/*

   * (C) Copyright 2000-2013

   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   * Andreas Heppel <aheppel@sysgo.de>

   *
   * Copyright 2011 Freescale Semiconductor, Inc.
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */

  /*

   * Support for persistent environment data
   *

   * The "environment" is stored on external storage as a list of '\0'
   * terminated "name=value" strings. The end of the list is marked by

   * a double '\0'. The environment is preceded by a 32 bit CRC over

   * the data part and, in case of redundant environment, a byte of
   * flags.

   *

   * This linearized representation will also be used before
   * relocation, i. e. as long as we don't have a full C runtime
   * environment. After that, we use a hash table.

   */
  
  #include <common.h>

  #include <cli.h>

  #include <command.h>

  #include <console.h>

  #include <environment.h>

  #include <search.h>
  #include <errno.h>

  #include <malloc.h>

  #include <mapmem.h>

  #include <watchdog.h>

  #include <linux/stddef.h>
  #include <asm/byteorder.h>

  #include <asm/io.h>

  DECLARE_GLOBAL_DATA_PTR;

  #if	!defined(CONFIG_ENV_IS_IN_EEPROM)	&& \
  	!defined(CONFIG_ENV_IS_IN_FLASH)	&& \

  	!defined(CONFIG_ENV_IS_IN_MMC)		&& \

  	!defined(CONFIG_ENV_IS_IN_FAT)		&& \

  	!defined(CONFIG_ENV_IS_IN_EXT4)		&& \

  	!defined(CONFIG_ENV_IS_IN_NAND)		&& \
  	!defined(CONFIG_ENV_IS_IN_NVRAM)	&& \
  	!defined(CONFIG_ENV_IS_IN_ONENAND)	&& \

  	!defined(CONFIG_ENV_IS_IN_SATA)		&& \

  	!defined(CONFIG_ENV_IS_IN_SPI_FLASH)	&& \

  	!defined(CONFIG_ENV_IS_IN_REMOTE)	&& \

  	!defined(CONFIG_ENV_IS_IN_UBI)		&& \

  	!defined(CONFIG_ENV_IS_NOWHERE)

  # error Define one of CONFIG_ENV_IS_IN_{EEPROM|FLASH|MMC|FAT|EXT4|\

  NAND|NVRAM|ONENAND|SATA|SPI_FLASH|REMOTE|UBI} or CONFIG_ENV_IS_NOWHERE

  #endif

  /*
   * Maximum expected input data size for import command
   */
  #define	MAX_ENV_SIZE	(1 << 20)	/* 1 MiB */

  /*

   * This variable is incremented on each do_env_set(), so it can

   * be used via get_env_id() as an indication, if the environment
   * has changed or not. So it is possible to reread an environment
   * variable only if the environment was changed ... done so for
   * example in NetInitLoop()
   */

  static int env_id = 1;

  int get_env_id(void)

  {
  	return env_id;
  }

  #ifndef CONFIG_SPL_BUILD

  /*

   * Command interface: print one or all environment variables
   *
   * Returns 0 in case of error, or length of printed string

   */

  static int env_print(char *name, int flag)

  {

  	char *res = NULL;

  	ssize_t len;

  
  	if (name) {		/* print a single name */
  		ENTRY e, *ep;
  
  		e.key = name;
  		e.data = NULL;

  		hsearch_r(e, FIND, &ep, &env_htab, flag);

  		if (ep == NULL)
  			return 0;

  		len = printf("%s=%s
  ", ep->key, ep->data);

  		return len;
  	}

  	/* print whole list */

  	len = hexport_r(&env_htab, '
  ', flag, &res, 0, 0, NULL);

  	if (len > 0) {
  		puts(res);
  		free(res);
  		return len;

  	}

  	/* should never happen */

  	printf("## Error: cannot export environment
  ");

  	return 0;

  }

  static int do_env_print(cmd_tbl_t *cmdtp, int flag, int argc,
  			char * const argv[])

  {
  	int i;
  	int rcode = 0;

  	int env_flag = H_HIDE_DOT;
  
  	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'a') {
  		argc--;
  		argv++;
  		env_flag &= ~H_HIDE_DOT;
  	}

  	if (argc == 1) {
  		/* print all env vars */

  		rcode = env_print(NULL, env_flag);

  		if (!rcode)

  			return 1;
  		printf("
  Environment size: %d/%ld bytes
  ",
  			rcode, (ulong)ENV_SIZE);
  		return 0;
  	}

  	/* print selected env vars */

  	env_flag &= ~H_HIDE_DOT;

  	for (i = 1; i < argc; ++i) {

  		int rc = env_print(argv[i], env_flag);

  		if (!rc) {
  			printf("## Error: \"%s\" not defined
  ", argv[i]);

  			++rcode;

  		}
  	}

  	return rcode;
  }

  #ifdef CONFIG_CMD_GREPENV

  static int do_env_grep(cmd_tbl_t *cmdtp, int flag,
  		       int argc, char * const argv[])

