common/autoboot.c

   1 /*
   2  * (C) Copyright 2000
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <autoboot.h>
  10 #include <bootretry.h>
  11 #include <cli.h>
  12 #include <console.h>
  13 #include <fdtdec.h>
  14 #include <menu.h>
  15 #include <post.h>
  16 #include <u-boot/sha256.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 #define MAX_DELAY_STOP_STR 32
  21
  22 #ifndef DEBUG_BOOTKEYS
  23 #define DEBUG_BOOTKEYS 0
  24 #endif
  25 #define debug_bootkeys(fmt, args...)            \
  26         debug_cond(DEBUG_BOOTKEYS, fmt, ##args)
  27
  28 /* Stored value of bootdelay, used by autoboot_command() */
  29 static int stored_bootdelay;
  30
  31 #if defined(CONFIG_AUTOBOOT_KEYED)
  32 #if defined(CONFIG_AUTOBOOT_STOP_STR_SHA256)
  33
  34 /*
  35  * Use a "constant-length" time compare function for this
  36  * hash compare:
  37  *
  38  * https://crackstation.net/hashing-security.htm
  39  */
  40 static int slow_equals(u8 *a, u8 *b, int len)
  41 {
  42         int diff = 0;
  43         int i;
  44
  45         for (i = 0; i < len; i++)
  46                 diff |= a[i] ^ b[i];
  47
  48         return diff == 0;
  49 }
  50
  51 static int passwd_abort(uint64_t etime)
  52 {
  53         const char *sha_env_str = getenv("bootstopkeysha256");
  54         u8 sha_env[SHA256_SUM_LEN];
  55         u8 sha[SHA256_SUM_LEN];
  56         char presskey[MAX_DELAY_STOP_STR];
  57         const char *algo_name = "sha256";
  58         u_int presskey_len = 0;
  59         int abort = 0;
  60         int size;
  61         int ret;
  62
  63         if (sha_env_str == NULL)
  64                 sha_env_str = CONFIG_AUTOBOOT_STOP_STR_SHA256;
  65
  66         /*
  67          * Generate the binary value from the environment hash value
  68          * so that we can compare this value with the computed hash
  69          * from the user input
  70          */
  71         ret = hash_parse_string(algo_name, sha_env_str, sha_env);
  72         if (ret) {
  73                 printf("Hash %s not supported!\n", algo_name);
  74                 return 0;
  75         }
  76
  77         /*
  78          * We don't know how long the stop-string is, so we need to
  79          * generate the sha256 hash upon each input character and
  80          * compare the value with the one saved in the environment
  81          */
  82         do {
  83                 if (tstc()) {
  84                         /* Check for input string overflow */
  85                         if (presskey_len >= MAX_DELAY_STOP_STR)
  86                                 return 0;
  87
  88                         presskey[presskey_len++] = getc();
  89
  90                         /* Calculate sha256 upon each new char */
  91                         hash_block(algo_name, (const void *)presskey,
  92                                    presskey_len, sha, &size);
  93
  94                         /* And check if sha matches saved value in env */
  95                         if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
  96                                 abort = 1;
  97                 }
  98         } while (!abort && get_ticks() <= etime);
  99
 100         return abort;
 101 }
 102 #else
 103 static int passwd_abort(uint64_t etime)
 104 {
 105         int abort = 0;
 106         struct {
 107                 char *str;
 108                 u_int len;
 109                 int retry;
 110         }
 111         delaykey[] = {
 112                 { .str = getenv("bootdelaykey"),  .retry = 1 },
 113                 { .str = getenv("bootstopkey"),   .retry = 0 },
 114         };
 115
 116         char presskey[MAX_DELAY_STOP_STR];
 117         u_int presskey_len = 0;
 118         u_int presskey_max = 0;
 119         u_int i;
 120
 121 #  ifdef CONFIG_AUTOBOOT_DELAY_STR
 122         if (delaykey[0].str == NULL)
 123                 delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
 124 #  endif
 125 #  ifdef CONFIG_AUTOBOOT_STOP_STR
 126         if (delaykey[1].str == NULL)
 127                 delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
 128 #  endif
 129
 130         for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 131                 delaykey[i].len = delaykey[i].str == NULL ?
