]> git.kernelconcepts.de Git - karo-tx-uboot.git/blobdiff - tools/env/fw_env.c
Revert "fw_env: fix building w/out a config.h"
[karo-tx-uboot.git] / tools / env / fw_env.c
index f723b5bca1d0f53f762fb8b20166e7ec02d81e42..37b60b80a7624566d9ecefdd04c0658134bd654d 100644 (file)
@@ -1,7 +1,10 @@
 /*
- * (C) Copyright 2000-2003
+ * (C) Copyright 2000-2010
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
+ * (C) Copyright 2008
+ * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
+ *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
@@ -22,7 +25,9 @@
  */
 
 #include <errno.h>
+#include <env_flags.h>
 #include <fcntl.h>
+#include <linux/stringify.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <unistd.h>
-#include <linux/mtd/mtd.h>
+
+#ifdef MTD_OLD
+# include <stdint.h>
+# include <linux/mtd/mtd.h>
+#else
+# define  __user       /* nothing */
+# include <mtd/mtd-user.h>
+#endif
+
 #include "fw_env.h"
 
-typedef unsigned char uchar;
+#define WHITESPACE(c) ((c == '\t') || (c == ' '))
 
-#define        CMD_GETENV      "fw_printenv"
-#define        CMD_SETENV      "fw_setenv"
+#define min(x, y) ({                           \
+       typeof(x) _min1 = (x);                  \
+       typeof(y) _min2 = (y);                  \
+       (void) (&_min1 == &_min2);              \
+       _min1 < _min2 ? _min1 : _min2; })
 
-typedef struct envdev_s {
-       uchar devname[16];              /* Device name */
+struct envdev_s {
+       char devname[16];               /* Device name */
        ulong devoff;                   /* Device offset */
        ulong env_size;                 /* environment size */
        ulong erase_size;               /* device erase size */
-} envdev_t;
+       ulong env_sectors;              /* number of environment sectors */
+       uint8_t mtd_type;               /* type of the MTD device */
+};
 
-static envdev_t envdevices[2];
-static int curdev;
+static struct envdev_s envdevices[2] =
+{
+       {
+               .mtd_type = MTD_ABSENT,
+       }, {
+               .mtd_type = MTD_ABSENT,
+       },
+};
+static int dev_current;
 
 #define DEVNAME(i)    envdevices[(i)].devname
 #define DEVOFFSET(i)  envdevices[(i)].devoff
 #define ENVSIZE(i)    envdevices[(i)].env_size
 #define DEVESIZE(i)   envdevices[(i)].erase_size
+#define ENVSECTORS(i) envdevices[(i)].env_sectors
+#define DEVTYPE(i)    envdevices[(i)].mtd_type
 
-#define CFG_ENV_SIZE ENVSIZE(curdev)
+#define CUR_ENVSIZE ENVSIZE(dev_current)
 
 #define ENV_SIZE      getenvsize()
 
-typedef struct environment_s {
-       ulong crc;                      /* CRC32 over data bytes    */
-       uchar flags;                    /* active or obsolete */
-       uchar *data;
-} env_t;
+struct env_image_single {
+       uint32_t        crc;    /* CRC32 over data bytes    */
+       char            data[];
+};
 
-static env_t environment;
+struct env_image_redundant {
+       uint32_t        crc;    /* CRC32 over data bytes    */
+       unsigned char   flags;  /* active or obsolete */
+       char            data[];
+};
 
-static int HaveRedundEnv = 0;
+enum flag_scheme {
+       FLAG_NONE,
+       FLAG_BOOLEAN,
+       FLAG_INCREMENTAL,
+};
 
-static uchar active_flag = 1;
-static uchar obsolete_flag = 0;
+struct environment {
+       void                    *image;
+       uint32_t                *crc;
+       unsigned char           *flags;
+       char                    *data;
+       enum flag_scheme        flag_scheme;
+};
 
+static struct environment environment = {
+       .flag_scheme = FLAG_NONE,
+};
 
-#define XMK_STR(x)     #x
-#define MK_STR(x)      XMK_STR(x)
+static int HaveRedundEnv = 0;
 
-static uchar default_environment[] = {
-#if defined(CONFIG_BOOTARGS)
-       "bootargs=" CONFIG_BOOTARGS "\0"
-#endif
-#if defined(CONFIG_BOOTCOMMAND)
-       "bootcmd=" CONFIG_BOOTCOMMAND "\0"
-#endif
-#if defined(CONFIG_RAMBOOTCOMMAND)
-       "ramboot=" CONFIG_RAMBOOTCOMMAND "\0"
-#endif
-#if defined(CONFIG_NFSBOOTCOMMAND)
-       "nfsboot=" CONFIG_NFSBOOTCOMMAND "\0"
-#endif
-#if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
-       "bootdelay=" MK_STR (CONFIG_BOOTDELAY) "\0"
-#endif
-#if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0)
-       "baudrate=" MK_STR (CONFIG_BAUDRATE) "\0"
-#endif
-#ifdef CONFIG_LOADS_ECHO
-       "loads_echo=" MK_STR (CONFIG_LOADS_ECHO) "\0"
-#endif
-#ifdef CONFIG_ETHADDR
-       "ethaddr=" MK_STR (CONFIG_ETHADDR) "\0"
-#endif
-#ifdef CONFIG_ETH1ADDR
-       "eth1addr=" MK_STR (CONFIG_ETH1ADDR) "\0"
-#endif
-#ifdef CONFIG_ETH2ADDR
-       "eth2addr=" MK_STR (CONFIG_ETH2ADDR) "\0"
-#endif
-#ifdef CONFIG_ETH3ADDR
-       "eth3addr=" MK_STR (CONFIG_ETH3ADDR) "\0"
-#endif
-#ifdef CONFIG_ETHPRIME
-       "ethprime=" CONFIG_ETHPRIME "\0"
-#endif
-#ifdef CONFIG_IPADDR
-       "ipaddr=" MK_STR (CONFIG_IPADDR) "\0"
-#endif
-#ifdef CONFIG_SERVERIP
-       "serverip=" MK_STR (CONFIG_SERVERIP) "\0"
-#endif
-#ifdef CFG_AUTOLOAD
-       "autoload=" CFG_AUTOLOAD "\0"
-#endif
-#ifdef CONFIG_ROOTPATH
-       "rootpath=" MK_STR (CONFIG_ROOTPATH) "\0"
-#endif
-#ifdef CONFIG_GATEWAYIP
-       "gatewayip=" MK_STR (CONFIG_GATEWAYIP) "\0"
-#endif
-#ifdef CONFIG_NETMASK
-       "netmask=" MK_STR (CONFIG_NETMASK) "\0"
-#endif
-#ifdef CONFIG_HOSTNAME
-       "hostname=" MK_STR (CONFIG_HOSTNAME) "\0"
-#endif
-#ifdef CONFIG_BOOTFILE
-       "bootfile=" MK_STR (CONFIG_BOOTFILE) "\0"
-#endif
-#ifdef CONFIG_LOADADDR
-       "loadaddr=" MK_STR (CONFIG_LOADADDR) "\0"
-#endif
-#ifdef CONFIG_PREBOOT
-       "preboot=" CONFIG_PREBOOT "\0"
-#endif
-#ifdef CONFIG_CLOCKS_IN_MHZ
-       "clocks_in_mhz=" "1" "\0"
-#endif
-#if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
-       "pcidelay=" MK_STR (CONFIG_PCI_BOOTDELAY) "\0"
-#endif
-#ifdef  CONFIG_EXTRA_ENV_SETTINGS
-       CONFIG_EXTRA_ENV_SETTINGS
-#endif
-       "\0"                    /* Termimate env_t data with 2 NULs */
-};
+static unsigned char active_flag = 1;
+/* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
+static unsigned char obsolete_flag = 0;
+
+#define DEFAULT_ENV_INSTANCE_STATIC
+#include <env_default.h>
 
