xref: /openbmc/u-boot/common/main.c (revision 522de019)
1 /*
2  * (C) Copyright 2000
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * Add to readline cmdline-editing by
6  * (C) Copyright 2005
7  * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 /* #define	DEBUG	*/
29 
30 #include <common.h>
31 #include <watchdog.h>
32 #include <command.h>
33 #include <malloc.h>
34 #include <version.h>
35 #ifdef CONFIG_MODEM_SUPPORT
36 #include <malloc.h>		/* for free() prototype */
37 #endif
38 
39 #ifdef CONFIG_SYS_HUSH_PARSER
40 #include <hush.h>
41 #endif
42 
43 #include <post.h>
44 #include <linux/ctype.h>
45 #include <menu.h>
46 
47 #if defined(CONFIG_SILENT_CONSOLE) || defined(CONFIG_POST) || defined(CONFIG_CMDLINE_EDITING)
48 DECLARE_GLOBAL_DATA_PTR;
49 #endif
50 
51 /*
52  * Board-specific Platform code can reimplement show_boot_progress () if needed
53  */
54 void inline __show_boot_progress (int val) {}
55 void show_boot_progress (int val) __attribute__((weak, alias("__show_boot_progress")));
56 
57 #if defined(CONFIG_UPDATE_TFTP)
58 int update_tftp (ulong addr);
59 #endif /* CONFIG_UPDATE_TFTP */
60 
61 #define MAX_DELAY_STOP_STR 32
62 
63 #undef DEBUG_PARSER
64 
65 char        console_buffer[CONFIG_SYS_CBSIZE + 1];	/* console I/O buffer	*/
66 
67 static char * delete_char (char *buffer, char *p, int *colp, int *np, int plen);
68 static const char erase_seq[] = "\b \b";		/* erase sequence	*/
69 static const char   tab_seq[] = "        ";		/* used to expand TABs	*/
70 
71 #ifdef CONFIG_BOOT_RETRY_TIME
72 static uint64_t endtime = 0;  /* must be set, default is instant timeout */
73 static int      retry_time = -1; /* -1 so can call readline before main_loop */
74 #endif
75 
76 #define	endtick(seconds) (get_ticks() + (uint64_t)(seconds) * get_tbclk())
77 
78 #ifndef CONFIG_BOOT_RETRY_MIN
79 #define CONFIG_BOOT_RETRY_MIN CONFIG_BOOT_RETRY_TIME
80 #endif
81 
82 #ifdef CONFIG_MODEM_SUPPORT
83 int do_mdm_init = 0;
84 extern void mdm_init(void); /* defined in board.c */
85 #endif
86 
87 /***************************************************************************
88  * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
89  * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
90  */
91 #if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
92 # if defined(CONFIG_AUTOBOOT_KEYED)
93 #ifndef CONFIG_MENU
94 static inline
95 #endif
96 int abortboot(int bootdelay)
97 {
98 	int abort = 0;
99 	uint64_t etime = endtick(bootdelay);
100 	struct {
101 		char* str;
102 		u_int len;
103 		int retry;
104 	}
105 	delaykey [] = {
106 		{ str: getenv ("bootdelaykey"),  retry: 1 },
107 		{ str: getenv ("bootdelaykey2"), retry: 1 },
108 		{ str: getenv ("bootstopkey"),   retry: 0 },
109 		{ str: getenv ("bootstopkey2"),  retry: 0 },
110 	};
111 
112 	char presskey [MAX_DELAY_STOP_STR];
113 	u_int presskey_len = 0;
114 	u_int presskey_max = 0;
115 	u_int i;
116 
117 #ifndef CONFIG_ZERO_BOOTDELAY_CHECK
118 	if (bootdelay == 0)
119 		return 0;
120 #endif
121 
122 #  ifdef CONFIG_AUTOBOOT_PROMPT
123 	printf(CONFIG_AUTOBOOT_PROMPT);
124 #  endif
125 
126 #  ifdef CONFIG_AUTOBOOT_DELAY_STR
127 	if (delaykey[0].str == NULL)
128 		delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
129 #  endif
130 #  ifdef CONFIG_AUTOBOOT_DELAY_STR2
131 	if (delaykey[1].str == NULL)
132 		delaykey[1].str = CONFIG_AUTOBOOT_DELAY_STR2;
133 #  endif
134 #  ifdef CONFIG_AUTOBOOT_STOP_STR
135 	if (delaykey[2].str == NULL)
136 		delaykey[2].str = CONFIG_AUTOBOOT_STOP_STR;
137 #  endif
138 #  ifdef CONFIG_AUTOBOOT_STOP_STR2
139 	if (delaykey[3].str == NULL)
140 		delaykey[3].str = CONFIG_AUTOBOOT_STOP_STR2;
141 #  endif
142 
143 	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i ++) {
144 		delaykey[i].len = delaykey[i].str == NULL ?
145 				    0 : strlen (delaykey[i].str);
146 		delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
147 				    MAX_DELAY_STOP_STR : delaykey[i].len;
148 
149 		presskey_max = presskey_max > delaykey[i].len ?
150 				    presskey_max : delaykey[i].len;
151 
152 #  if DEBUG_BOOTKEYS
153 		printf("%s key:<%s>\n",
154 		       delaykey[i].retry ? "delay" : "stop",
155 		       delaykey[i].str ? delaykey[i].str : "NULL");
156 #  endif
157 	}
158 
159 	/* In order to keep up with incoming data, check timeout only
160 	 * when catch up.