  {

  	char *res = NULL;

  	int len, grep_how, grep_what;

  
  	if (argc < 2)

  		return CMD_RET_USAGE;

  	grep_how  = H_MATCH_SUBSTR;	/* default: substring search	*/
  	grep_what = H_MATCH_BOTH;	/* default: grep names and values */

  	while (--argc > 0 && **++argv == '-') {
  		char *arg = *argv;

  		while (*++arg) {
  			switch (*arg) {

  #ifdef CONFIG_REGEX
  			case 'e':		/* use regex matching */
  				grep_how  = H_MATCH_REGEX;
  				break;
  #endif

  			case 'n':		/* grep for name */

  				grep_what = H_MATCH_KEY;

  				break;
  			case 'v':		/* grep for value */

  				grep_what = H_MATCH_DATA;

  				break;
  			case 'b':		/* grep for both */

  				grep_what = H_MATCH_BOTH;

  				break;
  			case '-':
  				goto DONE;
  			default:
  				return CMD_RET_USAGE;
  			}
  		}
  	}
  
  DONE:

  	len = hexport_r(&env_htab, '
  ',

  			flag | grep_what | grep_how,

  			&res, 0, argc, argv);

  	if (len > 0) {
  		puts(res);
  		free(res);

  	}

  	if (len < 2)
  		return 1;
  
  	return 0;

  }
  #endif

  #endif /* CONFIG_SPL_BUILD */

  /*

   * Set a new environment variable,
   * or replace or delete an existing one.

   */

  static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)

  {
  	int   i, len;
  	char  *name, *value, *s;
  	ENTRY e, *ep;

  	debug("Initial value for argc=%d
  ", argc);
  	while (argc > 1 && **(argv + 1) == '-') {
  		char *arg = *++argv;
  
  		--argc;
  		while (*++arg) {
  			switch (*arg) {
  			case 'f':		/* force */
  				env_flag |= H_FORCE;
  				break;
  			default:
  				return CMD_RET_USAGE;
  			}
  		}
  	}
  	debug("Final value for argc=%d
  ", argc);

  	name = argv[1];

  
  	if (strchr(name, '=')) {
  		printf("## Error: illegal character '='"
  		       "in variable name \"%s\"
  ", name);
  		return 1;
  	}
  
  	env_id++;

  	/* Delete only ? */

  	if (argc < 3 || argv[2] == NULL) {

  		int rc = hdelete_r(name, &env_htab, env_flag);

  		return !rc;

  	}
  
  	/*

  	 * Insert / replace new value

  	 */

  	for (i = 2, len = 0; i < argc; ++i)

  		len += strlen(argv[i]) + 1;

  
  	value = malloc(len);
  	if (value == NULL) {

  		printf("## Can't malloc %d bytes
  ", len);

  		return 1;
  	}

  	for (i = 2, s = value; i < argc; ++i) {

  		char *v = argv[i];

  		while ((*s++ = *v++) != '\0')

  			;

  		*(s - 1) = ' ';

  	}
  	if (s != value)
  		*--s = '\0';

  	e.key	= name;
  	e.data	= value;

  	hsearch_r(e, ENTER, &ep, &env_htab, env_flag);

  	free(value);
  	if (!ep) {
  		printf("## Error inserting \"%s\" variable, errno=%d
  ",
  			name, errno);
  		return 1;

  	}

  	return 0;
  }

  int env_set(const char *varname, const char *varvalue)

  {

  	const char * const argv[4] = { "setenv", varname, varvalue, NULL };

  	/* before import into hashtable */
  	if (!(gd->flags & GD_FLG_ENV_READY))
  		return 1;

  	if (varvalue == NULL || varvalue[0] == '\0')

  		return _do_env_set(0, 2, (char * const *)argv, H_PROGRAMMATIC);

  	else

  		return _do_env_set(0, 3, (char * const *)argv, H_PROGRAMMATIC);

  }

  /**
   * Set an environment variable to an integer value
   *

   * @param varname	Environment variable to set

   * @param value		Value to set it to
   * @return 0 if ok, 1 on error
   */

  int env_set_ulong(const char *varname, ulong value)

  {
  	/* TODO: this should be unsigned */
  	char *str = simple_itoa(value);

  	return env_set(varname, str);

  }
  
  /**

   * Set an environment variable to an value in hex

   *

   * @param varname	Environment variable to set

   * @param value		Value to set it to

   * @return 0 if ok, 1 on error
   */

  int env_set_hex(const char *varname, ulong value)

  {
  	char str[17];

  	sprintf(str, "%lx", value);

  	return env_set(varname, str);

  }

  ulong env_get_hex(const char *varname, ulong default_val)

  {
  	const char *s;
  	ulong value;
  	char *endp;

  	s = env_get(varname);

  	if (s)
  		value = simple_strtoul(s, &endp, 16);
  	if (!s || endp == s)
  		return default_val;
  
  	return value;
  }

  #ifndef CONFIG_SPL_BUILD

  static int do_env_set(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {

  	if (argc < 2)

  		return CMD_RET_USAGE;

  	return _do_env_set(flag, argc, argv, H_INTERACTIVE);

  }

  /*

   * Prompt for environment variable
   */

  #if defined(CONFIG_CMD_ASKENV)

  int do_env_ask(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {

  	char message[CONFIG_SYS_CBSIZE];

  	int i, len, pos, size;

  	char *local_args[4];

  	char *endptr;

  
  	local_args[0] = argv[0];
  	local_args[1] = argv[1];
  	local_args[2] = NULL;
  	local_args[3] = NULL;

