cmd/bcb.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Eugeniu Rosca <rosca.eugeniu@gmail.com>
   4  *
   5  * Command to read/modify/write Android BCB fields
   6  */
   7
   8 #include <android_bootloader_message.h>
   9 #include <command.h>
  10 #include <common.h>
  11 #include <part.h>
  12
  13 enum bcb_cmd {
  14         BCB_CMD_LOAD,
  15         BCB_CMD_FIELD_SET,
  16         BCB_CMD_FIELD_CLEAR,
  17         BCB_CMD_FIELD_TEST,
  18         BCB_CMD_FIELD_DUMP,
  19         BCB_CMD_STORE,
  20 };
  21
  22 static int bcb_dev = -1;
  23 static int bcb_part = -1;
  24 static struct bootloader_message bcb = { { 0 } };
  25
  26 static int bcb_cmd_get(char *cmd)
  27 {
  28         if (!strcmp(cmd, "load"))
  29                 return BCB_CMD_LOAD;
  30         if (!strcmp(cmd, "set"))
  31                 return BCB_CMD_FIELD_SET;
  32         if (!strcmp(cmd, "clear"))
  33                 return BCB_CMD_FIELD_CLEAR;
  34         if (!strcmp(cmd, "test"))
  35                 return BCB_CMD_FIELD_TEST;
  36         if (!strcmp(cmd, "store"))
  37                 return BCB_CMD_STORE;
  38         if (!strcmp(cmd, "dump"))
  39                 return BCB_CMD_FIELD_DUMP;
  40         else
  41                 return -1;
  42 }
  43
  44 static int bcb_is_misused(int argc, char *const argv[])
  45 {
  46         int cmd = bcb_cmd_get(argv[0]);
  47
  48         switch (cmd) {
  49         case BCB_CMD_LOAD:
  50         case BCB_CMD_FIELD_SET:
  51                 if (argc != 3)
  52                         goto err;
  53                 break;
  54         case BCB_CMD_FIELD_TEST:
  55                 if (argc != 4)
  56                         goto err;
  57                 break;
  58         case BCB_CMD_FIELD_CLEAR:
  59                 if (argc != 1 && argc != 2)
  60                         goto err;
  61                 break;
  62         case BCB_CMD_STORE:
  63                 if (argc != 1)
  64                         goto err;
  65                 break;
  66         case BCB_CMD_FIELD_DUMP:
  67                 if (argc != 2)
  68                         goto err;
  69                 break;
  70         default:
  71                 printf("Error: 'bcb %s' not supported\n", argv[0]);
  72                 return -1;
  73         }
  74
  75         if (cmd != BCB_CMD_LOAD && (bcb_dev < 0 || bcb_part < 0)) {
  76                 printf("Error: Please, load BCB first!\n");
  77                 return -1;
  78         }
  79
  80         return 0;
  81 err:
  82         printf("Error: Bad usage of 'bcb %s'\n", argv[0]);
  83
  84         return -1;
  85 }
  86
  87 static int bcb_field_get(char *name, char **fieldp, int *sizep)
  88 {
  89         if (!strcmp(name, "command")) {
  90                 *fieldp = bcb.command;
  91                 *sizep = sizeof(bcb.command);
  92         } else if (!strcmp(name, "status")) {
  93                 *fieldp = bcb.status;
  94                 *sizep = sizeof(bcb.status);
  95         } else if (!strcmp(name, "recovery")) {
  96                 *fieldp = bcb.recovery;
  97                 *sizep = sizeof(bcb.recovery);
  98         } else if (!strcmp(name, "stage")) {
  99                 *fieldp = bcb.stage;
 100                 *sizep = sizeof(bcb.stage);
 101         } else if (!strcmp(name, "reserved")) {
 102                 *fieldp = bcb.reserved;
 103                 *sizep = sizeof(bcb.reserved);
 104         } else {
 105                 printf("Error: Unknown bcb field '%s'\n", name);
 106                 return -1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static int do_bcb_load(struct cmd_tbl *cmdtp, int flag, int argc,
 113                        char *const argv[])
 114 {
 115         struct blk_desc *desc;
 116         struct disk_partition info;
 117         u64 cnt;
 118         char *endp;
 119         int part, ret;
 120
 121         ret = blk_get_device_by_str("mmc", argv[1], &desc);
 122         if (ret < 0)