161 	 */
162 	do {
163 		if (tstc()) {
164 			if (presskey_len < presskey_max) {
165 				presskey [presskey_len ++] = getc();
166 			}
167 			else {
168 				for (i = 0; i < presskey_max - 1; i ++)
169 					presskey [i] = presskey [i + 1];
170 
171 				presskey [i] = getc();
172 			}
173 		}
174 
175 		for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i ++) {
176 			if (delaykey[i].len > 0 &&
177 			    presskey_len >= delaykey[i].len &&
178 			    memcmp (presskey + presskey_len - delaykey[i].len,
179 				    delaykey[i].str,
180 				    delaykey[i].len) == 0) {
181 #  if DEBUG_BOOTKEYS
182 				printf("got %skey\n",
183 				       delaykey[i].retry ? "delay" : "stop");
184 #  endif
185 
186 #  ifdef CONFIG_BOOT_RETRY_TIME
187 				/* don't retry auto boot */
188 				if (! delaykey[i].retry)
189 					retry_time = -1;
190 #  endif
191 				abort = 1;
192 			}
193 		}
194 	} while (!abort && get_ticks() <= etime);
195 
196 #  if DEBUG_BOOTKEYS
197 	if (!abort)
198 		puts("key timeout\n");
199 #  endif
200 
201 #ifdef CONFIG_SILENT_CONSOLE
202 	if (abort)
203 		gd->flags &= ~GD_FLG_SILENT;
204 #endif
205 
206 	return abort;
207 }
208 
209 # else	/* !defined(CONFIG_AUTOBOOT_KEYED) */
210 
211 #ifdef CONFIG_MENUKEY
212 static int menukey = 0;
213 #endif
214 
215 #ifndef CONFIG_MENU
216 static inline
217 #endif
218 int abortboot(int bootdelay)
219 {
220 	int abort = 0;
221 
222 #ifdef CONFIG_MENUPROMPT
223 	printf(CONFIG_MENUPROMPT);
224 #else
225 	if (bootdelay >= 0)
226 		printf("Hit any key to stop autoboot: %2d ", bootdelay);
227 #endif
228 
229 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
230 	/*
231 	 * Check if key already pressed
232 	 * Don't check if bootdelay < 0
233 	 */
234 	if (bootdelay >= 0) {
235 		if (tstc()) {	/* we got a key press	*/
236 			(void) getc();  /* consume input	*/
237 			puts ("\b\b\b 0");
238 			abort = 1;	/* don't auto boot	*/
239 		}
240 	}
241 #endif
242 
243 	while ((bootdelay > 0) && (!abort)) {
244 		int i;
245 
246 		--bootdelay;
247 		/* delay 100 * 10ms */
248 		for (i=0; !abort && i<100; ++i) {
249 			if (tstc()) {	/* we got a key press	*/
250 				abort  = 1;	/* don't auto boot	*/
251 				bootdelay = 0;	/* no more delay	*/
252 # ifdef CONFIG_MENUKEY
253 				menukey = getc();
254 # else
255 				(void) getc();  /* consume input	*/
256 # endif
257 				break;
258 			}
259 			udelay(10000);
260 		}
261 
262 		printf("\b\b\b%2d ", bootdelay);
263 	}
264 
265 	putc('\n');
266 
267 #ifdef CONFIG_SILENT_CONSOLE
268 	if (abort)
269 		gd->flags &= ~GD_FLG_SILENT;
270 #endif
271 
272 	return abort;
273 }
274 # endif	/* CONFIG_AUTOBOOT_KEYED */
275 #endif	/* CONFIG_BOOTDELAY >= 0  */
276 
277 /****************************************************************************/
278 
279 void main_loop (void)
280 {
281 #ifndef CONFIG_SYS_HUSH_PARSER
282 	static char lastcommand[CONFIG_SYS_CBSIZE] = { 0, };
283 	int len;
284 	int rc = 1;
285 	int flag;
286 #endif
287 
288 #if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
289 	char *s;
290 	int bootdelay;
291 #endif
292 #ifdef CONFIG_PREBOOT
293 	char *p;
294 #endif
295 #ifdef CONFIG_BOOTCOUNT_LIMIT
296 	unsigned long bootcount = 0;
297 	unsigned long bootlimit = 0;
298 	char *bcs;
299 	char bcs_set[16];
300 #endif /* CONFIG_BOOTCOUNT_LIMIT */
301 
302 #ifdef CONFIG_BOOTCOUNT_LIMIT
303 	bootcount = bootcount_load();
304 	bootcount++;
305 	bootcount_store (bootcount);
306 	sprintf (bcs_set, "%lu", bootcount);
307 	setenv ("bootcount", bcs_set);
308 	bcs = getenv ("bootlimit");
309 	bootlimit = bcs ? simple_strtoul (bcs, NULL, 10) : 0;
310 #endif /* CONFIG_BOOTCOUNT_LIMIT */
311 
312 #ifdef CONFIG_MODEM_SUPPORT
313 	debug ("DEBUG: main_loop:   do_mdm_init=%d\n", do_mdm_init);
314 	if (do_mdm_init) {
315 		char *str = strdup(getenv("mdm_cmd"));
316 		setenv ("preboot", str);  /* set or delete definition */
317 		if (str != NULL)
318 			free (str);
319 		mdm_init(); /* wait for modem connection */
320 	}
321 #endif  /* CONFIG_MODEM_SUPPORT */
322 
323 #ifdef CONFIG_VERSION_VARIABLE
324 	{
325 		setenv ("ver", version_string);  /* set version variable */
326 	}
327 #endif /* CONFIG_VERSION_VARIABLE */
328 
329 #ifdef CONFIG_SYS_HUSH_PARSER
330 	u_boot_hush_start ();
331 #endif
332 
333 #if defined(CONFIG_HUSH_INIT_VAR)
334 	hush_init_var ();
335 #endif
336 
337 #ifdef CONFIG_PREBOOT