  	/*
  	 * Check the syntax:
  	 *
  	 * env_ask envname [message1 ...] [size]
  	 */
  	if (argc == 1)

  		return CMD_RET_USAGE;

  	/*
  	 * We test the last argument if it can be converted
  	 * into a decimal number.  If yes, we assume it's
  	 * the size.  Otherwise we echo it as part of the
  	 * message.
  	 */
  	i = simple_strtoul(argv[argc - 1], &endptr, 10);
  	if (*endptr != '\0') {			/* no size */
  		size = CONFIG_SYS_CBSIZE - 1;
  	} else {				/* size given */
  		size = i;
  		--argc;
  	}

  	if (argc <= 2) {
  		sprintf(message, "Please enter '%s': ", argv[1]);
  	} else {
  		/* env_ask envname message1 ... messagen [size] */

  		for (i = 2, pos = 0; i < argc && pos+1 < sizeof(message); i++) {

  			if (pos)

  				message[pos++] = ' ';

  			strncpy(message + pos, argv[i], sizeof(message) - pos);

  			pos += strlen(argv[i]);
  		}

  		if (pos < sizeof(message) - 1) {
  			message[pos++] = ' ';
  			message[pos] = '\0';
  		} else
  			message[CONFIG_SYS_CBSIZE - 1] = '\0';

  	}

  	if (size >= CONFIG_SYS_CBSIZE)
  		size = CONFIG_SYS_CBSIZE - 1;

  
  	if (size <= 0)
  		return 1;
  
  	/* prompt for input */

  	len = cli_readline(message);

  
  	if (size < len)
  		console_buffer[size] = '\0';
  
  	len = 2;
  	if (console_buffer[0] != '\0') {
  		local_args[2] = console_buffer;
  		len = 3;
  	}
  
  	/* Continue calling setenv code */

  	return _do_env_set(flag, len, local_args, H_INTERACTIVE);

  }

  #endif

  #if defined(CONFIG_CMD_ENV_CALLBACK)

  static int print_static_binding(const char *var_name, const char *callback_name,
  				void *priv)

  {
  	printf("\t%-20s %-20s
  ", var_name, callback_name);
  
  	return 0;
  }
  
  static int print_active_callback(ENTRY *entry)
  {
  	struct env_clbk_tbl *clbkp;
  	int i;
  	int num_callbacks;
  
  	if (entry->callback == NULL)
  		return 0;
  
  	/* look up the callback in the linker-list */
  	num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);
  	for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
  	     i < num_callbacks;
  	     i++, clbkp++) {
  #if defined(CONFIG_NEEDS_MANUAL_RELOC)
  		if (entry->callback == clbkp->callback + gd->reloc_off)
  #else
  		if (entry->callback == clbkp->callback)
  #endif
  			break;
  	}
  
  	if (i == num_callbacks)
  		/* this should probably never happen, but just in case... */
  		printf("\t%-20s %p
  ", entry->key, entry->callback);
  	else
  		printf("\t%-20s %-20s
  ", entry->key, clbkp->name);
  
  	return 0;
  }
  
  /*
   * Print the callbacks available and what they are bound to
   */
  int do_env_callback(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	struct env_clbk_tbl *clbkp;
  	int i;
  	int num_callbacks;
  
  	/* Print the available callbacks */
  	puts("Available callbacks:
  ");
  	puts("\tCallback Name
  ");
  	puts("\t-------------
  ");
  	num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);
  	for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
  	     i < num_callbacks;
  	     i++, clbkp++)
  		printf("\t%s
  ", clbkp->name);
  	puts("
  ");
  
  	/* Print the static bindings that may exist */
  	puts("Static callback bindings:
  ");
  	printf("\t%-20s %-20s
  ", "Variable Name", "Callback Name");
  	printf("\t%-20s %-20s
  ", "-------------", "-------------");

  	env_attr_walk(ENV_CALLBACK_LIST_STATIC, print_static_binding, NULL);

  	puts("
  ");
  
  	/* walk through each variable and print the callback if it has one */
  	puts("Active callback bindings:
  ");
  	printf("\t%-20s %-20s
  ", "Variable Name", "Callback Name");
  	printf("\t%-20s %-20s
  ", "-------------", "-------------");
  	hwalk_r(&env_htab, print_active_callback);
  	return 0;
  }
  #endif

  #if defined(CONFIG_CMD_ENV_FLAGS)

  static int print_static_flags(const char *var_name, const char *flags,
  			      void *priv)

