[U-Boot] [PATCH v6 5/6] cmd:gpt: randomly generate each partition uuid if undefined
Przemyslaw Marczak
p.marczak at samsung.com
Wed Apr 2 10:20:06 CEST 2014
Changes:
- randomly generate partition uuid if any is undefined and CONFIG_RAND_UUID
is defined
- print debug info about set/unset/generated uuid
- update doc/README.gpt
Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
Acked-by: Lukasz Majewski <l.majewski at samsung.com>
Cc: Piotr Wilczek <p.wilczek at samsung.com>
Cc: Tom Rini <trini at ti.com>
Cc: Stephen Warren <swarren at nvidia.com>
Cc: Lukasz Majewski <l.majewski at samsung.com>
---
Changes v2:
- cmd_gpt: extract_env: change return type from char to int
- add tmp array to generate uuid string
- store generated uuid in env and next get it from it - don't need to alloc
and maintain allcoated memory outside extract_env()
Changes v3:
- print info if uuid_gpt_* env is get from env/set random
- change some word in README.gpt to meaningful
Changes v4:
- change printf/puts to debug
- reduce indentation level in extract_env()
- generate rand uuid if CONFIG_RAND_UUID is defined
Changes v5:
- cosmetic changes only
Changes v6:
- none
---
common/cmd_gpt.c | 61 ++++++++++++++++++++++++++++++++++++++++++--------------
doc/README.gpt | 22 +++++++++++++++-----
lib/uuid.c | 4 ++--
3 files changed, 65 insertions(+), 22 deletions(-)
diff --git a/common/cmd_gpt.c b/common/cmd_gpt.c
index 1f12e6d..e38422d 100644
--- a/common/cmd_gpt.c
+++ b/common/cmd_gpt.c
@@ -29,30 +29,53 @@
*
* @return - zero on successful expand and env is set
*/
-static char extract_env(const char *str, char **env)
+static int extract_env(const char *str, char **env)
{
+ int ret = -1;
char *e, *s;
+#ifdef CONFIG_RANDOM_UUID
+ char uuid_str[UUID_STR_LEN + 1];
+#endif
if (!str || strlen(str) < 4)
return -1;
- if ((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')) {
- s = strdup(str);
- if (s == NULL)
- return -1;
- memset(s + strlen(s) - 1, '\0', 1);
- memmove(s, s + 2, strlen(s) - 1);
+ if (!((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')))
+ return -1;
+
+ s = strdup(str);
+ if (s == NULL)
+ return -1;
+
+ memset(s + strlen(s) - 1, '\0', 1);
+ memmove(s, s + 2, strlen(s) - 1);
+
+ e = getenv(s);
+ if (e == NULL) {
+#ifdef CONFIG_RANDOM_UUID
+ debug("%s unset. ", str);
+ gen_rand_uuid_str(uuid_str, UUID_STR_FORMAT_STD);
+ setenv(s, uuid_str);
+
e = getenv(s);
- free(s);
- if (e == NULL) {
- printf("Environmental '%s' not set\n", str);
- return -1; /* env not set */
+ if (e) {
+ debug("Set to random.\n");
+ ret = 0;
+ } else {
+ debug("Can't get random UUID.\n");
}
- *env = e;
- return 0;
+#else
+ debug("%s unset.\n", str);
+#endif
+ } else {
+ debug("%s get from environment.\n", str);
+ ret = 0;
}
- return -1;
+ *env = e;
+ free(s);
+
+ return ret;
}
/**
@@ -299,8 +322,16 @@ static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
return CMD_RET_FAILURE;
}
- if (gpt_default(blk_dev_desc, argv[4]))
+ puts("Writing GPT: ");
+
+ ret = gpt_default(blk_dev_desc, argv[4]);
+ if (!ret) {
+ puts("success!\n");
+ return CMD_RET_SUCCESS;
+ } else {
+ puts("error!\n");
return CMD_RET_FAILURE;
+ }
} else {
return CMD_RET_USAGE;
}
diff --git a/doc/README.gpt b/doc/README.gpt
index 5c133f3..f822894 100644
--- a/doc/README.gpt
+++ b/doc/README.gpt
@@ -132,8 +132,8 @@ of the Primary.
----------------------
Offset Size Description
- 0 16 B Partition type GUID
- 16 16 B Unique partition GUID
+ 0 16 B Partition type GUID (Big Endian)
+ 16 16 B Unique partition GUID in (Big Endian)
32 8 B First LBA (Little Endian)
40 8 B Last LBA (inclusive)
48 8 B Attribute flags [+]
@@ -160,6 +160,9 @@ To restore GUID partition table one needs to:
Fields 'name', 'size' and 'uuid' are mandatory for every partition.
The field 'start' is optional.
+ option: CONFIG_RANDOM_UUID
+ If any partition "UUID" no exists then it is randomly generated.
+
2. Define 'CONFIG_EFI_PARTITION' and 'CONFIG_CMD_GPT'
2. From u-boot prompt type:
@@ -168,11 +171,20 @@ To restore GUID partition table one needs to:
Useful info:
============
-Two programs, namely: 'fdisk' and 'parted' are recommended to work with GPT
-recovery. Parted is able to handle GUID partitions. Unfortunately the 'fdisk'
-hasn't got such ability.
+Two programs, namely: 'gdisk' and 'parted' are recommended to work with GPT
+recovery. Both are able to handle GUID partitions.
Please, pay attention at -l switch for parted.
"uuid" program is recommended to generate UUID string. Moreover it can decode
(-d switch) passed in UUID string. It can be used to generate partitions UUID
passed to u-boot environment variables.
+If optional CONFIG_RANDOM_UUID is defined then for any partition which environment
+uuid is unset, uuid is randomly generated and stored in correspond environment
+variable.
+
+note:
+Each string block of UUID generated by program "uuid" is in big endian and it is
+also stored in big endian in disk GPT.
+Partitions layout can be printed by typing "mmc part". Note that each partition
+GUID has different byte order than UUID generated before, this is because first
+three blocks of GUID string are in Little Endian.
diff --git a/lib/uuid.c b/lib/uuid.c
index f32b602..f6b4423 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -251,5 +251,5 @@ U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
"varname: for set result in a environment variable\n"
"e.g. guid guid_env"
);
-#endif
-#endif
+#endif /* CONFIG_CMD_UUID */
+#endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */
--
1.9.0
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