[J-u-boot.git] / lib / uuid.c

/*
 * Copyright 2011 Calxeda, Inc.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <linux/ctype.h>
#include <errno.h>
#include <common.h>
#include <asm/io.h>
#include <part_efi.h>
#include <malloc.h>

/*
 * UUID - Universally Unique IDentifier - 128 bits unique number.
 *        There are 5 versions and one variant of UUID defined by RFC4122
 *        specification. A UUID contains a set of fields. The set varies
 *        depending on the version of the UUID, as shown below:
 *        - time, MAC address(v1),
 *        - user ID(v2),
 *        - MD5 of name or URL(v3),
 *        - random data(v4),
 *        - SHA-1 of name or URL(v5),
 *
 * Layout of UUID:
 * timestamp - 60-bit: time_low, time_mid, time_hi_and_version
 * version   - 4 bit (bit 4 through 7 of the time_hi_and_version)
 * clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
 * variant:  - bit 6 and 7 of clock_seq_hi_and_reserved
 * node      - 48 bit
 *
 * source: https://www.ietf.org/rfc/rfc4122.txt
 *
 * UUID binary format (16 bytes):
 *
 * 4B-2B-2B-2B-6B (big endian - network byte order)
 *
 * UUID string is 36 length of characters (36 bytes):
 *
 * 0        9    14   19   24
 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
 *    be     be   be   be       be
 *
 * where x is a hexadecimal character. Fields are separated by '-'s.
 * When converting to a binary UUID, le means the field should be converted
 * to little endian and be means it should be converted to big endian.
 *
 * UUID is also used as GUID (Globally Unique Identifier) with the same binary
 * format but it differs in string format like below.
 *
 * GUID:
 * 0        9    14   19   24
 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
 *    le     le   le   be       be
 *
 * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
 */
int uuid_str_valid(const char *uuid)
{
	int i, valid;

	if (uuid == NULL)
		return 0;

	for (i = 0, valid = 1; uuid[i] && valid; i++) {
		switch (i) {
		case 8: case 13: case 18: case 23:
			valid = (uuid[i] == '-');
			break;
		default:
			valid = isxdigit(uuid[i]);
			break;
		}
	}

	if (i != UUID_STR_LEN || !valid)
		return 0;

	return 1;
}

#ifdef CONFIG_PARTITION_TYPE_GUID
static const struct {
	const char *string;
	efi_guid_t guid;
} list_guid[] = {
	{"system",	PARTITION_SYSTEM_GUID},
	{"mbr",		LEGACY_MBR_PARTITION_GUID},
	{"msft",	PARTITION_MSFT_RESERVED_GUID},
	{"data",	PARTITION_BASIC_DATA_GUID},
	{"linux",	PARTITION_LINUX_FILE_SYSTEM_DATA_GUID},
	{"raid",	PARTITION_LINUX_RAID_GUID},
	{"swap",	PARTITION_LINUX_SWAP_GUID},
	{"lvm",		PARTITION_LINUX_LVM_GUID}
};

/*
 * uuid_guid_get_bin() - this function get GUID bin for string
 *
 * @param guid_str - pointer to partition type string
 * @param guid_bin - pointer to allocated array for big endian output [16B]
 */
int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
		if (!strcmp(list_guid[i].string, guid_str)) {
			memcpy(guid_bin, &list_guid[i].guid, 16);
			return 0;
		}
	}
	return -ENODEV;
}

/*
 * uuid_guid_get_str() - this function get string for GUID.
 *
 * @param guid_bin - pointer to string with partition type guid [16B]
 * @param guid_str - pointer to allocated partition type string [7B]
 */
int uuid_guid_get_str(unsigned char *guid_bin, char *guid_str)
{
	int i;

	*guid_str = 0;
	for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
		if (!memcmp(list_guid[i].guid.b, guid_bin, 16)) {
			strcpy(guid_str, list_guid[i].string);
			return 0;
		}
	}
	return -ENODEV;
}
#endif

