struct disk_devdesc *dev;
208 	char *devstr;
209 	const char *p;
210 	char *endp;
211 
212 	*type = DEV_TYP_NONE;
213 	*unit = -1;
214 	*slice = D_SLICEWILD;
215 	*partition = D_PARTWILD;
216 
217 	devstr = ub_env_get("loaderdev");
218 	if (devstr == NULL) {
219 		printf("U-Boot env: loaderdev not set, will probe all devices.\n");
220 		return;
221 	}
222 	printf("U-Boot env: loaderdev='%s'\n", devstr);
223 
224 	p = get_device_type(devstr, type);
225 
226 	/*
227 	 * If type is DEV_TYP_STOR we have a disk-like device.  If the remainder
228 	 * of the string contains spaces, dots, or a colon in any location other
229 	 * than the last char, it's legacy format.  Otherwise it might be
230 	 * standard loader(8) format (e.g., disk0s2a or mmc1p12), so try to
231 	 * parse the remainder of the string as such, and if it works, return
232 	 * those results. Otherwise we'll fall through to the code that parses
233 	 * the legacy format.
234 	 *
235 	 * disk_parsedev now assumes that it points to the start of the device
236 	 * name, but since it doesn't know about uboot's usage, just subtract 4
237 	 * since it always adds 4. This is the least-bad solution since it makes
238 	 * all the other loader code easier (might be better to create a fake
239 	 * 'disk...' string, but that's more work than uboot is worth).
240 	 */
241 	if (*type & DEV_TYP_STOR) {
242 		size_t len = strlen(p);
243 		if (strcspn(p, " .") == len && strcspn(p, ":") >= len - 1 &&
244 		    disk_parsedev((struct devdesc **)&dev, p - 4, NULL) == 0) { /* Hack */
245 			*unit = dev->dd.d_unit;
246 			*slice = dev->d_slice;
247 			*partition = dev->d_partition;
248 			free(dev);
249 			return;
250 		}
251 	}
252 
253 	/* Ignore optional spaces after the device name. */
254 	while (*p == ' ')
255 		p++;
256 
257 	/* Unknown device name, or a known name without unit number.  */
258 	if ((*type == DEV_TYP_NONE) || (*p == '\0')) {
259 		return;
260 	}
261 
262 	/* Malformed unit number. */
263 	if (!isdigit(*p)) {
264 		*type = DEV_TYP_NONE;
265 		return;
266 	}
267 
268 	/* Guaranteed to extract a number from the string, as *p is a digit. */
269 	*unit = strtol(p, &endp, 10);
270 	p = endp;
271 
272 	/* Known device name with unit number and nothing else. */
273 	if (*p == '\0') {
274 		return;
275 	}
276 
277 	/* Device string is malformed beyond unit number. */
278 	if (*p != ':') {
279 		*type = DEV_TYP_NONE;
280 		*unit = -1;
281 		return;
282 	}
283 
284 	p++;
285 
286 	/* No slice and partition specification. */
287 	if ('\0' == *p )
288 		return;
289 
290 	/* Only DEV_TYP_STOR devices can have a slice specification. */
291 	if (!(*type & DEV_TYP_STOR)) {
292 		*type = DEV_TYP_NONE;
293 		*unit = -1;
294 		return;
295 	}
296 
297 	*slice = strtoul(p, &endp, 10);
298 
299 	/* Malformed slice number. */
300 	if (p == endp) {
301 		*type = DEV_TYP_NONE;
302 		*unit = -1;
303 		*slice = D_SLICEWILD;
304 		return;
305 	}
306 
307 	p = endp;
308 
309 	/* No partition specification. */
310 	if (*p == '\0')
311 		return;
312 
313 	/* Device string is malformed beyond slice number. */
314 	if (*p != '.') {
315 		*type = DEV_TYP_NONE;
316 		*unit = -1;
317 		*slice = D_SLICEWILD;
318 		return;
319 	}
320 
321 	p++;
322 
323 	/* No partition specification. */
324 	if (*p == '\0')
325 		return;
326 
327 	*partition = strtol(p, &endp, 10);
328 	p = endp;
329 
330 	/*  Full, valid device string. */
331 	if (*endp == '\0')
332 		return;
333 
334 	/* Junk beyond partition number. */
335 	*type = DEV_TYP_NONE;
336 	*unit = -1;
337 	*slice = D_SLICEWILD;
338 	*partition = D_PARTWILD;
339 }
340 
341 static void
342 print_disk_probe_info(void)
343 {
344 	char slice[32];
345 	char partition[32];
346 
347 	if (currdev.d_disk.d_slice == D_SLICENONE)
348 		strlcpy(slice, "<none>", sizeof(slice));
