main.c

/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * Add to readline cmdline-editing by
 * (C) Copyright 2005
 * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/* #define	DEBUG	*/

#include <common.h>
#include <command.h>
#include <fdtdec.h>
#include <hush.h>
#include <malloc.h>
#include <menu.h>
#include <post.h>
#include <version.h>
#include <watchdog.h>
#include <linux/ctype.h>

DECLARE_GLOBAL_DATA_PTR;

/*
 * Board-specific Platform code can reimplement show_boot_progress () if needed
 */
void inline __show_boot_progress (int val) {}
void show_boot_progress (int val) __attribute__((weak, alias("__show_boot_progress")));

#define MAX_DELAY_STOP_STR 32

#define DEBUG_PARSER	0	/* set to 1 to debug */

#define debug_parser(fmt, args...)		\
	debug_cond(DEBUG_PARSER, fmt, ##args)

#ifndef DEBUG_BOOTKEYS
#define DEBUG_BOOTKEYS 0
#endif
#define debug_bootkeys(fmt, args...)		\
	debug_cond(DEBUG_BOOTKEYS, fmt, ##args)

char        console_buffer[CONFIG_SYS_CBSIZE + 1];	/* console I/O buffer	*/

static char * delete_char (char *buffer, char *p, int *colp, int *np, int plen);
static const char erase_seq[] = "\b \b";		/* erase sequence	*/
static const char   tab_seq[] = "        ";		/* used to expand TABs	*/

#ifdef CONFIG_BOOT_RETRY_TIME
static uint64_t endtime = 0;  /* must be set, default is instant timeout */
static int      retry_time = -1; /* -1 so can call readline before main_loop */
#endif

#define	endtick(seconds) (get_ticks() + (uint64_t)(seconds) * get_tbclk())

#ifndef CONFIG_BOOT_RETRY_MIN
#define CONFIG_BOOT_RETRY_MIN CONFIG_BOOT_RETRY_TIME
#endif

#ifdef CONFIG_MODEM_SUPPORT
int do_mdm_init = 0;
extern void mdm_init(void); /* defined in board.c */
#endif

/***************************************************************************
 * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
 * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
 */
#if defined(CONFIG_BOOTDELAY)
# if defined(CONFIG_AUTOBOOT_KEYED)
static int abortboot_keyed(int bootdelay)
{
	int abort = 0;
	uint64_t etime = endtick(bootdelay);
	struct {
		char* str;
		u_int len;
		int retry;
	}
	delaykey [] = {
		{ str: getenv ("bootdelaykey"),  retry: 1 },
		{ str: getenv ("bootdelaykey2"), retry: 1 },
		{ str: getenv ("bootstopkey"),   retry: 0 },
		{ str: getenv ("bootstopkey2"),  retry: 0 },
	};

	char presskey [MAX_DELAY_STOP_STR];
	u_int presskey_len = 0;
	u_int presskey_max = 0;
	u_int i;

#ifndef CONFIG_ZERO_BOOTDELAY_CHECK
	if (bootdelay == 0)
		return 0;
#endif

#  ifdef CONFIG_AUTOBOOT_PROMPT
	printf(CONFIG_AUTOBOOT_PROMPT);
#  endif

#  ifdef CONFIG_AUTOBOOT_DELAY_STR
	if (delaykey[0].str == NULL)
		delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
#  endif
#  ifdef CONFIG_AUTOBOOT_DELAY_STR2
	if (delaykey[1].str == NULL)
		delaykey[1].str = CONFIG_AUTOBOOT_DELAY_STR2;
#  endif
#  ifdef CONFIG_AUTOBOOT_STOP_STR
	if (delaykey[2].str == NULL)
		delaykey[2].str = CONFIG_AUTOBOOT_STOP_STR;
#  endif
#  ifdef CONFIG_AUTOBOOT_STOP_STR2
	if (delaykey[3].str == NULL)
		delaykey[3].str = CONFIG_AUTOBOOT_STOP_STR2;
#  endif

