arc: introduce U-Boot port for ARCv2 ISA

[people/ms/u-boot.git] / common / cmd_mtdparts.c

/*
 * (C) Copyright 2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2002
 * Robert Schwebel, Pengutronix, <r.schwebel@pengutronix.de>
 *
 * (C) Copyright 2003
 * Kai-Uwe Bloem, Auerswald GmbH & Co KG, <linux-development@auerswald.de>
 *
 * (C) Copyright 2005
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 *   Added support for reading flash partition table from environment.
 *   Parsing routines are based on driver/mtd/cmdline.c from the linux 2.4
 *   kernel tree.
 *
 * (C) Copyright 2008
 * Harald Welte, OpenMoko, Inc., Harald Welte <laforge@openmoko.org>
 *
 *   $Id: cmdlinepart.c,v 1.17 2004/11/26 11:18:47 lavinen Exp $
 *   Copyright 2002 SYSGO Real-Time Solutions GmbH
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

/*
 * Three environment variables are used by the parsing routines:
 *
 * 'partition' - keeps current partition identifier
 *
 * partition  := <part-id>
 * <part-id>  := <dev-id>,part_num
 *
 *
 * 'mtdids' - linux kernel mtd device id <-> u-boot device id mapping
 *
 * mtdids=<idmap>[,<idmap>,...]
 *
 * <idmap>    := <dev-id>=<mtd-id>
 * <dev-id>   := 'nand'|'nor'|'onenand'<dev-num>
 * <dev-num>  := mtd device number, 0...
 * <mtd-id>   := unique device tag used by linux kernel to find mtd device (mtd->name)
 *
 *
 * 'mtdparts' - partition list
 *
 * mtdparts=mtdparts=<mtd-def>[;<mtd-def>...]
 *
 * <mtd-def>  := <mtd-id>:<part-def>[,<part-def>...]
 * <mtd-id>   := unique device tag used by linux kernel to find mtd device (mtd->name)
 * <part-def> := <size>[@<offset>][<name>][<ro-flag>]
 * <size>     := standard linux memsize OR '-' to denote all remaining space
 * <offset>   := partition start offset within the device
 * <name>     := '(' NAME ')'
 * <ro-flag>  := when set to 'ro' makes partition read-only (not used, passed to kernel)
 *
 * Notes:
 * - each <mtd-id> used in mtdparts must albo exist in 'mtddis' mapping
 * - if the above variables are not set defaults for a given target are used
 *
 * Examples:
 *
 * 1 NOR Flash, with 1 single writable partition:
 * mtdids=nor0=edb7312-nor
 * mtdparts=mtdparts=edb7312-nor:-
 *
 * 1 NOR Flash with 2 partitions, 1 NAND with one
 * mtdids=nor0=edb7312-nor,nand0=edb7312-nand
 * mtdparts=mtdparts=edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
 *
 */

#include <common.h>
#include <command.h>
#include <malloc.h>
#include <jffs2/load_kernel.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/mtd/mtd.h>

#if defined(CONFIG_CMD_NAND)
#include <linux/mtd/nand.h>
#include <nand.h>
#endif

#if defined(CONFIG_CMD_ONENAND)
#include <linux/mtd/onenand.h>
#include <onenand_uboot.h>
#endif

DECLARE_GLOBAL_DATA_PTR;

/* special size referring to all the remaining space in a partition */
#define SIZE_REMAINING          (~0llu)

/* special offset value, it is used when not provided by user
 *
 * this value is used temporarily during parsing, later such offests
 * are recalculated */
#define OFFSET_NOT_SPECIFIED    (~0llu)

/* minimum partition size */
#define MIN_PART_SIZE           4096

/* this flag needs to be set in part_info struct mask_flags
 * field for read-only partitions */
#define MTD_WRITEABLE_CMD               1

/* default values for mtdids and mtdparts variables */
#if defined(MTDIDS_DEFAULT)
static const char *const mtdids_default = MTDIDS_DEFAULT;
#else
static const char *const mtdids_default = NULL;
#endif

#if defined(MTDPARTS_DEFAULT)
static const char *const mtdparts_default = MTDPARTS_DEFAULT;
#else
static const char *const mtdparts_default = NULL;
#endif

/* copies of last seen 'mtdids', 'mtdparts' and 'partition' env variables */
#define MTDIDS_MAXLEN           128
#define MTDPARTS_MAXLEN         512
#define PARTITION_MAXLEN        16
static char last_ids[MTDIDS_MAXLEN];
static char last_parts[MTDPARTS_MAXLEN];
static char last_partition[PARTITION_MAXLEN];

/* low level jffs2 cache cleaning routine */
extern void jffs2_free_cache(struct part_info *part);

/* mtdids mapping list, filled by parse_ids() */
static struct list_head mtdids;

/* device/partition list, parse_cmdline() parses into here */
static struct list_head devices;

/* current active device and partition number */
struct mtd_device *current_mtd_dev = NULL;
u8 current_mtd_partnum = 0;

static struct part_info* mtd_part_info(struct mtd_device *dev, unsigned int part_num);

/* command line only routines */
static struct mtdids* id_find_by_mtd_id(const char *mtd_id, unsigned int mtd_id_len);
static int device_del(struct mtd_device *dev);

/**
 * Parses a string into a number.  The number stored at ptr is
 * potentially suffixed with K (for kilobytes, or 1024 bytes),
 * M (for megabytes, or 1048576 bytes), or G (for gigabytes, or
 * 1073741824).  If the number is suffixed with K, M, or G, then
 * the return value is the number multiplied by one kilobyte, one
 * megabyte, or one gigabyte, respectively.
 *
 * @param ptr where parse begins
 * @param retptr output pointer to next char after parse completes (output)
 * @return resulting unsigned int
 */
static u64 memsize_parse (const char *const ptr, const char **retptr)
{
        u64 ret = simple_strtoull(ptr, (char **)retptr, 0);

        switch (**retptr) {
                case 'G':
                case 'g':
                        ret <<= 10;
                case 'M':
                case 'm':
                        ret <<= 10;
                case 'K':
                case 'k':
                        ret <<= 10;
                        (*retptr)++;
                default:
                        break;
        }

        return ret;
}

/**
 * Format string describing supplied size. This routine does the opposite job
 * to memsize_parse(). Size in bytes is converted to string and if possible
 * shortened by using k (kilobytes), m (megabytes) or g (gigabytes) suffix.
 *
 * Note, that this routine does not check for buffer overflow, it's the caller
 * who must assure enough space.
 *
 * @param buf output buffer
 * @param size size to be converted to string
 */
static void memsize_format(char *buf, u64 size)
{
#define SIZE_GB ((u32)1024*1024*1024)
#define SIZE_MB ((u32)1024*1024)
#define SIZE_KB ((u32)1024)

        if ((size % SIZE_GB) == 0)
                sprintf(buf, "%llug", size/SIZE_GB);
        else if ((size % SIZE_MB) == 0)
                sprintf(buf, "%llum", size/SIZE_MB);
        else if (size % SIZE_KB == 0)
                sprintf(buf, "%lluk", size/SIZE_KB);
        else
                sprintf(buf, "%llu", size);
}

