From 39206382dea929b6a834c212b431821e06e68f39 Mon Sep 17 00:00:00 2001 From: Przemyslaw Marczak Date: Wed, 2 Apr 2014 10:20:06 +0200 Subject: [PATCH] cmd:gpt: randomly generate each partition uuid if undefined 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 Acked-by: Lukasz Majewski Cc: Piotr Wilczek Cc: Tom Rini Cc: Stephen Warren Cc: Lukasz Majewski --- 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 */ -- 1.9.1