	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i ++) {
		delaykey[i].len = delaykey[i].str == NULL ?
				    0 : strlen (delaykey[i].str);
		delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
				    MAX_DELAY_STOP_STR : delaykey[i].len;

		presskey_max = presskey_max > delaykey[i].len ?
				    presskey_max : delaykey[i].len;

		debug_bootkeys("%s key:<%s>\n",
			       delaykey[i].retry ? "delay" : "stop",
			       delaykey[i].str ? delaykey[i].str : "NULL");
	}

	/* In order to keep up with incoming data, check timeout only
	 * when catch up.
	 */
	do {
		if (tstc()) {
			if (presskey_len < presskey_max) {
				presskey [presskey_len ++] = getc();
			}
			else {
				for (i = 0; i < presskey_max - 1; i ++)
					presskey [i] = presskey [i + 1];

				presskey [i] = getc();
			}
		}

		for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i ++) {
			if (delaykey[i].len > 0 &&
			    presskey_len >= delaykey[i].len &&
			    memcmp (presskey + presskey_len - delaykey[i].len,
				    delaykey[i].str,
				    delaykey[i].len) == 0) {
				debug_bootkeys("got %skey\n",
					       delaykey[i].retry ? "delay" :
					       "stop");

#  ifdef CONFIG_BOOT_RETRY_TIME
				/* don't retry auto boot */
				if (! delaykey[i].retry)
					retry_time = -1;
#  endif
				abort = 1;
			}
		}
	} while (!abort && get_ticks() <= etime);

	if (!abort)
		debug_bootkeys("key timeout\n");

#ifdef CONFIG_SILENT_CONSOLE
	if (abort)
		gd->flags &= ~GD_FLG_SILENT;
#endif

	return abort;
}

# else	/* !defined(CONFIG_AUTOBOOT_KEYED) */

#ifdef CONFIG_MENUKEY
static int menukey = 0;
#endif

static int abortboot_normal(int bootdelay)
{
	int abort = 0;
	unsigned long ts;

#ifdef CONFIG_MENUPROMPT
	printf(CONFIG_MENUPROMPT);
#else
	if (bootdelay >= 0)
		printf("Hit any key to stop autoboot: %2d ", bootdelay);
#endif

#if defined CONFIG_ZERO_BOOTDELAY_CHECK
	/*
	 * Check if key already pressed
	 * Don't check if bootdelay < 0
	 */
	if (bootdelay >= 0) {
		if (tstc()) {	/* we got a key press	*/
			(void) getc();  /* consume input	*/
			puts ("\b\b\b 0");
			abort = 1;	/* don't auto boot	*/
		}
	}
#endif

	while ((bootdelay > 0) && (!abort)) {
		--bootdelay;
		/* delay 1000 ms */
		ts = get_timer(0);
		do {
			if (tstc()) {	/* we got a key press	*/
				abort  = 1;	/* don't auto boot	*/
				bootdelay = 0;	/* no more delay	*/
# ifdef CONFIG_MENUKEY
				menukey = getc();
# else
				(void) getc();  /* consume input	*/
# endif
				break;
			}
			udelay(10000);
		} while (!abort && get_timer(ts) < 1000);

		printf("\b\b\b%2d ", bootdelay);
	}

	putc('\n');

#ifdef CONFIG_SILENT_CONSOLE
	if (abort)
		gd->flags &= ~GD_FLG_SILENT;
#endif

	return abort;
}
# endif	/* CONFIG_AUTOBOOT_KEYED */

static int abortboot(int bootdelay)
{
#ifdef CONFIG_AUTOBOOT_KEYED
	return abortboot_keyed(bootdelay);
#else
	return abortboot_normal(bootdelay);
#endif
}
#endif	/* CONFIG_BOOTDELAY */

/*
 * Runs the given boot command securely.  Specifically:
 * - Doesn't run the command with the shell (run_command or parse_string_outer),
 *   since that's a lot of code surface that an attacker might exploit.
 *   Because of this, we don't do any argument parsing--the secure boot command
 *   has to be a full-fledged u-boot command.
 * - Doesn't check for keypresses before booting, since that could be a
 *   security hole; also disables Ctrl-C.
 * - Doesn't allow the command to return.
 *
 * Upon any failures, this function will drop into an infinite loop after
 * printing the error message to console.
 */