/**
 * This routine does global indexing of all partitions. Resulting index for
 * current partition is saved in 'mtddevnum'. Current partition name in
 * 'mtddevname'.
 */
static void index_partitions(void)
{
        u16 mtddevnum;
        struct part_info *part;
        struct list_head *dentry;
        struct mtd_device *dev;

        debug("--- index partitions ---\n");

        if (current_mtd_dev) {
                mtddevnum = 0;
                list_for_each(dentry, &devices) {
                        dev = list_entry(dentry, struct mtd_device, link);
                        if (dev == current_mtd_dev) {
                                mtddevnum += current_mtd_partnum;
                                setenv_ulong("mtddevnum", mtddevnum);
                                break;
                        }
                        mtddevnum += dev->num_parts;
                }

                part = mtd_part_info(current_mtd_dev, current_mtd_partnum);
                setenv("mtddevname", part->name);

                debug("=> mtddevnum %d,\n=> mtddevname %s\n", mtddevnum, part->name);
        } else {
                setenv("mtddevnum", NULL);
                setenv("mtddevname", NULL);

                debug("=> mtddevnum NULL\n=> mtddevname NULL\n");
        }
}

/**
 * Save current device and partition in environment variable 'partition'.
 */
static void current_save(void)
{
        char buf[16];

        debug("--- current_save ---\n");

        if (current_mtd_dev) {
                sprintf(buf, "%s%d,%d", MTD_DEV_TYPE(current_mtd_dev->id->type),
                                        current_mtd_dev->id->num, current_mtd_partnum);

                setenv("partition", buf);
                strncpy(last_partition, buf, 16);

                debug("=> partition %s\n", buf);
        } else {
                setenv("partition", NULL);
                last_partition[0] = '\0';

                debug("=> partition NULL\n");
        }
        index_partitions();
}


/**
 * Produce a mtd_info given a type and num.
 *
 * @param type mtd type
 * @param num mtd number
 * @param mtd a pointer to an mtd_info instance (output)
 * @return 0 if device is valid, 1 otherwise
 */
static int get_mtd_info(u8 type, u8 num, struct mtd_info **mtd)
{
        char mtd_dev[16];

        sprintf(mtd_dev, "%s%d", MTD_DEV_TYPE(type), num);
        *mtd = get_mtd_device_nm(mtd_dev);
        if (IS_ERR(*mtd)) {
                printf("Device %s not found!\n", mtd_dev);
                return 1;
        }
        put_mtd_device(*mtd);

        return 0;
}

/**
 * Performs sanity check for supplied flash partition.
 * Table of existing MTD flash devices is searched and partition device
 * is located. Alignment with the granularity of nand erasesize is verified.
 *
 * @param id of the parent device
 * @param part partition to validate
 * @return 0 if partition is valid, 1 otherwise
 */
static int part_validate_eraseblock(struct mtdids *id, struct part_info *part)
{
        struct mtd_info *mtd = NULL;
        int i, j;
        ulong start;
        u64 offset, size;

        if (get_mtd_info(id->type, id->num, &mtd))
                return 1;

        part->sector_size = mtd->erasesize;

        if (!mtd->numeraseregions) {
                /*
                 * Only one eraseregion (NAND, OneNAND or uniform NOR),
                 * checking for alignment is easy here
                 */
                offset = part->offset;
                if (do_div(offset, mtd->erasesize)) {
                        printf("%s%d: partition (%s) start offset"
                               "alignment incorrect\n",
                               MTD_DEV_TYPE(id->type), id->num, part->name);
                        return 1;
                }

                size = part->size;
                if (do_div(size, mtd->erasesize)) {
                        printf("%s%d: partition (%s) size alignment incorrect\n",
                               MTD_DEV_TYPE(id->type), id->num, part->name);
                        return 1;
                }
        } else {
                /*
                 * Multiple eraseregions (non-uniform NOR),
                 * checking for alignment is more complex here
                 */

                /* Check start alignment */
                for (i = 0; i < mtd->numeraseregions; i++) {
                        start = mtd->eraseregions[i].offset;
                        for (j = 0; j < mtd->eraseregions[i].numblocks; j++) {
                                if (part->offset == start)
                                        goto start_ok;
                                start += mtd->eraseregions[i].erasesize;
                        }
                }

                printf("%s%d: partition (%s) start offset alignment incorrect\n",
                       MTD_DEV_TYPE(id->type), id->num, part->name);
                return 1;

        start_ok:

                /* Check end/size alignment */
                for (i = 0; i < mtd->numeraseregions; i++) {
                        start = mtd->eraseregions[i].offset;
                        for (j = 0; j < mtd->eraseregions[i].numblocks; j++) {
                                if ((part->offset + part->size) == start)
                                        goto end_ok;
                                start += mtd->eraseregions[i].erasesize;
                        }
                }
                /* Check last sector alignment */
                if ((part->offset + part->size) == start)
                        goto end_ok;

                printf("%s%d: partition (%s) size alignment incorrect\n",
                       MTD_DEV_TYPE(id->type), id->num, part->name);
                return 1;

        end_ok:
                return 0;
        }

        return 0;
}


/**
 * Performs sanity check for supplied partition. Offset and size are
 * verified to be within valid range. Partition type is checked and
 * part_validate_eraseblock() is called with the argument of part.
 *
 * @param id of the parent device
 * @param part partition to validate
 * @return 0 if partition is valid, 1 otherwise
 */
static int part_validate(struct mtdids *id, struct part_info *part)
{
        if (part->size == SIZE_REMAINING)
                part->size = id->size - part->offset;

        if (part->offset > id->size) {
                printf("%s: offset %08llx beyond flash size %08llx\n",
                                id->mtd_id, part->offset, id->size);
                return 1;
        }

        if ((part->offset + part->size) <= part->offset) {
                printf("%s%d: partition (%s) size too big\n",
                                MTD_DEV_TYPE(id->type), id->num, part->name);
                return 1;
        }

        if (part->offset + part->size > id->size) {
                printf("%s: partitioning exceeds flash size\n", id->mtd_id);
                return 1;
        }

        /*
         * Now we need to check if the partition starts and ends on
         * sector (eraseblock) regions
         */
        return part_validate_eraseblock(id, part);
}

/**
 * Delete selected partition from the partition list of the specified device.
 *
 * @param dev device to delete partition from
 * @param part partition to delete
 * @return 0 on success, 1 otherwise
 */
static int part_del(struct mtd_device *dev, struct part_info *part)
{
        u8 current_save_needed = 0;

        /* if there is only one partition, remove whole device */
        if (dev->num_parts == 1)
                return device_del(dev);

        /* otherwise just delete this partition */

        if (dev == current_mtd_dev) {
                /* we are modyfing partitions for the current device,
                 * update current */
                struct part_info *curr_pi;
                curr_pi = mtd_part_info(current_mtd_dev, current_mtd_partnum);

                if (curr_pi) {
                        if (curr_pi == part) {
                                printf("current partition deleted, resetting current to 0\n");
                                current_mtd_partnum = 0;
                        } else if (part->offset <= curr_pi->offset) {
                                current_mtd_partnum--;
                        }
                        current_save_needed = 1;
                }
        }

        list_del(&part->link);
        free(part);
        dev->num_parts--;

        if (current_save_needed > 0)
                current_save();
        else
                index_partitions();

        return 0;
}

/**
 * Delete all partitions from parts head list, free memory.
 *
 * @param head list of partitions to delete
 */
static void part_delall(struct list_head *head)
{
        struct list_head *entry, *n;
        struct part_info *part_tmp;

        /* clean tmp_list and free allocated memory */
        list_for_each_safe(entry, n, head) {
                part_tmp = list_entry(entry, struct part_info, link);

                list_del(entry);
                free(part_tmp);
        }
}

/**
 * Add new partition to the supplied partition list. Make sure partitions are
 * sorted by offset in ascending order.
 *
 * @param head list this partition is to be added to
 * @param new partition to be added
 */
static int part_sort_add(struct mtd_device *dev, struct part_info *part)
{
        struct list_head *entry;
        struct part_info *new_pi, *curr_pi;

        /* link partition to parrent dev */
        part->dev = dev;

        if (list_empty(&dev->parts)) {
                debug("part_sort_add: list empty\n");
                list_add(&part->link, &dev->parts);
                dev->num_parts++;
                index_partitions();
                return 0;
        }

        new_pi = list_entry(&part->link, struct part_info, link);

