common/cmd_gpt.c

   1 /*
   2  * cmd_gpt.c -- GPT (GUID Partition Table) handling command
   3  *
   4  * Copyright (C) 2012 Samsung Electronics
   5  * author: Lukasz Majewski <l.majewski@samsung.com>
   6  * author: Piotr Wilczek <p.wilczek@samsung.com>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <malloc.h>
  13 #include <command.h>
  14 #include <mmc.h>
  15 #include <part_efi.h>
  16 #include <exports.h>
  17 #include <linux/ctype.h>
  18 #include <div64.h>
  19
  20 #ifndef CONFIG_PARTITION_UUIDS
  21 #error CONFIG_PARTITION_UUIDS must be enabled for CONFIG_CMD_GPT to be enabled
  22 #endif
  23
  24 /**
  25  * extract_env(): Expand env name from string format '&{env_name}'
  26  *                and return pointer to the env (if the env is set)
  27  *
  28  * @param str - pointer to string
  29  * @param env - pointer to pointer to extracted env
  30  *
  31  * @return - zero on successful expand and env is set
  32  */
  33 static char extract_env(const char *str, char **env)
  34 {
  35         char *e, *s;
  36
  37         if (!str || strlen(str) < 4)
  38                 return -1;
  39
  40         if ((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')) {
  41                 s = strdup(str);
  42                 if (s == NULL)
  43                         return -1;
  44                 memset(s + strlen(s) - 1, '\0', 1);
  45                 memmove(s, s + 2, strlen(s) - 1);
  46                 e = getenv(s);
  47                 free(s);
  48                 if (e == NULL) {
  49                         printf("Environmental '%s' not set\n", str);
  50                         return -1; /* env not set */
  51                 }
  52                 *env = e;
  53                 return 0;
  54         }
  55
  56         return -1;
  57 }
  58
  59 /**
  60  * extract_val(): Extract value from a key=value pair list (comma separated).
  61  *                Only value for the given key is returend.
  62  *                Function allocates memory for the value, remember to free!
  63  *
  64  * @param str - pointer to string with key=values pairs
  65  * @param key - pointer to the key to search for
  66  *
  67  * @return - pointer to allocated string with the value
  68  */
  69 static char *extract_val(const char *str, const char *key)
  70 {
  71         char *v, *k;
  72         char *s, *strcopy;
  73         char *new = NULL;
  74
  75         strcopy = strdup(str);
  76         if (strcopy == NULL)
  77                 return NULL;
  78
  79         s = strcopy;
  80         while (s) {
  81                 v = strsep(&s, ",");
  82                 if (!v)
  83                         break;
  84                 k = strsep(&v, "=");
  85                 if (!k)
  86                         break;
  87                 if  (strcmp(k, key) == 0) {
  88                         new = strdup(v);
  89                         break;
  90                 }
  91         }
  92
  93         free(strcopy);
  94
  95         return new;
  96 }
  97
  98 /**
  99  * set_gpt_info(): Fill partition information from string
 100  *              function allocates memory, remember to free!
 101  *
 102  * @param dev_desc - pointer block device descriptor
 103  * @param str_part - pointer to string with partition information
 104  * @param str_disk_guid - pointer to pointer to allocated string with disk guid
 105  * @param partitions - pointer to pointer to allocated partitions array
 106  * @param parts_count - number of partitions
 107  *
 108  * @return - zero on success, otherwise error
 109  *
 110  */
 111 static int set_gpt_info(block_dev_desc_t *dev_desc,
 112                         const char *str_part,
 113                         char **str_disk_guid,
 114                         disk_partition_t **partitions,
 115                         u8 *parts_count)
 116 {
 117         char *tok, *str, *s;
 118         int i;
 119         char *val, *p;
 120         int p_count;
 121         disk_partition_t *parts;
 122         int errno = 0;
 123         uint64_t size_ll, start_ll;
 124
 125         debug("%s: MMC lba num: 0x%x %d\n", __func__,
 126               (unsigned int)dev_desc->lba, (unsigned int)dev_desc->lba);
 127
 128         if (str_part == NULL)
 129                 return -1;
 130
 131         str = strdup(str_part);
 132
 133         /* extract disk guid */
 134         s = str;
 135         tok = strsep(&s, ";");
 136         val = extract_val(tok, "uuid_disk");
 137         if (!val) {
 138                 free(str);
 139                 return -2;
 140         }
 141         if (extract_env(val, &p))
 142                 p = val;
 143         *str_disk_guid = strdup(p);
 144         free(val);
 145
 146         if (strlen(s) == 0)
 147                 return -3;
 148
 149         i = strlen(s) - 1;
 150         if (s[i] == ';')
 151                 s[i] = '\0';
 152
 153         /* calculate expected number of partitions */
 154         p_count = 1;
 155         p = s;
 156         while (*p) {
 157                 if (*p++ == ';')
 158                         p_count++;
 159         }
 160
 161         /* allocate memory for partitions */
 162         parts = calloc(sizeof(disk_partition_t), p_count);
 163
 164         /* retrive partions data from string */
 165         for (i = 0; i < p_count; i++) {
 166                 tok = strsep(&s, ";");
 167
 168                 if (tok == NULL)
 169                         break;
 170
 171                 /* uuid */
 172                 val = extract_val(tok, "uuid");
