New implementation for internal handling of environment variables.

Motivation:

* Old environment code used a pessimizing implementation:
  - variable lookup used linear search => slow
  - changed/added variables were added at the end, i. e. most
    frequently used variables had the slowest access times => slow
  - each setenv() would calculate the CRC32 checksum over the whole
    environment block => slow
* "redundant" envrionment was locked down to two copies
* No easy way to implement features like "reset to factory defaults",
  or to select one out of several pre-defined (previously saved) sets
  of environment settings ("profiles")
* No easy way to import or export environment settings

======================================================================

API Changes:

- Variable names starting with '#' are no longer allowed

  I didn't find any such variable names being used; it is highly
  recommended to follow standard conventions and start variable names
  with an alphanumeric character

- "printenv" will now print a backslash at the end of all but the last
  lines of a multi-line variable value.

  Multi-line variables have never been formally defined, allthough
  there is no reason not to use them. Now we define rules how to deal
  with them, allowing for import and export.

- Function forceenv() and the related code in saveenv() was removed.
  At the moment this is causing build problems for the only user of
  this code (schmoogie - which has no entry in MAINTAINERS); may be
  fixed later by implementing the "env set -f" feature.

Inconsistencies:

- "printenv" will '\\'-escape the '\n' in multi-line variables, while
  "printenv var" will not do that.

======================================================================

Advantages:

- "printenv" output much better readable (sorted)
- faster!
- extendable (additional variable properties can be added)
- new, powerful features like "factory reset" or easy switching
  between several different environment settings ("profiles")

Disadvantages:

- Image size grows by typically 5...7 KiB (might shrink a bit again on
  systems with redundant environment with a following patch series)

======================================================================

Implemented:

- env command with subcommands:

  - env print [arg ...]

    same as "printenv": print environment

  - env set [-f] name [arg ...]

    same as "setenv": set (and delete) environment variables

    ["-f" - force setting even for read-only variables - not
    implemented yet.]

  - end delete [-f] name

    not implemented yet

    ["-f" - force delete even for read-only variables]

  - env save

    same as "saveenv": save environment

  - env export [-t | -b | -c] addr [size]

    export internal representation (hash table) in formats usable for
    persistent storage or processing:

	-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
	addr:	memory address where environment gets stored
	size:	size of output buffer

	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 resundant
	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 remainign 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 szenario: 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}

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

    import external format (text or binary) into hash table,
    optionally deleting existing values:

	-d:	delete existing environment before importing;
		otherwise overwrite / append to existion definitions
	-t:	assume text format; either "size" must be given or the
		text data must be '\0' terminated
	-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

  - env default -f

    reset default environment: drop all environment settings and load
    default environment

  - env ask name [message] [size]

    same as "askenv": ask for environment variable

  - env edit name

    same as "editenv": edit environment variable

  - env run

    same as "run": run commands in an environment variable

======================================================================

TODO:

- drop default env as implemented now; provide a text file based
  initialization instead (eventually using several text files to
  incrementally build it from common blocks) and a tool to convert it
  into a binary blob / object file.

- It would be nice if we could add wildcard support for environment
  variables; this is needed for variable name auto-completion,
  but it would also be nice to be able to say "printenv ip*" or
  "printenv *addr*"

- Some boards don't link any more due to the grown code size:
  DU405, canyonlands, sequoia, socrates.

	=> cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
	       Stefan Roese <sr@denx.de>,
	       Heiko Schocher <hs@denx.de>

- Dropping forceenv() causes build problems on schmoogie

	=> cc: Sergey Kubushyn <ksi@koi8.net>

- Build tested on PPC and ARM only; runtime tested with NOR and NAND
  flash only => needs testing!!