        /* get current partition info if we are updating current device */
        curr_pi = NULL;
        if (dev == current_mtd_dev)
                curr_pi = mtd_part_info(current_mtd_dev, current_mtd_partnum);

        list_for_each(entry, &dev->parts) {
                struct part_info *pi;

                pi = list_entry(entry, struct part_info, link);

                /* be compliant with kernel cmdline, allow only one partition at offset zero */
                if ((new_pi->offset == pi->offset) && (pi->offset == 0)) {
                        printf("cannot add second partition at offset 0\n");
                        return 1;
                }

                if (new_pi->offset <= pi->offset) {
                        list_add_tail(&part->link, entry);
                        dev->num_parts++;

                        if (curr_pi && (pi->offset <= curr_pi->offset)) {
                                /* we are modyfing partitions for the current
                                 * device, update current */
                                current_mtd_partnum++;
                                current_save();
                        } else {
                                index_partitions();
                        }
                        return 0;
                }
        }

        list_add_tail(&part->link, &dev->parts);
        dev->num_parts++;
        index_partitions();
        return 0;
}

/**
 * Add provided partition to the partition list of a given device.
 *
 * @param dev device to which partition is added
 * @param part partition to be added
 * @return 0 on success, 1 otherwise
 */
static int part_add(struct mtd_device *dev, struct part_info *part)
{
        /* verify alignment and size */
        if (part_validate(dev->id, part) != 0)
                return 1;

        /* partition is ok, add it to the list */
        if (part_sort_add(dev, part) != 0)
                return 1;

        return 0;
}

/**
 * Parse one partition definition, allocate memory and return pointer to this
 * location in retpart.
 *
 * @param partdef pointer to the partition definition string i.e. <part-def>
 * @param ret output pointer to next char after parse completes (output)
 * @param retpart pointer to the allocated partition (output)
 * @return 0 on success, 1 otherwise
 */
static int part_parse(const char *const partdef, const char **ret, struct part_info **retpart)
{
        struct part_info *part;
        u64 size;
        u64 offset;
        const char *name;
        int name_len;
        unsigned int mask_flags;
        const char *p;

        p = partdef;
        *retpart = NULL;
        *ret = NULL;

        /* fetch the partition size */
        if (*p == '-') {
                /* assign all remaining space to this partition */
                debug("'-': remaining size assigned\n");
                size = SIZE_REMAINING;
                p++;
        } else {
                size = memsize_parse(p, &p);
                if (size < MIN_PART_SIZE) {
                        printf("partition size too small (%llx)\n", size);
                        return 1;
                }
        }

        /* check for offset */
        offset = OFFSET_NOT_SPECIFIED;
        if (*p == '@') {
                p++;
                offset = memsize_parse(p, &p);
        }

        /* now look for the name */
        if (*p == '(') {
                name = ++p;
                if ((p = strchr(name, ')')) == NULL) {
                        printf("no closing ) found in partition name\n");
                        return 1;
                }
                name_len = p - name + 1;
                if ((name_len - 1) == 0) {
                        printf("empty partition name\n");
                        return 1;
                }
                p++;
        } else {
                /* 0x00000000@0x00000000 */
                name_len = 22;
                name = NULL;
        }

        /* test for options */
        mask_flags = 0;
        if (strncmp(p, "ro", 2) == 0) {
                mask_flags |= MTD_WRITEABLE_CMD;
                p += 2;
        }

        /* check for next partition definition */
        if (*p == ',') {
                if (size == SIZE_REMAINING) {
                        *ret = NULL;
                        printf("no partitions allowed after a fill-up partition\n");
                        return 1;
                }
                *ret = ++p;
        } else if ((*p == ';') || (*p == '\0')) {
                *ret = p;
        } else {
                printf("unexpected character '%c' at the end of partition\n", *p);
                *ret = NULL;
                return 1;
        }

        /*  allocate memory */
        part = (struct part_info *)malloc(sizeof(struct part_info) + name_len);
        if (!part) {
                printf("out of memory\n");
                return 1;
        }
        memset(part, 0, sizeof(struct part_info) + name_len);
        part->size = size;
        part->offset = offset;
        part->mask_flags = mask_flags;
        part->name = (char *)(part + 1);

        if (name) {
                /* copy user provided name */
                strncpy(part->name, name, name_len - 1);
                part->auto_name = 0;
        } else {
                /* auto generated name in form of size@offset */
                sprintf(part->name, "0x%08llx@0x%08llx", size, offset);
                part->auto_name = 1;
        }

        part->name[name_len - 1] = '\0';
        INIT_LIST_HEAD(&part->link);

        debug("+ partition: name %-22s size 0x%08llx offset 0x%08llx mask flags %d\n",
                        part->name, part->size,
                        part->offset, part->mask_flags);

        *retpart = part;
        return 0;
}

/**
 * Check device number to be within valid range for given device type.
 *
 * @param type mtd type
 * @param num mtd number
 * @param size a pointer to the size of the mtd device (output)
 * @return 0 if device is valid, 1 otherwise
 */
static int mtd_device_validate(u8 type, u8 num, u64 *size)
{
        struct mtd_info *mtd = NULL;

        if (get_mtd_info(type, num, &mtd))
                return 1;

        *size = mtd->size;

        return 0;
}

/**
 * Delete all mtd devices from a supplied devices list, free memory allocated for
 * each device and delete all device partitions.
 *
 * @return 0 on success, 1 otherwise
 */
static int device_delall(struct list_head *head)
{
        struct list_head *entry, *n;
        struct mtd_device *dev_tmp;

        /* clean devices list */
        list_for_each_safe(entry, n, head) {
                dev_tmp = list_entry(entry, struct mtd_device, link);
                list_del(entry);
                part_delall(&dev_tmp->parts);
                free(dev_tmp);
        }
        INIT_LIST_HEAD(&devices);

        return 0;
}

/**
 * If provided device exists it's partitions are deleted, device is removed
 * from device list and device memory is freed.
 *
 * @param dev device to be deleted
 * @return 0 on success, 1 otherwise
 */
static int device_del(struct mtd_device *dev)
{
        part_delall(&dev->parts);
        list_del(&dev->link);
        free(dev);

        if (dev == current_mtd_dev) {
                /* we just deleted current device */
                if (list_empty(&devices)) {
                        current_mtd_dev = NULL;
                } else {
                        /* reset first partition from first dev from the
                         * devices list as current */
                        current_mtd_dev = list_entry(devices.next, struct mtd_device, link);
                        current_mtd_partnum = 0;
                }
                current_save();
                return 0;
        }

        index_partitions();
        return 0;
}

/**
 * Search global device list and return pointer to the device of type and num
 * specified.
 *
 * @param type device type
 * @param num device number
 * @return NULL if requested device does not exist
 */
struct mtd_device *device_find(u8 type, u8 num)
{
        struct list_head *entry;
        struct mtd_device *dev_tmp;

        list_for_each(entry, &devices) {
                dev_tmp = list_entry(entry, struct mtd_device, link);

                if ((dev_tmp->id->type == type) && (dev_tmp->id->num == num))
                        return dev_tmp;
        }

        return NULL;
}

/**
 * Add specified device to the global device list.
 *
 * @param dev device to be added
 */
static void device_add(struct mtd_device *dev)
{
        u8 current_save_needed = 0;

        if (list_empty(&devices)) {
                current_mtd_dev = dev;
                current_mtd_partnum = 0;
                current_save_needed = 1;
        }

        list_add_tail(&dev->link, &devices);

        if (current_save_needed > 0)
                current_save();
        else
                index_partitions();
}