338 	if ((p = getenv ("preboot")) != NULL) {
339 # ifdef CONFIG_AUTOBOOT_KEYED
340 		int prev = disable_ctrlc(1);	/* disable Control C checking */
341 # endif
342 
343 		run_command_list(p, -1, 0);
344 
345 # ifdef CONFIG_AUTOBOOT_KEYED
346 		disable_ctrlc(prev);	/* restore Control C checking */
347 # endif
348 	}
349 #endif /* CONFIG_PREBOOT */
350 
351 #if defined(CONFIG_UPDATE_TFTP)
352 	update_tftp (0UL);
353 #endif /* CONFIG_UPDATE_TFTP */
354 
355 #if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
356 	s = getenv ("bootdelay");
357 	bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
358 
359 	debug ("### main_loop entered: bootdelay=%d\n\n", bootdelay);
360 
361 #if defined(CONFIG_MENU_SHOW)
362 	bootdelay = menu_show(bootdelay);
363 #endif
364 # ifdef CONFIG_BOOT_RETRY_TIME
365 	init_cmd_timeout ();
366 # endif	/* CONFIG_BOOT_RETRY_TIME */
367 
368 #ifdef CONFIG_POST
369 	if (gd->flags & GD_FLG_POSTFAIL) {
370 		s = getenv("failbootcmd");
371 	}
372 	else
373 #endif /* CONFIG_POST */
374 #ifdef CONFIG_BOOTCOUNT_LIMIT
375 	if (bootlimit && (bootcount > bootlimit)) {
376 		printf ("Warning: Bootlimit (%u) exceeded. Using altbootcmd.\n",
377 		        (unsigned)bootlimit);
378 		s = getenv ("altbootcmd");
379 	}
380 	else
381 #endif /* CONFIG_BOOTCOUNT_LIMIT */
382 		s = getenv ("bootcmd");
383 
384 	debug ("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
385 
386 	if (bootdelay != -1 && s && !abortboot(bootdelay)) {
387 # ifdef CONFIG_AUTOBOOT_KEYED
388 		int prev = disable_ctrlc(1);	/* disable Control C checking */
389 # endif
390 
391 		run_command_list(s, -1, 0);
392 
393 # ifdef CONFIG_AUTOBOOT_KEYED
394 		disable_ctrlc(prev);	/* restore Control C checking */
395 # endif
396 	}
397 
398 # ifdef CONFIG_MENUKEY
399 	if (menukey == CONFIG_MENUKEY) {
400 		s = getenv("menucmd");
401 		if (s)
402 			run_command_list(s, -1, 0);
403 	}
404 #endif /* CONFIG_MENUKEY */
405 #endif /* CONFIG_BOOTDELAY */
406 
407 	/*
408 	 * Main Loop for Monitor Command Processing
409 	 */
410 #ifdef CONFIG_SYS_HUSH_PARSER
411 	parse_file_outer();
412 	/* This point is never reached */
413 	for (;;);
414 #else
415 	for (;;) {
416 #ifdef CONFIG_BOOT_RETRY_TIME
417 		if (rc >= 0) {
418 			/* Saw enough of a valid command to
419 			 * restart the timeout.
420 			 */
421 			reset_cmd_timeout();
422 		}
423 #endif
424 		len = readline (CONFIG_SYS_PROMPT);
425 
426 		flag = 0;	/* assume no special flags for now */
427 		if (len > 0)
428 			strcpy (lastcommand, console_buffer);
429 		else if (len == 0)
430 			flag |= CMD_FLAG_REPEAT;
431 #ifdef CONFIG_BOOT_RETRY_TIME
432 		else if (len == -2) {
433 			/* -2 means timed out, retry autoboot
434 			 */
435 			puts ("\nTimed out waiting for command\n");
436 # ifdef CONFIG_RESET_TO_RETRY
437 			/* Reinit board to run initialization code again */
438 			do_reset (NULL, 0, 0, NULL);
439 # else
440 			return;		/* retry autoboot */
441 # endif
442 		}
443 #endif
444 
445 		if (len == -1)
446 			puts ("<INTERRUPT>\n");
447 		else
448 			rc = run_command(lastcommand, flag);
449 
450 		if (rc <= 0) {
451 			/* invalid command or not repeatable, forget it */
452 			lastcommand[0] = 0;
453 		}
454 	}
455 #endif /*CONFIG_SYS_HUSH_PARSER*/
456 }
457 
458 #ifdef CONFIG_BOOT_RETRY_TIME
459 /***************************************************************************
460  * initialize command line timeout
461  */
462 void init_cmd_timeout(void)
463 {
464 	char *s = getenv ("bootretry");
465 
466 	if (s != NULL)
467 		retry_time = (int)simple_strtol(s, NULL, 10);
468 	else
469 		retry_time =  CONFIG_BOOT_RETRY_TIME;
470 
471 	if (retry_time >= 0 && retry_time < CONFIG_BOOT_RETRY_MIN)
472 		retry_time = CONFIG_BOOT_RETRY_MIN;
473 }
474 
475 /***************************************************************************
476  * reset command line timeout to retry_time seconds
477  */
478 void reset_cmd_timeout(void)
479 {
480 	endtime = endtick(retry_time);
481 }
482 #endif
483 
484 #ifdef CONFIG_CMDLINE_EDITING
485 
486 /*
487  * cmdline-editing related codes from vivi.
488  * Author: Janghoon Lyu <nandy@mizi.com>
489  */
490 
491 #define putnstr(str,n)	do {			\
492 		printf ("%.*s", (int)n, str);	\
493 	} while (0)
494 
495 #define CTL_CH(c)		((c) - 'a' + 1)
496 #define CTL_BACKSPACE		('\b')
497 #define DEL			((char)255)
498 #define DEL7			((char)127)
499 #define CREAD_HIST_CHAR		('!')