 static int flash_io (int mode);
-static uchar *envmatch (uchar * s1, uchar * s2);
-static int env_init (void);
+static char *envmatch (char * s1, char * s2);
 static int parse_config (void);
 
 #if defined(CONFIG_FILE)
@@ -164,53 +132,93 @@ static int get_config (char *);
 #endif
 static inline ulong getenvsize (void)
 {
-       ulong rc = CFG_ENV_SIZE - sizeof (long);
+       ulong rc = CUR_ENVSIZE - sizeof(long);
 
        if (HaveRedundEnv)
                rc -= sizeof (char);
        return rc;
 }
 
+static char *fw_string_blank(char *s, int noblank)
+{
+       int i;
+       int len = strlen(s);
+
+       for (i = 0; i < len; i++, s++) {
+               if ((noblank && !WHITESPACE(*s)) ||
+                       (!noblank && WHITESPACE(*s)))
+                       break;
+       }
+       if (i == len)
+               return NULL;
+
+       return s;
+}
+
 /*
  * Search the environment for a variable.
  * Return the value, if found, or NULL, if not found.
  */
-unsigned char *fw_getenv (unsigned char *name)
+char *fw_getenv (char *name)
 {
-       uchar *env, *nxt;
-
-       if (env_init ())
-               return (NULL);
+       char *env, *nxt;
 
        for (env = environment.data; *env; env = nxt + 1) {
-               uchar *val;
+               char *val;
 
                for (nxt = env; *nxt; ++nxt) {
                        if (nxt >= &environment.data[ENV_SIZE]) {
                                fprintf (stderr, "## Error: "
                                        "environment not terminated\n");
-                               return (NULL);
+                               return NULL;
                        }
                }
                val = envmatch (name, env);
                if (!val)
                        continue;
-               return (val);
+               return val;
+       }
+       return NULL;
+}
+
+/*
+ * Search the default environment for a variable.
+ * Return the value, if found, or NULL, if not found.
+ */
+char *fw_getdefenv(char *name)
+{
+       char *env, *nxt;
+
+       for (env = default_environment; *env; env = nxt + 1) {
+               char *val;
+
+               for (nxt = env; *nxt; ++nxt) {
+                       if (nxt >= &default_environment[ENV_SIZE]) {
+                               fprintf(stderr, "## Error: "
+                                       "default environment not terminated\n");
+                               return NULL;
+                       }
+               }
+               val = envmatch(name, env);
+               if (!val)
+                       continue;
+               return val;
        }
-       return (NULL);
+       return NULL;
 }
 
 /*
  * Print the current definition of one, or more, or all
  * environment variables
  */
-void fw_printenv (int argc, char *argv[])
+int fw_printenv (int argc, char *argv[])
 {
-       uchar *env, *nxt;
+       char *env, *nxt;
        int i, n_flag;
+       int rc = 0;
 
-       if (env_init ())
-               return;
+       if (fw_env_open())
+               return -1;
 
        if (argc == 1) {                /* Print all env variables  */
                for (env = environment.data; *env; env = nxt + 1) {
@@ -218,13 +226,13 @@ void fw_printenv (int argc, char *argv[])
                                if (nxt >= &environment.data[ENV_SIZE]) {
                                        fprintf (stderr, "## Error: "
                                                "environment not terminated\n");
-                                       return;
+                                       return -1;
                                }
                        }
 
                        printf ("%s\n", env);
                }
-               return;
+               return 0;
        }
 
        if (strcmp (argv[1], "-n") == 0) {
@@ -234,15 +242,15 @@ void fw_printenv (int argc, char *argv[])
                if (argc != 2) {
                        fprintf (stderr, "## Error: "
                                "`-n' option requires exactly one argument\n");
-                       return;
+                       return -1;
                }
        } else {
                n_flag = 0;
        }
 
        for (i = 1; i < argc; ++i) {    /* print single env variables   */
-               uchar *name = argv[i];
-               uchar *val = NULL;
+               char *name = argv[i];
+               char *val = NULL;
 
                for (env = environment.data; *env; env = nxt + 1) {
 
@@ -250,7 +258,7 @@ void fw_printenv (int argc, char *argv[])
                                if (nxt >= &environment.data[ENV_SIZE]) {
                                        fprintf (stderr, "## Error: "
                                                "environment not terminated\n");
-                                       return;
+                                       return -1;
                                }
                        }
                        val = envmatch (name, env);
@@ -263,34 +271,44 @@ void fw_printenv (int argc, char *argv[])
                                break;
                        }
                }
-               if (!val)
+               if (!val) {
                        fprintf (stderr, "## Error: \"%s\" not defined\n", name);
+                       rc = -1;
+               }
        }
+
+       return rc;
 }
 
-/*
- * Deletes or sets environment variables. Returns errno style error codes:
- * 0     - OK
- * EINVAL - need at least 1 argument
- * EROFS  - certain variables ("ethaddr", "serial#") cannot be
- *         modified or deleted
- *
- */
-int fw_setenv (int argc, char *argv[])
+int fw_env_close(void)
 {
-       int i, len;
-       uchar *env, *nxt;
-       uchar *oldval = NULL;
-       uchar *name;
+       /*
+        * Update CRC
+        */
+       *environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
 
-       if (argc < 2) {
-               return (EINVAL);
+       /* write environment back to flash */
+       if (flash_io(O_RDWR)) {
+               fprintf(stderr,
+                       "Error: can't write fw_env to flash\n");
+                       return -1;
        }
 