#if defined(CONFIG_BOOTDELAY) && defined(CONFIG_OF_CONTROL)
static void secure_boot_cmd(char *cmd)
{
	cmd_tbl_t *cmdtp;
	int rc;

	if (!cmd) {
		printf("## Error: Secure boot command not specified\n");
		goto err;
	}

	/* Disable Ctrl-C just in case some command is used that checks it. */
	disable_ctrlc(1);

	/* Find the command directly. */
	cmdtp = find_cmd(cmd);
	if (!cmdtp) {
		printf("## Error: \"%s\" not defined\n", cmd);
		goto err;
	}

	/* Run the command, forcing no flags and faking argc and argv. */
	rc = (cmdtp->cmd)(cmdtp, 0, 1, &cmd);

	/* Shouldn't ever return from boot command. */
	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);

err:
	/*
	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
	 * just end up right back here.  Just loop.
	 */
	hang();
}

static void process_fdt_options(const void *blob)
{
	ulong addr;

	/* Add an env variable to point to a kernel payload, if available */
	addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
	if (addr)
		setenv_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));

	/* Add an env variable to point to a root disk, if available */
	addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
	if (addr)
		setenv_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
}
#endif /* CONFIG_OF_CONTROL */

#ifdef CONFIG_BOOTDELAY
static void process_boot_delay(void)
{
#ifdef CONFIG_OF_CONTROL
	char *env;
#endif
	char *s;
	int bootdelay;
#ifdef CONFIG_BOOTCOUNT_LIMIT
	unsigned long bootcount = 0;
	unsigned long bootlimit = 0;
#endif /* CONFIG_BOOTCOUNT_LIMIT */

#ifdef CONFIG_BOOTCOUNT_LIMIT
	bootcount = bootcount_load();
	bootcount++;
	bootcount_store (bootcount);
	setenv_ulong("bootcount", bootcount);
	bootlimit = getenv_ulong("bootlimit", 10, 0);
#endif /* CONFIG_BOOTCOUNT_LIMIT */

	s = getenv ("bootdelay");
	bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;

#ifdef CONFIG_OF_CONTROL
	bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
			bootdelay);
#endif

	debug ("### main_loop entered: bootdelay=%d\n\n", bootdelay);

#if defined(CONFIG_MENU_SHOW)
	bootdelay = menu_show(bootdelay);
#endif
# ifdef CONFIG_BOOT_RETRY_TIME
	init_cmd_timeout ();
# endif	/* CONFIG_BOOT_RETRY_TIME */

#ifdef CONFIG_POST
	if (gd->flags & GD_FLG_POSTFAIL) {
		s = getenv("failbootcmd");
	}
	else
#endif /* CONFIG_POST */
#ifdef CONFIG_BOOTCOUNT_LIMIT
	if (bootlimit && (bootcount > bootlimit)) {
		printf ("Warning: Bootlimit (%u) exceeded. Using altbootcmd.\n",
			(unsigned)bootlimit);
		s = getenv ("altbootcmd");
	}
	else
#endif /* CONFIG_BOOTCOUNT_LIMIT */
		s = getenv ("bootcmd");
#ifdef CONFIG_OF_CONTROL
	/* Allow the fdt to override the boot command */
	env = fdtdec_get_config_string(gd->fdt_blob, "bootcmd");
	if (env)
		s = env;

	process_fdt_options(gd->fdt_blob);

	/*
	 * If the bootsecure option was chosen, use secure_boot_cmd().
	 * Always use 'env' in this case, since bootsecure requres that the
	 * bootcmd was specified in the FDT too.
	 */
	if (fdtdec_get_config_int(gd->fdt_blob, "bootsecure", 0))
		secure_boot_cmd(env);