 132                                     0 : strlen(delaykey[i].str);
 133                 delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
 134                                     MAX_DELAY_STOP_STR : delaykey[i].len;
 135
 136                 presskey_max = presskey_max > delaykey[i].len ?
 137                                     presskey_max : delaykey[i].len;
 138
 139                 debug_bootkeys("%s key:<%s>\n",
 140                                delaykey[i].retry ? "delay" : "stop",
 141                                delaykey[i].str ? delaykey[i].str : "NULL");
 142         }
 143
 144         /* In order to keep up with incoming data, check timeout only
 145          * when catch up.
 146          */
 147         do {
 148                 if (tstc()) {
 149                         if (presskey_len < presskey_max) {
 150                                 presskey[presskey_len++] = getc();
 151                         } else {
 152                                 for (i = 0; i < presskey_max - 1; i++)
 153                                         presskey[i] = presskey[i + 1];
 154
 155                                 presskey[i] = getc();
 156                         }
 157                 }
 158
 159                 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 160                         if (delaykey[i].len > 0 &&
 161                             presskey_len >= delaykey[i].len &&
 162                                 memcmp(presskey + presskey_len -
 163                                         delaykey[i].len, delaykey[i].str,
 164                                         delaykey[i].len) == 0) {
 165                                         debug_bootkeys("got %skey\n",
 166                                                 delaykey[i].retry ? "delay" :
 167                                                 "stop");
 168
 169                                 /* don't retry auto boot */
 170                                 if (!delaykey[i].retry)
 171                                         bootretry_dont_retry();
 172                                 abort = 1;
 173                         }
 174                 }
 175         } while (!abort && get_ticks() <= etime);
 176
 177         return abort;
 178 }
 179 #endif
 180
 181 /***************************************************************************
 182  * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
 183  * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
 184  */
 185 static int abortboot_keyed(int bootdelay)
 186 {
 187         int abort;
 188         uint64_t etime = endtick(bootdelay);
 189
 190 #ifndef CONFIG_ZERO_BOOTDELAY_CHECK
 191         if (bootdelay == 0)
 192                 return 0;
 193 #endif
 194
 195 #  ifdef CONFIG_AUTOBOOT_PROMPT
 196         /*
 197          * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
 198          * To print the bootdelay value upon bootup.
 199          */
 200         printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
 201 #  endif
 202
 203         abort = passwd_abort(etime);
 204         if (!abort)
 205                 debug_bootkeys("key timeout\n");
 206
 207 #ifdef CONFIG_SILENT_CONSOLE
 208         if (abort)
 209                 gd->flags &= ~GD_FLG_SILENT;
 210 #endif
 211
 212         return abort;
 213 }
 214
 215 # else  /* !defined(CONFIG_AUTOBOOT_KEYED) */
 216
 217 #ifdef CONFIG_MENUKEY
 218 static int menukey;
 219 #endif
 220
 221 static int abortboot_normal(int bootdelay)
 222 {
 223         int abort = 0;
 224         unsigned long ts;
 225
 226 #ifdef CONFIG_MENUPROMPT
 227         printf(CONFIG_MENUPROMPT);
 228 #else
 229         if (bootdelay >= 0)
 230                 printf("Hit any key to stop autoboot: %2d ", bootdelay);
 231 #endif
 232
 233 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
 234         /*
 235          * Check if key already pressed
 236          * Don't check if bootdelay < 0
 237          */
 238         if (bootdelay >= 0) {
 239                 if (tstc()) {   /* we got a key press   */
 240                         (void) getc();  /* consume input        */
 241                         puts("\b\b\b 0");
 242                         abort = 1;      /* don't auto boot      */
 243                 }
 244         }
 245 #endif
 246
 247         while ((bootdelay > 0) && (!abort)) {
 248                 --bootdelay;
 249                 /* delay 1000 ms */
 250                 ts = get_timer(0);
 251                 do {
