lib_m68k/board.c

   1 /*
   2  * (C) Copyright 2003
   3  * Josef Baumgartner <josef.baumgartner@telex.de>
   4  *
   5  * (C) Copyright 2000-2002
   6  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #include <common.h>
  28 #include <watchdog.h>
  29 #include <command.h>
  30 #include <malloc.h>
  31 #include <devices.h>
  32
  33 #ifdef  CONFIG_M5272
  34 #include <asm/immap_5272.h>
  35 #endif
  36
  37 #if (CONFIG_COMMANDS & CFG_CMD_IDE)
  38 #include <ide.h>
  39 #endif
  40 #if (CONFIG_COMMANDS & CFG_CMD_SCSI)
  41 #include <scsi.h>
  42 #endif
  43 #if (CONFIG_COMMANDS & CFG_CMD_KGDB)
  44 #include <kgdb.h>
  45 #endif
  46 #ifdef CONFIG_STATUS_LED
  47 #include <status_led.h>
  48 #endif
  49 #include <net.h>
  50 #if (CONFIG_COMMANDS & CFG_CMD_BEDBUG)
  51 #include <cmd_bedbug.h>
  52 #endif
  53 #ifdef CFG_ALLOC_DPRAM
  54 #include <commproc.h>
  55 #endif
  56 #include <version.h>
  57
  58 static char *failed = "*** failed ***\n";
  59
  60 #ifdef  CONFIG_PCU_E
  61 extern flash_info_t flash_info[];
  62 #endif
  63
  64 #include <environment.h>
  65
  66 #if ( ((CFG_ENV_ADDR+CFG_ENV_SIZE) < CFG_MONITOR_BASE) || \
  67       (CFG_ENV_ADDR >= (CFG_MONITOR_BASE + CFG_MONITOR_LEN)) ) || \
  68     defined(CFG_ENV_IS_IN_NVRAM)
  69 #define TOTAL_MALLOC_LEN        (CFG_MALLOC_LEN + CFG_ENV_SIZE)
  70 #else
  71 #define TOTAL_MALLOC_LEN        CFG_MALLOC_LEN
  72 #endif
  73
  74 extern ulong __init_end;
  75 extern ulong _end;
  76
  77 extern  void timer_init(void);
  78
  79 #if defined(CONFIG_WATCHDOG)
  80 # define INIT_FUNC_WATCHDOG_INIT        watchdog_init,
  81 # define WATCHDOG_DISABLE               watchdog_disable
  82
  83 extern int watchdog_init(void);
  84 extern int watchdog_disable(void);
  85 #else
  86 # define INIT_FUNC_WATCHDOG_INIT        /* undef */
  87 # define WATCHDOG_DISABLE               /* undef */
  88 #endif /* CONFIG_WATCHDOG */
  89
  90 ulong monitor_flash_len;
  91
  92 /*
  93  * Begin and End of memory area for malloc(), and current "brk"
  94  */
  95 static  ulong   mem_malloc_start = 0;
  96 static  ulong   mem_malloc_end   = 0;
  97 static  ulong   mem_malloc_brk   = 0;
  98
  99 /************************************************************************
 100  * Utilities                                                            *
 101  ************************************************************************
 102  */
 103
 104 /*
 105  * The Malloc area is immediately below the monitor copy in DRAM
 106  */
 107 static void mem_malloc_init (void)
 108 {
 109         DECLARE_GLOBAL_DATA_PTR;
 110
 111         ulong dest_addr = CFG_MONITOR_BASE + gd->reloc_off;
 112
 113         mem_malloc_end = dest_addr;
 114         mem_malloc_start = dest_addr - TOTAL_MALLOC_LEN;
 115         mem_malloc_brk = mem_malloc_start;
 116
 117         memset ((void *) mem_malloc_start,
 118                 0,
 119                 mem_malloc_end - mem_malloc_start);
 120 }
 121
 122 void *sbrk (ptrdiff_t increment)
 123 {
 124         ulong old = mem_malloc_brk;
 125         ulong new = old + increment;
 126
 127         if ((new < mem_malloc_start) ||
 128             (new > mem_malloc_end) ) {
 129                 return (NULL);
 130         }
 131         mem_malloc_brk = new;
 132         return ((void *)old);
 133 }
 134
 135 char *strmhz(char *buf, long hz)
 136 {
 137     long l, n;
 138     long m;
 139
 140     n = hz / 1000000L;
 141
 142     l = sprintf (buf, "%ld", n);
 143
 144     m = (hz % 1000000L) / 1000L;
 145
 146     if (m != 0)
 147         sprintf (buf+l, ".%03ld", m);
 148
 149     return (buf);
 150 }
 151
 152 /*
 153  * All attempts to come up with a "common" initialization sequence
 154  * that works for all boards and architectures failed: some of the
 155  * requirements are just _too_ different. To get rid of the resulting
 156  * mess of board dependend #ifdef'ed code we now make the whole
 157  * initialization sequence configurable to the user.