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
Cc: Stefan Roese <sr@denx.de>,
Cc: Heiko Schocher <hs@denx.de>
Cc: Sergey Kubushyn <ksi@koi8.net>

1 files changed, 467 insertions, 201 deletions

diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
index 74a5069..c3d63b8 100644
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2000-2002
+ * (C) Copyright 2000-2010
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
@@ -24,27 +24,26 @@
  * MA 02111-1307 USA
  */
 
-/**************************************************************************
- *
+/*
  * Support for persistent environment data
  *
- * The "environment" is stored as a list of '\0' terminated
- * "name=value" strings. The end of the list is marked by a double
- * '\0'. New entries are always added at the end. Deleting an entry
- * shifts the remaining entries to the front. Replacing an entry is a
- * combination of deleting the old value and adding the new one.
- *
- * The environment is preceeded by a 32 bit CRC over the data part.
+ * 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 preceeded 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 <command.h>
 #include <environment.h>
-#if defined(CONFIG_CMD_EDITENV)
+#include <search.h>
+#include <errno.h>
 #include <malloc.h>
-#endif
 #include <watchdog.h>
 #include <serial.h>
 #include <linux/stddef.h>
@@ -72,8 +71,10 @@ SPI_FLASH|MG_DISK|NVRAM|MMC|NOWHERE}
 #define XMK_STR(x)	#x
 #define MK_STR(x)	XMK_STR(x)
 
-/************************************************************************
-************************************************************************/
+/*
+ * Maximum expected input data size for import command
+ */
+#define	MAX_ENV_SIZE	(1 << 20)	/* 1 MiB */
 
 /*
  * Table with supported baudrates (defined in config_xyz.h)
@@ -82,7 +83,7 @@ static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
 #define	N_BAUDRATES (sizeof(baudrate_table) / sizeof(baudrate_table[0]))
 
 /*
- * This variable is incremented on each do_setenv (), so it can
+ * 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
@@ -94,61 +95,51 @@ int get_env_id (void)
 {
 	return env_id;
 }
-/************************************************************************
- * Command interface: print one or all environment variables
- */
 
 /*
- * state 0: finish printing this string and return (matched!)
- * state 1: no matching to be done; print everything
- * state 2: continue searching for matched name
+ * Command interface: print one or all environment variables
+ *
+ * Returns 0 in case of error, or length of printed string
  */
-static int printenv(char *name, int state)
+static int env_print(char *name)
 {
-	int i, j;
-	char c, buf[17];
-
-	i = 0;
-	buf[16] = '\0';
-
-	while (state && env_get_char(i) != '\0') {
-		if (state == 2 && envmatch((uchar *)name, i) >= 0)
-			state = 0;
-
-		j = 0;
-		do {
-			buf[j++] = c = env_get_char(i++);
-			if (j == sizeof(buf) - 1) {
-				if (state <= 1)
-					puts(buf);
-				j = 0;
-			}
-		} while (c != '\0');
+	char *res = NULL;
+	size_t len;
+
+	if (name) {		/* print a single name */
+		ENTRY e, *ep;
+
+		e.key = name;
+		e.data = NULL;
+		ep = hsearch (e, FIND);
+		if (ep == NULL)
+			return 0;
+		len = printf ("%s=%s\n", ep->key, ep->data);
+		return len;
+	}
 
-		if (state <= 1) {
-			if (j)
-				puts(buf);
-			putc('\n');
-		}
+	/* print whole list */
+	len = hexport('\n', &res, 0);
 
-		if (ctrlc())
-			return -1;
+	if (len > 0) {
+		puts(res);
+		free(res);
+		return len;
 	}
 
-	if (state == 0)
-		i = 0;
-	return i;
+	/* should never happen */
+	return 0;
 }
 
-int do_printenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_env_print (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	int i;
 	int rcode = 0;
 
 	if (argc == 1) {
 		/* print all env vars */
-		rcode = printenv(NULL, 1);
-		if (rcode < 0)
+		rcode = env_print(NULL);
+		if (!rcode)
 			return 1;
 		printf("\nEnvironment size: %d/%ld bytes\n",
 			rcode, (ulong)ENV_SIZE);
@@ -157,9 +148,9 @@ int do_printenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 	/* print selected env vars */
 	for (i = 1; i < argc; ++i) {
-		char *name = argv[i];
-		if (printenv(name, 2)) {
-			printf("## Error: \"%s\" not defined\n", name);
+		int rc = env_print(argv[i]);
+		if (!rc) {
+			printf("## Error: \"%s\" not defined\n", argv[i]);
 			++rcode;
 		}
 	}
@@ -167,25 +158,18 @@ int do_printenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	return rcode;
 }
 