#endif /* CONFIG_OF_CONTROL */

	debug ("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");

	if (bootdelay != -1 && s && !abortboot(bootdelay)) {
#if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
		int prev = disable_ctrlc(1);	/* disable Control C checking */
#endif

		run_command_list(s, -1, 0);

#if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
		disable_ctrlc(prev);	/* restore Control C checking */
#endif
	}

#ifdef CONFIG_MENUKEY
	if (menukey == CONFIG_MENUKEY) {
		s = getenv("menucmd");
		if (s)
			run_command_list(s, -1, 0);
	}
#endif /* CONFIG_MENUKEY */
}
#endif /* CONFIG_BOOTDELAY */

void main_loop(void)
{
#ifndef CONFIG_SYS_HUSH_PARSER
	static char lastcommand[CONFIG_SYS_CBSIZE] = { 0, };
	int len;
	int rc = 1;
	int flag;
#endif
#ifdef CONFIG_PREBOOT
	char *p;
#endif

	bootstage_mark_name(BOOTSTAGE_ID_MAIN_LOOP, "main_loop");

#ifdef CONFIG_MODEM_SUPPORT
	debug("DEBUG: main_loop:   do_mdm_init=%d\n", do_mdm_init);
	if (do_mdm_init) {
		char *str = strdup(getenv("mdm_cmd"));
		setenv("preboot", str);  /* set or delete definition */
		if (str != NULL)
			free(str);
		mdm_init(); /* wait for modem connection */
	}
#endif  /* CONFIG_MODEM_SUPPORT */

#ifdef CONFIG_VERSION_VARIABLE
	{
		setenv("ver", version_string);  /* set version variable */
	}
#endif /* CONFIG_VERSION_VARIABLE */

#ifdef CONFIG_SYS_HUSH_PARSER
	u_boot_hush_start();
#endif

#if defined(CONFIG_HUSH_INIT_VAR)
	hush_init_var();
#endif

#ifdef CONFIG_PREBOOT
	p = getenv("preboot");
	if (p != NULL) {
# ifdef CONFIG_AUTOBOOT_KEYED
		int prev = disable_ctrlc(1);	/* disable Control C checking */
# endif

		run_command_list(p, -1, 0);

# ifdef CONFIG_AUTOBOOT_KEYED
		disable_ctrlc(prev);	/* restore Control C checking */
# endif
	}
#endif /* CONFIG_PREBOOT */

#if defined(CONFIG_UPDATE_TFTP)
	update_tftp(0UL);
#endif /* CONFIG_UPDATE_TFTP */

#ifdef CONFIG_BOOTDELAY
	process_boot_delay();
#endif
	/*
	 * Main Loop for Monitor Command Processing
	 */
#ifdef CONFIG_SYS_HUSH_PARSER
	parse_file_outer();
	/* This point is never reached */
	for (;;);
#else
	for (;;) {
#ifdef CONFIG_BOOT_RETRY_TIME
		if (rc >= 0) {
			/* Saw enough of a valid command to
			 * restart the timeout.
			 */
			reset_cmd_timeout();
		}
#endif
		len = readline (CONFIG_SYS_PROMPT);

		flag = 0;	/* assume no special flags for now */
		if (len > 0)
			strcpy (lastcommand, console_buffer);
		else if (len == 0)
			flag |= CMD_FLAG_REPEAT;
#ifdef CONFIG_BOOT_RETRY_TIME
		else if (len == -2) {
			/* -2 means timed out, retry autoboot
			 */
			puts ("\nTimed out waiting for command\n");
# ifdef CONFIG_RESET_TO_RETRY
			/* Reinit board to run initialization code again */
			do_reset (NULL, 0, 0, NULL);
# else
			return;		/* retry autoboot */
# endif
		}
#endif

		if (len == -1)
			puts ("<INTERRUPT>\n");
		else
			rc = run_command(lastcommand, flag);

		if (rc <= 0) {
			/* invalid command or not repeatable, forget it */
			lastcommand[0] = 0;
		}
	}
#endif /*CONFIG_SYS_HUSH_PARSER*/
}

