cmd_jffs2.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.
 *
 *   $Id: cmdlinepart.c,v 1.17 2004/11/26 11:18:47 lavinen Exp $
 *   Copyright 2002 SYSGO Real-Time Solutions GmbH
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * 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)
 *
 */

/*
 * JFFS2/CRAMFS support
 */
#include <common.h>
#include <command.h>
#include <malloc.h>
#include <jffs2/jffs2.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <cramfs/cramfs_fs.h>

#if defined(CONFIG_CMD_NAND)
#ifdef CONFIG_NAND_LEGACY
#include <linux/mtd/nand_legacy.h>
#else /* !CONFIG_NAND_LEGACY */
#include <linux/mtd/nand.h>
#include <nand.h>
#endif /* !CONFIG_NAND_LEGACY */
#endif

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

/* enable/disable debugging messages */
#define	DEBUG_JFFS
#undef	DEBUG_JFFS

#ifdef  DEBUG_JFFS
# define DEBUGF(fmt, args...)	printf(fmt ,##args)
#else
# define DEBUGF(fmt, args...)
#endif

/* special size referring to all the remaining space in a partition */
#define SIZE_REMAINING		0xFFFFFFFF

/* 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	0xFFFFFFFF

/* 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

#ifdef CONFIG_JFFS2_CMDLINE
/* default values for mtdids and mtdparts variables */
#if defined(MTDIDS_DEFAULT)
static const char *const mtdids_default = MTDIDS_DEFAULT;
#else
#warning "MTDIDS_DEFAULT not defined!"
static const char *const mtdids_default = NULL;
#endif

#if defined(MTDPARTS_DEFAULT)
static const char *const mtdparts_default = MTDPARTS_DEFAULT;
#else
#warning "MTDPARTS_DEFAULT not defined!"
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() */
struct list_head mtdids;

/* device/partition list, parse_cmdline() parses into here */
struct list_head devices;
#endif /* #ifdef CONFIG_JFFS2_CMDLINE */

/* current active device and partition number */
static struct mtd_device *current_dev = NULL;
static u8 current_partnum = 0;

#if defined(CONFIG_CMD_CRAMFS)
extern int cramfs_check (struct part_info *info);
extern int cramfs_load (char *loadoffset, struct part_info *info, char *filename);
extern int cramfs_ls (struct part_info *info, char *filename);
extern int cramfs_info (struct part_info *info);
#else
/* defining empty macros for function names is ugly but avoids ifdef clutter
 * all over the code */
#define cramfs_check(x)		(0)
#define cramfs_load(x,y,z)	(-1)
#define cramfs_ls(x,y)		(0)
#define cramfs_info(x)		(0)
#endif

static struct part_info* jffs2_part_info(struct mtd_device *dev, unsigned int part_num);

/* command line only routines */
#ifdef CONFIG_JFFS2_CMDLINE

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 unsigned long memsize_parse (const char *const ptr, const char **retptr)
{
	unsigned long ret = simple_strtoul(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, u32 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, "%ug", size/SIZE_GB);
	else if ((size % SIZE_MB) == 0)
		sprintf(buf, "%um", size/SIZE_MB);
	else if (size % SIZE_KB == 0)
		sprintf(buf, "%uk", size/SIZE_KB);
	else
		sprintf(buf, "%u", 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)
{
	char buf[16];
	u16 mtddevnum;
	struct part_info *part;
	struct list_head *dentry;
	struct mtd_device *dev;

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

	if (current_dev) {
		mtddevnum = 0;
		list_for_each(dentry, &devices) {
			dev = list_entry(dentry, struct mtd_device, link);
			if (dev == current_dev) {
				mtddevnum += current_partnum;
				sprintf(buf, "%d", mtddevnum);
				setenv("mtddevnum", buf);
				break;
			}
			mtddevnum += dev->num_parts;
		}

		part = jffs2_part_info(current_dev, current_partnum);
		setenv("mtddevname", part->name);

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

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

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

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

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

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

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

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

/**
 * Performs sanity check for supplied NOR flash partition. Table of existing
 * NOR flash devices is searched and partition device is located. Alignment
 * with the granularity of NOR flash sectors 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_nor(struct mtdids *id, struct part_info *part)
{
#if defined(CONFIG_CMD_FLASH)
	/* info for FLASH chips */
	extern flash_info_t flash_info[];
	flash_info_t *flash;
	int offset_aligned;
	u32 end_offset;
	int i;

	flash = &flash_info[id->num];

	offset_aligned = 0;
	for (i = 0; i < flash->sector_count; i++) {
		if ((flash->start[i] - flash->start[0]) == part->offset) {
			offset_aligned = 1;
			break;
		}
	}
	if (offset_aligned == 0) {
		printf("%s%d: partition (%s) start offset alignment incorrect\n",
				MTD_DEV_TYPE(id->type), id->num, part->name);
		return 1;
	}

	end_offset = part->offset + part->size;
	for (i = 0; i < flash->sector_count; i++) {
		if ((flash->start[i] - flash->start[0]) == end_offset)
			return 0;
	}

	if (flash->size == end_offset)
		return 0;

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

/**
 * Performs sanity check for supplied NAND flash partition. Table of existing
 * NAND 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_nand(struct mtdids *id, struct part_info *part)
{
#if defined(CONFIG_JFFS2_NAND) && defined(CONFIG_CMD_NAND)
	/* info for NAND chips */
	nand_info_t *nand;

	nand = &nand_info[id->num];

	if ((unsigned long)(part->offset) % nand->erasesize) {
		printf("%s%d: partition (%s) start offset alignment incorrect\n",
				MTD_DEV_TYPE(id->type), id->num, part->name);
		return 1;
	}