-       if (env_init ())
-               return (errno);
+       return 0;
+}
 
-       name = argv[1];
+
+/*
+ * Set/Clear a single variable in the environment.
+ * This is called in sequence to update the environment
+ * in RAM without updating the copy in flash after each set
+ */
+int fw_env_write(char *name, char *value)
+{
+       int len;
+       char *env, *nxt;
+       char *oldval = NULL;
+       int deleting, creating, overwriting;
 
        /*
         * search if variable with this name already exists
@@ -298,28 +316,59 @@ int fw_setenv (int argc, char *argv[])
        for (nxt = env = environment.data; *env; env = nxt + 1) {
                for (nxt = env; *nxt; ++nxt) {
                        if (nxt >= &environment.data[ENV_SIZE]) {
-                               fprintf (stderr, "## Error: "
+                               fprintf(stderr, "## Error: "
                                        "environment not terminated\n");
-                               return (EINVAL);
+                               errno = EINVAL;
+                               return -1;
                        }
                }
                if ((oldval = envmatch (name, env)) != NULL)
                        break;
        }
 
-       /*
-        * Delete any existing definition
-        */
-       if (oldval) {
-               /*
-                * Ethernet Address and serial# can be set only once
-                */
-               if ((strcmp (name, "ethaddr") == 0) ||
-                       (strcmp (name, "serial#") == 0)) {
-                       fprintf (stderr, "Can't overwrite \"%s\"\n", name);
-                       return (EROFS);
+       deleting = (oldval && !(value && strlen(value)));
+       creating = (!oldval && (value && strlen(value)));
+       overwriting = (oldval && (value && strlen(value)));
+
+       /* check for permission */
+       if (deleting) {
+               if (env_flags_validate_varaccess(name,
+                   ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
+                       printf("Can't delete \"%s\"\n", name);
+                       errno = EROFS;
+                       return -1;
+               }
+       } else if (overwriting) {
+               if (env_flags_validate_varaccess(name,
+                   ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
+                       printf("Can't overwrite \"%s\"\n", name);
+                       errno = EROFS;
+                       return -1;
+               } else if (env_flags_validate_varaccess(name,
+                   ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
+                       const char *defval = fw_getdefenv(name);
+
+                       if (defval == NULL)
+                               defval = "";
+                       if (strcmp(oldval, defval)
+                           != 0) {
+                               printf("Can't overwrite \"%s\"\n", name);
+                               errno = EROFS;
+                               return -1;
+                       }
+               }
+       } else if (creating) {
+               if (env_flags_validate_varaccess(name,
+                   ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
+                       printf("Can't create \"%s\"\n", name);
+                       errno = EROFS;
+                       return -1;
                }
+       } else
+               /* Nothing to do */
+               return 0;
 
+       if (deleting || overwriting) {
                if (*++nxt == '\0') {
                        *env = '\0';
                } else {
@@ -334,8 +383,8 @@ int fw_setenv (int argc, char *argv[])
        }
 
        /* Delete only ? */
-       if (argc < 3)
-               goto WRITE_FLASH;
+       if (!value || !strlen(value))
+               return 0;
 
        /*
         * Append new definition at the end
@@ -345,222 +394,640 @@ int fw_setenv (int argc, char *argv[])
                ++env;
        /*
         * Overflow when:
-        * "name" + "=" + "val" +"\0\0"  > CFG_ENV_SIZE - (env-environment)
+        * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
         */
        len = strlen (name) + 2;
        /* add '=' for first arg, ' ' for all others */
-       for (i = 2; i < argc; ++i) {
-               len += strlen (argv[i]) + 1;
-       }
+       len += strlen(value) + 1;
+
        if (len > (&environment.data[ENV_SIZE] - env)) {
                fprintf (stderr,
                        "Error: environment overflow, \"%s\" deleted\n",
                        name);
-               return (-1);
+               return -1;
        }
+
        while ((*env = *name++) != '\0')
                env++;
-       for (i = 2; i < argc; ++i) {
-               uchar *val = argv[i];
-
-               *env = (i == 2) ? '=' : ' ';
-               while ((*++env = *val++) != '\0');
-       }
+       *env = '=';
+       while ((*++env = *value++) != '\0')
+               ;
 
        /* end is marked with double '\0' */
        *++env = '\0';
 
-  WRITE_FLASH:
+       return 0;
+}
 
-       /* Update CRC */
-       environment.crc = crc32 (0, environment.data, ENV_SIZE);
+/*
+ * Deletes or sets environment variables. Returns -1 and sets errno error codes:
+ * 0     - OK
+ * EINVAL - need at least 1 argument
+ * EROFS  - certain variables ("ethaddr", "serial#") cannot be
+ *         modified or deleted
+ *
+ */
+int fw_setenv(int argc, char *argv[])
+{
+       int i;
+       size_t len;
+       char *name;
+       char *value = NULL;
 
-       /* write environment back to flash */
-       if (flash_io (O_RDWR)) {
-               fprintf (stderr, "Error: can't write fw_env to flash\n");
-               return (-1);
+       if (argc < 2) {
+               errno = EINVAL;
+               return -1;
        }
 
-       return (0);
+       if (fw_env_open()) {
+               fprintf(stderr, "Error: environment not initialized\n");
+               return -1;
+       }
+
+       name = argv[1];
+
+       if (env_flags_validate_env_set_params(argc, argv) < 0)
+               return 1;
+
+       len = 0;
+       for (i = 2; i < argc; ++i) {
+               char *val = argv[i];
+               size_t val_len = strlen(val);
+
+               if (value)
+                       value[len - 1] = ' ';
+               value = realloc(value, len + val_len + 1);
+               if (!value) {
+                       fprintf(stderr,
+                               "Cannot malloc %zu bytes: %s\n",
+                               len, strerror(errno));
+                       return -1;
+               }
+
+               memcpy(value + len, val, val_len);
+               len += val_len;
+               value[len++] = '\0';
+       }
+
+       fw_env_write(name, value);
+
+       free(value);
+
+       return fw_env_close();
 }
 
-static int flash_io (int mode)
+/*
+ * Parse  a file  and configure the u-boot variables.
+ * The script file has a very simple format, as follows:
+ *
+ * Each line has a couple with name, value:
+ * <white spaces>variable_name<white spaces>variable_value
+ *
+ * Both variable_name and variable_value are interpreted as strings.
+ * Any character after <white spaces> and before ending \r\n is interpreted
+ * as variable's value (no comment allowed on these lines !)
+ *
+ * Comments are allowed if the first character in the line is #
+ *
+ * Returns -1 and sets errno error codes:
+ * 0     - OK
+ * -1     - Error
+ */
+int fw_parse_script(char *fname)
 {
-       int fd, fdr, rc, otherdev, len, resid;
-       erase_info_t erase;
-       char *data = NULL;
-
-       if ((fd = open (DEVNAME (curdev), mode)) < 0) {
-               fprintf (stderr,
-                       "Can't open %s: %s\n",
-                       DEVNAME (curdev), strerror (errno));
-               return (-1);
+       FILE *fp;
+       char dump[1024];        /* Maximum line length in the file */
+       char *name;
+       char *val;
+       int lineno = 0;
+       int len;
+       int ret = 0;
+
+       if (fw_env_open()) {
+               fprintf(stderr, "Error: environment not initialized\n");
+               return -1;
        }
 