349 	else if (currdev.d_disk.d_slice == D_SLICEWILD)
350 		strlcpy(slice, "<auto>", sizeof(slice));
351 	else
352 		snprintf(slice, sizeof(slice), "%d", currdev.d_disk.d_slice);
353 
354 	if (currdev.d_disk.d_partition == D_PARTNONE)
355 		strlcpy(partition, "<none>", sizeof(partition));
356 	else if (currdev.d_disk.d_partition == D_PARTWILD)
357 		strlcpy(partition, "<auto>", sizeof(partition));
358 	else
359 		snprintf(partition, sizeof(partition), "%d",
360 		    currdev.d_disk.d_partition);
361 
362 	printf("  Checking unit=%d slice=%s partition=%s...",
363 	    currdev.dd.d_unit, slice, partition);
364 
365 }
366 
367 static int
368 probe_disks(int devidx, int load_type, int load_unit, int load_slice,
369     int load_partition)
370 {
371 	int open_result, unit;
372 	struct open_file f;
373 
374 	currdev.d_disk.d_slice = load_slice;
375 	currdev.d_disk.d_partition = load_partition;
376 
377 	f.f_devdata = &currdev;
378 	open_result = -1;
379 
380 	if (load_type == -1) {
381 		printf("  Probing all disk devices...\n");
382 		/* Try each disk in succession until one works.  */
383 		for (currdev.dd.d_unit = 0; currdev.dd.d_unit < UB_MAX_DEV;
384 		     currdev.dd.d_unit++) {
385 			print_disk_probe_info();
386 			open_result = devsw[devidx]->dv_open(&f, &currdev);
387 			if (open_result == 0) {
388 				printf(" good.\n");
389 				return (0);
390 			}
391 			printf("\n");
392 		}
393 		return (-1);
394 	}
395 
396 	if (load_unit == -1) {
397 		printf("  Probing all %s devices...\n", device_typename(load_type));
398 		/* Try each disk of given type in succession until one works. */
399 		for (unit = 0; unit < UB_MAX_DEV; unit++) {
400 			currdev.dd.d_unit = uboot_diskgetunit(load_type, unit);
401 			if (currdev.dd.d_unit == -1)
402 				break;
403 			print_disk_probe_info();
404 			open_result = devsw[devidx]->dv_open(&f, &currdev);
405 			if (open_result == 0) {
406 				printf(" good.\n");
407 				return (0);
408 			}
409 			printf("\n");
410 		}
411 		return (-1);
412 	}
413 
414 	if ((currdev.dd.d_unit = uboot_diskgetunit(load_type, load_unit)) != -1) {
415 		print_disk_probe_info();
416 		open_result = devsw[devidx]->dv_open(&f,&currdev);
417 		if (open_result == 0) {
418 			printf(" good.\n");
419 			return (0);
420 		}
421 		printf("\n");
422 	}
423 
424 	printf("  Requested disk type/unit/slice/partition not found\n");
425 	return (-1);
426 }
427 
428 int
429 main(int argc, char **argv)
430 {
431 	struct api_signature *sig = NULL;
432 	int load_type, load_unit, load_slice, load_partition;
433 	int i;
434 	const char *ldev;
435 
436 	/*
437 	 * We first check if a command line argument was passed to us containing
438 	 * API's signature address. If it wasn't then we try to search for the
439 	 * API signature via the usual hinted address.
440 	 * If we can't find the magic signature and related info, exit with a
441 	 * unique error code that U-Boot reports as "## Application terminated,
442 	 * rc = 0xnnbadab1". Hopefully 'badab1' looks enough like "bad api" to
443 	 * provide a clue. It's better than 0xffffffff anyway.
444 	 */
445 	if (!api_parse_cmdline_sig(argc, argv, &sig) && !api_search_sig(&sig))
446 		return (0x01badab1);
447 
448 	syscall_ptr = sig->syscall;
449 	if (syscall_ptr == NULL)
450 		return (0x02badab1);
451 
452 	if (sig->version > API_SIG_VERSION)
453 		return (0x03badab1);
454 
455         /* Clear BSS sections */
456 	bzero(__sbss_start, __sbss_end - __sbss_start);
457 	bzero(__bss_start, _end - __bss_start);
458 
459 	/*
460 	 * Initialise the heap as early as possible.  Once this is done,
461 	 * alloc() is usable.  We are using the stack u-boot set up near the top
462 	 * of physical ram; hopefully there is sufficient space between the end
463 	 * of our bss and the bottom of the u-boot stack to avoid overlap.