500 
501 #define getcmd_putch(ch)	putc(ch)
502 #define getcmd_getch()		getc()
503 #define getcmd_cbeep()		getcmd_putch('\a')
504 
505 #define HIST_MAX		20
506 #define HIST_SIZE		CONFIG_SYS_CBSIZE
507 
508 static int hist_max = 0;
509 static int hist_add_idx = 0;
510 static int hist_cur = -1;
511 unsigned hist_num = 0;
512 
513 char* hist_list[HIST_MAX];
514 char hist_lines[HIST_MAX][HIST_SIZE + 1];	 /* Save room for NULL */
515 
516 #define add_idx_minus_one() ((hist_add_idx == 0) ? hist_max : hist_add_idx-1)
517 
518 static void hist_init(void)
519 {
520 	int i;
521 
522 	hist_max = 0;
523 	hist_add_idx = 0;
524 	hist_cur = -1;
525 	hist_num = 0;
526 
527 	for (i = 0; i < HIST_MAX; i++) {
528 		hist_list[i] = hist_lines[i];
529 		hist_list[i][0] = '\0';
530 	}
531 }
532 
533 static void cread_add_to_hist(char *line)
534 {
535 	strcpy(hist_list[hist_add_idx], line);
536 
537 	if (++hist_add_idx >= HIST_MAX)
538 		hist_add_idx = 0;
539 
540 	if (hist_add_idx > hist_max)
541 		hist_max = hist_add_idx;
542 
543 	hist_num++;
544 }
545 
546 static char* hist_prev(void)
547 {
548 	char *ret;
549 	int old_cur;
550 
551 	if (hist_cur < 0)
552 		return NULL;
553 
554 	old_cur = hist_cur;
555 	if (--hist_cur < 0)
556 		hist_cur = hist_max;
557 
558 	if (hist_cur == hist_add_idx) {
559 		hist_cur = old_cur;
560 		ret = NULL;
561 	} else
562 		ret = hist_list[hist_cur];
563 
564 	return (ret);
565 }
566 
567 static char* hist_next(void)
568 {
569 	char *ret;
570 
571 	if (hist_cur < 0)
572 		return NULL;
573 
574 	if (hist_cur == hist_add_idx)
575 		return NULL;
576 
577 	if (++hist_cur > hist_max)
578 		hist_cur = 0;
579 
580 	if (hist_cur == hist_add_idx) {
581 		ret = "";
582 	} else
583 		ret = hist_list[hist_cur];
584 
585 	return (ret);
586 }
587 
588 #ifndef CONFIG_CMDLINE_EDITING
589 static void cread_print_hist_list(void)
590 {
591 	int i;
592 	unsigned long n;
593 
594 	n = hist_num - hist_max;
595 
596 	i = hist_add_idx + 1;
597 	while (1) {
598 		if (i > hist_max)
599 			i = 0;
600 		if (i == hist_add_idx)
601 			break;
602 		printf("%s\n", hist_list[i]);
603 		n++;
604 		i++;
605 	}
606 }
607 #endif /* CONFIG_CMDLINE_EDITING */
608 
609 #define BEGINNING_OF_LINE() {			\
610 	while (num) {				\
611 		getcmd_putch(CTL_BACKSPACE);	\
612 		num--;				\
613 	}					\
614 }
615 
616 #define ERASE_TO_EOL() {				\
617 	if (num < eol_num) {				\
618 		printf("%*s", (int)(eol_num - num), ""); \
619 		do {					\
620 			getcmd_putch(CTL_BACKSPACE);	\
621 		} while (--eol_num > num);		\
622 	}						\
623 }
624 
625 #define REFRESH_TO_EOL() {			\
626 	if (num < eol_num) {			\
627 		wlen = eol_num - num;		\
628 		putnstr(buf + num, wlen);	\
629 		num = eol_num;			\
630 	}					\
631 }
632 
633 static void cread_add_char(char ichar, int insert, unsigned long *num,
634 	       unsigned long *eol_num, char *buf, unsigned long len)
635 {
636 	unsigned long wlen;
637 
638 	/* room ??? */
639 	if (insert || *num == *eol_num) {
640 		if (*eol_num > len - 1) {
641 			getcmd_cbeep();
642 			return;
643 		}
644 		(*eol_num)++;
645 	}
646 
647 	if (insert) {
648 		wlen = *eol_num - *num;
649 		if (wlen > 1) {
650 			memmove(&buf[*num+1], &buf[*num], wlen-1);
651 		}
652 
653 		buf[*num] = ichar;
654 		putnstr(buf + *num, wlen);
655 		(*num)++;
656 		while (--wlen) {
657 			getcmd_putch(CTL_BACKSPACE);
658 		}
659 	} else {
660 		/* echo the character */
661 		wlen = 1;
662 		buf[*num] = ichar;
663 		putnstr(buf + *num, wlen);
664 		(*num)++;
665 	}
666 }
667 
668 static void cread_add_str(char *str, int strsize, int insert, unsigned long *num,
669 	      unsigned long *eol_num, char *buf, unsigned long len)
670 {
671 	while (strsize--) {
672 		cread_add_char(*str, insert, num, eol_num, buf, len);
673 		str++;
674 	}
675 }
676 
677 static int cread_line(const char *const prompt, char *buf, unsigned int *len,
678 		int timeout)
679 {
680 	unsigned long num = 0;
681 	unsigned long eol_num = 0;
682 	unsigned long wlen;
683 	char ichar;
684 	int insert = 1;
685 	int esc_len = 0;
686 	char esc_save[8];
687 	int init_len = strlen(buf);
688 	int first = 1;
689 
690 	if (init_len)
691 		cread_add_str(buf, init_len, 1, &num, &eol_num, buf, *len);
692 
693 	while (1) {
694 #ifdef CONFIG_BOOT_RETRY_TIME
695 		while (!tstc()) {	/* while no incoming data */
696 			if (retry_time >= 0 && get_ticks() > endtime)
697 				return (-2);	/* timed out */
698 			WATCHDOG_RESET();
699 		}
700 #endif
701 		if (first && timeout) {
702 			uint64_t etime = endtick(timeout);
703 
704 			while (!tstc()) {	/* while no incoming data */
705 				if (get_ticks() >= etime)
706 					return -2;	/* timed out */
707 				WATCHDOG_RESET();
708 			}
709 			first = 0;
710 		}
711 
712 		ichar = getcmd_getch();
713 
714 		if ((ichar == '\n') || (ichar == '\r')) {
715 			putc('\n');
716 			break;
717 		}
718 
719 		/*
720 		 * handle standard linux xterm esc sequences for arrow key, etc.