-       len = sizeof (environment.crc);
-       if (HaveRedundEnv) {
-               len += sizeof (environment.flags);
+       if (strcmp(fname, "-") == 0)
+               fp = stdin;
+       else {
+               fp = fopen(fname, "r");
+               if (fp == NULL) {
+                       fprintf(stderr, "I cannot open %s for reading\n",
+                                fname);
+                       return -1;
+               }
        }
 
-       if (mode == O_RDWR) {
-               if (HaveRedundEnv) {
-                       /* switch to next partition for writing */
-                       otherdev = !curdev;
-                       if ((fdr = open (DEVNAME (otherdev), mode)) < 0) {
-                               fprintf (stderr,
-                                       "Can't open %s: %s\n",
-                                       DEVNAME (otherdev),
-                                       strerror (errno));
-                               return (-1);
-                       }
-               } else {
-                       otherdev = curdev;
-                       fdr = fd;
+       while (fgets(dump, sizeof(dump), fp)) {
+               lineno++;
+               len = strlen(dump);
+
+               /*
+                * Read a whole line from the file. If the line is too long
+                * or is not terminated, reports an error and exit.
+                */
+               if (dump[len - 1] != '\n') {
+                       fprintf(stderr,
+                       "Line %d not corrected terminated or too long\n",
+                               lineno);
+                       ret = -1;
+                       break;
                }
-               printf ("Unlocking flash...\n");
-               erase.length = DEVESIZE (otherdev);
-               erase.start = DEVOFFSET (otherdev);
-               ioctl (fdr, MEMUNLOCK, &erase);
 
-               if (HaveRedundEnv) {
-                       erase.length = DEVESIZE (curdev);
-                       erase.start = DEVOFFSET (curdev);
-                       ioctl (fd, MEMUNLOCK, &erase);
-                       environment.flags = active_flag;
+               /* Drop ending line feed / carriage return */
+               while (len > 0 && (dump[len - 1] == '\n' ||
+                               dump[len - 1] == '\r')) {
+                       dump[len - 1] = '\0';
+                       len--;
                }
 
-               printf ("Done\n");
-               resid = DEVESIZE (otherdev) - CFG_ENV_SIZE;
-               if (resid) {
-                       if ((data = malloc (resid)) == NULL) {
-                               fprintf (stderr,
-                                       "Cannot malloc %d bytes: %s\n",
-                                       resid,
-                                       strerror (errno));
-                               return (-1);
-                       }
-                       if (lseek (fdr, DEVOFFSET (otherdev) + CFG_ENV_SIZE, SEEK_SET)
-                               == -1) {
-                               fprintf (stderr, "seek error on %s: %s\n",
-                                       DEVNAME (otherdev),
-                                       strerror (errno));
-                               return (-1);
-                       }
-                       if ((rc = read (fdr, data, resid)) != resid) {
-                               fprintf (stderr,
-                                       "read error on %s: %s\n",
-                                       DEVNAME (otherdev),
-                                       strerror (errno));
-                               return (-1);
-                       }
+               /* Skip comment or empty lines */
+               if ((len == 0) || dump[0] == '#')
+                       continue;
+
+               /*
+                * Search for variable's name,
+                * remove leading whitespaces
+                */
+               name = fw_string_blank(dump, 1);
+               if (!name)
+                       continue;
+
+               /* The first white space is the end of variable name */
+               val = fw_string_blank(name, 0);
+               len = strlen(name);
+               if (val) {
+                       *val++ = '\0';
+                       if ((val - name) < len)
+                               val = fw_string_blank(val, 1);
+                       else
+                               val = NULL;
                }
 
-               printf ("Erasing old environment...\n");
+#ifdef DEBUG
+               fprintf(stderr, "Setting %s : %s\n",
+                       name, val ? val : " removed");
+#endif
 
-               erase.length = DEVESIZE (otherdev);
-               erase.start = DEVOFFSET (otherdev);
-               if (ioctl (fdr, MEMERASE, &erase) != 0) {
-                       fprintf (stderr, "MTD erase error on %s: %s\n",
-                               DEVNAME (otherdev),
-                               strerror (errno));
-                       return (-1);
+               if (env_flags_validate_type(name, val) < 0) {
+                       ret = -1;
+                       break;
                }
 
-               printf ("Done\n");
+               /*
+                * If there is an error setting a variable,
+                * try to save the environment and returns an error
+                */
+               if (fw_env_write(name, val)) {
+                       fprintf(stderr,
+                       "fw_env_write returns with error : %s\n",
+                               strerror(errno));
+                       ret = -1;
+                       break;
+               }
 
