image.c

 * @fit: pointer to the FIT format image header
 * @noffset: node offset
 * @desc: double pointer to the char, will hold pointer to the descrption
 *
 * fit_get_desc() reads description property from a given node, if
 * description is found pointer to it is returened in third call argument.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_get_desc (const void *fit, int noffset, char **desc)
{
	int len;

	*desc = (char *)fdt_getprop (fit, noffset, FIT_DESC_PROP, &len);
	if (*desc == NULL) {
		fit_get_debug (fit, noffset, FIT_DESC_PROP, len);
		return -1;
	}

	return 0;
}

/**
 * fit_get_timestamp - get node timestamp property
 * @fit: pointer to the FIT format image header
 * @noffset: node offset
 * @timestamp: pointer to the time_t, will hold read timestamp
 *
 * fit_get_timestamp() reads timestamp poperty from given node, if timestamp
 * is found and has a correct size its value is retured in third call
 * argument.
 *
 * returns:
 *     0, on success
 *     -1, on property read failure
 *     -2, on wrong timestamp size
 */
int fit_get_timestamp (const void *fit, int noffset, time_t *timestamp)
{
	int len;
	const void *data;

	data = fdt_getprop (fit, noffset, FIT_TIMESTAMP_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_TIMESTAMP_PROP, len);
		return -1;
	}
	if (len != sizeof (uint32_t)) {
		debug ("FIT timestamp with incorrect size of (%u)\n", len);
		return -2;
	}

	*timestamp = uimage_to_cpu (*((uint32_t *)data));
	return 0;
}

/**
 * fit_image_get_node - get node offset for component image of a given unit name
 * @fit: pointer to the FIT format image header
 * @image_uname: component image node unit name
 *
 * fit_image_get_node() finds a component image (withing the '/images'
 * node) of a provided unit name. If image is found its node offset is
 * returned to the caller.
 *
 * returns:
 *     image node offset when found (>=0)
 *     negative number on failure (FDT_ERR_* code)
 */
int fit_image_get_node (const void *fit, const char *image_uname)
{
	int noffset, images_noffset;

	images_noffset = fdt_path_offset (fit, FIT_IMAGES_PATH);
	if (images_noffset < 0) {
		debug ("Can't find images parent node '%s' (%s)\n",
			FIT_IMAGES_PATH, fdt_strerror (images_noffset));
		return images_noffset;
	}

	noffset = fdt_subnode_offset (fit, images_noffset, image_uname);
	if (noffset < 0) {
		debug ("Can't get node offset for image unit name: '%s' (%s)\n",
			image_uname, fdt_strerror (noffset));
	}

	return noffset;
}

/**
 * fit_image_get_os - get os id for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @os: pointer to the uint8_t, will hold os numeric id
 *
 * fit_image_get_os() finds os property in a given component image node.
 * If the property is found, its (string) value is translated to the numeric
 * id which is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_os (const void *fit, int noffset, uint8_t *os)
{
	int len;
	const void *data;

	/* Get OS name from property data */
	data = fdt_getprop (fit, noffset, FIT_OS_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_OS_PROP, len);
		*os = -1;
		return -1;
	}

	/* Translate OS name to id */
	*os = genimg_get_os_id (data);
	return 0;
}

/**
 * fit_image_get_arch - get arch id for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @arch: pointer to the uint8_t, will hold arch numeric id
 *
 * fit_image_get_arch() finds arch property in a given component image node.
 * If the property is found, its (string) value is translated to the numeric
 * id which is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_arch (const void *fit, int noffset, uint8_t *arch)
{
	int len;
	const void *data;

	/* Get architecture name from property data */
	data = fdt_getprop (fit, noffset, FIT_ARCH_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_ARCH_PROP, len);
		*arch = -1;
		return -1;
	}

	/* Translate architecture name to id */
	*arch = genimg_get_arch_id (data);
	return 0;
}

/**
 * fit_image_get_type - get type id for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @type: pointer to the uint8_t, will hold type numeric id
 *
 * fit_image_get_type() finds type property in a given component image node.
 * If the property is found, its (string) value is translated to the numeric
 * id which is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_type (const void *fit, int noffset, uint8_t *type)
{
	int len;
	const void *data;