/*
 * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
 *
 * @param uuid_str - pointer to UUID or GUID string [37B] or GUID shorcut
 * @param uuid_bin - pointer to allocated array for big endian output [16B]
 * @str_format     - UUID string format: 0 - UUID; 1 - GUID
 */
int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
{
	uint16_t tmp16;
	uint32_t tmp32;
	uint64_t tmp64;

	if (!uuid_str_valid(uuid_str)) {
#ifdef CONFIG_PARTITION_TYPE_GUID
		if (!uuid_guid_get_bin(uuid_str, uuid_bin))
			return 0;
#endif
		return -EINVAL;
	}

	if (str_format == UUID_STR_FORMAT_STD) {
		tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16));
		memcpy(uuid_bin, &tmp32, 4);

		tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16));
		memcpy(uuid_bin + 4, &tmp16, 2);

		tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16));
		memcpy(uuid_bin + 6, &tmp16, 2);
	} else {
		tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16));
		memcpy(uuid_bin, &tmp32, 4);

		tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16));
		memcpy(uuid_bin + 4, &tmp16, 2);

		tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16));
		memcpy(uuid_bin + 6, &tmp16, 2);
	}

	tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16));
	memcpy(uuid_bin + 8, &tmp16, 2);

	tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16));
	memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6);

	return 0;
}

/*
 * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
 *
 * @param uuid_bin - pointer to binary data of UUID (big endian) [16B]
 * @param uuid_str - pointer to allocated array for output string [37B]
 * @str_format     - UUID string format: 0 - UUID; 1 - GUID
 */
void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
{
	const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
						  9, 10, 11, 12, 13, 14, 15};
	const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
						  9, 10, 11, 12, 13, 14, 15};
	const u8 *char_order;
	int i;

	/*
	 * UUID and GUID bin data - always in big endian:
	 * 4B-2B-2B-2B-6B
	 * be be be be be
	 */
	if (str_format == UUID_STR_FORMAT_STD)
		char_order = uuid_char_order;
	else
		char_order = guid_char_order;

	for (i = 0; i < 16; i++) {
		sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]);
		uuid_str += 2;
		switch (i) {
		case 3:
		case 5:
		case 7:
		case 9:
			*uuid_str++ = '-';
			break;
		}
	}
}

/*
 * gen_rand_uuid() - this function generates a random binary UUID version 4.
 *                   In this version all fields beside 4 bits of version and
 *                   2 bits of variant are randomly generated.
 *
 * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
*/
#if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
void gen_rand_uuid(unsigned char *uuid_bin)
{
	struct uuid uuid;
	unsigned int *ptr = (unsigned int *)&uuid;
	int i;

	/* Set all fields randomly */
	for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
		*(ptr + i) = cpu_to_be32(rand());

	clrsetbits_be16(&uuid.time_hi_and_version,
			UUID_VERSION_MASK,
			UUID_VERSION << UUID_VERSION_SHIFT);

	clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
		     UUID_VARIANT_MASK,
		     UUID_VARIANT << UUID_VARIANT_SHIFT);

	memcpy(uuid_bin, &uuid, sizeof(struct uuid));
}

/*
 * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
 *                       formats UUID or GUID.
 *
 * @param uuid_str - pointer to allocated array [37B].
 * @param          - uuid output type: UUID - 0, GUID - 1
 */
void gen_rand_uuid_str(char *uuid_str, int str_format)
{
	unsigned char uuid_bin[UUID_BIN_LEN];

	/* Generate UUID (big endian) */
	gen_rand_uuid(uuid_bin);

	/* Convert UUID bin to UUID or GUID formated STRING  */
	uuid_bin_to_str(uuid_bin, uuid_str, str_format);
}

#ifdef CONFIG_CMD_UUID
int do_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	char uuid[UUID_STR_LEN + 1];
	int str_format;

	if (!strcmp(argv[0], "uuid"))
		str_format = UUID_STR_FORMAT_STD;
	else
		str_format = UUID_STR_FORMAT_GUID;

	if (argc > 2)
		return CMD_RET_USAGE;

	gen_rand_uuid_str(uuid, str_format);

	if (argc == 1)
		printf("%s\n", uuid);
	else
		env_set(argv[1], uuid);

	return CMD_RET_SUCCESS;
}

U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
	   "UUID - generate random Universally Unique Identifier",
	   "[<varname>]\n"
	   "Argument:\n"
	   "varname: for set result in a environment variable\n"
	   "e.g. uuid uuid_env"
);

