[U-Boot] [PATCH v6 4/6] new commands: uuid and guid - generate random unique identifier

[Przemyslaw Marczak]

Those commands basis on implementation of random UUID generator version 4
which is described in RFC4122. The same algorithm is used for generation
both ids but string representation is different as below.

char:  0        9    14   19   24         36
       xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
UUID:     be     be   be   be       be
GUID:     le     le   le   be       be

Commands usage:
- uuid [<varname>]
- guid [<varname>]

The result is saved in environment as a "varname" variable if argument is given,
if not then it is printed.

New config:
- CONFIG_CMD_UUID

Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
Cc: Stephen Warren <swarren at nvidia.com>
Cc: Lukasz Majewski <l.majewski at samsung.com>
Cc: trini at ti.com

---
Changes v4:
- new commit

Changes v5:
- reword commands description
- uuid command code refactor
- remove use of typedef uuid_str_t

Changes v6:
- none
---
 README                     |  2 +-
 include/config_fallbacks.h |  8 +++++---
 lib/uuid.c                 | 44 +++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/README b/README
index 7cb7c4f..025386f 100644
--- a/README
+++ b/README
@@ -1012,7 +1012,7 @@ The following options need to be configured:
 		CONFIG_CMD_CDP		* Cisco Discover Protocol support
 		CONFIG_CMD_MFSL		* Microblaze FSL support
 		CONFIG_CMD_XIMG		  Load part of Multi Image
-
+		CONFIG_CMD_UUID		* Generate random UUID or GUID string
 
 		EXAMPLE: If you want all functions except of network
 		support you can write:
diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h
index a8630ab..5eacfb6 100644
--- a/include/config_fallbacks.h
+++ b/include/config_fallbacks.h
@@ -57,14 +57,16 @@
 
 #if (defined(CONFIG_PARTITION_UUIDS) || \
 	defined(CONFIG_RANDOM_UUID) || \
+	defined(CONFIG_CMD_UUID) || \
 	defined(CONFIG_BOOTP_PXE)) && \
 	!defined(CONFIG_LIB_UUID)
 #define CONFIG_LIB_UUID
 #endif
 
-#if defined(CONFIG_RANDOM_UUID) && \
-	!defined(CONFIG_LIB_RAND) && \
-	!defined(CONFIG_LIB_HW_RAND)
+#if (defined(CONFIG_RANDOM_UUID) || \
+	defined(CONFIG_CMD_UUID)) && \
+	(!defined(CONFIG_LIB_RAND) && \
+	!defined(CONFIG_LIB_HW_RAND))
 #define CONFIG_LIB_RAND
 #endif
 
diff --git a/lib/uuid.c b/lib/uuid.c
index 44d0c93..f32b602 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#include <common.h>
 #include <linux/ctype.h>
 #include <errno.h>
 #include <common.h>
@@ -171,7 +172,7 @@ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
  *
  * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
 */
-#ifdef CONFIG_RANDOM_UUID
+#if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
 void gen_rand_uuid(unsigned char *uuid_bin)
 {
 	struct uuid uuid;
@@ -210,4 +211,45 @@ void gen_rand_uuid_str(char *uuid_str, int str_format)
 	/* 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
+		setenv(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
 #endif
-- 
1.9.0