#ifdef CONFIG_BOOT_RETRY_TIME
/***************************************************************************
 * initialize command line timeout
 */
void init_cmd_timeout(void)
{
	char *s = getenv ("bootretry");

	if (s != NULL)
		retry_time = (int)simple_strtol(s, NULL, 10);
	else
		retry_time =  CONFIG_BOOT_RETRY_TIME;

	if (retry_time >= 0 && retry_time < CONFIG_BOOT_RETRY_MIN)
		retry_time = CONFIG_BOOT_RETRY_MIN;
}

/***************************************************************************
 * reset command line timeout to retry_time seconds
 */
void reset_cmd_timeout(void)
{
	endtime = endtick(retry_time);
}
#endif

#ifdef CONFIG_CMDLINE_EDITING

/*
 * cmdline-editing related codes from vivi.
 * Author: Janghoon Lyu <nandy@mizi.com>
 */

#define putnstr(str,n)	do {			\
		printf ("%.*s", (int)n, str);	\
	} while (0)

#define CTL_CH(c)		((c) - 'a' + 1)
#define CTL_BACKSPACE		('\b')
#define DEL			((char)255)
#define DEL7			((char)127)
#define CREAD_HIST_CHAR		('!')

#define getcmd_putch(ch)	putc(ch)
#define getcmd_getch()		getc()
#define getcmd_cbeep()		getcmd_putch('\a')

#define HIST_MAX		20
#define HIST_SIZE		CONFIG_SYS_CBSIZE

static int hist_max;
static int hist_add_idx;
static int hist_cur = -1;
static unsigned hist_num;

static char *hist_list[HIST_MAX];
static char hist_lines[HIST_MAX][HIST_SIZE + 1];	/* Save room for NULL */

#define add_idx_minus_one() ((hist_add_idx == 0) ? hist_max : hist_add_idx-1)

static void hist_init(void)
{
	int i;

	hist_max = 0;
	hist_add_idx = 0;
	hist_cur = -1;
	hist_num = 0;

	for (i = 0; i < HIST_MAX; i++) {
		hist_list[i] = hist_lines[i];
		hist_list[i][0] = '\0';
	}
}

static void cread_add_to_hist(char *line)
{
	strcpy(hist_list[hist_add_idx], line);

	if (++hist_add_idx >= HIST_MAX)
		hist_add_idx = 0;

	if (hist_add_idx > hist_max)
		hist_max = hist_add_idx;

	hist_num++;
}

static char* hist_prev(void)
{
	char *ret;
	int old_cur;

	if (hist_cur < 0)
		return NULL;

	old_cur = hist_cur;
	if (--hist_cur < 0)
		hist_cur = hist_max;

	if (hist_cur == hist_add_idx) {
		hist_cur = old_cur;
		ret = NULL;
	} else
		ret = hist_list[hist_cur];

	return (ret);
}

static char* hist_next(void)
{
	char *ret;

	if (hist_cur < 0)
		return NULL;

	if (hist_cur == hist_add_idx)
		return NULL;

	if (++hist_cur > hist_max)
		hist_cur = 0;

	if (hist_cur == hist_add_idx) {
		ret = "";
	} else
		ret = hist_list[hist_cur];

	return (ret);
}

#ifndef CONFIG_CMDLINE_EDITING
static void cread_print_hist_list(void)
{
	int i;
	unsigned long n;

	n = hist_num - hist_max;

	i = hist_add_idx + 1;
	while (1) {
		if (i > hist_max)
			i = 0;
		if (i == hist_add_idx)
			break;
		printf("%s\n", hist_list[i]);
		n++;
		i++;
	}
}
#endif /* CONFIG_CMDLINE_EDITING */

#define BEGINNING_OF_LINE() {			\
	while (num) {				\
		getcmd_putch(CTL_BACKSPACE);	\
		num--;				\
	}					\
}

#define ERASE_TO_EOL() {				\
	if (num < eol_num) {				\
		printf("%*s", (int)(eol_num - num), ""); \
		do {					\
			getcmd_putch(CTL_BACKSPACE);	\
		} while (--eol_num > num);		\
	}						\
}