  {
  	enum env_flags_vartype type = env_flags_parse_vartype(flags);

  	enum env_flags_varaccess access = env_flags_parse_varaccess(flags);

  	printf("\t%-20s %-20s %-20s
  ", var_name,
  		env_flags_get_vartype_name(type),
  		env_flags_get_varaccess_name(access));

  
  	return 0;
  }
  
  static int print_active_flags(ENTRY *entry)
  {
  	enum env_flags_vartype type;

  	enum env_flags_varaccess access;

  
  	if (entry->flags == 0)
  		return 0;
  
  	type = (enum env_flags_vartype)
  		(entry->flags & ENV_FLAGS_VARTYPE_BIN_MASK);

  	access = env_flags_parse_varaccess_from_binflags(entry->flags);
  	printf("\t%-20s %-20s %-20s
  ", entry->key,
  		env_flags_get_vartype_name(type),
  		env_flags_get_varaccess_name(access));

  
  	return 0;
  }
  
  /*
   * Print the flags available and what variables have flags
   */
  int do_env_flags(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	/* Print the available variable types */
  	printf("Available variable type flags (position %d):
  ",
  		ENV_FLAGS_VARTYPE_LOC);
  	puts("\tFlag\tVariable Type Name
  ");
  	puts("\t----\t------------------
  ");
  	env_flags_print_vartypes();
  	puts("
  ");

  	/* Print the available variable access types */
  	printf("Available variable access flags (position %d):
  ",
  		ENV_FLAGS_VARACCESS_LOC);
  	puts("\tFlag\tVariable Access Name
  ");
  	puts("\t----\t--------------------
  ");
  	env_flags_print_varaccess();
  	puts("
  ");

  	/* Print the static flags that may exist */
  	puts("Static flags:
  ");

  	printf("\t%-20s %-20s %-20s
  ", "Variable Name", "Variable Type",
  		"Variable Access");
  	printf("\t%-20s %-20s %-20s
  ", "-------------", "-------------",
  		"---------------");

  	env_attr_walk(ENV_FLAGS_LIST_STATIC, print_static_flags, NULL);

  	puts("
  ");
  
  	/* walk through each variable and print the flags if non-default */
  	puts("Active flags:
  ");

  	printf("\t%-20s %-20s %-20s
  ", "Variable Name", "Variable Type",
  		"Variable Access");
  	printf("\t%-20s %-20s %-20s
  ", "-------------", "-------------",
  		"---------------");

  	hwalk_r(&env_htab, print_active_flags);
  	return 0;
  }
  #endif

  /*

   * Interactively edit an environment variable
   */
  #if defined(CONFIG_CMD_EDITENV)

  static int do_env_edit(cmd_tbl_t *cmdtp, int flag, int argc,
  		       char * const argv[])

  {
  	char buffer[CONFIG_SYS_CBSIZE];
  	char *init_val;

  	if (argc < 2)

  		return CMD_RET_USAGE;

  	/* before import into hashtable */
  	if (!(gd->flags & GD_FLG_ENV_READY))
  		return 1;

  	/* Set read buffer to initial value or empty sting */

  	init_val = env_get(argv[1]);

  	if (init_val)

  		snprintf(buffer, CONFIG_SYS_CBSIZE, "%s", init_val);

  	else
  		buffer[0] = '\0';

  	if (cli_readline_into_buffer("edit: ", buffer, 0) < 0)

  		return 1;

  	if (buffer[0] == '\0') {
  		const char * const _argv[3] = { "setenv", argv[1], NULL };
  
  		return _do_env_set(0, 2, (char * const *)_argv, H_INTERACTIVE);
  	} else {
  		const char * const _argv[4] = { "setenv", argv[1], buffer,
  			NULL };
  
  		return _do_env_set(0, 3, (char * const *)_argv, H_INTERACTIVE);
  	}

  }
  #endif /* CONFIG_CMD_EDITENV */

  #endif /* CONFIG_SPL_BUILD */

  /*

   * Look up variable from environment,
   * return address of storage for that variable,
   * or NULL if not found
   */

  char *env_get(const char *name)

  {

  	if (gd->flags & GD_FLG_ENV_READY) { /* after import into hashtable */

  		ENTRY e, *ep;

  		WATCHDOG_RESET();

  		e.key	= name;
  		e.data	= NULL;

  		hsearch_r(e, FIND, &ep, &env_htab, 0);

  		return ep ? ep->data : NULL;

  	}

  	/* restricted capabilities before import */

  	if (env_get_f(name, (char *)(gd->env_buf), sizeof(gd->env_buf)) > 0)

  		return (char *)(gd->env_buf);

  	return NULL;

  }

  /*
   * Look up variable from environment for restricted C runtime env.
   */

  int env_get_f(const char *name, char *buf, unsigned len)

  {

  	int i, nxt, c;

  	for (i = 0; env_get_char(i) != '\0'; i = nxt + 1) {

  		int val, n;

  		for (nxt = i; (c = env_get_char(nxt)) != '\0'; ++nxt) {
  			if (c < 0)
  				return c;

  			if (nxt >= CONFIG_ENV_SIZE)
  				return -1;

  		}

  
  		val = envmatch((uchar *)name, i);
  		if (val < 0)

  			continue;

  		/* found; copy out */

  		for (n = 0; n < len; ++n, ++buf) {

  			c = env_get_char(val++);
  			if (c < 0)
  				return c;
  			*buf = c;

  			if (*buf == '\0')

  				return n;
  		}
  
  		if (n)
  			*--buf = '\0';

  		printf("env_buf [%d bytes] too small for value of \"%s\"
  ",
  			len, name);

  
  		return n;