	/* Get image type name from property data */
	data = fdt_getprop (fit, noffset, FIT_TYPE_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_TYPE_PROP, len);
		*type = -1;
		return -1;
	}

	/* Translate image type name to id */
	*type = genimg_get_type_id (data);
	return 0;
}

/**
 * fit_image_get_comp - get comp id for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @comp: pointer to the uint8_t, will hold comp numeric id
 *
 * fit_image_get_comp() finds comp property in a given component image node.
 * If the property is found, its (string) value is translated to the numeric
 * id which is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_comp (const void *fit, int noffset, uint8_t *comp)
{
	int len;
	const void *data;

	/* Get compression name from property data */
	data = fdt_getprop (fit, noffset, FIT_COMP_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_COMP_PROP, len);
		*comp = -1;
		return -1;
	}

	/* Translate compression name to id */
	*comp = genimg_get_comp_id (data);
	return 0;
}

/**
 * fit_image_get_load - get load address property for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @load: pointer to the uint32_t, will hold load address
 *
 * fit_image_get_load() finds load address property in a given component image node.
 * If the property is found, its value is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_load (const void *fit, int noffset, ulong *load)
{
	int len;
	const uint32_t *data;

	data = fdt_getprop (fit, noffset, FIT_LOAD_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_LOAD_PROP, len);
		return -1;
	}

	*load = uimage_to_cpu (*data);
	return 0;
}

/**
 * fit_image_get_entry - get entry point address property for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @entry: pointer to the uint32_t, will hold entry point address
 *
 * fit_image_get_entry() finds entry point address property in a given component image node.
 * If the property is found, its value is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_entry (const void *fit, int noffset, ulong *entry)
{
	int len;
	const uint32_t *data;

	data = fdt_getprop (fit, noffset, FIT_ENTRY_PROP, &len);
	if (data == NULL) {
		fit_get_debug (fit, noffset, FIT_ENTRY_PROP, len);
		return -1;
	}

	*entry = uimage_to_cpu (*data);
	return 0;
}

/**
 * fit_image_get_data - get data property and its size for a given component image node
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @data: double pointer to void, will hold data property's data address
 * @size: pointer to size_t, will hold data property's data size
 *
 * fit_image_get_data() finds data property in a given component image node.
 * If the property is found its data start address and size are returned to
 * the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_get_data (const void *fit, int noffset,
		const void **data, size_t *size)
{
	int len;

	*data = fdt_getprop (fit, noffset, FIT_DATA_PROP, &len);
	if (*data == NULL) {
		fit_get_debug (fit, noffset, FIT_DATA_PROP, len);
		*size = 0;
		return -1;
	}

	*size = len;
	return 0;
}

/**
 * fit_image_hash_get_algo - get hash algorithm name
 * @fit: pointer to the FIT format image header
 * @noffset: hash node offset
 * @algo: double pointer to char, will hold pointer to the algorithm name
 *
 * fit_image_hash_get_algo() finds hash algorithm property in a given hash node.
 * If the property is found its data start address is returned to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_hash_get_algo (const void *fit, int noffset, char **algo)
{
	int len;

	*algo = (char *)fdt_getprop (fit, noffset, FIT_ALGO_PROP, &len);
	if (*algo == NULL) {
		fit_get_debug (fit, noffset, FIT_ALGO_PROP, len);
		return -1;
	}

	return 0;
}

/**
 * fit_image_hash_get_value - get hash value and length
 * @fit: pointer to the FIT format image header
 * @noffset: hash node offset
 * @value: double pointer to uint8_t, will hold address of a hash value data
 * @value_len: pointer to an int, will hold hash data length
 *
 * fit_image_hash_get_value() finds hash value property in a given hash node.
 * If the property is found its data start address and size are returned to
 * the caller.
 *
 * returns:
 *     0, on success
 *     -1, on failure
 */
int fit_image_hash_get_value (const void *fit, int noffset, uint8_t **value,
				int *value_len)
{
	int len;

	*value = (uint8_t *)fdt_getprop (fit, noffset, FIT_VALUE_PROP, &len);
	if (*value == NULL) {
		fit_get_debug (fit, noffset, FIT_VALUE_PROP, len);
		*value_len = 0;
		return -1;
	}