-/************************************************************************
+/*
  * Set a new environment variable,
  * or replace or delete an existing one.
- *
- * This function will ONLY work with a in-RAM copy of the environment
  */
 
-int _do_setenv (int flag, int argc, char * const argv[])
+int _do_env_set (int flag, int argc, char * const argv[])
 {
-	int   i, len, oldval;
+	bd_t  *bd = gd->bd;
+	int   i, len;
 	int   console = -1;
-	uchar *env, *nxt = NULL;
-	char *name;
-	bd_t *bd = gd->bd;
-
-	uchar *env_data = env_get_addr(0);
-
-	if (!env_data)	/* need copy in RAM */
-		return 1;
+	char  *name, *value, *s;
+	ENTRY e, *ep;
 
 	name = argv[1];
 
@@ -198,13 +182,9 @@ int _do_setenv (int flag, int argc, char * const argv[])
 	/*
 	 * search if variable with this name already exists
 	 */
-	oldval = -1;
-	for (env=env_data; *env; env=nxt+1) {
-		for (nxt=env; *nxt; ++nxt)
-			;
-		if ((oldval = envmatch((uchar *)name, env-env_data)) >= 0)
-			break;
-	}
+	e.key = name;
+	e.data = NULL;
+	ep = hsearch (e, FIND);
 
 	/* Check for console redirection */
 	if (strcmp(name,"stdin") == 0) {
@@ -238,31 +218,25 @@ int _do_setenv (int flag, int argc, char * const argv[])
 	}
 
 	/*
-	 * Delete any existing definition
+	 * Some variables like "ethaddr" and "serial#" can be set only
+	 * once and cannot be deleted; also, "ver" is readonly.
 	 */
-	if (oldval >= 0) {
+	if (ep) {		/* variable exists */
 #ifndef CONFIG_ENV_OVERWRITE
-
-		/*
-		 * Ethernet Address and serial# can be set only once,
-		 * ver is readonly.
-		 */
-		if (
-		    (strcmp (name, "serial#") == 0) ||
+		if ((strcmp (name, "serial#") == 0) ||
 		    ((strcmp (name, "ethaddr") == 0)
 #if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR)
-		     && (strcmp ((char *)env_get_addr(oldval),MK_STR(CONFIG_ETHADDR)) != 0)
+		     && (strcmp (ep->data,MK_STR(CONFIG_ETHADDR)) != 0)
 #endif	/* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */
 		    ) ) {
 			printf ("Can't overwrite \"%s\"\n", name);
 			return 1;
 		}
 #endif
-
 		/*
 		 * Switch to new baudrate if new baudrate is supported
 		 */
-		if (strcmp(argv[1],"baudrate") == 0) {
+		if (strcmp(name,"baudrate") == 0) {
 			int baudrate = simple_strtoul(argv[2], NULL, 10);
 			int i;
 			for (i=0; i<N_BAUDRATES; ++i) {
@@ -289,75 +263,50 @@ int _do_setenv (int flag, int argc, char * const argv[])
 				      break;
 			}
 		}
-
-		if (*++nxt == '\0') {
-			if (env > env_data) {
-				env--;
-			} else {
-				*env = '\0';
-			}
-		} else {
-			for (;;) {
-				*env = *nxt++;
-				if ((*env == '\0') && (*nxt == '\0'))
-					break;
-				++env;
-			}
-		}
-		*++env = '\0';
 	}
 
 	/* Delete only ? */
 	if ((argc < 3) || argv[2] == NULL) {
-		env_crc_update ();
-		return 0;
+		int rc = hdelete(name);
+		return !rc;
 	}
 
 	/*
-	 * Append new definition at the end
+	 * Insert / replace new value
 	 */
-	for (env=env_data; *env || *(env+1); ++env)
-		;
-	if (env > env_data)
-		++env;
-	/*
-	 * Overflow when:
-	 * "name" + "=" + "val" +"\0\0"  > ENV_SIZE - (env-env_data)
-	 */
-	len = strlen(name) + 2;
-	/* add '=' for first arg, ' ' for all others */
-	for (i=2; i<argc; ++i) {
+	for (i=2,len=0; i<argc; ++i) {
 		len += strlen(argv[i]) + 1;
 	}
-	if (len > (&env_data[ENV_SIZE]-env)) {
-		printf ("## Error: environment overflow, \"%s\" deleted\n", name);
+	if ((value = malloc(len)) == NULL) {
+		printf("## Can't malloc %d bytes\n", len);
 		return 1;
 	}
-	while ((*env = *name++) != '\0')
-		env++;
-	for (i=2; i<argc; ++i) {
-		char *val = argv[i];
+	for (i=2,s=value; i<argc; ++i) {
+		char *v = argv[i];
 