  	}

  	return -1;

  }

  /**
   * Decode the integer value of an environment variable and return it.
   *
   * @param name		Name of environemnt variable
   * @param base		Number base to use (normally 10, or 16 for hex)
   * @param default_val	Default value to return if the variable is not
   *			found
   * @return the decoded value, or default_val if not found
   */

  ulong env_get_ulong(const char *name, int base, ulong default_val)

  {
  	/*

  	 * We can use env_get() here, even before relocation, since the

  	 * environment variable value is an integer and thus short.
  	 */

  	const char *str = env_get(name);

  
  	return str ? simple_strtoul(str, NULL, base) : default_val;
  }

  #ifndef CONFIG_SPL_BUILD

  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)

  static int do_env_save(cmd_tbl_t *cmdtp, int flag, int argc,
  		       char * const argv[])

  {

  	return env_save() ? 1 : 0;

  }

  U_BOOT_CMD(

  	saveenv, 1, 0,	do_env_save,

  	"save environment variables to persistent storage",

  	""

  );

  #endif

  #endif /* CONFIG_SPL_BUILD */

  /*

   * Match a name / name=value pair
   *
   * s1 is either a simple 'name', or a 'name=value' pair.
   * i2 is the environment index for a 'name2=value2' pair.

   * If the names match, return the index for the value2, else -1.

   */

  int envmatch(uchar *s1, int i2)

  {

  	if (s1 == NULL)
  		return -1;

  	while (*s1 == env_get_char(i2++))
  		if (*s1++ == '=')

  			return i2;

  	if (*s1 == '\0' && env_get_char(i2-1) == '=')

  		return i2;

  	return -1;

  }

  #ifndef CONFIG_SPL_BUILD

  static int do_env_default(cmd_tbl_t *cmdtp, int __flag,

  			  int argc, char * const argv[])

  {

  	int all = 0, flag = 0;

  	debug("Initial value for argc=%d
  ", argc);
  	while (--argc > 0 && **++argv == '-') {
  		char *arg = *argv;
  
  		while (*++arg) {
  			switch (*arg) {
  			case 'a':		/* default all */
  				all = 1;
  				break;
  			case 'f':		/* force */
  				flag |= H_FORCE;
  				break;
  			default:
  				return cmd_usage(cmdtp);
  			}
  		}
  	}
  	debug("Final value for argc=%d
  ", argc);
  	if (all && (argc == 0)) {
  		/* Reset the whole environment */
  		set_default_env("## Resetting to default environment
  ");
  		return 0;
  	}
  	if (!all && (argc > 0)) {
  		/* Reset individual variables */
  		set_default_vars(argc, argv);
  		return 0;
  	}
  
  	return cmd_usage(cmdtp);

  }

  static int do_env_delete(cmd_tbl_t *cmdtp, int flag,
  			 int argc, char * const argv[])

  {

  	int env_flag = H_INTERACTIVE;
  	int ret = 0;
  
  	debug("Initial value for argc=%d
  ", argc);
  	while (argc > 1 && **(argv + 1) == '-') {
  		char *arg = *++argv;
  
  		--argc;
  		while (*++arg) {
  			switch (*arg) {
  			case 'f':		/* force */
  				env_flag |= H_FORCE;
  				break;
  			default:
  				return CMD_RET_USAGE;
  			}
  		}
  	}
  	debug("Final value for argc=%d
  ", argc);
  
  	env_id++;
  
  	while (--argc > 0) {
  		char *name = *++argv;
  
  		if (!hdelete_r(name, &env_htab, env_flag))
  			ret = 1;
  	}
  
  	return ret;

  }

  #ifdef CONFIG_CMD_EXPORTENV

  /*

   * env export [-t | -b | -c] [-s size] addr [var ...]

   *	-t:	export as text format; if size is given, data will be
   *		padded with '\0' bytes; if not, one terminating '\0'
   *		will be added (which is included in the "filesize"
   *		setting so you can for exmple copy this to flash and
   *		keep the termination).
   *	-b:	export as binary format (name=value pairs separated by
   *		'\0', list end marked by double "\0\0")
   *	-c:	export as checksum protected environment format as
   *		used for example by "saveenv" command

   *	-s size:
   *		size of output buffer

   *	addr:	memory address where environment gets stored

   *	var...	List of variable names that get included into the
   *		export. Without arguments, the whole environment gets
   *		exported.

   *
   * With "-c" and size is NOT given, then the export command will
   * format the data as currently used for the persistent storage,
   * i. e. it will use CONFIG_ENV_SECT_SIZE as output block size and

   * prepend a valid CRC32 checksum and, in case of redundant

   * environment, a "current" redundancy flag. If size is given, this
   * value will be used instead of CONFIG_ENV_SECT_SIZE; again, CRC32
   * checksum and redundancy flag will be inserted.
   *
   * With "-b" and "-t", always only the real data (including a
   * terminating '\0' byte) will be written; here the optional size
   * argument will be used to make sure not to overflow the user
   * provided buffer; the command will abort if the size is not

   * sufficient. Any remaining space will be '\0' padded.