 123                 goto err_read_fail;
 124
 125         part = simple_strtoul(argv[2], &endp, 0);
 126         if (*endp == '\0') {
 127                 ret = part_get_info(desc, part, &info);
 128                 if (ret)
 129                         goto err_read_fail;
 130         } else {
 131                 part = part_get_info_by_name(desc, argv[2], &info);
 132                 if (part < 0) {
 133                         ret = part;
 134                         goto err_read_fail;
 135                 }
 136         }
 137
 138         cnt = DIV_ROUND_UP(sizeof(struct bootloader_message), info.blksz);
 139         if (cnt > info.size)
 140                 goto err_too_small;
 141
 142         if (blk_dread(desc, info.start, cnt, &bcb) != cnt) {
 143                 ret = -EIO;
 144                 goto err_read_fail;
 145         }
 146
 147         bcb_dev = desc->devnum;
 148         bcb_part = part;
 149         debug("%s: Loaded from mmc %d:%d\n", __func__, bcb_dev, bcb_part);
 150
 151         return CMD_RET_SUCCESS;
 152 err_read_fail:
 153         printf("Error: mmc %s:%s read failed (%d)\n", argv[1], argv[2], ret);
 154         goto err;
 155 err_too_small:
 156         printf("Error: mmc %s:%s too small!", argv[1], argv[2]);
 157         goto err;
 158 err:
 159         bcb_dev = -1;
 160         bcb_part = -1;
 161
 162         return CMD_RET_FAILURE;
 163 }
 164
 165 static int do_bcb_set(struct cmd_tbl *cmdtp, int flag, int argc,
 166                       char *const argv[])
 167 {
 168         int size, len;
 169         char *field, *str, *found;
 170
 171         if (bcb_field_get(argv[1], &field, &size))
 172                 return CMD_RET_FAILURE;
 173
 174         len = strlen(argv[2]);
 175         if (len >= size) {
 176                 printf("Error: sizeof('%s') = %d >= %d = sizeof(bcb.%s)\n",
 177                        argv[2], len, size, argv[1]);
 178                 return CMD_RET_FAILURE;
 179         }
 180         str = argv[2];
 181
 182         field[0] = '\0';
 183         while ((found = strsep(&str, ":"))) {
 184                 if (field[0] != '\0')
 185                         strcat(field, "\n");
 186                 strcat(field, found);
 187         }
 188
 189         return CMD_RET_SUCCESS;
 190 }
 191
 192 static int do_bcb_clear(struct cmd_tbl *cmdtp, int flag, int argc,
 193                         char *const argv[])
 194 {
 195         int size;
 196         char *field;
 197
 198         if (argc == 1) {
 199                 memset(&bcb, 0, sizeof(bcb));
 200                 return CMD_RET_SUCCESS;
 201         }
 202
 203         if (bcb_field_get(argv[1], &field, &size))
 204                 return CMD_RET_FAILURE;
 205
 206         memset(field, 0, size);
 207
 208         return CMD_RET_SUCCESS;
 209 }
 210
 211 static int do_bcb_test(struct cmd_tbl *cmdtp, int flag, int argc,
 212                        char *const argv[])
 213 {
 214         int size;
 215         char *field;
 216         char *op = argv[2];
 217
 218         if (bcb_field_get(argv[1], &field, &size))
 219                 return CMD_RET_FAILURE;
 220
 221         if (*op == '=' && *(op + 1) == '\0') {
 222                 if (!strncmp(argv[3], field, size))
 223                         return CMD_RET_SUCCESS;
 224                 else
 225                         return CMD_RET_FAILURE;
 226         } else if (*op == '~' && *(op + 1) == '\0') {
 227                 if (!strstr(field, argv[3]))
 228                         return CMD_RET_FAILURE;
 229                 else
 230                         return CMD_RET_SUCCESS;
 231         } else {
 232                 printf("Error: Unknown operator '%s'\n", op);
 233         }
 234
 235         return CMD_RET_FAILURE;
 236 }
 237
 238 static int do_bcb_dump(struct cmd_tbl *cmdtp, int flag, int argc,
 239                        char *const argv[])
 240 {
 241         int size;
 242         char *field;
 243