U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
	   "GUID - generate Globally Unique Identifier based on random UUID",
	   "[<varname>]\n"
	   "Argument:\n"
	   "varname: for set result in a environment variable\n"
	   "e.g. guid guid_env"
);
#endif /* CONFIG_CMD_UUID */
#endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */
Commit	Line	Data
e11938ea JH	1	/*
	2	* Copyright 2011 Calxeda, Inc.
	3	*
1a459660	4	* SPDX-License-Identifier: GPL-2.0+
e11938ea JH	5	*/
e11938ea JH	6
89c8230d	7	#include <common.h>
e11938ea	8	#include <linux/ctype.h>
a96a0e61 PM	9	#include <errno.h>
a96a0e61 PM	10	#include <common.h>
d718ded0 PM	11	#include <asm/io.h>
	12	#include <part_efi.h>
	13	#include <malloc.h>
e11938ea JH	14
e11938ea JH	15	/*
a96a0e61 PM	16	* UUID - Universally Unique IDentifier - 128 bits unique number.
a96a0e61 PM	17	* There are 5 versions and one variant of UUID defined by RFC4122
4e4815fe PM	18	* specification. A UUID contains a set of fields. The set varies
	19	* depending on the version of the UUID, as shown below:
	20	* - time, MAC address(v1),
	21	* - user ID(v2),
	22	* - MD5 of name or URL(v3),
	23	* - random data(v4),
	24	* - SHA-1 of name or URL(v5),
	25	*
	26	* Layout of UUID:
	27	* timestamp - 60-bit: time_low, time_mid, time_hi_and_version
	28	* version - 4 bit (bit 4 through 7 of the time_hi_and_version)
	29	* clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
	30	* variant: - bit 6 and 7 of clock_seq_hi_and_reserved
	31	* node - 48 bit
	32	*
	33	* source: https://www.ietf.org/rfc/rfc4122.txt
a96a0e61 PM	34	*
	35	* UUID binary format (16 bytes):
	36	*
	37	* 4B-2B-2B-2B-6B (big endian - network byte order)
	38	*
	39	* UUID string is 36 length of characters (36 bytes):
	40	*
	41	* 0 9 14 19 24
	42	* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
	43	* be be be be be
	44	*
	45	* where x is a hexadecimal character. Fields are separated by '-'s.
	46	* When converting to a binary UUID, le means the field should be converted
	47	* to little endian and be means it should be converted to big endian.
e11938ea	48	*
a96a0e61 PM	49	* UUID is also used as GUID (Globally Unique Identifier) with the same binary
a96a0e61 PM	50	* format but it differs in string format like below.
e11938ea	51	*
a96a0e61	52	* GUID:
e11938ea JH	53	* 0 9 14 19 24
	54	* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
	55	* le le le be be
a96a0e61 PM	56	*
a96a0e61 PM	57	* GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
e11938ea	58	*/
e11938ea JH	59	int uuid_str_valid(const char *uuid)
	60	{
	61	int i, valid;
	62
	63	if (uuid == NULL)
	64	return 0;
	65
	66	for (i = 0, valid = 1; uuid[i] && valid; i++) {
	67	switch (i) {
	68	case 8: case 13: case 18: case 23:
	69	valid = (uuid[i] == '-');
	70	break;
	71	default:
	72	valid = isxdigit(uuid[i]);
	73	break;
	74	}
	75	}
	76
d718ded0	77	if (i != UUID_STR_LEN \|\| !valid)
e11938ea JH	78	return 0;
	79
	80	return 1;
	81	}
	82
bcb41dca PD	83	#ifdef CONFIG_PARTITION_TYPE_GUID
	84	static const struct {
	85	const char *string;
	86	efi_guid_t guid;
	87	} list_guid[] = {
	88	{"system", PARTITION_SYSTEM_GUID},
	89	{"mbr", LEGACY_MBR_PARTITION_GUID},
	90	{"msft", PARTITION_MSFT_RESERVED_GUID},
	91	{"data", PARTITION_BASIC_DATA_GUID},
	92	{"linux", PARTITION_LINUX_FILE_SYSTEM_DATA_GUID},
	93	{"raid", PARTITION_LINUX_RAID_GUID},
	94	{"swap", PARTITION_LINUX_SWAP_GUID},
	95	{"lvm", PARTITION_LINUX_LVM_GUID}
	96	};
	97
	98	/*