721 		 */
722 		if (esc_len != 0) {
723 			if (esc_len == 1) {
724 				if (ichar == '[') {
725 					esc_save[esc_len] = ichar;
726 					esc_len = 2;
727 				} else {
728 					cread_add_str(esc_save, esc_len, insert,
729 						      &num, &eol_num, buf, *len);
730 					esc_len = 0;
731 				}
732 				continue;
733 			}
734 
735 			switch (ichar) {
736 
737 			case 'D':	/* <- key */
738 				ichar = CTL_CH('b');
739 				esc_len = 0;
740 				break;
741 			case 'C':	/* -> key */
742 				ichar = CTL_CH('f');
743 				esc_len = 0;
744 				break;	/* pass off to ^F handler */
745 			case 'H':	/* Home key */
746 				ichar = CTL_CH('a');
747 				esc_len = 0;
748 				break;	/* pass off to ^A handler */
749 			case 'A':	/* up arrow */
750 				ichar = CTL_CH('p');
751 				esc_len = 0;
752 				break;	/* pass off to ^P handler */
753 			case 'B':	/* down arrow */
754 				ichar = CTL_CH('n');
755 				esc_len = 0;
756 				break;	/* pass off to ^N handler */
757 			default:
758 				esc_save[esc_len++] = ichar;
759 				cread_add_str(esc_save, esc_len, insert,
760 					      &num, &eol_num, buf, *len);
761 				esc_len = 0;
762 				continue;
763 			}
764 		}
765 
766 		switch (ichar) {
767 		case 0x1b:
768 			if (esc_len == 0) {
769 				esc_save[esc_len] = ichar;
770 				esc_len = 1;
771 			} else {
772 				puts("impossible condition #876\n");
773 				esc_len = 0;
774 			}
775 			break;
776 
777 		case CTL_CH('a'):
778 			BEGINNING_OF_LINE();
779 			break;
780 		case CTL_CH('c'):	/* ^C - break */
781 			*buf = '\0';	/* discard input */
782 			return (-1);
783 		case CTL_CH('f'):
784 			if (num < eol_num) {
785 				getcmd_putch(buf[num]);
786 				num++;
787 			}
788 			break;
789 		case CTL_CH('b'):
790 			if (num) {
791 				getcmd_putch(CTL_BACKSPACE);
792 				num--;
793 			}
794 			break;
795 		case CTL_CH('d'):
796 			if (num < eol_num) {
797 				wlen = eol_num - num - 1;
798 				if (wlen) {
799 					memmove(&buf[num], &buf[num+1], wlen);
800 					putnstr(buf + num, wlen);
801 				}
802 
803 				getcmd_putch(' ');
804 				do {
805 					getcmd_putch(CTL_BACKSPACE);
806 				} while (wlen--);
807 				eol_num--;
808 			}
809 			break;
810 		case CTL_CH('k'):
811 			ERASE_TO_EOL();
812 			break;
813 		case CTL_CH('e'):
814 			REFRESH_TO_EOL();
815 			break;
816 		case CTL_CH('o'):
817 			insert = !insert;
818 			break;
819 		case CTL_CH('x'):
820 		case CTL_CH('u'):
821 			BEGINNING_OF_LINE();
822 			ERASE_TO_EOL();
823 			break;
824 		case DEL:
825 		case DEL7:
826 		case 8:
827 			if (num) {
828 				wlen = eol_num - num;
829 				num--;
830 				memmove(&buf[num], &buf[num+1], wlen);
831 				getcmd_putch(CTL_BACKSPACE);
832 				putnstr(buf + num, wlen);
833 				getcmd_putch(' ');
834 				do {
835 					getcmd_putch(CTL_BACKSPACE);
836 				} while (wlen--);
837 				eol_num--;
838 			}
839 			break;
840 		case CTL_CH('p'):
841 		case CTL_CH('n'):
842 		{
843 			char * hline;
844 
845 			esc_len = 0;
846 
847 			if (ichar == CTL_CH('p'))
848 				hline = hist_prev();
849 			else
850 				hline = hist_next();
851 
852 			if (!hline) {
853 				getcmd_cbeep();
854 				continue;
855 			}
856 
857 			/* nuke the current line */
858 			/* first, go home */
859 			BEGINNING_OF_LINE();
860 
861 			/* erase to end of line */
862 			ERASE_TO_EOL();
863 
864 			/* copy new line into place and display */
865 			strcpy(buf, hline);
866 			eol_num = strlen(buf);
867 			REFRESH_TO_EOL();
868 			continue;
869 		}
870 #ifdef CONFIG_AUTO_COMPLETE
871 		case '\t': {
872 			int num2, col;
873 
874 			/* do not autocomplete when in the middle */
875 			if (num < eol_num) {
876 				getcmd_cbeep();
877 				break;
878 			}
879 
880 			buf[num] = '\0';
881 			col = strlen(prompt) + eol_num;
882 			num2 = num;
883 			if (cmd_auto_complete(prompt, buf, &num2, &col)) {
884 				col = num2 - num;
885 				num += col;
886 				eol_num += col;
887 			}
888 			break;
889 		}
890 #endif
891 		default:
892 			cread_add_char(ichar, insert, &num, &eol_num, buf, *len);
893 			break;
894 		}
895 	}
896 	*len = eol_num;
897 	buf[eol_num] = '\0';	/* lose the newline */
898 
899 	if (buf[0] && buf[0] != CREAD_HIST_CHAR)
900 		cread_add_to_hist(buf);
901 	hist_cur = hist_add_idx;
902 
903 	return 0;
904 }
905 
906 #endif /* CONFIG_CMDLINE_EDITING */
907 
908 /****************************************************************************/
909 
910 /*
911  * Prompt for input and read a line.
912  * If  CONFIG_BOOT_RETRY_TIME is defined and retry_time >= 0,
913  * time out when time goes past endtime (timebase time in ticks).
914  * Return:	number of read characters
915  *		-1 if break
916  *		-2 if timed out
917  */
918 int readline (const char *const prompt)
919 {
920 	/*
921 	 * If console_buffer isn't 0-length the user will be prompted to modify
922 	 * it instead of entering it from scratch as desired.
923 	 */
924 	console_buffer[0] = '\0';
925 
926 	return readline_into_buffer(prompt, console_buffer, 0);
927 }
928 
929 
930 int readline_into_buffer(const char *const prompt, char *buffer, int timeout)
931 {
932 	char *p = buffer;
933 #ifdef CONFIG_CMDLINE_EDITING
934 	unsigned int len = CONFIG_SYS_CBSIZE;
935 	int rc;
936 	static int initted = 0;
937 
938 	/*
939 	 * History uses a global array which is not
940 	 * writable until after relocation to RAM.