   *
   * On successful return, the variable "filesize" will be set.
   * Note that filesize includes the trailing/terminating '\0' byte(s).
   *

   * Usage scenario:  create a text snapshot/backup of the current settings:

   *
   *	=> env export -t 100000
   *	=> era ${backup_addr} +${filesize}
   *	=> cp.b 100000 ${backup_addr} ${filesize}
   *
   * Re-import this snapshot, deleting all other settings:
   *
   *	=> env import -d -t ${backup_addr}
   */

  static int do_env_export(cmd_tbl_t *cmdtp, int flag,
  			 int argc, char * const argv[])

  {
  	char	buf[32];

  	ulong	addr;
  	char	*ptr, *cmd, *res;

  	size_t	size = 0;

  	ssize_t	len;
  	env_t	*envp;
  	char	sep = '
  ';
  	int	chk = 0;
  	int	fmt = 0;
  
  	cmd = *argv;
  
  	while (--argc > 0 && **++argv == '-') {
  		char *arg = *argv;
  		while (*++arg) {
  			switch (*arg) {
  			case 'b':		/* raw binary format */
  				if (fmt++)
  					goto sep_err;
  				sep = '\0';
  				break;
  			case 'c':		/* external checksum format */
  				if (fmt++)
  					goto sep_err;
  				sep = '\0';
  				chk = 1;
  				break;

  			case 's':		/* size given */
  				if (--argc <= 0)
  					return cmd_usage(cmdtp);
  				size = simple_strtoul(*++argv, NULL, 16);
  				goto NXTARG;

  			case 't':		/* text format */
  				if (fmt++)
  					goto sep_err;
  				sep = '
  ';
  				break;
  			default:

  				return CMD_RET_USAGE;

  			}
  		}

  NXTARG:		;

  	}

  	if (argc < 1)

  		return CMD_RET_USAGE;

  	addr = simple_strtoul(argv[0], NULL, 16);
  	ptr = map_sysmem(addr, size);

  	if (size)

  		memset(ptr, '\0', size);

  
  	argc--;
  	argv++;

  
  	if (sep) {		/* export as text file */

  		len = hexport_r(&env_htab, sep,
  				H_MATCH_KEY | H_MATCH_IDENT,

  				&ptr, size, argc, argv);

  		if (len < 0) {

  			pr_err("Cannot export environment: errno = %d
  ", errno);

  			return 1;
  		}

  		sprintf(buf, "%zX", (size_t)len);

  		env_set("filesize", buf);

  
  		return 0;
  	}

  	envp = (env_t *)ptr;

  
  	if (chk)		/* export as checksum protected block */
  		res = (char *)envp->data;
  	else			/* export as raw binary data */

  		res = ptr;

  	len = hexport_r(&env_htab, '\0',
  			H_MATCH_KEY | H_MATCH_IDENT,
  			&res, ENV_SIZE, argc, argv);

  	if (len < 0) {

  		pr_err("Cannot export environment: errno = %d
  ", errno);

  		return 1;
  	}
  
  	if (chk) {

  		envp->crc = crc32(0, envp->data, ENV_SIZE);

  #ifdef CONFIG_ENV_ADDR_REDUND
  		envp->flags = ACTIVE_FLAG;
  #endif
  	}

  	env_set_hex("filesize", len + offsetof(env_t, data));

  
  	return 0;
  
  sep_err:

  	printf("## %s: only one of \"-b\", \"-c\" or \"-t\" allowed
  ",	cmd);

  	return 1;
  }

  #endif

  #ifdef CONFIG_CMD_IMPORTENV

  /*

   * env import [-d] [-t [-r] | -b | -c] addr [size]

   *	-d:	delete existing environment before importing;

   *		otherwise overwrite / append to existing definitions

   *	-t:	assume text format; either "size" must be given or the
   *		text data must be '\0' terminated

   *	-r:	handle CRLF like LF, that means exported variables with
   *		a content which ends with \r won't get imported. Used
   *		to import text files created with editors which are using CRLF
   *		for line endings. Only effective in addition to -t.

   *	-b:	assume binary format ('\0' separated, "\0\0" terminated)
   *	-c:	assume checksum protected environment format
   *	addr:	memory address to read from
   *	size:	length of input data; if missing, proper '\0'
   *		termination is mandatory
   */

  static int do_env_import(cmd_tbl_t *cmdtp, int flag,
  			 int argc, char * const argv[])

  {

  	ulong	addr;
  	char	*cmd, *ptr;

  	char	sep = '
  ';
  	int	chk = 0;
  	int	fmt = 0;
  	int	del = 0;

  	int	crlf_is_lf = 0;

  	size_t	size;
  
  	cmd = *argv;
  
  	while (--argc > 0 && **++argv == '-') {
  		char *arg = *argv;
  		while (*++arg) {
  			switch (*arg) {
  			case 'b':		/* raw binary format */
  				if (fmt++)
  					goto sep_err;
  				sep = '\0';
  				break;
  			case 'c':		/* external checksum format */
  				if (fmt++)
  					goto sep_err;
  				sep = '\0';
  				chk = 1;
  				break;
  			case 't':		/* text format */
  				if (fmt++)
  					goto sep_err;
  				sep = '
  ';
  				break;

  			case 'r':		/* handle CRLF like LF */
  				crlf_is_lf = 1;
  				break;

  			case 'd':
  				del = 1;
  				break;
  			default:

  				return CMD_RET_USAGE;