464 	 */
465 	uboot_heap_start = round_page((uintptr_t)end);
466 	uboot_heap_end   = uboot_heap_start + HEAP_SIZE;
467 	setheap((void *)uboot_heap_start, (void *)uboot_heap_end);
468 
469 	/*
470 	 * Set up console.
471 	 */
472 	cons_probe();
473 	printf("Compatible U-Boot API signature found @%p\n", sig);
474 
475 	printf("\n%s", bootprog_info);
476 	printf("\n");
477 
478 	dump_sig(sig);
479 	dump_addr_info();
480 
481 	meminfo();
482 
483 	archsw.arch_loadaddr = uboot_loadaddr;
484 	archsw.arch_getdev = uboot_getdev;
485 	archsw.arch_copyin = uboot_copyin;
486 	archsw.arch_copyout = uboot_copyout;
487 	archsw.arch_readin = uboot_readin;
488 	archsw.arch_autoload = uboot_autoload;
489 
490 	/* Set up currdev variable to have hooks in place. */
491 	env_setenv("currdev", EV_VOLATILE, "", uboot_setcurrdev, env_nounset);
492 
493 	/*
494 	 * Enumerate U-Boot devices
495 	 */
496 	if ((devs_no = ub_dev_enum()) == 0) {
497 		printf("no U-Boot devices found");
498 		goto do_interact;
499 	}
500 	printf("Number of U-Boot devices: %d\n", devs_no);
501 
502 	get_load_device(&load_type, &load_unit, &load_slice, &load_partition);
503 
504 	/*
505 	 * March through the device switch probing for things.
506 	 */
507 	for (i = 0; devsw[i] != NULL; i++) {
508 
509 		if (devsw[i]->dv_init == NULL)
510 			continue;
511 		if ((devsw[i]->dv_init)() != 0)
512 			continue;
513 
514 		printf("Found U-Boot device: %s\n", devsw[i]->dv_name);
515 
516 		currdev.dd.d_dev = devsw[i];
517 		currdev.dd.d_unit = 0;
518 
519 		if ((load_type == DEV_TYP_NONE || (load_type & DEV_TYP_STOR)) &&
520 		    strcmp(devsw[i]->dv_name, "disk") == 0) {
521 			if (probe_disks(i, load_type, load_unit, load_slice,
522 			    load_partition) == 0)
523 				break;
524 		}
525 
526 		if ((load_type == DEV_TYP_NONE || (load_type & DEV_TYP_NET)) &&
527 		    strcmp(devsw[i]->dv_name, "net") == 0)
528 			break;
529 	}
530 
531 	/*
532 	 * If we couldn't find a boot device, return an error to u-boot.
533 	 * U-boot may be running a boot script that can try something different
534 	 * so returning an error is better than forcing a reboot.
535 	 */
536 	if (devsw[i] == NULL) {
537 		printf("No boot device found!\n");
538 		return (0xbadef1ce);
539 	}
540 
541 	ldev = devformat(&currdev.dd);
542 	env_setenv("currdev", EV_VOLATILE, ldev, uboot_setcurrdev, env_nounset);
543 	env_setenv("loaddev", EV_VOLATILE, ldev, env_noset, env_nounset);
544 	printf("Booting from %s\n", ldev);
545 
546 do_interact:
547 	setenv("LINES", "24", 1);		/* optional */
548 	setenv("prompt", "loader>", 1);
549 #ifdef __powerpc__
550 	setenv("usefdt", "1", 1);
551 #endif
552 
553 	interact();				/* doesn't return */
554 
555 	return (0);
556 }
557 
558 
559 COMMAND_SET(heap, "heap", "show heap usage", command_heap);
560 static int
561 command_heap(int argc, char *argv[])
562 {
563 
564 	printf("heap base at %p, top at %p, used %td\n", end, sbrk(0),
565 	    sbrk(0) - end);
566 
567 	return (CMD_OK);
568 }
569 
570 COMMAND_SET(reboot, "reboot", "reboot the system", command_reboot);
571 static int
572 command_reboot(int argc, char *argv[])
573 {
574 
575 	printf("Resetting...\n");
576 	ub_reset();
577 
578 	printf("Reset failed!\n");
579 	while (1);
580 	__unreachable();
581 }
582 
583 COMMAND_SET(devinfo, "devinfo", "show U-Boot devices", command_devinfo);
584 static int
585 command_devinfo(int argc, char *argv[])
586 {
587 	int i;
588 
589 	if ((devs_no = ub_dev_enum()) == 0) {
590 		command_errmsg = "no U-Boot devices found!?";
591 		return (CMD_ERROR);
592 	}
593 
594 	printf("U-Boot devices:\n");
595 	for (i = 0; i < devs_no; i++) {
596 		ub_dump_di(i);
597 		printf("\n");
598 	}
599 	return (CMD_OK);
600 }
601 
602 COMMAND_SET(sysinfo, "sysinfo", "show U-Boot system info", command_sysinfo);
603 static int
604 command_sysinfo(int argc, char *argv[])
605 {
606 	struct sys_info *si;
607 
608 	if ((si = ub_get_sys_info()) == NULL) {
609 		command_errmsg = "could not retrieve U-Boot sys info!?";
610 		return (CMD_ERROR);
611 	}
612 
613 	printf("U-Boot system info:\n");
614 	ub_dump_si(si);
615 	return (CMD_OK);
616 }
617 
618 enum ubenv_action {
619 	UBENV_UNKNOWN,
620 	UBENV_SHOW,
621 	UBENV_IMPORT
622 };
623 
624 static void
625 handle_uboot_env_var(enum ubenv_action action, const char * var)
626 {
627 	char ldvar[128];
628 	const char *val;
629 	char *wrk;
630 	int len;
631 
632 	/*
633 	 * On an import with the variable name formatted as ldname=ubname,
634 	 * import the uboot variable ubname into the loader variable ldname,
635 	 * otherwise the historical behavior is to import to uboot.ubname.