-		*env = (i==2) ? '=' : ' ';
-		while ((*++env = *val++) != '\0')
+		while ((*s++ = *v++) != '\0')
 			;
+		*(s-1) = ' ';
+	}
+	if (s != value)
+		*--s = '\0';
+
+	e.key  = name;
+	e.data = value;
+	ep = hsearch(e, ENTER);
+	free(value);
+	if (!ep) {
+		printf("## Error inserting \"%s\" variable, errno=%d\n",
+			name, errno);
+		return 1;
 	}
-
-	/* end is marked with double '\0' */
-	*++env = '\0';
-
-	/* Update CRC */
-	env_crc_update ();
 
 	/*
 	 * Some variables should be updated when the corresponding
-	 * entry in the enviornment is changed
+	 * entry in the environment is changed
 	 */
 
-	if (strcmp(argv[1],"ethaddr") == 0)
-		return 0;
-
-	if (strcmp(argv[1],"ipaddr") == 0) {
+	if (strcmp(name,"ipaddr") == 0) {
 		char *s = argv[2];	/* always use only one arg */
 		char *e;
 		unsigned long addr;
@@ -370,13 +319,12 @@ int _do_setenv (int flag, int argc, char * const argv[])
 		}
 		bd->bi_ip_addr = htonl(addr);
 		return 0;
-	}
-	if (strcmp(argv[1],"loadaddr") == 0) {
+	} else if (strcmp(argv[1],"loadaddr") == 0) {
 		load_addr = simple_strtoul(argv[2], NULL, 16);
 		return 0;
 	}
 #if defined(CONFIG_CMD_NET)
-	if (strcmp(argv[1],"bootfile") == 0) {
+	else if (strcmp(argv[1],"bootfile") == 0) {
 		copy_filename (BootFile, argv[2], sizeof(BootFile));
 		return 0;
 	}
@@ -388,30 +336,29 @@ int setenv (char *varname, char *varvalue)
 {
 	char * const argv[4] = { "setenv", varname, varvalue, NULL };
 	if ((varvalue == NULL) || (varvalue[0] == '\0'))
-		return _do_setenv (0, 2, argv);
+		return _do_env_set(0, 2, argv);
 	else
-		return _do_setenv (0, 3, argv);
+		return _do_env_set(0, 3, argv);
 }
 
-int do_setenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_env_set (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	if (argc < 2)
 		return cmd_usage(cmdtp);
 
-	return _do_setenv (flag, argc, argv);
+	return _do_env_set(flag, argc, argv);
 }
 
-/************************************************************************
+/*
  * Prompt for environment variable
  */
-
 #if defined(CONFIG_CMD_ASKENV)
-int do_askenv ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_env_ask ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	extern char console_buffer[CONFIG_SYS_CBSIZE];
 	char message[CONFIG_SYS_CBSIZE];
 	int size = CONFIG_SYS_CBSIZE - 1;
-	int len;
+	int i, len, pos;
 	char *local_args[4];
 
 	local_args[0] = argv[0];
@@ -419,38 +366,30 @@ int do_askenv ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	local_args[2] = NULL;
 	local_args[3] = NULL;
 
-	if (argc < 2)
-		return cmd_usage(cmdtp);
-
 	/* Check the syntax */
 	switch (argc) {
 	case 1:
 		return cmd_usage(cmdtp);
 
-	case 2:		/* askenv envname */
-		sprintf (message, "Please enter '%s':", argv[1]);
+	case 2:		/* env_ask envname */
+		sprintf(message, "Please enter '%s':", argv[1]);
 		break;
 