 158  *
 159  * The requirements for any new initalization function is simple: it
 160  * receives a pointer to the "global data" structure as it's only
 161  * argument, and returns an integer return code, where 0 means
 162  * "continue" and != 0 means "fatal error, hang the system".
 163  */
 164 typedef int (init_fnc_t) (void);
 165
 166 /************************************************************************
 167  * Init Utilities                                                       *
 168  ************************************************************************
 169  * Some of this code should be moved into the core functions,
 170  * but let's get it working (again) first...
 171  */
 172
 173 static int init_baudrate (void)
 174 {
 175         DECLARE_GLOBAL_DATA_PTR;
 176
 177         uchar tmp[64];  /* long enough for environment variables */
 178         int i = getenv_r ("baudrate", tmp, sizeof (tmp));
 179
 180         gd->baudrate = (i > 0)
 181                         ? (int) simple_strtoul (tmp, NULL, 10)
 182                         : CONFIG_BAUDRATE;
 183         return (0);
 184 }
 185
 186 /***********************************************************************/
 187
 188 static int init_func_ram (void)
 189 {
 190         DECLARE_GLOBAL_DATA_PTR;
 191
 192         int board_type = 0;     /* use dummy arg */
 193         puts ("DRAM:  ");
 194
 195         if ((gd->ram_size = initdram (board_type)) > 0) {
 196                 print_size (gd->ram_size, "\n");
 197                 return (0);
 198         }
 199         puts (failed);
 200         return (1);
 201 }
 202
 203 /***********************************************************************/
 204
 205 /************************************************************************
 206  * Initialization sequence                                              *
 207  ************************************************************************
 208  */
 209
 210 init_fnc_t *init_sequence[] = {
 211         env_init,
 212         init_baudrate,
 213         serial_init,
 214         console_init_f,
 215         display_options,
 216         checkcpu,
 217         checkboard,
 218         init_func_ram,
 219 #if defined(CFG_DRAM_TEST)
 220         testdram,
 221 #endif /* CFG_DRAM_TEST */
 222         INIT_FUNC_WATCHDOG_INIT
 223         NULL,                   /* Terminate this list */
 224 };
 225
 226
 227 /************************************************************************
 228  *
 229  * This is the first part of the initialization sequence that is
 230  * implemented in C, but still running from ROM.
 231  *
 232  * The main purpose is to provide a (serial) console interface as
 233  * soon as possible (so we can see any error messages), and to
 234  * initialize the RAM so that we can relocate the monitor code to
 235  * RAM.
 236  *
 237  * Be aware of the restrictions: global data is read-only, BSS is not
 238  * initialized, and stack space is limited to a few kB.
 239  *
 240  ************************************************************************
 241  */
 242
 243 void
 244 board_init_f (ulong bootflag)
 245 {
 246     DECLARE_GLOBAL_DATA_PTR;
 247
 248         bd_t *bd;
 249         ulong len, addr, addr_sp;
 250         gd_t *id;
 251         init_fnc_t **init_fnc_ptr;
 252 #ifdef CONFIG_PRAM
 253         int i;
 254         ulong reg;
 255         uchar tmp[64];          /* long enough for environment variables */
 256 #endif
 257
 258         /* Pointer is writable since we allocated a register for it */
 259         gd = (gd_t *) (CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET);
 260         /* compiler optimization barrier needed for GCC >= 3.4 */
 261         __asm__ __volatile__("": : :"memory");
 262
 263         /* Clear initial global data */
 264         memset ((void *) gd, 0, sizeof (gd_t));
 265
 266         for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
 267                 if ((*init_fnc_ptr)() != 0) {
 268                         hang ();
 269                 }
 270         }
 271
 272         /*
 273          * Now that we have DRAM mapped and working, we can
 274          * relocate the code and continue running from DRAM.