	99	* uuid_guid_get_bin() - this function get GUID bin for string
	100	*
	101	* @param guid_str - pointer to partition type string
	102	* @param guid_bin - pointer to allocated array for big endian output [16B]
	103	*/
	104	int uuid_guid_get_bin(const char guid_str, unsigned char guid_bin)
	105	{
	106	int i;
	107
	108	for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
	109	if (!strcmp(list_guid[i].string, guid_str)) {
	110	memcpy(guid_bin, &list_guid[i].guid, 16);
	111	return 0;
	112	}
	113	}
	114	return -ENODEV;
	115	}
	116
	117	/*
	118	* uuid_guid_get_str() - this function get string for GUID.
	119	*
	120	* @param guid_bin - pointer to string with partition type guid [16B]
	121	* @param guid_str - pointer to allocated partition type string [7B]
	122	*/
	123	int uuid_guid_get_str(unsigned char guid_bin, char guid_str)
	124	{
	125	int i;
	126
	127	*guid_str = 0;
	128	for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
	129	if (!memcmp(list_guid[i].guid.b, guid_bin, 16)) {
	130	strcpy(guid_str, list_guid[i].string);
	131	return 0;
	132	}
	133	}
	134	return -ENODEV;
	135	}
	136	#endif
	137
d718ded0 PM	138	/*
	139	* uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
	140	*
bcb41dca	141	* @param uuid_str - pointer to UUID or GUID string [37B] or GUID shorcut
d718ded0 PM	142	* @param uuid_bin - pointer to allocated array for big endian output [16B]
	143	* @str_format - UUID string format: 0 - UUID; 1 - GUID
	144	*/
	145	int uuid_str_to_bin(char uuid_str, unsigned char uuid_bin, int str_format)
e11938ea JH	146	{
	147	uint16_t tmp16;
	148	uint32_t tmp32;
	149	uint64_t tmp64;
	150
bcb41dca PD	151	if (!uuid_str_valid(uuid_str)) {
	152	#ifdef CONFIG_PARTITION_TYPE_GUID
	153	if (!uuid_guid_get_bin(uuid_str, uuid_bin))
	154	return 0;
	155	#endif
a96a0e61	156	return -EINVAL;
bcb41dca	157	}
a96a0e61	158
d718ded0 PM	159	if (str_format == UUID_STR_FORMAT_STD) {
	160	tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16));
	161	memcpy(uuid_bin, &tmp32, 4);
e11938ea	162
d718ded0 PM	163	tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16));
d718ded0 PM	164	memcpy(uuid_bin + 4, &tmp16, 2);
e11938ea	165
d718ded0 PM	166	tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16));
	167	memcpy(uuid_bin + 6, &tmp16, 2);
	168	} else {
	169	tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16));
	170	memcpy(uuid_bin, &tmp32, 4);
e11938ea	171
d718ded0 PM	172	tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16));
d718ded0 PM	173	memcpy(uuid_bin + 4, &tmp16, 2);
e11938ea	174
d718ded0 PM	175	tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16));
	176	memcpy(uuid_bin + 6, &tmp16, 2);
	177	}
	178
	179	tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16));
	180	memcpy(uuid_bin + 8, &tmp16, 2);
e11938ea	181
d718ded0 PM	182	tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16));
d718ded0 PM	183	memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6);
a96a0e61 PM	184
	185	return 0;
	186	}
	187
d718ded0 PM	188	/*
	189	* uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
	190	*
	191	* @param uuid_bin - pointer to binary data of UUID (big endian) [16B]
	192	* @param uuid_str - pointer to allocated array for output string [37B]
	193	* @str_format - UUID string format: 0 - UUID; 1 - GUID
	194	*/
	195	void uuid_bin_to_str(unsigned char uuid_bin, char uuid_str, int str_format)
a96a0e61	196	{
d718ded0 PM	197	const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
	198	9, 10, 11, 12, 13, 14, 15};