-               printf ("Writing environment to %s...\n", DEVNAME (otherdev));
-               if (lseek (fdr, DEVOFFSET (otherdev), SEEK_SET) == -1) {
-                       fprintf (stderr,
-                               "seek error on %s: %s\n",
-                               DEVNAME (otherdev), strerror (errno));
-                       return (-1);
+       }
+
+       /* Close file if not stdin */
+       if (strcmp(fname, "-") != 0)
+               fclose(fp);
+
+       ret |= fw_env_close();
+
+       return ret;
+
+}
+
+/*
+ * Test for bad block on NAND, just returns 0 on NOR, on NAND:
+ * 0   - block is good
+ * > 0 - block is bad
+ * < 0 - failed to test
+ */
+static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
+{
+       if (mtd_type == MTD_NANDFLASH) {
+               int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
+
+               if (badblock < 0) {
+                       perror ("Cannot read bad block mark");
+                       return badblock;
                }
-               if (write (fdr, &environment, len) != len) {
+
+               if (badblock) {
+#ifdef DEBUG
+                       fprintf (stderr, "Bad block at 0x%llx, "
+                                "skipping\n", *blockstart);
+#endif
+                       return badblock;
+               }
+       }
+
+       return 0;
+}
+
+/*
+ * Read data from flash at an offset into a provided buffer. On NAND it skips
+ * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
+ * the DEVOFFSET (dev) block. On NOR the loop is only run once.
+ */
+static int flash_read_buf (int dev, int fd, void *buf, size_t count,
+                          off_t offset, uint8_t mtd_type)
+{
+       size_t blocklen;        /* erase / write length - one block on NAND,
+                                  0 on NOR */
+       size_t processed = 0;   /* progress counter */
+       size_t readlen = count; /* current read length */
+       off_t top_of_range;     /* end of the last block we may use */
+       off_t block_seek;       /* offset inside the current block to the start
+                                  of the data */
+       loff_t blockstart;      /* running start of the current block -
+                                  MEMGETBADBLOCK needs 64 bits */
+       int rc;
+
+       blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
+
+       /* Offset inside a block */
+       block_seek = offset - blockstart;
+
+       if (mtd_type == MTD_NANDFLASH) {
+               /*
+                * NAND: calculate which blocks we are reading. We have
+                * to read one block at a time to skip bad blocks.
+                */
+               blocklen = DEVESIZE (dev);
+
+               /*
+                * To calculate the top of the range, we have to use the
+                * global DEVOFFSET (dev), which can be different from offset
+                */
+               top_of_range = ((DEVOFFSET(dev) / blocklen) +
+                               ENVSECTORS (dev)) * blocklen;
+
+               /* Limit to one block for the first read */
+               if (readlen > blocklen - block_seek)
+                       readlen = blocklen - block_seek;
+       } else {
+               blocklen = 0;
+               top_of_range = offset + count;
+       }
+
+       /* This only runs once on NOR flash */
+       while (processed < count) {
+               rc = flash_bad_block (fd, mtd_type, &blockstart);
+               if (rc < 0)             /* block test failed */
+                       return -1;
+
+               if (blockstart + block_seek + readlen > top_of_range) {
+                       /* End of range is reached */
                        fprintf (stderr,
-                               "CRC write error on %s: %s\n",
-                               DEVNAME (otherdev), strerror (errno));
-                       return (-1);
+                                "Too few good blocks within range\n");
+                       return -1;
                }
-               if (write (fdr, environment.data, ENV_SIZE) != ENV_SIZE) {
+
+               if (rc) {               /* block is bad */
+                       blockstart += blocklen;
+                       continue;
+               }
+
+               /*
+                * If a block is bad, we retry in the next block at the same
+                * offset - see common/env_nand.c::writeenv()
+                */
+               lseek (fd, blockstart + block_seek, SEEK_SET);
+
+               rc = read (fd, buf + processed, readlen);
+               if (rc != readlen) {
+                       fprintf (stderr, "Read error on %s: %s\n",
+                                DEVNAME (dev), strerror (errno));
+                       return -1;
+               }
+#ifdef DEBUG
+               fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
+                        rc, blockstart + block_seek, DEVNAME(dev));
+#endif
+               processed += readlen;
+               readlen = min (blocklen, count - processed);
+               block_seek = 0;
+               blockstart += blocklen;
+       }
+
+       return processed;
+}
+
+/*
+ * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
+ * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
+ * erase and write the whole data at once.
+ */
+static int flash_write_buf (int dev, int fd, void *buf, size_t count,
+                           off_t offset, uint8_t mtd_type)
+{
+       void *data;
+       struct erase_info_user erase;
+       size_t blocklen;        /* length of NAND block / NOR erase sector */
+       size_t erase_len;       /* whole area that can be erased - may include
+                                  bad blocks */
+       size_t erasesize;       /* erase / write length - one block on NAND,
+                                  whole area on NOR */
+       size_t processed = 0;   /* progress counter */
+       size_t write_total;     /* total size to actually write - excluding
+                                  bad blocks */
+       off_t erase_offset;     /* offset to the first erase block (aligned)
+                                  below offset */
+       off_t block_seek;       /* offset inside the erase block to the start
+                                  of the data */
+       off_t top_of_range;     /* end of the last block we may use */
+       loff_t blockstart;      /* running start of the current block -
+                                  MEMGETBADBLOCK needs 64 bits */
+       int rc;
+
+       blocklen = DEVESIZE (dev);
+
+       top_of_range = ((DEVOFFSET(dev) / blocklen) +
+                                       ENVSECTORS (dev)) * blocklen;
+
+       erase_offset = (offset / blocklen) * blocklen;
+
+       /* Maximum area we may use */
+       erase_len = top_of_range - erase_offset;
+
+       blockstart = erase_offset;
+       /* Offset inside a block */
+       block_seek = offset - erase_offset;
+
+       /*
+        * Data size we actually have to write: from the start of the block
+        * to the start of the data, then count bytes of data, and to the
+        * end of the block
+        */
+       write_total = ((block_seek + count + blocklen - 1) /
+                                               blocklen) * blocklen;
+
+       /*
+        * Support data anywhere within erase sectors: read out the complete
+        * area to be erased, replace the environment image, write the whole
+        * block back again.
+        */
+       if (write_total > count) {
+               data = malloc (erase_len);
+               if (!data) {
                        fprintf (stderr,
-                               "Write error on %s: %s\n",
-                               DEVNAME (otherdev), strerror (errno));
-                       return (-1);
+                                "Cannot malloc %zu bytes: %s\n",
+                                erase_len, strerror (errno));
+                       return -1;
                }
-               if (resid) {
-                       if (write (fdr, data, resid) != resid) {
-                               fprintf (stderr,
-                                       "write error on %s: %s\n",
-                                       DEVNAME (curdev), strerror (errno));
-                               return (-1);
+
+               rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
+                                    mtd_type);
+               if (write_total != rc)
+                       return -1;
+
+#ifdef DEBUG
+               fprintf(stderr, "Preserving data ");
+               if (block_seek != 0)
+                       fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
+               if (block_seek + count != write_total) {
+                       if (block_seek != 0)
+                               fprintf(stderr, " and ");
+                       fprintf(stderr, "0x%lx - 0x%x",
+                               block_seek + count, write_total - 1);
+               }
+               fprintf(stderr, "\n");
+#endif
+               /* Overwrite the old environment */
+               memcpy (data + block_seek, buf, count);
+       } else {
+               /*
+                * We get here, iff offset is block-aligned and count is a
+                * multiple of blocklen - see write_total calculation above
+                */
+               data = buf;
+       }
+
+       if (mtd_type == MTD_NANDFLASH) {
+               /*