/**
 * Parse device type, name and mtd-id. If syntax is ok allocate memory and
 * return pointer to the device structure.
 *
 * @param mtd_dev pointer to the device definition string i.e. <mtd-dev>
 * @param ret output pointer to next char after parse completes (output)
 * @param retdev pointer to the allocated device (output)
 * @return 0 on success, 1 otherwise
 */
static int device_parse(const char *const mtd_dev, const char **ret, struct mtd_device **retdev)
{
        struct mtd_device *dev;
        struct part_info *part;
        struct mtdids *id;
        const char *mtd_id;
        unsigned int mtd_id_len;
        const char *p;
        const char *pend;
        LIST_HEAD(tmp_list);
        struct list_head *entry, *n;
        u16 num_parts;
        u64 offset;
        int err = 1;

        debug("===device_parse===\n");

        assert(retdev);
        *retdev = NULL;

        if (ret)
                *ret = NULL;

        /* fetch <mtd-id> */
        mtd_id = p = mtd_dev;
        if (!(p = strchr(mtd_id, ':'))) {
                printf("no <mtd-id> identifier\n");
                return 1;
        }
        mtd_id_len = p - mtd_id + 1;
        p++;

        /* verify if we have a valid device specified */
        if ((id = id_find_by_mtd_id(mtd_id, mtd_id_len - 1)) == NULL) {
                printf("invalid mtd device '%.*s'\n", mtd_id_len - 1, mtd_id);
                return 1;
        }

#ifdef DEBUG
        pend = strchr(p, ';');
#endif
        debug("dev type = %d (%s), dev num = %d, mtd-id = %s\n",
                        id->type, MTD_DEV_TYPE(id->type),
                        id->num, id->mtd_id);
        debug("parsing partitions %.*s\n", (int)(pend ? pend - p : strlen(p)), p);


        /* parse partitions */
        num_parts = 0;

        offset = 0;
        if ((dev = device_find(id->type, id->num)) != NULL) {
                /* if device already exists start at the end of the last partition */
                part = list_entry(dev->parts.prev, struct part_info, link);
                offset = part->offset + part->size;
        }

        while (p && (*p != '\0') && (*p != ';')) {
                err = 1;
                if ((part_parse(p, &p, &part) != 0) || (!part))
                        break;

                /* calculate offset when not specified */
                if (part->offset == OFFSET_NOT_SPECIFIED)
                        part->offset = offset;
                else
                        offset = part->offset;

                /* verify alignment and size */
                if (part_validate(id, part) != 0)
                        break;

                offset += part->size;

                /* partition is ok, add it to the list */
                list_add_tail(&part->link, &tmp_list);
                num_parts++;
                err = 0;
        }
        if (err == 1) {
                part_delall(&tmp_list);
                return 1;
        }

        if (num_parts == 0) {
                printf("no partitions for device %s%d (%s)\n",
                                MTD_DEV_TYPE(id->type), id->num, id->mtd_id);
                return 1;
        }

        debug("\ntotal partitions: %d\n", num_parts);

        /* check for next device presence */
        if (p) {
                if (*p == ';') {
                        if (ret)
                                *ret = ++p;
                } else if (*p == '\0') {
                        if (ret)
                                *ret = p;
                } else {
                        printf("unexpected character '%c' at the end of device\n", *p);
                        if (ret)
                                *ret = NULL;
                        return 1;
                }
        }

        /* allocate memory for mtd_device structure */
        if ((dev = (struct mtd_device *)malloc(sizeof(struct mtd_device))) == NULL) {
                printf("out of memory\n");
                return 1;
        }
        memset(dev, 0, sizeof(struct mtd_device));
        dev->id = id;
        dev->num_parts = 0; /* part_sort_add increments num_parts */
        INIT_LIST_HEAD(&dev->parts);
        INIT_LIST_HEAD(&dev->link);

        /* move partitions from tmp_list to dev->parts */
        list_for_each_safe(entry, n, &tmp_list) {
                part = list_entry(entry, struct part_info, link);
                list_del(entry);
                if (part_sort_add(dev, part) != 0) {
                        device_del(dev);
                        return 1;
                }
        }

        *retdev = dev;

        debug("===\n\n");
        return 0;
}

/**
 * Initialize global device list.
 *
 * @return 0 on success, 1 otherwise
 */
static int mtd_devices_init(void)
{
        last_parts[0] = '\0';
        current_mtd_dev = NULL;
        current_save();

        return device_delall(&devices);
}

/*
 * Search global mtdids list and find id of requested type and number.
 *
 * @return pointer to the id if it exists, NULL otherwise
 */
static struct mtdids* id_find(u8 type, u8 num)
{
        struct list_head *entry;
        struct mtdids *id;

        list_for_each(entry, &mtdids) {
                id = list_entry(entry, struct mtdids, link);

                if ((id->type == type) && (id->num == num))
                        return id;
        }

        return NULL;
}

/**
 * Search global mtdids list and find id of a requested mtd_id.
 *
 * Note: first argument is not null terminated.
 *
 * @param mtd_id string containing requested mtd_id
 * @param mtd_id_len length of supplied mtd_id
 * @return pointer to the id if it exists, NULL otherwise
 */
static struct mtdids* id_find_by_mtd_id(const char *mtd_id, unsigned int mtd_id_len)
{
        struct list_head *entry;
        struct mtdids *id;

        debug("--- id_find_by_mtd_id: '%.*s' (len = %d)\n",
                        mtd_id_len, mtd_id, mtd_id_len);

        list_for_each(entry, &mtdids) {
                id = list_entry(entry, struct mtdids, link);

                debug("entry: '%s' (len = %zu)\n",
                                id->mtd_id, strlen(id->mtd_id));

                if (mtd_id_len != strlen(id->mtd_id))
                        continue;
                if (strncmp(id->mtd_id, mtd_id, mtd_id_len) == 0)
                        return id;
        }

        return NULL;
}

/**
 * Parse device id string <dev-id> := 'nand'|'nor'|'onenand'<dev-num>,
 * return device type and number.
 *
 * @param id string describing device id
 * @param ret_id output pointer to next char after parse completes (output)
 * @param dev_type parsed device type (output)
 * @param dev_num parsed device number (output)
 * @return 0 on success, 1 otherwise
 */
int mtd_id_parse(const char *id, const char **ret_id, u8 *dev_type,
                 u8 *dev_num)
{
        const char *p = id;

        *dev_type = 0;
        if (strncmp(p, "nand", 4) == 0) {
                *dev_type = MTD_DEV_TYPE_NAND;
                p += 4;
        } else if (strncmp(p, "nor", 3) == 0) {
                *dev_type = MTD_DEV_TYPE_NOR;
                p += 3;
        } else if (strncmp(p, "onenand", 7) == 0) {
                *dev_type = MTD_DEV_TYPE_ONENAND;
                p += 7;
        } else {
                printf("incorrect device type in %s\n", id);
                return 1;
        }

        if (!isdigit(*p)) {
                printf("incorrect device number in %s\n", id);
                return 1;
        }

        *dev_num = simple_strtoul(p, (char **)&p, 0);
        if (ret_id)
                *ret_id = p;
        return 0;
}

/**
 * Process all devices and generate corresponding mtdparts string describing
 * all partitions on all devices.
 *
 * @param buf output buffer holding generated mtdparts string (output)
 * @param buflen buffer size
 * @return 0 on success, 1 otherwise
 */
static int generate_mtdparts(char *buf, u32 buflen)
{
        struct list_head *pentry, *dentry;
        struct mtd_device *dev;
        struct part_info *part, *prev_part;
        char *p = buf;
        char tmpbuf[32];
        u64 size, offset;
        u32 len, part_cnt;
        u32 maxlen = buflen - 1;

        debug("--- generate_mtdparts ---\n");

        if (list_empty(&devices)) {
                buf[0] = '\0';
                return 0;
        }

        sprintf(p, "mtdparts=");
        p += 9;

        list_for_each(dentry, &devices) {
                dev = list_entry(dentry, struct mtd_device, link);

                /* copy mtd_id */
                len = strlen(dev->id->mtd_id) + 1;
                if (len > maxlen)
                        goto cleanup;
                memcpy(p, dev->id->mtd_id, len - 1);
                p += len - 1;
                *(p++) = ':';
                maxlen -= len;