 275          *
 276          * Reserve memory at end of RAM for (top down in that order):
 277          *      - protected RAM
 278          *      - LCD framebuffer
 279          *      - monitor code
 280          *      - board info struct
 281          */
 282         len = (ulong)&_end - CFG_MONITOR_BASE;
 283
 284         addr = CFG_SDRAM_BASE + gd->ram_size;
 285
 286 #ifdef CONFIG_LOGBUFFER
 287         /* reserve kernel log buffer */
 288         addr -= (LOGBUFF_RESERVE);
 289         debug ("Reserving %dk for kernel logbuffer at %08lx\n", LOGBUFF_LEN, addr);
 290 #endif
 291
 292 #ifdef CONFIG_PRAM
 293         /*
 294          * reserve protected RAM
 295          */
 296         i = getenv_r ("pram", tmp, sizeof (tmp));
 297         reg = (i > 0) ? simple_strtoul (tmp, NULL, 10) : CONFIG_PRAM;
 298         addr -= (reg << 10);            /* size is in kB */
 299         debug ("Reserving %ldk for protected RAM at %08lx\n", reg, addr);
 300 #endif /* CONFIG_PRAM */
 301
 302         /*
 303          * reserve memory for U-Boot code, data & bss
 304          * round down to next 4 kB limit
 305          */
 306         addr -= len;
 307         addr &= ~(4096 - 1);
 308
 309         debug ("Reserving %ldk for U-Boot at: %08lx\n", len >> 10, addr);
 310
 311         /*
 312          * reserve memory for malloc() arena
 313          */
 314         addr_sp = addr - TOTAL_MALLOC_LEN;
 315         debug ("Reserving %dk for malloc() at: %08lx\n",
 316                         TOTAL_MALLOC_LEN >> 10, addr_sp);
 317
 318         /*
 319          * (permanently) allocate a Board Info struct
 320          * and a permanent copy of the "global" data
 321          */
 322         addr_sp -= sizeof (bd_t);
 323         bd = (bd_t *) addr_sp;
 324         gd->bd = bd;
 325         debug ("Reserving %d Bytes for Board Info at: %08lx\n",
 326                         sizeof (bd_t), addr_sp);
 327         addr_sp -= sizeof (gd_t);
 328         id = (gd_t *) addr_sp;
 329         debug ("Reserving %d Bytes for Global Data at: %08lx\n",
 330                         sizeof (gd_t), addr_sp);
 331
 332         /* Reserve memory for boot params. */
 333         addr_sp -= CFG_BOOTPARAMS_LEN;
 334         bd->bi_boot_params = addr_sp;
 335         debug ("Reserving %dk for boot parameters at: %08lx\n",
 336                         CFG_BOOTPARAMS_LEN >> 10, addr_sp);
 337
 338         /*
 339          * Finally, we set up a new (bigger) stack.