941 	 * Revert to non-history version if still
942 	 * running from flash.
943 	 */
944 	if (gd->flags & GD_FLG_RELOC) {
945 		if (!initted) {
946 			hist_init();
947 			initted = 1;
948 		}
949 
950 		if (prompt)
951 			puts (prompt);
952 
953 		rc = cread_line(prompt, p, &len, timeout);
954 		return rc < 0 ? rc : len;
955 
956 	} else {
957 #endif	/* CONFIG_CMDLINE_EDITING */
958 	char * p_buf = p;
959 	int	n = 0;				/* buffer index		*/
960 	int	plen = 0;			/* prompt length	*/
961 	int	col;				/* output column cnt	*/
962 	char	c;
963 
964 	/* print prompt */
965 	if (prompt) {
966 		plen = strlen (prompt);
967 		puts (prompt);
968 	}
969 	col = plen;
970 
971 	for (;;) {
972 #ifdef CONFIG_BOOT_RETRY_TIME
973 		while (!tstc()) {	/* while no incoming data */
974 			if (retry_time >= 0 && get_ticks() > endtime)
975 				return (-2);	/* timed out */
976 			WATCHDOG_RESET();
977 		}
978 #endif
979 		WATCHDOG_RESET();		/* Trigger watchdog, if needed */
980 
981 #ifdef CONFIG_SHOW_ACTIVITY
982 		while (!tstc()) {
983 			show_activity(0);
984 			WATCHDOG_RESET();
985 		}
986 #endif
987 		c = getc();
988 
989 		/*
990 		 * Special character handling
991 		 */
992 		switch (c) {
993 		case '\r':				/* Enter		*/
994 		case '\n':
995 			*p = '\0';
996 			puts ("\r\n");
997 			return (p - p_buf);
998 
999 		case '\0':				/* nul			*/
1000 			continue;
1001 
1002 		case 0x03:				/* ^C - break		*/
1003 			p_buf[0] = '\0';	/* discard input */
1004 			return (-1);
1005 
1006 		case 0x15:				/* ^U - erase line	*/
1007 			while (col > plen) {
1008 				puts (erase_seq);
1009 				--col;
1010 			}
1011 			p = p_buf;
1012 			n = 0;
1013 			continue;
1014 
1015 		case 0x17:				/* ^W - erase word	*/
1016 			p=delete_char(p_buf, p, &col, &n, plen);
1017 			while ((n > 0) && (*p != ' ')) {
1018 				p=delete_char(p_buf, p, &col, &n, plen);
1019 			}
1020 			continue;
1021 
1022 		case 0x08:				/* ^H  - backspace	*/
1023 		case 0x7F:				/* DEL - backspace	*/
1024 			p=delete_char(p_buf, p, &col, &n, plen);
1025 			continue;
1026 
1027 		default:
1028 			/*
1029 			 * Must be a normal character then
1030 			 */
1031 			if (n < CONFIG_SYS_CBSIZE-2) {
1032 				if (c == '\t') {	/* expand TABs		*/
1033 #ifdef CONFIG_AUTO_COMPLETE
1034 					/* if auto completion triggered just continue */
1035 					*p = '\0';
1036 					if (cmd_auto_complete(prompt, console_buffer, &n, &col)) {
1037 						p = p_buf + n;	/* reset */
1038 						continue;
1039 					}
1040 #endif
1041 					puts (tab_seq+(col&07));
1042 					col += 8 - (col&07);
1043 				} else {
1044 					++col;		/* echo input		*/
1045 					putc (c);
1046 				}
1047 				*p++ = c;
1048 				++n;
1049 			} else {			/* Buffer full		*/
1050 				putc ('\a');
1051 			}
1052 		}
1053 	}
1054 #ifdef CONFIG_CMDLINE_EDITING
1055 	}
1056 #endif
1057 }
1058 
1059 /****************************************************************************/
1060 
1061 static char * delete_char (char *buffer, char *p, int *colp, int *np, int plen)
1062 {
1063 	char *s;
1064 
1065 	if (*np == 0) {
1066 		return (p);
1067 	}
1068 
1069 	if (*(--p) == '\t') {			/* will retype the whole line	*/
1070 		while (*colp > plen) {
1071 			puts (erase_seq);
1072 			(*colp)--;
1073 		}
1074 		for (s=buffer; s<p; ++s) {
1075 			if (*s == '\t') {
1076 				puts (tab_seq+((*colp) & 07));
1077 				*colp += 8 - ((*colp) & 07);
1078 			} else {
1079 				++(*colp);
1080 				putc (*s);
1081 			}
1082 		}
1083 	} else {
1084 		puts (erase_seq);
1085 		(*colp)--;
1086 	}
1087 	(*np)--;
1088 	return (p);
1089 }
1090 
1091 /****************************************************************************/
1092 
1093 int parse_line (char *line, char *argv[])
1094 {
1095 	int nargs = 0;
1096 
1097 #ifdef DEBUG_PARSER
1098 	printf ("parse_line: \"%s\"\n", line);
1099 #endif
1100 	while (nargs < CONFIG_SYS_MAXARGS) {
1101 
1102 		/* skip any white space */
1103 		while (isblank(*line))
1104 			++line;
1105 
1106 		if (*line == '\0') {	/* end of line, no more args	*/
1107 			argv[nargs] = NULL;
1108 #ifdef DEBUG_PARSER
1109 		printf ("parse_line: nargs=%d\n", nargs);
1110 #endif
1111 			return (nargs);
1112 		}
1113 
1114 		argv[nargs++] = line;	/* begin of argument string	*/
1115 
1116 		/* find end of string */