                /* format partitions */
                prev_part = NULL;
                part_cnt = 0;
                list_for_each(pentry, &dev->parts) {
                        part = list_entry(pentry, struct part_info, link);
                        size = part->size;
                        offset = part->offset;
                        part_cnt++;

                        /* partition size */
                        memsize_format(tmpbuf, size);
                        len = strlen(tmpbuf);
                        if (len > maxlen)
                                goto cleanup;
                        memcpy(p, tmpbuf, len);
                        p += len;
                        maxlen -= len;


                        /* add offset only when there is a gap between
                         * partitions */
                        if ((!prev_part && (offset != 0)) ||
                                        (prev_part && ((prev_part->offset + prev_part->size) != part->offset))) {

                                memsize_format(tmpbuf, offset);
                                len = strlen(tmpbuf) + 1;
                                if (len > maxlen)
                                        goto cleanup;
                                *(p++) = '@';
                                memcpy(p, tmpbuf, len - 1);
                                p += len - 1;
                                maxlen -= len;
                        }

                        /* copy name only if user supplied */
                        if(!part->auto_name) {
                                len = strlen(part->name) + 2;
                                if (len > maxlen)
                                        goto cleanup;

                                *(p++) = '(';
                                memcpy(p, part->name, len - 2);
                                p += len - 2;
                                *(p++) = ')';
                                maxlen -= len;
                        }

                        /* ro mask flag */
                        if (part->mask_flags && MTD_WRITEABLE_CMD) {
                                len = 2;
                                if (len > maxlen)
                                        goto cleanup;
                                *(p++) = 'r';
                                *(p++) = 'o';
                                maxlen -= 2;
                        }

                        /* print ',' separator if there are other partitions
                         * following */
                        if (dev->num_parts > part_cnt) {
                                if (1 > maxlen)
                                        goto cleanup;
                                *(p++) = ',';
                                maxlen--;
                        }
                        prev_part = part;
                }
                /* print ';' separator if there are other devices following */
                if (dentry->next != &devices) {
                        if (1 > maxlen)
                                goto cleanup;
                        *(p++) = ';';
                        maxlen--;
                }
        }

        /* we still have at least one char left, as we decremented maxlen at
         * the begining */
        *p = '\0';

        return 0;

cleanup:
        last_parts[0] = '\0';
        return 1;
}

/**
 * Call generate_mtdparts to process all devices and generate corresponding
 * mtdparts string, save it in mtdparts environment variable.
 *
 * @param buf output buffer holding generated mtdparts string (output)
 * @param buflen buffer size
 * @return 0 on success, 1 otherwise
 */
static int generate_mtdparts_save(char *buf, u32 buflen)
{
        int ret;

        ret = generate_mtdparts(buf, buflen);

        if ((buf[0] != '\0') && (ret == 0))
                setenv("mtdparts", buf);
        else
                setenv("mtdparts", NULL);

        return ret;
}

#if defined(CONFIG_CMD_MTDPARTS_SHOW_NET_SIZES)
/**
 * Get the net size (w/o bad blocks) of the given partition.
 *
 * @param mtd the mtd info
 * @param part the partition
 * @return the calculated net size of this partition
 */
static uint64_t net_part_size(struct mtd_info *mtd, struct part_info *part)
{
        uint64_t i, net_size = 0;

        if (!mtd->block_isbad)
                return part->size;

        for (i = 0; i < part->size; i += mtd->erasesize) {
                if (!mtd->block_isbad(mtd, part->offset + i))
                        net_size += mtd->erasesize;
        }

        return net_size;
}
#endif

static void print_partition_table(void)
{
        struct list_head *dentry, *pentry;
        struct part_info *part;
        struct mtd_device *dev;
        int part_num;

        list_for_each(dentry, &devices) {
                dev = list_entry(dentry, struct mtd_device, link);
                /* list partitions for given device */
                part_num = 0;
#if defined(CONFIG_CMD_MTDPARTS_SHOW_NET_SIZES)
                struct mtd_info *mtd;

                if (get_mtd_info(dev->id->type, dev->id->num, &mtd))
                        return;

                printf("\ndevice %s%d <%s>, # parts = %d\n",
                                MTD_DEV_TYPE(dev->id->type), dev->id->num,
                                dev->id->mtd_id, dev->num_parts);
                printf(" #: name\t\tsize\t\tnet size\toffset\t\tmask_flags\n");

                list_for_each(pentry, &dev->parts) {
                        u32 net_size;
                        char *size_note;

                        part = list_entry(pentry, struct part_info, link);
                        net_size = net_part_size(mtd, part);
                        size_note = part->size == net_size ? " " : " (!)";
                        printf("%2d: %-20s0x%08x\t0x%08x%s\t0x%08x\t%d\n",
                                        part_num, part->name, part->size,
                                        net_size, size_note, part->offset,
                                        part->mask_flags);
#else /* !defined(CONFIG_CMD_MTDPARTS_SHOW_NET_SIZES) */
                printf("\ndevice %s%d <%s>, # parts = %d\n",
                                MTD_DEV_TYPE(dev->id->type), dev->id->num,
                                dev->id->mtd_id, dev->num_parts);
                printf(" #: name\t\tsize\t\toffset\t\tmask_flags\n");

                list_for_each(pentry, &dev->parts) {
                        part = list_entry(pentry, struct part_info, link);
                        printf("%2d: %-20s0x%08llx\t0x%08llx\t%d\n",
                                        part_num, part->name, part->size,
                                        part->offset, part->mask_flags);
#endif /* defined(CONFIG_CMD_MTDPARTS_SHOW_NET_SIZES) */
                        part_num++;
                }
        }

        if (list_empty(&devices))
                printf("no partitions defined\n");
}

/**
 * Format and print out a partition list for each device from global device
 * list.
 */
static void list_partitions(void)
{
        struct part_info *part;

        debug("\n---list_partitions---\n");
        print_partition_table();

        /* current_mtd_dev is not NULL only when we have non empty device list */
        if (current_mtd_dev) {
                part = mtd_part_info(current_mtd_dev, current_mtd_partnum);
                if (part) {
                        printf("\nactive partition: %s%d,%d - (%s) 0x%08llx @ 0x%08llx\n",
                                        MTD_DEV_TYPE(current_mtd_dev->id->type),
                                        current_mtd_dev->id->num, current_mtd_partnum,
                                        part->name, part->size, part->offset);
                } else {
                        printf("could not get current partition info\n\n");
                }
        }

        printf("\ndefaults:\n");
        printf("mtdids  : %s\n",
                mtdids_default ? mtdids_default : "none");
        /*
         * Using printf() here results in printbuffer overflow
         * if default mtdparts string is greater than console
         * printbuffer. Use puts() to prevent system crashes.
         */
        puts("mtdparts: ");
        puts(mtdparts_default ? mtdparts_default : "none");
        puts("\n");
}

/**
 * Given partition identifier in form of <dev_type><dev_num>,<part_num> find
 * corresponding device and verify partition number.
 *
 * @param id string describing device and partition or partition name
 * @param dev pointer to the requested device (output)
 * @param part_num verified partition number (output)
 * @param part pointer to requested partition (output)
 * @return 0 on success, 1 otherwise
 */
int find_dev_and_part(const char *id, struct mtd_device **dev,
                u8 *part_num, struct part_info **part)
{
        struct list_head *dentry, *pentry;
        u8 type, dnum, pnum;
        const char *p;

        debug("--- find_dev_and_part ---\nid = %s\n", id);

        list_for_each(dentry, &devices) {
                *part_num = 0;
                *dev = list_entry(dentry, struct mtd_device, link);
                list_for_each(pentry, &(*dev)->parts) {
                        *part = list_entry(pentry, struct part_info, link);
                        if (strcmp((*part)->name, id) == 0)
                                return 0;
                        (*part_num)++;
                }
        }

        p = id;
        *dev = NULL;
        *part = NULL;
        *part_num = 0;

        if (mtd_id_parse(p, &p, &type, &dnum) != 0)
                return 1;

        if ((*p++ != ',') || (*p == '\0')) {
                printf("no partition number specified\n");
                return 1;
        }
        pnum = simple_strtoul(p, (char **)&p, 0);
        if (*p != '\0') {
                printf("unexpected trailing character '%c'\n", *p);
                return 1;
        }

        if ((*dev = device_find(type, dnum)) == NULL) {
                printf("no such device %s%d\n", MTD_DEV_TYPE(type), dnum);
                return 1;
        }

        if ((*part = mtd_part_info(*dev, pnum)) == NULL) {
                printf("no such partition\n");
                *dev = NULL;
                return 1;
        }