#define REFRESH_TO_EOL() {			\
	if (num < eol_num) {			\
		wlen = eol_num - num;		\
		putnstr(buf + num, wlen);	\
		num = eol_num;			\
	}					\
}

static void cread_add_char(char ichar, int insert, unsigned long *num,
	       unsigned long *eol_num, char *buf, unsigned long len)
{
	unsigned long wlen;

	/* room ??? */
	if (insert || *num == *eol_num) {
		if (*eol_num > len - 1) {
			getcmd_cbeep();
			return;
		}
		(*eol_num)++;
	}

	if (insert) {
		wlen = *eol_num - *num;
		if (wlen > 1) {
			memmove(&buf[*num+1], &buf[*num], wlen-1);
		}

		buf[*num] = ichar;
		putnstr(buf + *num, wlen);
		(*num)++;
		while (--wlen) {
			getcmd_putch(CTL_BACKSPACE);
		}
	} else {
		/* echo the character */
		wlen = 1;
		buf[*num] = ichar;
		putnstr(buf + *num, wlen);
		(*num)++;
	}
}

static void cread_add_str(char *str, int strsize, int insert, unsigned long *num,
	      unsigned long *eol_num, char *buf, unsigned long len)
{
	while (strsize--) {
		cread_add_char(*str, insert, num, eol_num, buf, len);
		str++;
	}
}

static int cread_line(const char *const prompt, char *buf, unsigned int *len,
		int timeout)
{
	unsigned long num = 0;
	unsigned long eol_num = 0;
	unsigned long wlen;
	char ichar;
	int insert = 1;
	int esc_len = 0;
	char esc_save[8];
	int init_len = strlen(buf);
	int first = 1;

	if (init_len)
		cread_add_str(buf, init_len, 1, &num, &eol_num, buf, *len);

	while (1) {
#ifdef CONFIG_BOOT_RETRY_TIME
		while (!tstc()) {	/* while no incoming data */
			if (retry_time >= 0 && get_ticks() > endtime)
				return (-2);	/* timed out */
			WATCHDOG_RESET();
		}
#endif
		if (first && timeout) {
			uint64_t etime = endtick(timeout);

			while (!tstc()) {	/* while no incoming data */
				if (get_ticks() >= etime)
					return -2;	/* timed out */
				WATCHDOG_RESET();
			}
			first = 0;
		}

		ichar = getcmd_getch();

		if ((ichar == '\n') || (ichar == '\r')) {
			putc('\n');
			break;
		}

		/*
		 * handle standard linux xterm esc sequences for arrow key, etc.
		 */
		if (esc_len != 0) {
			if (esc_len == 1) {
				if (ichar == '[') {
					esc_save[esc_len] = ichar;
					esc_len = 2;
				} else {
					cread_add_str(esc_save, esc_len, insert,
						      &num, &eol_num, buf, *len);
					esc_len = 0;
				}
				continue;
			}

			switch (ichar) {

			case 'D':	/* <- key */
				ichar = CTL_CH('b');
				esc_len = 0;
				break;
			case 'C':	/* -> key */
				ichar = CTL_CH('f');
				esc_len = 0;
				break;	/* pass off to ^F handler */
			case 'H':	/* Home key */
				ichar = CTL_CH('a');
				esc_len = 0;
				break;	/* pass off to ^A handler */
			case 'A':	/* up arrow */
				ichar = CTL_CH('p');
				esc_len = 0;
				break;	/* pass off to ^P handler */
			case 'B':	/* down arrow */
				ichar = CTL_CH('n');
				esc_len = 0;
				break;	/* pass off to ^N handler */
			default:
				esc_save[esc_len++] = ichar;
				cread_add_str(esc_save, esc_len, insert,
					      &num, &eol_num, buf, *len);
				esc_len = 0;
				continue;
			}
		}