1117 		while (*line && !isblank(*line))
1118 			++line;
1119 
1120 		if (*line == '\0') {	/* end of line, no more args	*/
1121 			argv[nargs] = NULL;
1122 #ifdef DEBUG_PARSER
1123 		printf ("parse_line: nargs=%d\n", nargs);
1124 #endif
1125 			return (nargs);
1126 		}
1127 
1128 		*line++ = '\0';		/* terminate current arg	 */
1129 	}
1130 
1131 	printf ("** Too many args (max. %d) **\n", CONFIG_SYS_MAXARGS);
1132 
1133 #ifdef DEBUG_PARSER
1134 	printf ("parse_line: nargs=%d\n", nargs);
1135 #endif
1136 	return (nargs);
1137 }
1138 
1139 /****************************************************************************/
1140 
1141 #ifndef CONFIG_SYS_HUSH_PARSER
1142 static void process_macros (const char *input, char *output)
1143 {
1144 	char c, prev;
1145 	const char *varname_start = NULL;
1146 	int inputcnt = strlen (input);
1147 	int outputcnt = CONFIG_SYS_CBSIZE;
1148 	int state = 0;		/* 0 = waiting for '$'  */
1149 
1150 	/* 1 = waiting for '(' or '{' */
1151 	/* 2 = waiting for ')' or '}' */
1152 	/* 3 = waiting for '''  */
1153 #ifdef DEBUG_PARSER
1154 	char *output_start = output;
1155 
1156 	printf ("[PROCESS_MACROS] INPUT len %d: \"%s\"\n", strlen (input),
1157 		input);
1158 #endif
1159 
1160 	prev = '\0';		/* previous character   */
1161 
1162 	while (inputcnt && outputcnt) {
1163 		c = *input++;
1164 		inputcnt--;
1165 
1166 		if (state != 3) {
1167 			/* remove one level of escape characters */
1168 			if ((c == '\\') && (prev != '\\')) {
1169 				if (inputcnt-- == 0)
1170 					break;
1171 				prev = c;
1172 				c = *input++;
1173 			}
1174 		}
1175 
1176 		switch (state) {
1177 		case 0:	/* Waiting for (unescaped) $    */
1178 			if ((c == '\'') && (prev != '\\')) {
1179 				state = 3;
1180 				break;
1181 			}
1182 			if ((c == '$') && (prev != '\\')) {
1183 				state++;
1184 			} else {
1185 				*(output++) = c;
1186 				outputcnt--;
1187 			}
1188 			break;
1189 		case 1:	/* Waiting for (        */
1190 			if (c == '(' || c == '{') {
1191 				state++;
1192 				varname_start = input;
1193 			} else {
1194 				state = 0;
1195 				*(output++) = '$';
1196 				outputcnt--;
1197 
1198 				if (outputcnt) {
1199 					*(output++) = c;
1200 					outputcnt--;
1201 				}
1202 			}
1203 			break;
1204 		case 2:	/* Waiting for )        */
1205 			if (c == ')' || c == '}') {
1206 				int i;
1207 				char envname[CONFIG_SYS_CBSIZE], *envval;
1208 				int envcnt = input - varname_start - 1;	/* Varname # of chars */
1209 
1210 				/* Get the varname */
1211 				for (i = 0; i < envcnt; i++) {
1212 					envname[i] = varname_start[i];
1213 				}
1214 				envname[i] = 0;
1215 
1216 				/* Get its value */
1217 				envval = getenv (envname);
1218 
1219 				/* Copy into the line if it exists */
1220 				if (envval != NULL)
1221 					while ((*envval) && outputcnt) {
1222 						*(output++) = *(envval++);
1223 						outputcnt--;
1224 					}
1225 				/* Look for another '$' */
1226 				state = 0;
1227 			}
1228 			break;
1229 		case 3:	/* Waiting for '        */
1230 			if ((c == '\'') && (prev != '\\')) {
1231 				state = 0;
1232 			} else {
1233 				*(output++) = c;
1234 				outputcnt--;
1235 			}
1236 			break;
1237 		}
1238 		prev = c;
1239 	}
1240 
1241 	if (outputcnt)
1242 		*output = 0;
1243 	else
1244 		*(output - 1) = 0;
1245 
1246 #ifdef DEBUG_PARSER
1247 	printf ("[PROCESS_MACROS] OUTPUT len %d: \"%s\"\n",
1248 		strlen (output_start), output_start);
1249 #endif
1250 }
1251 
1252 /****************************************************************************
1253  * returns:
1254  *	1  - command executed, repeatable
1255  *	0  - command executed but not repeatable, interrupted commands are
1256  *	     always considered not repeatable
1257  *	-1 - not executed (unrecognized, bootd recursion or too many args)
1258  *           (If cmd is NULL or "" or longer than CONFIG_SYS_CBSIZE-1 it is
1259  *           considered unrecognized)
1260  *
1261  * WARNING:
1262  *
1263  * We must create a temporary copy of the command since the command we get
1264  * may be the result from getenv(), which returns a pointer directly to
1265  * the environment data, which may change magicly when the command we run
1266  * creates or modifies environment variables (like "bootp" does).