-	case 3:		/* askenv envname size */
-		sprintf (message, "Please enter '%s':", argv[1]);
-		size = simple_strtoul (argv[2], NULL, 10);
+	case 3:		/* env_ask envname size */
+		sprintf(message, "Please enter '%s':", argv[1]);
+		size = simple_strtoul(argv[2], NULL, 10);
 		break;
 
-	default:	/* askenv envname message1 ... messagen size */
-	    {
-		int i;
-		int pos = 0;
-
-		for (i = 2; i < argc - 1; i++) {
+	default:	/* env_ask envname message1 ... messagen size */
+		for (i=2,pos=0; i < argc - 1; i++) {
 			if (pos) {
 				message[pos++] = ' ';
 			}
-			strcpy (message+pos, argv[i]);
+			strcpy(message+pos, argv[i]);
 			pos += strlen(argv[i]);
 		}
 		message[pos] = '\0';
-		size = simple_strtoul (argv[argc - 1], NULL, 10);
-	    }
+		size = simple_strtoul(argv[argc - 1], NULL, 10);
 		break;
 	}
 
@@ -461,7 +400,7 @@ int do_askenv ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		return 1;
 
 	/* prompt for input */
-	len = readline (message);
+	len = readline(message);
 
 	if (size < len)
 		console_buffer[size] = '\0';
@@ -473,15 +412,15 @@ int do_askenv ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	}
 
 	/* Continue calling setenv code */
-	return _do_setenv (flag, len, local_args);
+	return _do_env_set(flag, len, local_args);
 }
 #endif
 
-/************************************************************************
+/*
  * Interactively edit an environment variable
  */
 #if defined(CONFIG_CMD_EDITENV)
-int do_editenv(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_env_edit(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	char buffer[CONFIG_SYS_CBSIZE];
 	char *init_val;
@@ -503,42 +442,37 @@ int do_editenv(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 }
 #endif /* CONFIG_CMD_EDITENV */
 
-/************************************************************************
+/*
  * Look up variable from environment,
  * return address of storage for that variable,
  * or NULL if not found
  */
-
 char *getenv (char *name)
 {
-	if (gd->flags & GD_FLG_RELOC) {	/* full C runtime after reloc */
-		int i, nxt;
+	if (gd->flags & GD_FLG_ENV_READY) {	/* after import into hashtable */
+		ENTRY e, *ep;
 
 		WATCHDOG_RESET();
 
-		for (i=0; env_get_char(i) != '\0'; i=nxt+1) {
-			int val;
-
-			for (nxt=i; env_get_char(nxt) != '\0'; ++nxt) {
-				if (nxt >= CONFIG_ENV_SIZE) {
-					return (NULL);
-				}
-			}
-			if ((val=envmatch((uchar *)name, i)) < 0)
-				continue;
-			return ((char *)env_get_addr(val));
-		}
+		e.key  = name;
+		e.data = NULL;
+		ep = hsearch (e, FIND);
 
-		return (NULL);
+		return (ep ? ep->data : NULL);
 	}
 
-	/* restricted C runtime before reloc */
+	/* restricted capabilities before import */
+
+	if (getenv_f(name, (char *)(gd->env_buf), sizeof(gd->env_buf)) > 0)
+		return (char *)(gd->env_buf);
 
-	return ((getenv_f(name,gd->env_buf,sizeof(gd->env_buf)) > 0) ?
-		gd->env_buf : NULL);
+	return NULL;
 }
 
-int getenv_f(char *name, char *buf, unsigned len)
+/*
+ * Look up variable from environment for restricted C runtime env.
+ */
+int getenv_f (char *name, char *buf, unsigned len)
 {
 	int i, nxt;
 
@@ -571,7 +505,7 @@ int getenv_f(char *name, char *buf, unsigned len)
 
 #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
 
-int do_saveenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_env_save (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	extern char * env_name_spec;
 
@@ -581,7 +515,7 @@ int do_saveenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 }
 
 U_BOOT_CMD(
-	saveenv, 1, 0,	do_saveenv,
+	saveenv, 1, 0,	do_env_save,
 	"save environment variables to persistent storage",
 	""
 );
@@ -589,7 +523,7 @@ U_BOOT_CMD(
 #endif
 