        *part_num = pnum;

        return 0;
}

/**
 * Find and delete partition. For partition id format see find_dev_and_part().
 *
 * @param id string describing device and partition
 * @return 0 on success, 1 otherwise
 */
static int delete_partition(const char *id)
{
        u8 pnum;
        struct mtd_device *dev;
        struct part_info *part;

        if (find_dev_and_part(id, &dev, &pnum, &part) == 0) {

                debug("delete_partition: device = %s%d, partition %d = (%s) 0x%08llx@0x%08llx\n",
                                MTD_DEV_TYPE(dev->id->type), dev->id->num, pnum,
                                part->name, part->size, part->offset);

                if (part_del(dev, part) != 0)
                        return 1;

                if (generate_mtdparts_save(last_parts, MTDPARTS_MAXLEN) != 0) {
                        printf("generated mtdparts too long, resetting to null\n");
                        return 1;
                }
                return 0;
        }

        printf("partition %s not found\n", id);
        return 1;
}

#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
/**
 * Increase the size of the given partition so that it's net size is at least
 * as large as the size member and such that the next partition would start on a
 * good block if it were adjacent to this partition.
 *
 * @param mtd the mtd device
 * @param part the partition
 * @param next_offset pointer to the offset of the next partition after this
 *                    partition's size has been modified (output)
 */
static void spread_partition(struct mtd_info *mtd, struct part_info *part,
                             uint64_t *next_offset)
{
        uint64_t net_size, padding_size = 0;
        int truncated;

        mtd_get_len_incl_bad(mtd, part->offset, part->size, &net_size,
                             &truncated);

        /*
         * Absorb bad blocks immediately following this
         * partition also into the partition, such that
         * the next partition starts with a good block.
         */
        if (!truncated) {
                mtd_get_len_incl_bad(mtd, part->offset + net_size,
                                     mtd->erasesize, &padding_size, &truncated);
                if (truncated)
                        padding_size = 0;
                else
                        padding_size -= mtd->erasesize;
        }

        if (truncated) {
                printf("truncated partition %s to %lld bytes\n", part->name,
                       (uint64_t) net_size + padding_size);
        }

        part->size = net_size + padding_size;
        *next_offset = part->offset + part->size;
}

/**
 * Adjust all of the partition sizes, such that all partitions are at least
 * as big as their mtdparts environment variable sizes and they each start
 * on a good block.
 *
 * @return 0 on success, 1 otherwise
 */
static int spread_partitions(void)
{
        struct list_head *dentry, *pentry;
        struct mtd_device *dev;
        struct part_info *part;
        struct mtd_info *mtd;
        int part_num;
        uint64_t cur_offs;

        list_for_each(dentry, &devices) {
                dev = list_entry(dentry, struct mtd_device, link);

                if (get_mtd_info(dev->id->type, dev->id->num, &mtd))
                        return 1;

                part_num = 0;
                cur_offs = 0;
                list_for_each(pentry, &dev->parts) {
                        part = list_entry(pentry, struct part_info, link);

                        debug("spread_partitions: device = %s%d, partition %d ="
                                " (%s) 0x%08x@0x%08x\n",
                                MTD_DEV_TYPE(dev->id->type), dev->id->num,
                                part_num, part->name, part->size,
                                part->offset);

                        if (cur_offs > part->offset)
                                part->offset = cur_offs;

                        spread_partition(mtd, part, &cur_offs);

                        part_num++;
                }
        }

        index_partitions();

        if (generate_mtdparts_save(last_parts, MTDPARTS_MAXLEN) != 0) {
                printf("generated mtdparts too long, resetting to null\n");
                return 1;
        }
        return 0;
}
#endif /* CONFIG_CMD_MTDPARTS_SPREAD */

/**
 * Accept character string describing mtd partitions and call device_parse()
 * for each entry. Add created devices to the global devices list.
 *
 * @param mtdparts string specifing mtd partitions
 * @return 0 on success, 1 otherwise
 */
static int parse_mtdparts(const char *const mtdparts)
{
        const char *p = mtdparts;
        struct mtd_device *dev;
        int err = 1;
        char tmp_parts[MTDPARTS_MAXLEN];

        debug("\n---parse_mtdparts---\nmtdparts = %s\n\n", p);

        /* delete all devices and partitions */
        if (mtd_devices_init() != 0) {
                printf("could not initialise device list\n");
                return err;
        }

        /* re-read 'mtdparts' variable, mtd_devices_init may be updating env */
        if (gd->flags & GD_FLG_ENV_READY) {
                p = getenv("mtdparts");
        } else {
                p = tmp_parts;
                getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN);
        }

        if (strncmp(p, "mtdparts=", 9) != 0) {
                printf("mtdparts variable doesn't start with 'mtdparts='\n");
                return err;
        }
        p += 9;

        while (p && (*p != '\0')) {
                err = 1;
                if ((device_parse(p, &p, &dev) != 0) || (!dev))
                        break;

                debug("+ device: %s\t%d\t%s\n", MTD_DEV_TYPE(dev->id->type),
                                dev->id->num, dev->id->mtd_id);

                /* check if parsed device is already on the list */
                if (device_find(dev->id->type, dev->id->num) != NULL) {
                        printf("device %s%d redefined, please correct mtdparts variable\n",
                                        MTD_DEV_TYPE(dev->id->type), dev->id->num);
                        break;
                }

                list_add_tail(&dev->link, &devices);
                err = 0;
        }
        if (err == 1) {
                device_delall(&devices);
                return 1;
        }

        return 0;
}

/**
 * Parse provided string describing mtdids mapping (see file header for mtdids
 * variable format). Allocate memory for each entry and add all found entries
 * to the global mtdids list.
 *
 * @param ids mapping string
 * @return 0 on success, 1 otherwise
 */
static int parse_mtdids(const char *const ids)
{
        const char *p = ids;
        const char *mtd_id;
        int mtd_id_len;
        struct mtdids *id;
        struct list_head *entry, *n;
        struct mtdids *id_tmp;
        u8 type, num;
        u64 size;
        int ret = 1;

        debug("\n---parse_mtdids---\nmtdids = %s\n\n", ids);

        /* clean global mtdids list */
        list_for_each_safe(entry, n, &mtdids) {
                id_tmp = list_entry(entry, struct mtdids, link);
                debug("mtdids del: %d %d\n", id_tmp->type, id_tmp->num);
                list_del(entry);
                free(id_tmp);
        }
        last_ids[0] = '\0';
        INIT_LIST_HEAD(&mtdids);

        while(p && (*p != '\0')) {

                ret = 1;
                /* parse 'nor'|'nand'|'onenand'<dev-num> */
                if (mtd_id_parse(p, &p, &type, &num) != 0)
                        break;

                if (*p != '=') {
                        printf("mtdids: incorrect <dev-num>\n");
                        break;
                }
                p++;

                /* check if requested device exists */
                if (mtd_device_validate(type, num, &size) != 0)
                        return 1;