	199	const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
	200	9, 10, 11, 12, 13, 14, 15};
	201	const u8 *char_order;
a96a0e61 PM	202	int i;
a96a0e61 PM	203
d718ded0 PM	204	/*
	205	* UUID and GUID bin data - always in big endian:
	206	* 4B-2B-2B-2B-6B
	207	* be be be be be
	208	*/
	209	if (str_format == UUID_STR_FORMAT_STD)
	210	char_order = uuid_char_order;
	211	else
	212	char_order = guid_char_order;
	213
a96a0e61	214	for (i = 0; i < 16; i++) {
d718ded0 PM	215	sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]);
d718ded0 PM	216	uuid_str += 2;
a96a0e61 PM	217	switch (i) {
	218	case 3:
	219	case 5:
	220	case 7:
	221	case 9:
d718ded0	222	*uuid_str++ = '-';
a96a0e61 PM	223	break;
	224	}
	225	}
e11938ea	226	}
4e4815fe PM	227
	228	/*
	229	* gen_rand_uuid() - this function generates a random binary UUID version 4.
	230	* In this version all fields beside 4 bits of version and
	231	* 2 bits of variant are randomly generated.
	232	*
	233	* @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
	234	*/
89c8230d	235	#if defined(CONFIG_RANDOM_UUID) \|\| defined(CONFIG_CMD_UUID)
4e4815fe PM	236	void gen_rand_uuid(unsigned char *uuid_bin)
	237	{
	238	struct uuid uuid;
	239	unsigned int ptr = (unsigned int )&uuid;
	240	int i;
	241
	242	/* Set all fields randomly */
	243	for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
	244	*(ptr + i) = cpu_to_be32(rand());
	245
	246	clrsetbits_be16(&uuid.time_hi_and_version,
	247	UUID_VERSION_MASK,
	248	UUID_VERSION << UUID_VERSION_SHIFT);
	249
	250	clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
	251	UUID_VARIANT_MASK,
	252	UUID_VARIANT << UUID_VARIANT_SHIFT);
	253
	254	memcpy(uuid_bin, &uuid, sizeof(struct uuid));
	255	}
	256
	257	/*
	258	* gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
	259	* formats UUID or GUID.
	260	*
	261	* @param uuid_str - pointer to allocated array [37B].
	262	* @param - uuid output type: UUID - 0, GUID - 1
	263	*/
	264	void gen_rand_uuid_str(char *uuid_str, int str_format)
	265	{
	266	unsigned char uuid_bin[UUID_BIN_LEN];
	267
	268	/* Generate UUID (big endian) */
	269	gen_rand_uuid(uuid_bin);
	270
	271	/* Convert UUID bin to UUID or GUID formated STRING */
	272	uuid_bin_to_str(uuid_bin, uuid_str, str_format);
	273	}
89c8230d PM	274
	275	#ifdef CONFIG_CMD_UUID
	276	int do_uuid(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	277	{
	278	char uuid[UUID_STR_LEN + 1];
	279	int str_format;
	280
	281	if (!strcmp(argv[0], "uuid"))
	282	str_format = UUID_STR_FORMAT_STD;
	283	else
	284	str_format = UUID_STR_FORMAT_GUID;
	285
	286	if (argc > 2)
	287	return CMD_RET_USAGE;
	288
	289	gen_rand_uuid_str(uuid, str_format);
	290
	291	if (argc == 1)
	292	printf("%s\n", uuid);
	293	else
382bee57	294	env_set(argv[1], uuid);
89c8230d PM	295
	296	return CMD_RET_SUCCESS;
	297	}
	298
	299	U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
	300	"UUID - generate random Universally Unique Identifier",
	301	"[<varname>]\n"
	302	"Argument:\n"
	303	"varname: for set result in a environment variable\n"
	304	"e.g. uuid uuid_env"
	305	);
	306
	307	U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
	308	"GUID - generate Globally Unique Identifier based on random UUID",
	309	"[<varname>]\n"
	310	"Argument:\n"
	311	"varname: for set result in a environment variable\n"
	312	"e.g. guid guid_env"
	313	);
39206382 PM	314	#endif /* CONFIG_CMD_UUID */
39206382 PM	315	#endif /* CONFIG_RANDOM_UUID \|\| CONFIG_CMD_UUID */