  			}
  		}
  	}

  	if (argc < 1)

  		return CMD_RET_USAGE;

  
  	if (!fmt)
  		printf("## Warning: defaulting to text format
  ");

  	if (sep != '
  ' && crlf_is_lf )
  		crlf_is_lf = 0;

  	addr = simple_strtoul(argv[0], NULL, 16);
  	ptr = map_sysmem(addr, 0);

  
  	if (argc == 2) {
  		size = simple_strtoul(argv[1], NULL, 16);

  	} else if (argc == 1 && chk) {
  		puts("## Error: external checksum format must pass size
  ");
  		return CMD_RET_FAILURE;

  	} else {

  		char *s = ptr;

  
  		size = 0;
  
  		while (size < MAX_ENV_SIZE) {
  			if ((*s == sep) && (*(s+1) == '\0'))
  				break;
  			++s;
  			++size;
  		}
  		if (size == MAX_ENV_SIZE) {
  			printf("## Warning: Input data exceeds %d bytes"
  				" - truncated
  ", MAX_ENV_SIZE);
  		}

  		size += 2;

  		printf("## Info: input data size = %zu = 0x%zX
  ", size, size);

  	}
  
  	if (chk) {
  		uint32_t crc;

  		env_t *ep = (env_t *)ptr;

  
  		size -= offsetof(env_t, data);
  		memcpy(&crc, &ep->crc, sizeof(crc));
  
  		if (crc32(0, ep->data, size) != crc) {
  			puts("## Error: bad CRC, import failed
  ");
  			return 1;
  		}

  		ptr = (char *)ep->data;

  	}

  	if (himport_r(&env_htab, ptr, size, sep, del ? 0 : H_NOCLEAR,
  			crlf_is_lf, 0, NULL) == 0) {

  		pr_err("Environment import failed: errno = %d
  ", errno);

  		return 1;
  	}
  	gd->flags |= GD_FLG_ENV_READY;
  
  	return 0;
  
  sep_err:
  	printf("## %s: only one of \"-b\", \"-c\" or \"-t\" allowed
  ",
  		cmd);
  	return 1;
  }

  #endif

  #if defined(CONFIG_CMD_ENV_EXISTS)
  static int do_env_exists(cmd_tbl_t *cmdtp, int flag, int argc,
  		       char * const argv[])
  {
  	ENTRY e, *ep;
  
  	if (argc < 2)
  		return CMD_RET_USAGE;
  
  	e.key = argv[1];
  	e.data = NULL;
  	hsearch_r(e, FIND, &ep, &env_htab, 0);
  
  	return (ep == NULL) ? 1 : 0;
  }
  #endif

  /*
   * New command line interface: "env" command with subcommands
   */
  static cmd_tbl_t cmd_env_sub[] = {
  #if defined(CONFIG_CMD_ASKENV)
  	U_BOOT_CMD_MKENT(ask, CONFIG_SYS_MAXARGS, 1, do_env_ask, "", ""),
  #endif
  	U_BOOT_CMD_MKENT(default, 1, 0, do_env_default, "", ""),

  	U_BOOT_CMD_MKENT(delete, CONFIG_SYS_MAXARGS, 0, do_env_delete, "", ""),

  #if defined(CONFIG_CMD_EDITENV)
  	U_BOOT_CMD_MKENT(edit, 2, 0, do_env_edit, "", ""),
  #endif

  #if defined(CONFIG_CMD_ENV_CALLBACK)
  	U_BOOT_CMD_MKENT(callbacks, 1, 0, do_env_callback, "", ""),
  #endif

  #if defined(CONFIG_CMD_ENV_FLAGS)
  	U_BOOT_CMD_MKENT(flags, 1, 0, do_env_flags, "", ""),
  #endif

  #if defined(CONFIG_CMD_EXPORTENV)

  	U_BOOT_CMD_MKENT(export, 4, 0, do_env_export, "", ""),

  #endif

  #if defined(CONFIG_CMD_GREPENV)
  	U_BOOT_CMD_MKENT(grep, CONFIG_SYS_MAXARGS, 1, do_env_grep, "", ""),
  #endif

  #if defined(CONFIG_CMD_IMPORTENV)

  	U_BOOT_CMD_MKENT(import, 5, 0, do_env_import, "", ""),

  #endif

  	U_BOOT_CMD_MKENT(print, CONFIG_SYS_MAXARGS, 1, do_env_print, "", ""),
  #if defined(CONFIG_CMD_RUN)
  	U_BOOT_CMD_MKENT(run, CONFIG_SYS_MAXARGS, 1, do_run, "", ""),
  #endif
  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
  	U_BOOT_CMD_MKENT(save, 1, 0, do_env_save, "", ""),
  #endif
  	U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 0, do_env_set, "", ""),

  #if defined(CONFIG_CMD_ENV_EXISTS)
  	U_BOOT_CMD_MKENT(exists, 2, 0, do_env_exists, "", ""),
  #endif

  };