636 	 */
637 	if (action == UBENV_IMPORT) {
638 		len = strcspn(var, "=");
639 		if (len == 0) {
640 			printf("name cannot start with '=': '%s'\n", var);
641 			return;
642 		}
643 		if (var[len] == 0) {
644 			strcpy(ldvar, "uboot.");
645 			strncat(ldvar, var, sizeof(ldvar) - 7);
646 		} else {
647 			len = MIN(len, sizeof(ldvar) - 1);
648 			strncpy(ldvar, var, len);
649 			ldvar[len] = 0;
650 			var = &var[len + 1];
651 		}
652 	}
653 
654 	/*
655 	 * If the user prepended "uboot." (which is how they usually see these
656 	 * names) strip it off as a convenience.
657 	 */
658 	if (strncmp(var, "uboot.", 6) == 0) {
659 		var = &var[6];
660 	}
661 
662 	/* If there is no variable name left, punt. */
663 	if (var[0] == 0) {
664 		printf("empty variable name\n");
665 		return;
666 	}
667 
668 	val = ub_env_get(var);
669 	if (action == UBENV_SHOW) {
670 		if (val == NULL)
671 			printf("uboot.%s is not set\n", var);
672 		else
673 			printf("uboot.%s=%s\n", var, val);
674 	} else if (action == UBENV_IMPORT) {
675 		if (val != NULL) {
676 			setenv(ldvar, val, 1);
677 		}
678 	}
679 }
680 
681 static int
682 command_ubenv(int argc, char *argv[])
683 {
684 	enum ubenv_action action;
685 	const char *var;
686 	int i;
687 
688 	action = UBENV_UNKNOWN;
689 	if (argc > 1) {
690 		if (strcasecmp(argv[1], "import") == 0)
691 			action = UBENV_IMPORT;
692 		else if (strcasecmp(argv[1], "show") == 0)
693 			action = UBENV_SHOW;
694 	}
695 	if (action == UBENV_UNKNOWN) {
696 		command_errmsg = "usage: 'ubenv <import|show> [var ...]";
697 		return (CMD_ERROR);
698 	}
699 
700 	if (argc > 2) {
701 		for (i = 2; i < argc; i++)
702 			handle_uboot_env_var(action, argv[i]);
703 	} else {
704 		var = NULL;
705 		for (;;) {
706 			if ((var = ub_env_enum(var)) == NULL)
707 				break;
708 			handle_uboot_env_var(action, var);
709 		}
710 	}
711 
712 	return (CMD_OK);
713 }
714 COMMAND_SET(ubenv, "ubenv", "show or import U-Boot env vars", command_ubenv);
715 
716 #ifdef LOADER_FDT_SUPPORT
717 /*
718  * Since proper fdt command handling function is defined in fdt_loader_cmd.c,
719  * and declaring it as extern is in contradiction with COMMAND_SET() macro
720  * (which uses static pointer), we're defining wrapper function, which
721  * calls the proper fdt handling routine.
722  */
723 static int
724 command_fdt(int argc, char *argv[])
725 {
726 
727 	return (command_fdt_internal(argc, argv));
728 }
729 
730 COMMAND_SET(fdt, "fdt", "flattened device tree handling", command_fdt);
731 #endif
732