 173                 if (!val) { /* 'uuid' is mandatory */
 174                         errno = -4;
 175                         goto err;
 176                 }
 177                 if (extract_env(val, &p))
 178                         p = val;
 179                 if (strlen(p) >= sizeof(parts[i].uuid)) {
 180                         printf("Wrong uuid format for partition %d\n", i);
 181                         errno = -4;
 182                         goto err;
 183                 }
 184                 strcpy((char *)parts[i].uuid, p);
 185                 free(val);
 186
 187                 /* name */
 188                 val = extract_val(tok, "name");
 189                 if (!val) { /* name is mandatory */
 190                         errno = -4;
 191                         goto err;
 192                 }
 193                 if (extract_env(val, &p))
 194                         p = val;
 195                 if (strlen(p) >= sizeof(parts[i].name)) {
 196                         errno = -4;
 197                         goto err;
 198                 }
 199                 strcpy((char *)parts[i].name, p);
 200                 free(val);
 201
 202                 /* size */
 203                 val = extract_val(tok, "size");
 204                 if (!val) { /* 'size' is mandatory */
 205                         errno = -4;
 206                         goto err;
 207                 }
 208                 if (extract_env(val, &p))
 209                         p = val;
 210                 size_ll = ustrtoull(p, &p, 0);
 211                 parts[i].size = lldiv(size_ll, dev_desc->blksz);
 212                 free(val);
 213
 214                 /* start address */
 215                 val = extract_val(tok, "start");
 216                 if (val) { /* start address is optional */
 217                         if (extract_env(val, &p))
 218                                 p = val;
 219                         start_ll = ustrtoull(p, &p, 0);
 220                         parts[i].start = lldiv(start_ll, dev_desc->blksz);
 221                         free(val);
 222                 }
 223         }
 224
 225         *parts_count = p_count;
 226         *partitions = parts;
 227         free(str);
 228
 229         return 0;
 230 err:
 231         free(str);
 232         free(*str_disk_guid);
 233         free(parts);
 234
 235         return errno;
 236 }
 237
 238 static int gpt_mmc_default(int dev, const char *str_part)
 239 {
 240         int ret;
 241         char *str_disk_guid;
 242         u8 part_count = 0;
 243         disk_partition_t *partitions = NULL;
 244
 245         struct mmc *mmc = find_mmc_device(dev);
 246
 247         if (mmc == NULL) {
 248                 printf("%s: mmc dev %d NOT available\n", __func__, dev);
 249                 return CMD_RET_FAILURE;
 250         }
 251
 252         if (!str_part)
 253                 return -1;
 254
 255         /* fill partitions */
 256         ret = set_gpt_info(&mmc->block_dev, str_part,
 257                         &str_disk_guid, &partitions, &part_count);
 258         if (ret) {
 259                 if (ret == -1)
 260                         printf("No partition list provided\n");
 261                 if (ret == -2)
 262                         printf("Missing disk guid\n");
 263                 if ((ret == -3) || (ret == -4))
 264                         printf("Partition list incomplete\n");
 265                 return -1;
 266         }
 267
 268         /* save partitions layout to disk */
 269         gpt_restore(&mmc->block_dev, str_disk_guid, partitions, part_count);
 270         free(str_disk_guid);
 271         free(partitions);
 272
 273         return 0;
 274 }
 275
 276 /**
 277  * do_gpt(): Perform GPT operations
 278  *
 279  * @param cmdtp - command name
 280  * @param flag
 281  * @param argc
 282  * @param argv
 283  *
 284  * @return zero on success; otherwise error
 285  */
 286 static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 287 {
 288         int ret = CMD_RET_SUCCESS;
 289         int dev = 0;
 290         char *pstr;
 291
 292         if (argc < 5)
 293                 return CMD_RET_USAGE;
 294
 295         /* command: 'write' */
 296         if ((strcmp(argv[1], "write") == 0) && (argc == 5)) {
 297                 /* device: 'mmc' */
 298                 if (strcmp(argv[2], "mmc") == 0) {
 299                         /* check if 'dev' is a number */
 300                         for (pstr = argv[3]; *pstr != '\0'; pstr++)
 301                                 if (!isdigit(*pstr)) {
 302                                         printf("'%s' is not a number\n",
 303                                                 argv[3]);
 304                                         return CMD_RET_USAGE;
 305                                 }
 306                         dev = (int)simple_strtoul(argv[3], NULL, 10);
 307                         /* write to mmc */
 308                         if (gpt_mmc_default(dev, argv[4]))
 309                                 return CMD_RET_FAILURE;
 310                 }
 311         } else {
 312                 return CMD_RET_USAGE;
 313         }
 314         return ret;
 315 }
 316
 317 U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
 318         "GUID Partition Table",
 319         "<command> <interface> <dev> <partions_list>\n"
 320         " - GUID partition table restoration\n"
 321         " Restore GPT information on a device connected\n"
 322         " to interface\n"
 323 );