1267  */
1268 static int builtin_run_command(const char *cmd, int flag)
1269 {
1270 	char cmdbuf[CONFIG_SYS_CBSIZE];	/* working copy of cmd		*/
1271 	char *token;			/* start of token in cmdbuf	*/
1272 	char *sep;			/* end of token (separator) in cmdbuf */
1273 	char finaltoken[CONFIG_SYS_CBSIZE];
1274 	char *str = cmdbuf;
1275 	char *argv[CONFIG_SYS_MAXARGS + 1];	/* NULL terminated	*/
1276 	int argc, inquotes;
1277 	int repeatable = 1;
1278 	int rc = 0;
1279 
1280 #ifdef DEBUG_PARSER
1281 	printf ("[RUN_COMMAND] cmd[%p]=\"", cmd);
1282 	puts (cmd ? cmd : "NULL");	/* use puts - string may be loooong */
1283 	puts ("\"\n");
1284 #endif
1285 
1286 	clear_ctrlc();		/* forget any previous Control C */
1287 
1288 	if (!cmd || !*cmd) {
1289 		return -1;	/* empty command */
1290 	}
1291 
1292 	if (strlen(cmd) >= CONFIG_SYS_CBSIZE) {
1293 		puts ("## Command too long!\n");
1294 		return -1;
1295 	}
1296 
1297 	strcpy (cmdbuf, cmd);
1298 
1299 	/* Process separators and check for invalid
1300 	 * repeatable commands
1301 	 */
1302 
1303 #ifdef DEBUG_PARSER
1304 	printf ("[PROCESS_SEPARATORS] %s\n", cmd);
1305 #endif
1306 	while (*str) {
1307 
1308 		/*
1309 		 * Find separator, or string end
1310 		 * Allow simple escape of ';' by writing "\;"
1311 		 */
1312 		for (inquotes = 0, sep = str; *sep; sep++) {
1313 			if ((*sep=='\'') &&
1314 			    (*(sep-1) != '\\'))
1315 				inquotes=!inquotes;
1316 
1317 			if (!inquotes &&
1318 			    (*sep == ';') &&	/* separator		*/
1319 			    ( sep != str) &&	/* past string start	*/
1320 			    (*(sep-1) != '\\'))	/* and NOT escaped	*/
1321 				break;
1322 		}
1323 
1324 		/*
1325 		 * Limit the token to data between separators
1326 		 */
1327 		token = str;
1328 		if (*sep) {
1329 			str = sep + 1;	/* start of command for next pass */
1330 			*sep = '\0';
1331 		}
1332 		else
1333 			str = sep;	/* no more commands for next pass */
1334 #ifdef DEBUG_PARSER
1335 		printf ("token: \"%s\"\n", token);
1336 #endif
1337 
1338 		/* find macros in this token and replace them */
1339 		process_macros (token, finaltoken);
1340 
1341 		/* Extract arguments */
1342 		if ((argc = parse_line (finaltoken, argv)) == 0) {
1343 			rc = -1;	/* no command at all */
1344 			continue;
1345 		}
1346 
1347 		if (cmd_process(flag, argc, argv, &repeatable))
1348 			rc = -1;
1349 
1350 		/* Did the user stop this? */
1351 		if (had_ctrlc ())
1352 			return -1;	/* if stopped then not repeatable */
1353 	}
1354 
1355 	return rc ? rc : repeatable;
1356 }
1357 #endif
1358 
1359 /*
1360  * Run a command using the selected parser.
1361  *
1362  * @param cmd	Command to run
1363  * @param flag	Execution flags (CMD_FLAG_...)
1364  * @return 0 on success, or != 0 on error.
1365  */
1366 int run_command(const char *cmd, int flag)
1367 {
1368 #ifndef CONFIG_SYS_HUSH_PARSER
1369 	/*
1370 	 * builtin_run_command can return 0 or 1 for success, so clean up
1371 	 * its result.
1372 	 */
1373 	if (builtin_run_command(cmd, flag) == -1)
1374 		return 1;
1375 
1376 	return 0;
1377 #else
1378 	return parse_string_outer(cmd,
1379 			FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP);
1380 #endif
1381 }
1382 
1383 #ifndef CONFIG_SYS_HUSH_PARSER
1384 /**
1385  * Execute a list of command separated by ; or \n using the built-in parser.
1386  *
1387  * This function cannot take a const char * for the command, since if it
1388  * finds newlines in the string, it replaces them with \0.
1389  *
1390  * @param cmd	String containing list of commands
1391  * @param flag	Execution flags (CMD_FLAG_...)
1392  * @return 0 on success, or != 0 on error.
1393  */
1394 static int builtin_run_command_list(char *cmd, int flag)
1395 {
1396 	char *line, *next;
1397 	int rcode = 0;
1398 
1399 	/*
1400 	 * Break into individual lines, and execute each line; terminate on
1401 	 * error.
1402 	 */
1403 	line = next = cmd;
1404 	while (*next) {
1405 		if (*next == '\n') {
1406 			*next = '\0';
1407 			/* run only non-empty commands */
1408 			if (*line) {
1409 				debug("** exec: \"%s\"\n", line);
1410 				if (builtin_run_command(line, 0) < 0) {
1411 					rcode = 1;
1412 					break;
1413 				}
1414 			}
1415 			line = next + 1;
1416 		}
1417 		++next;
1418 	}
1419 	if (rcode == 0 && *line)
1420 		rcode = (builtin_run_command(line, 0) >= 0);
1421 
1422 	return rcode;
1423 }
1424 #endif
1425 
1426 int run_command_list(const char *cmd, int len, int flag)
1427 {
1428 	int need_buff = 1;
1429 	char *buff = (char *)cmd;	/* cast away const */
1430 	int rcode = 0;
1431 
1432 	if (len == -1) {
1433 		len = strlen(cmd);
1434 #ifdef CONFIG_SYS_HUSH_PARSER
1435 		/* hush will never change our string */
1436 		need_buff = 0;
1437 #else
1438 		/* the built-in parser will change our string if it sees \n */
1439 		need_buff = strchr(cmd, '\n') != NULL;
1440 #endif
1441 	}
1442 	if (need_buff) {
1443 		buff = malloc(len + 1);
1444 		if (!buff)
1445 			return 1;
1446 		memcpy(buff, cmd, len);
1447 		buff[len] = '\0';
1448 	}
1449 #ifdef CONFIG_SYS_HUSH_PARSER
1450 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
1451 #else
1452 	/*
1453 	 * This function will overwrite any \n it sees with a \0, which
1454 	 * is why it can't work with a const char *. Here we are making
1455 	 * using of internal knowledge of this function, to avoid always
1456 	 * doing a malloc() which is actually required only in a case that
1457 	 * is pretty rare.
1458 	 */
1459 	rcode = builtin_run_command_list(buff, flag);
1460 	if (need_buff)
1461 		free(buff);
1462 #endif
1463 
1464 	return rcode;
1465 }
1466 
1467 /****************************************************************************/
1468 
1469 #if defined(CONFIG_CMD_RUN)
1470 int do_run (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
1471 {
1472 	int i;
1473 
1474 	if (argc < 2)
1475 		return CMD_RET_USAGE;
1476 
1477 	for (i=1; i<argc; ++i) {
1478 		char *arg;
1479 
1480 		if ((arg = getenv (argv[i])) == NULL) {
1481 			printf ("## Error: \"%s\" not defined\n", argv[i]);
1482 			return 1;
1483 		}
1484 
1485 		if (run_command(arg, flag) != 0)
1486 			return 1;
1487 	}
1488 	return 0;
1489 }
1490 #endif
1491