  #if defined(CONFIG_NEEDS_MANUAL_RELOC)

  void env_reloc(void)
  {
  	fixup_cmdtable(cmd_env_sub, ARRAY_SIZE(cmd_env_sub));
  }
  #endif

  static int do_env(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	cmd_tbl_t *cp;

  	if (argc < 2)

  		return CMD_RET_USAGE;

  	/* drop initial "env" arg */
  	argc--;
  	argv++;
  
  	cp = find_cmd_tbl(argv[0], cmd_env_sub, ARRAY_SIZE(cmd_env_sub));
  
  	if (cp)
  		return cp->cmd(cmdtp, flag, argc, argv);

  	return CMD_RET_USAGE;

  }

  #ifdef CONFIG_SYS_LONGHELP
  static char env_help_text[] =

  #if defined(CONFIG_CMD_ASKENV)
  	"ask name [message] [size] - ask for environment variable
  env "
  #endif

  #if defined(CONFIG_CMD_ENV_CALLBACK)
  	"callbacks - print callbacks and their associated variables
  env "
  #endif

  	"default [-f] -a - [forcibly] reset default environment
  "
  	"env default [-f] var [...] - [forcibly] reset variable(s) to their default values
  "

  	"env delete [-f] var [...] - [forcibly] delete variable(s)
  "

  #if defined(CONFIG_CMD_EDITENV)
  	"env edit name - edit environment variable
  "
  #endif

  #if defined(CONFIG_CMD_ENV_EXISTS)
  	"env exists name - tests for existence of variable
  "
  #endif

  #if defined(CONFIG_CMD_EXPORTENV)

  	"env export [-t | -b | -c] [-s size] addr [var ...] - export environment
  "

  #endif

  #if defined(CONFIG_CMD_ENV_FLAGS)
  	"env flags - print variables that have non-default flags
  "
  #endif

  #if defined(CONFIG_CMD_GREPENV)

  #ifdef CONFIG_REGEX
  	"env grep [-e] [-n | -v | -b] string [...] - search environment
  "
  #else

  	"env grep [-n | -v | -b] string [...] - search environment
  "

  #endif

  #endif

  #if defined(CONFIG_CMD_IMPORTENV)

  	"env import [-d] [-t [-r] | -b | -c] addr [size] - import environment
  "

  #endif

  	"env print [-a | name ...] - print environment
  "

  #if defined(CONFIG_CMD_RUN)
  	"env run var [...] - run commands in an environment variable
  "
  #endif

  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)

  	"env save - save environment
  "

  #endif

  	"env set [-f] name [arg ...]
  ";
  #endif
  
  U_BOOT_CMD(
  	env, CONFIG_SYS_MAXARGS, 1, do_env,
  	"environment handling commands", env_help_text

  );
  
  /*
   * Old command line interface, kept for compatibility
   */

  #if defined(CONFIG_CMD_EDITENV)

  U_BOOT_CMD_COMPLETE(

  	editenv, 2, 0,	do_env_edit,

  	"edit environment variable",
  	"name
  "

  	"    - edit environment variable 'name'",
  	var_complete

  );
  #endif

  U_BOOT_CMD_COMPLETE(

  	printenv, CONFIG_SYS_MAXARGS, 1,	do_env_print,

  	"print environment variables",

  	"[-a]
      - print [all] values of all environment variables
  "

  	"printenv name ...
  "

  	"    - print value of environment variable 'name'",
  	var_complete

  );

  #ifdef CONFIG_CMD_GREPENV
  U_BOOT_CMD_COMPLETE(
  	grepenv, CONFIG_SYS_MAXARGS, 0,  do_env_grep,
  	"search environment variables",

  #ifdef CONFIG_REGEX
  	"[-e] [-n | -v | -b] string ...
  "
  #else

  	"[-n | -v | -b] string ...
  "

  #endif

  	"    - list environment name=value pairs matching 'string'
  "

  #ifdef CONFIG_REGEX
  	"      \"-e\": enable regular expressions;
  "
  #endif

  	"      \"-n\": search variable names; \"-v\": search values;
  "
  	"      \"-b\": search both names and values (default)",

  	var_complete
  );
  #endif

  U_BOOT_CMD_COMPLETE(

  	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,

  	"set environment variables",

  	"[-f] name value ...
  "
  	"    - [forcibly] set environment variable 'name' to 'value ...'
  "
  	"setenv [-f] name
  "
  	"    - [forcibly] delete environment variable 'name'",

  	var_complete

  );

  #if defined(CONFIG_CMD_ASKENV)

  U_BOOT_CMD(

  	askenv,	CONFIG_SYS_MAXARGS,	1,	do_env_ask,

  	"get environment variables from stdin",

  	"name [message] [size]
  "

  	"    - get environment variable 'name' from stdin (max 'size' chars)"

  );

  #endif

  #if defined(CONFIG_CMD_RUN)

  U_BOOT_CMD_COMPLETE(

  	run,	CONFIG_SYS_MAXARGS,	1,	do_run,

  	"run commands in an environment variable",

  	"var [...]
  "

  	"    - run the commands in the environment variable(s) 'var'",
  	var_complete

  );

  #endif

  #endif /* CONFIG_SPL_BUILD */