 340          *
 341          * Leave some safety gap for SP, force alignment on 16 byte boundary
 342          * Clear initial stack frame
 343          */
 344         addr_sp -= 16;
 345         addr_sp &= ~0xF;
 346         *((ulong *) addr_sp)-- = 0;
 347         *((ulong *) addr_sp)-- = 0;
 348         debug ("Stack Pointer at: %08lx\n", addr_sp);
 349
 350         /*
 351          * Save local variables to board info struct
 352          */
 353         bd->bi_memstart  = CFG_SDRAM_BASE;      /* start of  DRAM memory      */
 354         bd->bi_memsize   = gd->ram_size;        /* size  of  DRAM memory in bytes */
 355         bd->bi_mbar_base = CFG_MBAR;            /* base of internal registers */
 356
 357         bd->bi_bootflags = bootflag;            /* boot / reboot flag (for LynxOS)    */
 358
 359         WATCHDOG_RESET ();
 360         bd->bi_intfreq = gd->cpu_clk;   /* Internal Freq, in Hz */
 361         bd->bi_busfreq = gd->bus_clk;   /* Bus Freq,      in Hz */
 362         bd->bi_baudrate = gd->baudrate; /* Console Baudrate     */
 363
 364 #ifdef CFG_EXTBDINFO
 365         strncpy (bd->bi_s_version, "1.2", sizeof (bd->bi_s_version));
 366         strncpy (bd->bi_r_version, U_BOOT_VERSION, sizeof (bd->bi_r_version));
 367 #endif
 368
 369         WATCHDOG_RESET ();
 370
 371 #ifdef CONFIG_POST
 372         post_bootmode_init();
 373         post_run (NULL, POST_ROM | post_bootmode_get(0));
 374 #endif
 375
 376         WATCHDOG_RESET();
 377
 378         memcpy (id, (void *)gd, sizeof (gd_t));
 379
 380         debug ("Start relocate of code from %08x to %08lx\n", CFG_MONITOR_BASE, addr);
 381         relocate_code (addr_sp, id, addr);
 382
 383         /* NOTREACHED - jump_to_ram() does not return */
 384 }
 385
 386 /************************************************************************
 387  *
 388  * This is the next part if the initialization sequence: we are now
 389  * running from RAM and have a "normal" C environment, i. e. global
 390  * data can be written, BSS has been cleared, the stack size in not
 391  * that critical any more, etc.
 392  *
 393  ************************************************************************
 394  */
 395 void board_init_r (gd_t *id, ulong dest_addr)
 396 {
 397         DECLARE_GLOBAL_DATA_PTR;
 398         cmd_tbl_t *cmdtp;
 399         char *s, *e;
 400         bd_t *bd;
 401         int i;
 402         extern void malloc_bin_reloc (void);
 403
 404 #ifndef CFG_ENV_IS_NOWHERE
 405         extern char * env_name_spec;
 406 #endif
 407 #ifndef CFG_NO_FLASH
 408         ulong flash_size;
 409 #endif
 410         gd = id;                /* initialize RAM version of global data */
 411         bd = gd->bd;
 412
 413         gd->flags |= GD_FLG_RELOC;      /* tell others: relocation done */
 414
 415         debug ("Now running in RAM - U-Boot at: %08lx\n", dest_addr);
 416
 417         WATCHDOG_RESET ();
 418
 419         gd->reloc_off =  dest_addr - CFG_MONITOR_BASE;
 420
 421         monitor_flash_len = (ulong)&__init_end - dest_addr;
 422
 423         /*
 424          * We have to relocate the command table manually
 425          */
 426         for (cmdtp = &__u_boot_cmd_start; cmdtp !=  &__u_boot_cmd_end; cmdtp++) {
 427                 ulong addr;
 428                 addr = (ulong) (cmdtp->cmd) + gd->reloc_off;
 429 #if 0
 430                 printf ("Command \"%s\": 0x%08lx => 0x%08lx\n",
 431                                 cmdtp->name, (ulong) (cmdtp->cmd), addr);
 432 #endif
 433                 cmdtp->cmd =
 434                         (int (*)(struct cmd_tbl_s *, int, int, char *[]))addr;
 435
 436                 addr = (ulong)(cmdtp->name) + gd->reloc_off;
 437                 cmdtp->name = (char *)addr;
 438
 439                 if (cmdtp->usage) {
 440                         addr = (ulong)(cmdtp->usage) + gd->reloc_off;
 441                         cmdtp->usage = (char *)addr;
 442                 }
 443 #ifdef  CFG_LONGHELP
 444                 if (cmdtp->help) {
 445                         addr = (ulong)(cmdtp->help) + gd->reloc_off;