                /* locate <mtd-id> */
                mtd_id = p;
                if ((p = strchr(mtd_id, ',')) != NULL) {
                        mtd_id_len = p - mtd_id + 1;
                        p++;
                } else {
                        mtd_id_len = strlen(mtd_id) + 1;
                }
                if (mtd_id_len == 0) {
                        printf("mtdids: no <mtd-id> identifier\n");
                        break;
                }

                /* check if this id is already on the list */
                int double_entry = 0;
                list_for_each(entry, &mtdids) {
                        id_tmp = list_entry(entry, struct mtdids, link);
                        if ((id_tmp->type == type) && (id_tmp->num == num)) {
                                double_entry = 1;
                                break;
                        }
                }
                if (double_entry) {
                        printf("device id %s%d redefined, please correct mtdids variable\n",
                                        MTD_DEV_TYPE(type), num);
                        break;
                }

                /* allocate mtdids structure */
                if (!(id = (struct mtdids *)malloc(sizeof(struct mtdids) + mtd_id_len))) {
                        printf("out of memory\n");
                        break;
                }
                memset(id, 0, sizeof(struct mtdids) + mtd_id_len);
                id->num = num;
                id->type = type;
                id->size = size;
                id->mtd_id = (char *)(id + 1);
                strncpy(id->mtd_id, mtd_id, mtd_id_len - 1);
                id->mtd_id[mtd_id_len - 1] = '\0';
                INIT_LIST_HEAD(&id->link);

                debug("+ id %s%d\t%16lld bytes\t%s\n",
                                MTD_DEV_TYPE(id->type), id->num,
                                id->size, id->mtd_id);

                list_add_tail(&id->link, &mtdids);
                ret = 0;
        }
        if (ret == 1) {
                /* clean mtdids list and free allocated memory */
                list_for_each_safe(entry, n, &mtdids) {
                        id_tmp = list_entry(entry, struct mtdids, link);
                        list_del(entry);
                        free(id_tmp);
                }
                return 1;
        }

        return 0;
}

/**
 * Parse and initialize global mtdids mapping and create global
 * device/partition list.
 *
 * @return 0 on success, 1 otherwise
 */
int mtdparts_init(void)
{
        static int initialized = 0;
        const char *ids, *parts;
        const char *current_partition;
        int ids_changed;
        char tmp_ep[PARTITION_MAXLEN];
        char tmp_parts[MTDPARTS_MAXLEN];

        debug("\n---mtdparts_init---\n");
        if (!initialized) {
                INIT_LIST_HEAD(&mtdids);
                INIT_LIST_HEAD(&devices);
                memset(last_ids, 0, MTDIDS_MAXLEN);
                memset(last_parts, 0, MTDPARTS_MAXLEN);
                memset(last_partition, 0, PARTITION_MAXLEN);
                initialized = 1;
        }

        /* get variables */
        ids = getenv("mtdids");
        /*
         * The mtdparts variable tends to be long. If we need to access it
         * before the env is relocated, then we need to use our own stack
         * buffer.  gd->env_buf will be too small.
         */
        if (gd->flags & GD_FLG_ENV_READY) {
                parts = getenv("mtdparts");
        } else {
                parts = tmp_parts;
                getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN);
        }
        current_partition = getenv("partition");

        /* save it for later parsing, cannot rely on current partition pointer
         * as 'partition' variable may be updated during init */
        tmp_ep[0] = '\0';
        if (current_partition)
                strncpy(tmp_ep, current_partition, PARTITION_MAXLEN);

        debug("last_ids  : %s\n", last_ids);
        debug("env_ids   : %s\n", ids);
        debug("last_parts: %s\n", last_parts);
        debug("env_parts : %s\n\n", parts);

        debug("last_partition : %s\n", last_partition);
        debug("env_partition  : %s\n", current_partition);

        /* if mtdids varible is empty try to use defaults */
        if (!ids) {
                if (mtdids_default) {
                        debug("mtdids variable not defined, using default\n");
                        ids = mtdids_default;
                        setenv("mtdids", (char *)ids);
                } else {
                        printf("mtdids not defined, no default present\n");
                        return 1;
                }
        }
        if (strlen(ids) > MTDIDS_MAXLEN - 1) {
                printf("mtdids too long (> %d)\n", MTDIDS_MAXLEN);
                return 1;
        }

        /* do no try to use defaults when mtdparts variable is not defined,
         * just check the length */
        if (!parts)
                printf("mtdparts variable not set, see 'help mtdparts'\n");

        if (parts && (strlen(parts) > MTDPARTS_MAXLEN - 1)) {
                printf("mtdparts too long (> %d)\n", MTDPARTS_MAXLEN);
                return 1;
        }

        /* check if we have already parsed those mtdids */
        if ((last_ids[0] != '\0') && (strcmp(last_ids, ids) == 0)) {
                ids_changed = 0;
        } else {
                ids_changed = 1;

                if (parse_mtdids(ids) != 0) {
                        mtd_devices_init();
                        return 1;
                }

                /* ok it's good, save new ids */
                strncpy(last_ids, ids, MTDIDS_MAXLEN);
        }

        /* parse partitions if either mtdparts or mtdids were updated */
        if (parts && ((last_parts[0] == '\0') || ((strcmp(last_parts, parts) != 0)) || ids_changed)) {
                if (parse_mtdparts(parts) != 0)
                        return 1;

                if (list_empty(&devices)) {
                        printf("mtdparts_init: no valid partitions\n");
                        return 1;
                }

                /* ok it's good, save new parts */
                strncpy(last_parts, parts, MTDPARTS_MAXLEN);

                /* reset first partition from first dev from the list as current */
                current_mtd_dev = list_entry(devices.next, struct mtd_device, link);
                current_mtd_partnum = 0;
                current_save();

                debug("mtdparts_init: current_mtd_dev  = %s%d, current_mtd_partnum = %d\n",
                                MTD_DEV_TYPE(current_mtd_dev->id->type),
                                current_mtd_dev->id->num, current_mtd_partnum);
        }

        /* mtdparts variable was reset to NULL, delete all devices/partitions */
        if (!parts && (last_parts[0] != '\0'))
                return mtd_devices_init();

        /* do not process current partition if mtdparts variable is null */
        if (!parts)
                return 0;

        /* is current partition set in environment? if so, use it */
        if ((tmp_ep[0] != '\0') && (strcmp(tmp_ep, last_partition) != 0)) {
                struct part_info *p;
                struct mtd_device *cdev;
                u8 pnum;

                debug("--- getting current partition: %s\n", tmp_ep);

                if (find_dev_and_part(tmp_ep, &cdev, &pnum, &p) == 0) {
                        current_mtd_dev = cdev;
                        current_mtd_partnum = pnum;
                        current_save();
                }
        } else if (getenv("partition") == NULL) {
                debug("no partition variable set, setting...\n");
                current_save();
        }

        return 0;
}

/**
 * Return pointer to the partition of a requested number from a requested
 * device.
 *
 * @param dev device that is to be searched for a partition
 * @param part_num requested partition number
 * @return pointer to the part_info, NULL otherwise
 */
static struct part_info* mtd_part_info(struct mtd_device *dev, unsigned int part_num)
{
        struct list_head *entry;
        struct part_info *part;
        int num;

        if (!dev)
                return NULL;

        debug("\n--- mtd_part_info: partition number %d for device %s%d (%s)\n",
                        part_num, MTD_DEV_TYPE(dev->id->type),
                        dev->id->num, dev->id->mtd_id);

        if (part_num >= dev->num_parts) {
                printf("invalid partition number %d for device %s%d (%s)\n",
                                part_num, MTD_DEV_TYPE(dev->id->type),
                                dev->id->num, dev->id->mtd_id);
                return NULL;
        }