+                * NAND: calculate which blocks we are writing. We have
+                * to write one block at a time to skip bad blocks.
+                */
+               erasesize = blocklen;
+       } else {
+               erasesize = erase_len;
+       }
+
+       erase.length = erasesize;
+
+       /* This only runs once on NOR flash and SPI-dataflash */
+       while (processed < write_total) {
+               rc = flash_bad_block (fd, mtd_type, &blockstart);
+               if (rc < 0)             /* block test failed */
+                       return rc;
+
+               if (blockstart + erasesize > top_of_range) {
+                       fprintf (stderr, "End of range reached, aborting\n");
+                       return -1;
+               }
+
+               if (rc) {               /* block is bad */
+                       blockstart += blocklen;
+                       continue;
+               }
+
+               erase.start = blockstart;
+               ioctl (fd, MEMUNLOCK, &erase);
+
+               /* Dataflash does not need an explicit erase cycle */
+               if (mtd_type != MTD_DATAFLASH)
+                       if (ioctl (fd, MEMERASE, &erase) != 0) {
+                               fprintf (stderr, "MTD erase error on %s: %s\n",
+                                        DEVNAME (dev),
+                                        strerror (errno));
+                               return -1;
                        }
-                       free (data);
+
+               if (lseek (fd, blockstart, SEEK_SET) == -1) {
+                       fprintf (stderr,
+                                "Seek error on %s: %s\n",
+                                DEVNAME (dev), strerror (errno));
+                       return -1;
+               }
+
+#ifdef DEBUG
+               fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
+                       blockstart);
+#endif
+               if (write (fd, data + processed, erasesize) != erasesize) {
+                       fprintf (stderr, "Write error on %s: %s\n",
+                                DEVNAME (dev), strerror (errno));
+                       return -1;
                }
+
+               ioctl (fd, MEMLOCK, &erase);
+
+               processed  += blocklen;
+               block_seek = 0;
+               blockstart += blocklen;
+       }
+
+       if (write_total > count)
+               free (data);
+
+       return processed;
+}
+
+/*
+ * Set obsolete flag at offset - NOR flash only
+ */
+static int flash_flag_obsolete (int dev, int fd, off_t offset)
+{
+       int rc;
+       struct erase_info_user erase;
+
+       erase.start  = DEVOFFSET (dev);
+       erase.length = DEVESIZE (dev);
+       /* This relies on the fact, that obsolete_flag == 0 */
+       rc = lseek (fd, offset, SEEK_SET);
+       if (rc < 0) {
+               fprintf (stderr, "Cannot seek to set the flag on %s \n",
+                        DEVNAME (dev));
+               return rc;
+       }
+       ioctl (fd, MEMUNLOCK, &erase);
+       rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
+       ioctl (fd, MEMLOCK, &erase);
+       if (rc < 0)
+               perror ("Could not set obsolete flag");
+
+       return rc;
+}
+
+static int flash_write (int fd_current, int fd_target, int dev_target)
+{
+       int rc;
+
+       switch (environment.flag_scheme) {
+       case FLAG_NONE:
+               break;
+       case FLAG_INCREMENTAL:
+               (*environment.flags)++;
+               break;
+       case FLAG_BOOLEAN:
+               *environment.flags = active_flag;
+               break;
+       default:
+               fprintf (stderr, "Unimplemented flash scheme %u \n",
+                        environment.flag_scheme);
+               return -1;
+       }
+
+#ifdef DEBUG
+       fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
+               DEVOFFSET (dev_target), DEVNAME (dev_target));
+#endif
+       rc = flash_write_buf(dev_target, fd_target, environment.image,
+                             CUR_ENVSIZE, DEVOFFSET(dev_target),
+                             DEVTYPE(dev_target));
+       if (rc < 0)
+               return rc;
+
+       if (environment.flag_scheme == FLAG_BOOLEAN) {
+               /* Have to set obsolete flag */
+               off_t offset = DEVOFFSET (dev_current) +
+                       offsetof (struct env_image_redundant, flags);
+#ifdef DEBUG
+               fprintf(stderr,
+                       "Setting obsolete flag in environment at 0x%lx on %s\n",
+                       DEVOFFSET (dev_current), DEVNAME (dev_current));
+#endif
+               flash_flag_obsolete (dev_current, fd_current, offset);
+       }
+
+       return 0;
+}
+
+static int flash_read (int fd)
+{
+       struct mtd_info_user mtdinfo;
+       int rc;
+
+       rc = ioctl (fd, MEMGETINFO, &mtdinfo);
+       if (rc < 0) {
+               perror ("Cannot get MTD information");
+               return -1;
+       }
+
+       if (mtdinfo.type != MTD_NORFLASH &&
+           mtdinfo.type != MTD_NANDFLASH &&
+           mtdinfo.type != MTD_DATAFLASH) {
+               fprintf (stderr, "Unsupported flash type %u\n", mtdinfo.type);
+               return -1;
+       }
+
+       DEVTYPE(dev_current) = mtdinfo.type;
+
+       rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
+                            DEVOFFSET (dev_current), mtdinfo.type);
+
+       return (rc != CUR_ENVSIZE) ? -1 : 0;
+}
+
+static int flash_io (int mode)
+{
+       int fd_current, fd_target, rc, dev_target;
+
+       /* dev_current: fd_current, erase_current */
+       fd_current = open (DEVNAME (dev_current), mode);
+       if (fd_current < 0) {
+               fprintf (stderr,
+                        "Can't open %s: %s\n",
+                        DEVNAME (dev_current), strerror (errno));
+               return -1;
+       }
+
+       if (mode == O_RDWR) {
                if (HaveRedundEnv) {
-                       /* change flag on current active env partition */
-                       if (lseek (fd, DEVOFFSET (curdev) + sizeof (ulong), SEEK_SET)
-                               == -1) {
-                               fprintf (stderr, "seek error on %s: %s\n",
-                                       DEVNAME (curdev), strerror (errno));
-                               return (-1);
-                       }
-                       if (write (fd, &obsolete_flag, sizeof (obsolete_flag)) !=
-                               sizeof (obsolete_flag)) {
+                       /* switch to next partition for writing */
+                       dev_target = !dev_current;
+                       /* dev_target: fd_target, erase_target */
+                       fd_target = open (DEVNAME (dev_target), mode);
+                       if (fd_target < 0) {
                                fprintf (stderr,
-                                       "Write error on %s: %s\n",
-                                       DEVNAME (curdev), strerror (errno));
-                               return (-1);
+                                        "Can't open %s: %s\n",
+                                        DEVNAME (dev_target),
+                                        strerror (errno));
+                               rc = -1;
+                               goto exit;
                        }
+               } else {
+                       dev_target = dev_current;
+                       fd_target = fd_current;
                }
-               printf ("Done\n");
-               printf ("Locking ...\n");
-               erase.length = DEVESIZE (otherdev);
-               erase.start = DEVOFFSET (otherdev);
-               ioctl (fdr, MEMLOCK, &erase);
+
+               rc = flash_write (fd_current, fd_target, dev_target);
+
                if (HaveRedundEnv) {
-                       erase.length = DEVESIZE (curdev);
-                       erase.start = DEVOFFSET (curdev);
-                       ioctl (fd, MEMLOCK, &erase);
-                       if (close (fdr)) {
+                       if (close (fd_target)) {
                                fprintf (stderr,
                                        "I/O error on %s: %s\n",
-                                       DEVNAME (otherdev),
+                                       DEVNAME (dev_target),
                                        strerror (errno));
-                               return (-1);
+                               rc = -1;
                        }
                }
-               printf ("Done\n");
        } else {
-
-               if (lseek (fd, DEVOFFSET (curdev), SEEK_SET) == -1) {
-                       fprintf (stderr,
-                               "seek error on %s: %s\n",
-                               DEVNAME (curdev), strerror (errno));
-                       return (-1);
-               }
-               if (read (fd, &environment, len) != len) {
-                       fprintf (stderr,
-                               "CRC read error on %s: %s\n",
-                               DEVNAME (curdev), strerror (errno));
-                       return (-1);
-               }
-               if ((rc = read (fd, environment.data, ENV_SIZE)) != ENV_SIZE) {
-                       fprintf (stderr,
-                               "Read error on %s: %s\n",
-                               DEVNAME (curdev), strerror (errno));
-                       return (-1);
-               }
+               rc = flash_read (fd_current);
        }
 