 
-/************************************************************************
+/*
  * Match a name / name=value pair
  *
  * s1 is either a simple 'name', or a 'name=value' pair.
@@ -608,12 +542,345 @@ int envmatch (uchar *s1, int i2)
 	return(-1);
 }
 
+static int do_env_default(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
+{
+	if ((argc != 2) || (strcmp(argv[1], "-f") != 0)) {
+		cmd_usage(cmdtp);
+		return 1;
+	}
+	set_default_env("## Resetting to default environment\n");
+	return 0;
+}
+
+static int do_env_delete(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
+{
+	printf("Not implemented yet\n");
+	return 0;
+}
+
+/*
+ * env export [-t | -b | -c] addr [size]
+ *	-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
+ *	addr:	memory address where environment gets stored
+ *	size:	size of output buffer
+ *
+ * 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 resundant
+ * 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 remainign 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 szenario:  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];
+	char	*addr, *cmd, *res;
+	size_t	size;
+	ssize_t	len;
+	env_t	*envp;
+	char	sep = '\n';
+	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 't':		/* text format */
+				if (fmt++)
+					goto sep_err;
+				sep = '\n';
+				break;
+			default:
+				cmd_usage(cmdtp);
+				return 1;
+			}
+		}
+	}
+
+	if (argc < 1) {
+		cmd_usage(cmdtp);
+		return 1;
+	}
 
-/**************************************************/
+	addr = (char *)simple_strtoul(argv[0], NULL, 16);
+
+	if (argc == 2) {
+		size = simple_strtoul(argv[1], NULL, 16);
+		memset(addr, '\0', size);
+	} else {
+		size = 0;
+	}
+
+	if (sep) {		/* export as text file */
+		len = hexport(sep, &addr, size);
+		if (len < 0) {
+			error("Cannot export environment: errno = %d\n",
+				errno);
+			return 1;
+		}
+		sprintf(buf, "%zX", len);
+		setenv("filesize", buf);
+
+		return 0;
+	}
+
+	envp = (env_t *)addr;
+
+	if (chk)		/* export as checksum protected block */
+		res = (char *)envp->data;
+	else			/* export as raw binary data */
+		res = addr;
+
+	len = hexport('\0', &res, ENV_SIZE);
+	if (len < 0) {
+		error("Cannot export environment: errno = %d\n",
+			errno);
+		return 1;
+	}
+
+	if (chk) {
+		envp->crc   = crc32(0, envp->data, ENV_SIZE);
+#ifdef CONFIG_ENV_ADDR_REDUND
+		envp->flags = ACTIVE_FLAG;
+#endif
+	}
+	sprintf(buf, "%zX", len + offsetof(env_t,data));
+	setenv("filesize", buf);
+
+	return 0;
+
+sep_err:
+	printf("## %s: only one of \"-b\", \"-c\" or \"-t\" allowed\n",
+		cmd);
+	return 1;
+}
+
+/*
+ * env import [-d] [-t | -b | -c] addr [size]
+ *	-d:	delete existing environment before importing;
+ *		otherwise overwrite / append to existion definitions
+ *	-t:	assume text format; either "size" must be given or the
+ *		text data must be '\0' terminated
+ *	-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[])
+{
+	char	*cmd, *addr;
+	char	sep = '\n';
+	int	chk = 0;
+	int	fmt = 0;
+	int	del = 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 = '\n';
+				break;
+			case 'd':
+				del = 1;
+				break;
+			default:
+				cmd_usage(cmdtp);
+				return 1;
+			}
+		}
+	}
+
+	if (argc < 1) {
+		cmd_usage(cmdtp);
+		return 1;
+	}
+
+	if (!fmt)
+		printf("## Warning: defaulting to text format\n");
+
+	addr = (char *)simple_strtoul(argv[0], NULL, 16);
+
+	if (argc == 2) {
+		size = simple_strtoul(argv[1], NULL, 16);
+	} else {
+		char *s = addr;
+
+		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\n", MAX_ENV_SIZE);
+		}
+		++size;
+		printf("## Info: input data size = %zd = 0x%zX\n", size, size);
+	}
+
+	if (chk) {
+		uint32_t crc;
+		env_t *ep = (env_t *)addr;
+
+		size -= offsetof(env_t, data);
+		memcpy(&crc, &ep->crc, sizeof(crc));
+
+		if (crc32(0, ep->data, size) != crc) {
+			puts("## Error: bad CRC, import failed\n");
+			return 1;
+		}
+		addr = (char *)ep->data;
+	}
+
+	if (himport(addr, size, sep, del ? 0 : H_NOCLEAR) == 0) {
+		error("Environment import failed: errno = %d\n", errno);
+		return 1;
+	}
+	gd->flags |= GD_FLG_ENV_READY;
+
+	return 0;
+
+sep_err:
+	printf("## %s: only one of \"-b\", \"-c\" or \"-t\" allowed\n",
+		cmd);
+	return 1;
+}
+
+#if defined(CONFIG_CMD_RUN)
+extern int do_run (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+#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, 2, 0, do_env_delete, "", ""),
+#if defined(CONFIG_CMD_EDITENV)
+	U_BOOT_CMD_MKENT(edit, 2, 0, do_env_edit, "", ""),
+#endif
+	U_BOOT_CMD_MKENT(export, 4, 0, do_env_export, "", ""),
+	U_BOOT_CMD_MKENT(import, 5, 0, do_env_import, "", ""),
+	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, "", ""),
+};
+
+static int do_env (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	cmd_tbl_t *cp;
+
+	/* 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);
+
+	cmd_usage(cmdtp);
+	return 1;
+}
+
+U_BOOT_CMD(
+	env, CONFIG_SYS_MAXARGS, 1, do_env,
+	"environment handling commands",
+#if defined(CONFIG_CMD_ASKENV)
+	"ask name [message] [size] - ask for environment variable\nenv "
+#endif
+	"default -f - reset default environment\n"
+#if defined(CONFIG_CMD_EDITENV)
+	"env edit name - edit environment variable\n"
+#endif
+	"env export [-t | -b | -c] addr [size] - export environmnt\n"
+	"env import [-d] [-t | -b | -c] addr [size] - import environmnt\n"
+	"env print [name ...] - print environment\n"
+#if defined(CONFIG_CMD_RUN)
+	"env run var [...] - run commands in an environment variable\n"
+#endif
+	"env save - save environment\n"
+	"env set [-f] name [arg ...]\n"
+);
+
+/*
+ * Old command line interface, kept for compatibility
+ */
 