 252                         if (tstc()) {   /* we got a key press   */
 253                                 abort  = 1;     /* don't auto boot      */
 254                                 bootdelay = 0;  /* no more delay        */
 255 # ifdef CONFIG_MENUKEY
 256                                 menukey = getc();
 257 # else
 258                                 (void) getc();  /* consume input        */
 259 # endif
 260                                 break;
 261                         }
 262                         udelay(10000);
 263                 } while (!abort && get_timer(ts) < 1000);
 264
 265                 printf("\b\b\b%2d ", bootdelay);
 266         }
 267
 268         putc('\n');
 269
 270 #ifdef CONFIG_SILENT_CONSOLE
 271         if (abort)
 272                 gd->flags &= ~GD_FLG_SILENT;
 273 #endif
 274
 275         return abort;
 276 }
 277 # endif /* CONFIG_AUTOBOOT_KEYED */
 278
 279 static int abortboot(int bootdelay)
 280 {
 281 #ifdef CONFIG_AUTOBOOT_KEYED
 282         return abortboot_keyed(bootdelay);
 283 #else
 284         return abortboot_normal(bootdelay);
 285 #endif
 286 }
 287
 288 static void process_fdt_options(const void *blob)
 289 {
 290 #if defined(CONFIG_OF_CONTROL) && defined(CONFIG_SYS_TEXT_BASE)
 291         ulong addr;
 292
 293         /* Add an env variable to point to a kernel payload, if available */
 294         addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
 295         if (addr)
 296                 setenv_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 297
 298         /* Add an env variable to point to a root disk, if available */
 299         addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
 300         if (addr)
 301                 setenv_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 302 #endif /* CONFIG_OF_CONTROL && CONFIG_SYS_TEXT_BASE */
 303 }
 304
 305 const char *bootdelay_process(void)
 306 {
 307         char *s;
 308         int bootdelay;
 309 #ifdef CONFIG_BOOTCOUNT_LIMIT
 310         unsigned long bootcount = 0;
 311         unsigned long bootlimit = 0;
 312 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 313
 314 #ifdef CONFIG_BOOTCOUNT_LIMIT
 315         bootcount = bootcount_load();
 316         bootcount++;
 317         bootcount_store(bootcount);
 318         setenv_ulong("bootcount", bootcount);
 319         bootlimit = getenv_ulong("bootlimit", 10, 0);
 320 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 321
 322         s = getenv("bootdelay");
 323         bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
 324
 325 #ifdef CONFIG_OF_CONTROL
 326         bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
 327                         bootdelay);
 328 #endif
 329
 330         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 331
 332 #if defined(CONFIG_MENU_SHOW)
 333         bootdelay = menu_show(bootdelay);
 334 #endif
 335         bootretry_init_cmd_timeout();
 336
 337 #ifdef CONFIG_POST
 338         if (gd->flags & GD_FLG_POSTFAIL) {
 339                 s = getenv("failbootcmd");
 340         } else
 341 #endif /* CONFIG_POST */
 342 #ifdef CONFIG_BOOTCOUNT_LIMIT
 343         if (bootlimit && (bootcount > bootlimit)) {
 344                 printf("Warning: Bootlimit (%u) exceeded. Using altbootcmd.\n",
 345                        (unsigned)bootlimit);
 346                 s = getenv("altbootcmd");
 347         } else
 348 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 349                 s = getenv("bootcmd");
 350
 351         process_fdt_options(gd->fdt_blob);
 352         stored_bootdelay = bootdelay;
 353
 354         return s;
 355 }
 356
 357 void autoboot_command(const char *s)
 358 {
 359         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
 360
 361         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 362 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 363                 int prev = disable_ctrlc(1);    /* disable Control C checking */
 364 #endif
 365
 366                 run_command_list(s, -1, 0);
 367
 368 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 369                 disable_ctrlc(prev);    /* restore Control C checking */
 370 #endif
 371         }
 372
 373 #ifdef CONFIG_MENUKEY
 374         if (menukey == CONFIG_MENUKEY) {
 375                 s = getenv("menucmd");
 376                 if (s)
 377                         run_command_list(s, -1, 0);
 378         }
 379 #endif /* CONFIG_MENUKEY */
 380 }