-       if (close (fd)) {
+exit:
+       if (close (fd_current)) {
                fprintf (stderr,
-                       "I/O error on %s: %s\n",
-                       DEVNAME (curdev), strerror (errno));
-               return (-1);
+                        "I/O error on %s: %s\n",
+                        DEVNAME (dev_current), strerror (errno));
+               return -1;
        }
 
-       /* everything ok */
-       return (0);
+       return rc;
 }
 
 /*
@@ -569,124 +1036,179 @@ static int flash_io (int mode)
  * If the names match, return the value of s2, else NULL.
  */
 
-static uchar *envmatch (uchar * s1, uchar * s2)
+static char *envmatch (char * s1, char * s2)
 {
+       if (s1 == NULL || s2 == NULL)
+               return NULL;
 
        while (*s1 == *s2++)
                if (*s1++ == '=')
-                       return (s2);
+                       return s2;
        if (*s1 == '\0' && *(s2 - 1) == '=')
-               return (s2);
-       return (NULL);
+               return s2;
+       return NULL;
 }
 
 /*
  * Prevent confusion if running from erased flash memory
  */
-static int env_init (void)
+int fw_env_open(void)
 {
+       int crc0, crc0_ok;
+       unsigned char flag0;
+       void *addr0;
+
        int crc1, crc1_ok;
-       uchar *addr1;
+       unsigned char flag1;
+       void *addr1;
 
-       int crc2, crc2_ok;
-       uchar flag1, flag2, *addr2;
+       struct env_image_single *single;
+       struct env_image_redundant *redundant;
 
        if (parse_config ())            /* should fill envdevices */
-               return 1;
+               return -1;
 
-       if ((addr1 = calloc (1, ENV_SIZE)) == NULL) {
-               fprintf (stderr,
+       addr0 = calloc(1, CUR_ENVSIZE);
+       if (addr0 == NULL) {
+               fprintf(stderr,
                        "Not enough memory for environment (%ld bytes)\n",
-                       ENV_SIZE);
-               return (errno);
+                       CUR_ENVSIZE);
+               return -1;
        }
 
        /* read environment from FLASH to local buffer */
-       environment.data = addr1;
-       curdev = 0;
-       if (flash_io (O_RDONLY)) {
-               return (errno);
+       environment.image = addr0;
+
+       if (HaveRedundEnv) {
+               redundant = addr0;
+               environment.crc         = &redundant->crc;
+               environment.flags       = &redundant->flags;
+               environment.data        = redundant->data;
+       } else {
+               single = addr0;
+               environment.crc         = &single->crc;
+               environment.flags       = NULL;
+               environment.data        = single->data;
        }
 
-       crc1_ok = ((crc1 = crc32 (0, environment.data, ENV_SIZE))
-                          == environment.crc);
+       dev_current = 0;
+       if (flash_io (O_RDONLY))
+               return -1;
+
+       crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
+       crc0_ok = (crc0 == *environment.crc);
        if (!HaveRedundEnv) {
-               if (!crc1_ok) {
+               if (!crc0_ok) {
                        fprintf (stderr,
                                "Warning: Bad CRC, using default environment\n");
                        memcpy(environment.data, default_environment, sizeof default_environment);
                }
        } else {
-               flag1 = environment.flags;
+               flag0 = *environment.flags;
 