 #if defined(CONFIG_CMD_EDITENV)
 U_BOOT_CMD(
-	editenv, 2, 0,	do_editenv,
+	editenv, 2, 0,	do_env_edit,
 	"edit environment variable",
 	"name\n"
 	"    - edit environment variable 'name'"
@@ -621,7 +888,7 @@ U_BOOT_CMD(
 #endif
 
 U_BOOT_CMD(
-	printenv, CONFIG_SYS_MAXARGS, 1,	do_printenv,
+	printenv, CONFIG_SYS_MAXARGS, 1,	do_env_print,
 	"print environment variables",
 	"\n    - print values of all environment variables\n"
 	"printenv name ...\n"
@@ -629,7 +896,7 @@ U_BOOT_CMD(
 );
 
 U_BOOT_CMD(
-	setenv, CONFIG_SYS_MAXARGS, 0,	do_setenv,
+	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,
 	"set environment variables",
 	"name value ...\n"
 	"    - set environment variable 'name' to 'value ...'\n"
@@ -640,7 +907,7 @@ U_BOOT_CMD(
 #if defined(CONFIG_CMD_ASKENV)
 
 U_BOOT_CMD(
-	askenv,	CONFIG_SYS_MAXARGS,	1,	do_askenv,
+	askenv,	CONFIG_SYS_MAXARGS,	1,	do_env_ask,
 	"get environment variables from stdin",
 	"name [message] [size]\n"
 	"    - get environment variable 'name' from stdin (max 'size' chars)\n"
@@ -655,7 +922,6 @@ U_BOOT_CMD(
 #endif
 
 #if defined(CONFIG_CMD_RUN)
-int do_run (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
 U_BOOT_CMD(
 	run,	CONFIG_SYS_MAXARGS,	1,	do_run,
 	"run commands in an environment variable",