 446                         cmdtp->help = (char *)addr;
 447                 }
 448 #endif
 449         }
 450         /* there are some other pointer constants we must deal with */
 451 #ifndef CFG_ENV_IS_NOWHERE
 452         env_name_spec += gd->reloc_off;
 453 #endif
 454
 455         WATCHDOG_RESET ();
 456
 457 #ifdef CONFIG_LOGBUFFER
 458         logbuff_init_ptrs ();
 459 #endif
 460 #ifdef CONFIG_POST
 461         post_output_backlog ();
 462         post_reloc ();
 463 #endif
 464         WATCHDOG_RESET();
 465
 466 #if 0
 467         /* instruction cache enabled in cpu_init_f() for faster relocation */
 468         icache_enable ();       /* it's time to enable the instruction cache */
 469 #endif
 470
 471         /*
 472          * Setup trap handlers
 473          */
 474         trap_init (0);
 475
 476 #if !defined(CFG_NO_FLASH)
 477         puts ("FLASH: ");
 478
 479         if ((flash_size = flash_init ()) > 0) {
 480 # ifdef CFG_FLASH_CHECKSUM
 481                 print_size (flash_size, "");
 482                 /*
 483                  * Compute and print flash CRC if flashchecksum is set to 'y'
 484                  *
 485                  * NOTE: Maybe we should add some WATCHDOG_RESET()? XXX
 486                  */
 487                 s = getenv ("flashchecksum");
 488                 if (s && (*s == 'y')) {
 489                         printf ("  CRC: %08lX",
 490                                         crc32 (0,
 491                                                    (const unsigned char *) CFG_FLASH_BASE,
 492                                                    flash_size)
 493                                         );
 494                 }
 495                 putc ('\n');
 496 # else  /* !CFG_FLASH_CHECKSUM */
 497                 print_size (flash_size, "\n");
 498 # endif /* CFG_FLASH_CHECKSUM */
 499         } else {
 500                 puts (failed);
 501                 hang ();
 502         }
 503
 504         bd->bi_flashstart = CFG_FLASH_BASE;     /* update start of FLASH memory    */
 505         bd->bi_flashsize = flash_size;  /* size of FLASH memory (final value) */
 506         bd->bi_flashoffset = 0;
 507 #else   /* CFG_NO_FLASH */
 508         bd->bi_flashsize = 0;
 509         bd->bi_flashstart = 0;
 510         bd->bi_flashoffset = 0;
 511 #endif /* !CFG_NO_FLASH */
 512
 513         WATCHDOG_RESET ();
 514
 515         /* initialize higher level parts of CPU like time base and timers */
 516         cpu_init_r ();
 517
 518         WATCHDOG_RESET ();
 519
 520         /* initialize malloc() area */
 521         mem_malloc_init ();
 522         malloc_bin_reloc ();
 523
 524 #ifdef CONFIG_SPI
 525 # if !defined(CFG_ENV_IS_IN_EEPROM)
 526         spi_init_f ();
 527 # endif
 528         spi_init_r ();
 529 #endif
 530
 531         /* relocate environment function pointers etc. */
 532         env_relocate ();
 533
 534         /*
 535          * Fill in missing fields of bd_info.
 536          * We do this here, where we have "normal" access to the
 537          * environment; we used to do this still running from ROM,
 538          * where had to use getenv_r(), which can be pretty slow when
 539          * the environment is in EEPROM.
 540          */
 541         s = getenv ("ethaddr");
 542         for (i = 0; i < 6; ++i) {
 543                 bd->bi_enetaddr[i] = s ? simple_strtoul (s, &e, 16) : 0;
 544                 if (s)
 545                         s = (*e) ? e + 1 : e;
 546         }
 547
 548         /* IP Address */
 549         bd->bi_ip_addr = getenv_IPaddr ("ipaddr");
 550
 551         WATCHDOG_RESET ();
 552
 553
 554         /** leave this here (after malloc(), environment and PCI are working) **/
 555         /* Initialize devices */
 556         devices_init ();
 557
 558         /* Initialize the jump table for applications */
 559         jumptable_init ();
 560
 561         /* Initialize the console (after the relocation and devices init) */
 562         console_init_r ();
 563
 564 #if (CONFIG_COMMANDS & CFG_CMD_KGDB)
 565         WATCHDOG_RESET ();
 566         puts ("KGDB:  ");