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

	return 0;
#else
	return 1;
#endif
}

/**
 * Performs sanity check for supplied OneNAND flash partition.
 * Table of existing OneNAND 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_onenand(struct mtdids *id, struct part_info *part)
{
#if defined(CONFIG_CMD_ONENAND)
	/* info for OneNAND chips */
	struct mtd_info *mtd;

	mtd = &onenand_mtd;

	if ((unsigned long)(part->offset) % mtd->erasesize) {
		printf("%s%d: partition (%s) start offset"
			"alignment incorrect\n",
				MTD_DEV_TYPE(id->type), id->num, part->name);
		return 1;
	}

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

	return 0;
#else
	return 1;
#endif
}


/**
 * Performs sanity check for supplied partition. Offset and size are verified
 * to be within valid range. Partition type is checked and either
 * parts_validate_nor() or parts_validate_nand() 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 %08x beyond flash size %08x\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;
	}

	if (id->type == MTD_DEV_TYPE_NAND)
		return part_validate_nand(id, part);
	else if (id->type == MTD_DEV_TYPE_NOR)
		return part_validate_nor(id, part);
	else if (id->type == MTD_DEV_TYPE_ONENAND)
		return part_validate_onenand(id, part);
	else
		DEBUGF("part_validate: invalid dev type\n");

	return 1;
}

/**
 * Delete selected partition from the partion 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_dev) {
		/* we are modyfing partitions for the current device,
		 * update current */
		struct part_info *curr_pi;
		curr_pi = jffs2_part_info(current_dev, current_partnum);

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

#ifdef CONFIG_NAND_LEGACY
	jffs2_free_cache(part);
#endif
	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);

#ifdef CONFIG_NAND_LEGACY
		jffs2_free_cache(part_tmp);
#endif
		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)) {
		DEBUGF("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_dev)
		curr_pi = jffs2_part_info(current_dev, current_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_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;
	unsigned long size;
	unsigned long 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 */
		DEBUGF("'-': remaining size assigned\n");
		size = SIZE_REMAINING;
		p++;
	} else {
		size = memsize_parse(p, &p);
		if (size < MIN_PART_SIZE) {
			printf("partition size too small (%lx)\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%08lx@0x%08lx", size, offset);
		part->auto_name = 1;
	}

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

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

	*retpart = part;
	return 0;
}
#endif/* #ifdef CONFIG_JFFS2_CMDLINE */

/**
 * Check device number to be within valid range for given device type.
 *
 * @param dev device to validate
 * @return 0 if device is valid, 1 otherwise
 */
static int device_validate(u8 type, u8 num, u32 *size)
{
	if (type == MTD_DEV_TYPE_NOR) {
#if defined(CONFIG_CMD_FLASH)
		if (num < CONFIG_SYS_MAX_FLASH_BANKS) {
			extern flash_info_t flash_info[];
			*size = flash_info[num].size;

			return 0;
		}

		printf("no such FLASH device: %s%d (valid range 0 ... %d\n",
				MTD_DEV_TYPE(type), num, CONFIG_SYS_MAX_FLASH_BANKS - 1);
#else
		printf("support for FLASH devices not present\n");
#endif
	} else if (type == MTD_DEV_TYPE_NAND) {
#if defined(CONFIG_JFFS2_NAND) && defined(CONFIG_CMD_NAND)
		if (num < CONFIG_SYS_MAX_NAND_DEVICE) {
#ifndef CONFIG_NAND_LEGACY
			*size = nand_info[num].size;
#else
			extern struct nand_chip nand_dev_desc[CONFIG_SYS_MAX_NAND_DEVICE];
			*size = nand_dev_desc[num].totlen;
#endif
			return 0;
		}

		printf("no such NAND device: %s%d (valid range 0 ... %d)\n",
				MTD_DEV_TYPE(type), num, CONFIG_SYS_MAX_NAND_DEVICE - 1);
#else
		printf("support for NAND devices not present\n");
#endif
	} else if (type == MTD_DEV_TYPE_ONENAND) {
#if defined(CONFIG_CMD_ONENAND)
		*size = onenand_mtd.size;
		return 0;
#else
		printf("support for OneNAND devices not present\n");
#endif
	} else
		printf("Unknown defice type %d\n", type);

	return 1;
}

#ifdef CONFIG_JFFS2_CMDLINE
/**
 * 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_dev) {
		/* we just deleted current device */
		if (list_empty(&devices)) {
			current_dev = NULL;
		} else {
			/* reset first partition from first dev from the
			 * devices list as current */
			current_dev = list_entry(devices.next, struct mtd_device, link);
			current_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
 */
static 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_dev = dev;
		current_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, *pend;
	LIST_HEAD(tmp_list);
	struct list_head *entry, *n;
	u16 num_parts;
	u32 offset;
	int err = 1;

	p = mtd_dev;
	*retdev = NULL;
	*ret = NULL;

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

	/* fetch <mtd-id> */
	mtd_id = p;
	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;
	}

	DEBUGF("dev type = %d (%s), dev num = %d, mtd-id = %s\n",
			id->type, MTD_DEV_TYPE(id->type),
			id->num, id->mtd_id);
	pend = strchr(p, ';');
	DEBUGF("parsing partitions %.*s\n", (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;
	}