        /* locate partition number, return it */
        num = 0;
        list_for_each(entry, &dev->parts) {
                part = list_entry(entry, struct part_info, link);

                if (part_num == num++) {
                        return part;
                }
        }

        return NULL;
}

/***************************************************/
/* U-boot commands                                 */
/***************************************************/
/* command line only */
/**
 * Routine implementing u-boot chpart command. Sets new current partition based
 * on the user supplied partition id. For partition id format see find_dev_and_part().
 *
 * @param cmdtp command internal data
 * @param flag command flag
 * @param argc number of arguments supplied to the command
 * @param argv arguments list
 * @return 0 on success, 1 otherwise
 */
static int do_chpart(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
/* command line only */
        struct mtd_device *dev;
        struct part_info *part;
        u8 pnum;

        if (mtdparts_init() !=0)
                return 1;

        if (argc < 2) {
                printf("no partition id specified\n");
                return 1;
        }

        if (find_dev_and_part(argv[1], &dev, &pnum, &part) != 0)
                return 1;

        current_mtd_dev = dev;
        current_mtd_partnum = pnum;
        current_save();

        printf("partition changed to %s%d,%d\n",
                        MTD_DEV_TYPE(dev->id->type), dev->id->num, pnum);

        return 0;
}

/**
 * Routine implementing u-boot mtdparts command. Initialize/update default global
 * partition list and process user partition request (list, add, del).
 *
 * @param cmdtp command internal data
 * @param flag command flag
 * @param argc number of arguments supplied to the command
 * @param argv arguments list
 * @return 0 on success, 1 otherwise
 */
static int do_mtdparts(cmd_tbl_t *cmdtp, int flag, int argc,
                       char * const argv[])
{
        if (argc == 2) {
                if (strcmp(argv[1], "default") == 0) {
                        setenv("mtdids", (char *)mtdids_default);
                        setenv("mtdparts", (char *)mtdparts_default);
                        setenv("partition", NULL);

                        mtdparts_init();
                        return 0;
                } else if (strcmp(argv[1], "delall") == 0) {
                        /* this may be the first run, initialize lists if needed */
                        mtdparts_init();

                        setenv("mtdparts", NULL);

                        /* mtd_devices_init() calls current_save() */
                        return mtd_devices_init();
                }
        }

        /* make sure we are in sync with env variables */
        if (mtdparts_init() != 0)
                return 1;

        if (argc == 1) {
                list_partitions();
                return 0;
        }

        /* mtdparts add <mtd-dev> <size>[@<offset>] <name> [ro] */
        if (((argc == 5) || (argc == 6)) && (strncmp(argv[1], "add", 3) == 0)) {
#define PART_ADD_DESC_MAXLEN 64
                char tmpbuf[PART_ADD_DESC_MAXLEN];
#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
                struct mtd_info *mtd;
                uint64_t next_offset;
#endif
                u8 type, num, len;
                struct mtd_device *dev;
                struct mtd_device *dev_tmp;
                struct mtdids *id;
                struct part_info *p;

                if (mtd_id_parse(argv[2], NULL, &type, &num) != 0)
                        return 1;

                if ((id = id_find(type, num)) == NULL) {
                        printf("no such device %s defined in mtdids variable\n", argv[2]);
                        return 1;
                }

                len = strlen(id->mtd_id) + 1;   /* 'mtd_id:' */
                len += strlen(argv[3]);         /* size@offset */
                len += strlen(argv[4]) + 2;     /* '(' name ')' */
                if (argv[5] && (strlen(argv[5]) == 2))
                        len += 2;               /* 'ro' */

                if (len >= PART_ADD_DESC_MAXLEN) {
                        printf("too long partition description\n");
                        return 1;
                }
                sprintf(tmpbuf, "%s:%s(%s)%s",
                                id->mtd_id, argv[3], argv[4], argv[5] ? argv[5] : "");
                debug("add tmpbuf: %s\n", tmpbuf);

                if ((device_parse(tmpbuf, NULL, &dev) != 0) || (!dev))
                        return 1;

                debug("+ %s\t%d\t%s\n", MTD_DEV_TYPE(dev->id->type),
                                dev->id->num, dev->id->mtd_id);

                p = list_entry(dev->parts.next, struct part_info, link);

#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
                if (get_mtd_info(dev->id->type, dev->id->num, &mtd))
                        return 1;

                if (!strcmp(&argv[1][3], ".spread")) {
                        spread_partition(mtd, p, &next_offset);
                        debug("increased %s to %d bytes\n", p->name, p->size);
                }
#endif

                dev_tmp = device_find(dev->id->type, dev->id->num);
                if (dev_tmp == NULL) {
                        device_add(dev);
                } else if (part_add(dev_tmp, p) != 0) {
                        /* merge new partition with existing ones*/
                        device_del(dev);
                        return 1;
                }

                if (generate_mtdparts_save(last_parts, MTDPARTS_MAXLEN) != 0) {
                        printf("generated mtdparts too long, resetting to null\n");
                        return 1;
                }

                return 0;
        }

        /* mtdparts del part-id */
        if ((argc == 3) && (strcmp(argv[1], "del") == 0)) {
                debug("del: part-id = %s\n", argv[2]);

                return delete_partition(argv[2]);
        }

#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
        if ((argc == 2) && (strcmp(argv[1], "spread") == 0))
                return spread_partitions();
#endif /* CONFIG_CMD_MTDPARTS_SPREAD */

        return CMD_RET_USAGE;
}

/***************************************************/
U_BOOT_CMD(
        chpart, 2,      0,      do_chpart,
        "change active partition",
        "part-id\n"
        "    - change active partition (e.g. part-id = nand0,1)"
);

#ifdef CONFIG_SYS_LONGHELP
static char mtdparts_help_text[] =
        "\n"
        "    - list partition table\n"
        "mtdparts delall\n"
        "    - delete all partitions\n"
        "mtdparts del part-id\n"
        "    - delete partition (e.g. part-id = nand0,1)\n"
        "mtdparts add <mtd-dev> <size>[@<offset>] [<name>] [ro]\n"
        "    - add partition\n"
#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
        "mtdparts add.spread <mtd-dev> <size>[@<offset>] [<name>] [ro]\n"
        "    - add partition, padding size by skipping bad blocks\n"
#endif
        "mtdparts default\n"
        "    - reset partition table to defaults\n"
#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
        "mtdparts spread\n"
        "    - adjust the sizes of the partitions so they are\n"
        "      at least as big as the mtdparts variable specifies\n"
        "      and they each start on a good block\n\n"
#else
        "\n"
#endif /* CONFIG_CMD_MTDPARTS_SPREAD */
        "-----\n\n"
        "this command uses three environment variables:\n\n"
        "'partition' - keeps current partition identifier\n\n"
        "partition  := <part-id>\n"
        "<part-id>  := <dev-id>,part_num\n\n"
        "'mtdids' - linux kernel mtd device id <-> u-boot device id mapping\n\n"
        "mtdids=<idmap>[,<idmap>,...]\n\n"
        "<idmap>    := <dev-id>=<mtd-id>\n"
        "<dev-id>   := 'nand'|'nor'|'onenand'<dev-num>\n"
        "<dev-num>  := mtd device number, 0...\n"
        "<mtd-id>   := unique device tag used by linux kernel to find mtd device (mtd->name)\n\n"
        "'mtdparts' - partition list\n\n"
        "mtdparts=mtdparts=<mtd-def>[;<mtd-def>...]\n\n"
        "<mtd-def>  := <mtd-id>:<part-def>[,<part-def>...]\n"
        "<mtd-id>   := unique device tag used by linux kernel to find mtd device (mtd->name)\n"
        "<part-def> := <size>[@<offset>][<name>][<ro-flag>]\n"
        "<size>     := standard linux memsize OR '-' to denote all remaining space\n"
        "<offset>   := partition start offset within the device\n"
        "<name>     := '(' NAME ')'\n"
        "<ro-flag>  := when set to 'ro' makes partition read-only (not used, passed to kernel)";
#endif

U_BOOT_CMD(
        mtdparts,       6,      0,      do_mtdparts,
        "define flash/nand partitions", mtdparts_help_text
);
/***************************************************/