 567         kgdb_init ();
 568 #endif
 569
 570         debug ("U-Boot relocated to %08lx\n", dest_addr);
 571
 572         /*
 573          * Enable Interrupts
 574          */
 575         interrupt_init ();
 576
 577         /* Must happen after interrupts are initialized since
 578          * an irq handler gets installed
 579          */
 580         timer_init();
 581
 582 #ifdef CONFIG_SERIAL_SOFTWARE_FIFO
 583         serial_buffered_init();
 584 #endif
 585
 586 #ifdef CONFIG_STATUS_LED
 587         status_led_set (STATUS_LED_BOOT, STATUS_LED_BLINKING);
 588 #endif
 589
 590         udelay (20);
 591
 592         set_timer (0);
 593
 594         /* Insert function pointers now that we have relocated the code */
 595
 596         /* Initialize from environment */
 597         if ((s = getenv ("loadaddr")) != NULL) {
 598                 load_addr = simple_strtoul (s, NULL, 16);
 599         }
 600 #if (CONFIG_COMMANDS & CFG_CMD_NET)
 601         if ((s = getenv ("bootfile")) != NULL) {
 602                 copy_filename (BootFile, s, sizeof (BootFile));
 603         }
 604 #endif /* CFG_CMD_NET */
 605
 606         WATCHDOG_RESET ();
 607
 608 #if (CONFIG_COMMANDS & CFG_CMD_DOC)
 609         WATCHDOG_RESET ();
 610         puts ("DOC:   ");
 611         doc_init ();
 612 #endif
 613
 614 #if (CONFIG_COMMANDS & CFG_CMD_NAND)
 615         WATCHDOG_RESET ();
 616         puts ("NAND:");
 617         nand_init();            /* go init the NAND */
 618 #endif
 619
 620 #if (CONFIG_COMMANDS & CFG_CMD_NET) && defined(FEC_ENET)
 621         WATCHDOG_RESET();
 622         eth_init(bd);
 623 #endif
 624
 625 #ifdef CONFIG_POST
 626         post_run (NULL, POST_RAM | post_bootmode_get(0));
 627 #endif
 628
 629 #ifdef CONFIG_LAST_STAGE_INIT
 630         WATCHDOG_RESET ();
 631         /*
 632          * Some parts can be only initialized if all others (like
 633          * Interrupts) are up and running (i.e. the PC-style ISA
 634          * keyboard).
 635          */
 636         last_stage_init ();
 637 #endif
 638
 639 #if (CONFIG_COMMANDS & CFG_CMD_BEDBUG)
 640         WATCHDOG_RESET ();
 641         bedbug_init ();
 642 #endif
 643
 644 #if defined(CONFIG_PRAM) || defined(CONFIG_LOGBUFFER)
 645         /*
 646          * Export available size of memory for Linux,
 647          * taking into account the protected RAM at top of memory
 648          */
 649         {
 650                 ulong pram;
 651                 uchar memsz[32];
 652 #ifdef CONFIG_PRAM
 653                 char *s;
 654
 655                 if ((s = getenv ("pram")) != NULL) {
 656                         pram = simple_strtoul (s, NULL, 10);
 657                 } else {
 658                         pram = CONFIG_PRAM;
 659                 }
 660 #else
 661                 pram=0;
 662 #endif
 663 #ifdef CONFIG_LOGBUFFER
 664                 /* Also take the logbuffer into account (pram is in kB) */
 665                 pram += (LOGBUFF_LEN+LOGBUFF_OVERHEAD)/1024;
 666 #endif
 667                 sprintf (memsz, "%ldk", (bd->bi_memsize / 1024) - pram);
 668                 setenv ("mem", memsz);
 669         }
 670 #endif
 671
 672 #ifdef CONFIG_MODEM_SUPPORT
 673  {
 674          extern int do_mdm_init;
 675          do_mdm_init = gd->do_mdm_init;
 676  }
 677 #endif
 678
 679 #ifdef CONFIG_WATCHDOG
 680         /* disable watchdog if environment is set */
 681         if ((s = getenv ("watchdog")) != NULL) {
 682                 if (strncmp (s, "off", 3) == 0) {
 683                         WATCHDOG_DISABLE ();
 684                 }
 685         }
 686 #endif /* CONFIG_WATCHDOG*/
 687
 688
 689         /* Initialization complete - start the monitor */
 690
 691         /* main_loop() can return to retry autoboot, if so just run it again. */
 692         for (;;) {
 693                 WATCHDOG_RESET ();
 694                 main_loop ();
 695         }
 696
 697         /* NOTREACHED - no way out of command loop except booting */
 698 }
 699
 700
 701 void hang(void)
 702 {
 703         puts ("### ERROR ### Please RESET the board ###\n");
 704         for (;;);
 705 }