 244         if (bcb_field_get(argv[1], &field, &size))
 245                 return CMD_RET_FAILURE;
 246
 247         print_buffer((ulong)field - (ulong)&bcb, (void *)field, 1, size, 16);
 248
 249         return CMD_RET_SUCCESS;
 250 }
 251
 252 static int do_bcb_store(struct cmd_tbl *cmdtp, int flag, int argc,
 253                         char *const argv[])
 254 {
 255         struct blk_desc *desc;
 256         struct disk_partition info;
 257         u64 cnt;
 258         int ret;
 259
 260         desc = blk_get_devnum_by_type(IF_TYPE_MMC, bcb_dev);
 261         if (!desc) {
 262                 ret = -ENODEV;
 263                 goto err;
 264         }
 265
 266         ret = part_get_info(desc, bcb_part, &info);
 267         if (ret)
 268                 goto err;
 269
 270         cnt = DIV_ROUND_UP(sizeof(struct bootloader_message), info.blksz);
 271
 272         if (blk_dwrite(desc, info.start, cnt, &bcb) != cnt) {
 273                 ret = -EIO;
 274                 goto err;
 275         }
 276
 277         return CMD_RET_SUCCESS;
 278 err:
 279         printf("Error: mmc %d:%d write failed (%d)\n", bcb_dev, bcb_part, ret);
 280
 281         return CMD_RET_FAILURE;
 282 }
 283
 284 static struct cmd_tbl cmd_bcb_sub[] = {
 285         U_BOOT_CMD_MKENT(load, CONFIG_SYS_MAXARGS, 1, do_bcb_load, "", ""),
 286         U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 1, do_bcb_set, "", ""),
 287         U_BOOT_CMD_MKENT(clear, CONFIG_SYS_MAXARGS, 1, do_bcb_clear, "", ""),
 288         U_BOOT_CMD_MKENT(test, CONFIG_SYS_MAXARGS, 1, do_bcb_test, "", ""),
 289         U_BOOT_CMD_MKENT(dump, CONFIG_SYS_MAXARGS, 1, do_bcb_dump, "", ""),
 290         U_BOOT_CMD_MKENT(store, CONFIG_SYS_MAXARGS, 1, do_bcb_store, "", ""),
 291 };
 292
 293 static int do_bcb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 294 {
 295         struct cmd_tbl *c;
 296
 297         if (argc < 2)
 298                 return CMD_RET_USAGE;
 299
 300         argc--;
 301         argv++;
 302
 303         c = find_cmd_tbl(argv[0], cmd_bcb_sub, ARRAY_SIZE(cmd_bcb_sub));
 304         if (!c)
 305                 return CMD_RET_USAGE;
 306
 307         if (bcb_is_misused(argc, argv)) {
 308                 /*
 309                  * We try to improve the user experience by reporting the
 310                  * root-cause of misusage, so don't return CMD_RET_USAGE,
 311                  * since the latter prints out the full-blown help text
 312                  */
 313                 return CMD_RET_FAILURE;
 314         }
 315
 316         return c->cmd(cmdtp, flag, argc, argv);
 317 }
 318
 319 U_BOOT_CMD(
 320         bcb, CONFIG_SYS_MAXARGS, 1, do_bcb,
 321         "Load/set/clear/test/dump/store Android BCB fields",
 322         "load  <dev> <part>       - load  BCB from mmc <dev>:<part>\n"
 323         "bcb set   <field> <val>      - set   BCB <field> to <val>\n"
 324         "bcb clear [<field>]          - clear BCB <field> or all fields\n"
 325         "bcb test  <field> <op> <val> - test  BCB <field> against <val>\n"
 326         "bcb dump  <field>            - dump  BCB <field>\n"
 327         "bcb store                    - store BCB back to mmc\n"
 328         "\n"
 329         "Legend:\n"
 330         "<dev>   - MMC device index containing the BCB partition\n"
 331         "<part>  - MMC partition index or name containing the BCB\n"
 332         "<field> - one of {command,status,recovery,stage,reserved}\n"
 333         "<op>    - the binary operator used in 'bcb test':\n"
 334         "          '=' returns true if <val> matches the string stored in <field>\n"
 335         "          '~' returns true if <val> matches a subset of <field>'s string\n"
 336         "<val>   - string/text provided as input to bcb {set,test}\n"
 337         "          NOTE: any ':' character in <val> will be replaced by line feed\n"
 338         "          during 'bcb set' and used as separator by upper layers\n"
 339 );