-               curdev = 1;
-               if ((addr2 = calloc (1, ENV_SIZE)) == NULL) {
-                       fprintf (stderr,
+               dev_current = 1;
+               addr1 = calloc(1, CUR_ENVSIZE);
+               if (addr1 == NULL) {
+                       fprintf(stderr,
                                "Not enough memory for environment (%ld bytes)\n",
-                               ENV_SIZE);
-                       return (errno);
-               }
-               environment.data = addr2;
-
-               if (flash_io (O_RDONLY)) {
-                       return (errno);
-               }
-
-               crc2_ok = ((crc2 = crc32 (0, environment.data, ENV_SIZE))
-                                  == environment.crc);
-               flag2 = environment.flags;
-
-               if (crc1_ok && !crc2_ok) {
-                       environment.data = addr1;
-                       environment.flags = flag1;
-                       environment.crc = crc1;
-                       curdev = 0;
-                       free (addr2);
-               } else if (!crc1_ok && crc2_ok) {
-                       environment.data = addr2;
-                       environment.flags = flag2;
-                       environment.crc = crc2;
-                       curdev = 1;
-                       free (addr1);
-               } else if (!crc1_ok && !crc2_ok) {
+                               CUR_ENVSIZE);
+                       return -1;
+               }
+               redundant = addr1;
+
+               /*
+                * have to set environment.image for flash_read(), careful -
+                * other pointers in environment still point inside addr0
+                */
+               environment.image = addr1;
+               if (flash_io (O_RDONLY))
+                       return -1;
+
+               /* Check flag scheme compatibility */
+               if (DEVTYPE(dev_current) == MTD_NORFLASH &&
+                   DEVTYPE(!dev_current) == MTD_NORFLASH) {
+                       environment.flag_scheme = FLAG_BOOLEAN;
+               } else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
+                          DEVTYPE(!dev_current) == MTD_NANDFLASH) {
+                       environment.flag_scheme = FLAG_INCREMENTAL;
+               } else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
+                          DEVTYPE(!dev_current) == MTD_DATAFLASH) {
+                       environment.flag_scheme = FLAG_BOOLEAN;
+               } else {
+                       fprintf (stderr, "Incompatible flash types!\n");
+                       return -1;
+               }
+
+               crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
+               crc1_ok = (crc1 == redundant->crc);
+               flag1 = redundant->flags;
+
+               if (crc0_ok && !crc1_ok) {
+                       dev_current = 0;
+               } else if (!crc0_ok && crc1_ok) {
+                       dev_current = 1;
+               } else if (!crc0_ok && !crc1_ok) {
                        fprintf (stderr,
                                "Warning: Bad CRC, using default environment\n");
-                       memcpy(environment.data, default_environment, sizeof default_environment);
-                       curdev = 0;
-                       free (addr1);
-               } else if (flag1 == active_flag && flag2 == obsolete_flag) {
-                       environment.data = addr1;
-                       environment.flags = flag1;
-                       environment.crc = crc1;
-                       curdev = 0;
-                       free (addr2);
-               } else if (flag1 == obsolete_flag && flag2 == active_flag) {
-                       environment.data = addr2;
-                       environment.flags = flag2;
-                       environment.crc = crc2;
-                       curdev = 1;
-                       free (addr1);
-               } else if (flag1 == flag2) {
-                       environment.data = addr1;
-                       environment.flags = flag1;
-                       environment.crc = crc1;
-                       curdev = 0;
-                       free (addr2);
-               } else if (flag1 == 0xFF) {
-                       environment.data = addr1;
-                       environment.flags = flag1;
-                       environment.crc = crc1;
-                       curdev = 0;
-                       free (addr2);
-               } else if (flag2 == 0xFF) {
-                       environment.data = addr2;
-                       environment.flags = flag2;
-                       environment.crc = crc2;
-                       curdev = 1;
+                       memcpy (environment.data, default_environment,
+                               sizeof default_environment);
+                       dev_current = 0;
+               } else {
+                       switch (environment.flag_scheme) {
+                       case FLAG_BOOLEAN:
+                               if (flag0 == active_flag &&
+                                   flag1 == obsolete_flag) {
+                                       dev_current = 0;
+                               } else if (flag0 == obsolete_flag &&
+                                          flag1 == active_flag) {
+                                       dev_current = 1;
+                               } else if (flag0 == flag1) {
+                                       dev_current = 0;
+                               } else if (flag0 == 0xFF) {
+                                       dev_current = 0;
+                               } else if (flag1 == 0xFF) {
+                                       dev_current = 1;
+                               } else {
+                                       dev_current = 0;
+                               }
+                               break;
+                       case FLAG_INCREMENTAL:
+                               if (flag0 == 255 && flag1 == 0)
+                                       dev_current = 1;
+                               else if ((flag1 == 255 && flag0 == 0) ||
+                                        flag0 >= flag1)
+                                       dev_current = 0;
+                               else /* flag1 > flag0 */
+                                       dev_current = 1;
+                               break;
+                       default:
+                               fprintf (stderr, "Unknown flag scheme %u \n",
+                                        environment.flag_scheme);
+                               return -1;
+                       }
+               }
+
+               /*
+                * If we are reading, we don't need the flag and the CRC any
+                * more, if we are writing, we will re-calculate CRC and update
+                * flags before writing out
+                */
+               if (dev_current) {
+                       environment.image       = addr1;
+                       environment.crc         = &redundant->crc;
+                       environment.flags       = &redundant->flags;
+                       environment.data        = redundant->data;
+                       free (addr0);
+               } else {
+                       environment.image       = addr0;
+                       /* Other pointers are already set */
                        free (addr1);
                }
+#ifdef DEBUG
+               fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
+#endif
        }
-       return (0);
+       return 0;
 }
 
 
@@ -699,18 +1221,35 @@ static int parse_config ()
        if (get_config (CONFIG_FILE)) {
                fprintf (stderr,
                        "Cannot parse config file: %s\n", strerror (errno));
-               return 1;
+               return -1;
        }
 #else
        strcpy (DEVNAME (0), DEVICE1_NAME);
        DEVOFFSET (0) = DEVICE1_OFFSET;
        ENVSIZE (0) = ENV1_SIZE;
+       /* Default values are: erase-size=env-size, #sectors=1 */
+       DEVESIZE (0) = ENVSIZE (0);
+       ENVSECTORS (0) = 1;
+#ifdef DEVICE1_ESIZE
        DEVESIZE (0) = DEVICE1_ESIZE;
+#endif
+#ifdef DEVICE1_ENVSECTORS
+       ENVSECTORS (0) = DEVICE1_ENVSECTORS;
+#endif
+
 #ifdef HAVE_REDUND
        strcpy (DEVNAME (1), DEVICE2_NAME);
        DEVOFFSET (1) = DEVICE2_OFFSET;
        ENVSIZE (1) = ENV2_SIZE;
+       /* Default values are: erase-size=env-size, #sectors=1 */
+       DEVESIZE (1) = ENVSIZE (1);
+       ENVSECTORS (1) = 1;
+#ifdef DEVICE2_ESIZE
        DEVESIZE (1) = DEVICE2_ESIZE;
+#endif
+#ifdef DEVICE2_ENVSECTORS
+       ENVSECTORS (1) = DEVICE2_ENVSECTORS;
+#endif
        HaveRedundEnv = 1;
 #endif
 #endif
@@ -718,14 +1257,14 @@ static int parse_config ()
                fprintf (stderr,
                        "Cannot access MTD device %s: %s\n",
                        DEVNAME (0), strerror (errno));
-               return 1;
+               return -1;
        }
 
        if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
                fprintf (stderr,
                        "Cannot access MTD device %s: %s\n",
                        DEVNAME (1), strerror (errno));
-               return 1;
+               return -1;
        }
        return 0;
 }
@@ -738,21 +1277,32 @@ static int get_config (char *fname)
        int rc;
        char dump[128];
 
-       if ((fp = fopen (fname, "r")) == NULL) {
-               return 1;
-       }
-
-       while ((i < 2) && ((rc = fscanf (fp, "%s %lx %lx %lx",
-                                 DEVNAME (i),
-                                 &DEVOFFSET (i),
-                                 &ENVSIZE (i),
-                                 &DEVESIZE (i)  )) != EOF)) {
+       fp = fopen (fname, "r");
+       if (fp == NULL)
+               return -1;
 
+       while (i < 2 && fgets (dump, sizeof (dump), fp)) {
                /* Skip incomplete conversions and comment strings */
-               if ((rc < 3) || (*DEVNAME (i) == '#')) {
-                       fgets (dump, sizeof (dump), fp);        /* Consume till end */
+               if (dump[0] == '#')
                        continue;
-               }
+
+               rc = sscanf (dump, "%s %lx %lx %lx %lx",
+                            DEVNAME (i),
+                            &DEVOFFSET (i),
+                            &ENVSIZE (i),
+                            &DEVESIZE (i),
+                            &ENVSECTORS (i));
+
+               if (rc < 3)
+                       continue;
+
+               if (rc < 4)
+                       /* Assume the erase size is the same as the env-size */
+                       DEVESIZE(i) = ENVSIZE(i);
+
+               if (rc < 5)
+                       /* Default - 1 sector */
+                       ENVSECTORS (i) = 1;
 
                i++;
        }
@@ -761,7 +1311,7 @@ static int get_config (char *fname)
        HaveRedundEnv = i - 1;
        if (!i) {                       /* No valid entries found */
                errno = EINVAL;
-               return 1;
+               return -1;
        } else
                return 0;
 }