		switch (ichar) {
		case 0x1b:
			if (esc_len == 0) {
				esc_save[esc_len] = ichar;
				esc_len = 1;
			} else {
				puts("impossible condition #876\n");
				esc_len = 0;
			}
			break;

		case CTL_CH('a'):
			BEGINNING_OF_LINE();
			break;
		case CTL_CH('c'):	/* ^C - break */
			*buf = '\0';	/* discard input */
			return (-1);
		case CTL_CH('f'):
			if (num < eol_num) {
				getcmd_putch(buf[num]);
				num++;
			}
			break;
		case CTL_CH('b'):
			if (num) {
				getcmd_putch(CTL_BACKSPACE);
				num--;
			}
			break;
		case CTL_CH('d'):
			if (num < eol_num) {
				wlen = eol_num - num - 1;
				if (wlen) {
					memmove(&buf[num], &buf[num+1], wlen);
					putnstr(buf + num, wlen);
				}

				getcmd_putch(' ');
				do {
					getcmd_putch(CTL_BACKSPACE);
				} while (wlen--);
				eol_num--;
			}
			break;
		case CTL_CH('k'):
			ERASE_TO_EOL();
			break;
		case CTL_CH('e'):
			REFRESH_TO_EOL();
			break;
		case CTL_CH('o'):
			insert = !insert;
			break;
		case CTL_CH('x'):
		case CTL_CH('u'):
			BEGINNING_OF_LINE();
			ERASE_TO_EOL();
			break;
		case DEL:
		case DEL7:
		case 8:
			if (num) {
				wlen = eol_num - num;
				num--;
				memmove(&buf[num], &buf[num+1], wlen);
				getcmd_putch(CTL_BACKSPACE);
				putnstr(buf + num, wlen);
				getcmd_putch(' ');
				do {
					getcmd_putch(CTL_BACKSPACE);
				} while (wlen--);
				eol_num--;
			}
			break;
		case CTL_CH('p'):
		case CTL_CH('n'):
		{
			char * hline;

			esc_len = 0;

			if (ichar == CTL_CH('p'))
				hline = hist_prev();
			else
				hline = hist_next();

			if (!hline) {
				getcmd_cbeep();
				continue;
			}

			/* nuke the current line */
			/* first, go home */
			BEGINNING_OF_LINE();

			/* erase to end of line */
			ERASE_TO_EOL();

			/* copy new line into place and display */
			strcpy(buf, hline);
			eol_num = strlen(buf);
			REFRESH_TO_EOL();
			continue;
		}
#ifdef CONFIG_AUTO_COMPLETE
		case '\t': {
			int num2, col;

			/* do not autocomplete when in the middle */
			if (num < eol_num) {
				getcmd_cbeep();
				break;
			}

			buf[num] = '\0';
			col = strlen(prompt) + eol_num;
			num2 = num;
			if (cmd_auto_complete(prompt, buf, &num2, &col)) {
				col = num2 - num;
				num += col;
				eol_num += col;
			}
			break;
		}
#endif
		default:
			cread_add_char(ichar, insert, &num, &eol_num, buf, *len);
			break;
		}
	}
	*len = eol_num;
	buf[eol_num] = '\0';	/* lose the newline */

	if (buf[0] && buf[0] != CREAD_HIST_CHAR)
		cread_add_to_hist(buf);
	hist_cur = hist_add_idx;

	return 0;
}

#endif /* CONFIG_CMDLINE_EDITING */

/****************************************************************************/

/*
 * Prompt for input and read a line.
 * If  CONFIG_BOOT_RETRY_TIME is defined and retry_time >= 0,
 * time out when time goes past endtime (timebase time in ticks).
 * Return:	number of read characters
 *		-1 if break
 *		-2 if timed out
 */
int readline (const char *const prompt)
{
	/*
	 * If console_buffer isn't 0-length the user will be prompted to modify
	 * it instead of entering it from scratch as desired.
	 */
	console_buffer[0] = '\0';

	return readline_into_buffer(prompt, console_buffer, 0);
}


int readline_into_buffer(const char *const prompt, char *buffer, int timeout)