	*value_len = len;
	return 0;
}

/**
 * fit_set_timestamp - set node timestamp property
 * @fit: pointer to the FIT format image header
 * @noffset: node offset
 * @timestamp: timestamp value to be set
 *
 * fit_set_timestamp() attempts to set timestamp property in the requested
 * node and returns operation status to the caller.
 *
 * returns:
 *     0, on success
 *     -1, on property read failure
 */
int fit_set_timestamp (void *fit, int noffset, time_t timestamp)
{
	uint32_t t;
	int ret;

	t = cpu_to_uimage (timestamp);
	ret = fdt_setprop (fit, noffset, FIT_TIMESTAMP_PROP, &t,
				sizeof (uint32_t));
	if (ret) {
		printf ("Can't set '%s' property for '%s' node (%s)\n",
			FIT_TIMESTAMP_PROP, fit_get_name (fit, noffset, NULL),
			fdt_strerror (ret));
		return -1;
	}

	return 0;
}

/**
 * calculate_hash - calculate and return hash for provided input data
 * @data: pointer to the input data
 * @data_len: data length
 * @algo: requested hash algorithm
 * @value: pointer to the char, will hold hash value data (caller must
 * allocate enough free space)
 * value_len: length of the calculated hash
 *
 * calculate_hash() computes input data hash according to the requested algorithm.
 * Resulting hash value is placed in caller provided 'value' buffer, length
 * of the calculated hash is returned via value_len pointer argument.
 *
 * returns:
 *     0, on success
 *    -1, when algo is unsupported
 */
static int calculate_hash (const void *data, int data_len, const char *algo,
			uint8_t *value, int *value_len)
{
	if (strcmp (algo, "crc32") == 0 ) {
		*((uint32_t *)value) = crc32_wd (0, data, data_len,
							CHUNKSZ_CRC32);
		*((uint32_t *)value) = cpu_to_uimage (*((uint32_t *)value));
		*value_len = 4;
	} else if (strcmp (algo, "sha1") == 0 ) {
		sha1_csum_wd ((unsigned char *) data, data_len,
				(unsigned char *) value, CHUNKSZ_SHA1);
		*value_len = 20;
	} else if (strcmp (algo, "md5") == 0 ) {
		md5_wd ((unsigned char *)data, data_len, value, CHUNKSZ_MD5);
		*value_len = 16;
	} else {
		debug ("Unsupported hash alogrithm\n");
		return -1;
	}
	return 0;
}

#ifdef USE_HOSTCC
/**
 * fit_set_hashes - process FIT component image nodes and calculate hashes
 * @fit: pointer to the FIT format image header
 *
 * fit_set_hashes() adds hash values for all component images in the FIT blob.
 * Hashes are calculated for all component images which have hash subnodes
 * with algorithm property set to one of the supported hash algorithms.
 *
 * returns
 *     0, on success
 *     libfdt error code, on failure
 */
int fit_set_hashes (void *fit)
{
	int images_noffset;
	int noffset;
	int ndepth;
	int ret;

	/* Find images parent node offset */
	images_noffset = fdt_path_offset (fit, FIT_IMAGES_PATH);
	if (images_noffset < 0) {
		printf ("Can't find images parent node '%s' (%s)\n",
			FIT_IMAGES_PATH, fdt_strerror (images_noffset));
		return images_noffset;
	}

	/* Process its subnodes, print out component images details */
	for (ndepth = 0, noffset = fdt_next_node (fit, images_noffset, &ndepth);
	     (noffset >= 0) && (ndepth > 0);
	     noffset = fdt_next_node (fit, noffset, &ndepth)) {
		if (ndepth == 1) {
			/*
			 * Direct child node of the images parent node,
			 * i.e. component image node.
			 */
			ret = fit_image_set_hashes (fit, noffset);
			if (ret)
				return ret;
		}
	}

	return 0;
}

/**
 * fit_image_set_hashes - calculate/set hashes for given component image node
 * @fit: pointer to the FIT format image header
 * @image_noffset: requested component image node
 *
 * fit_image_set_hashes() adds hash values for an component image node. All
 * existing hash subnodes are checked, if algorithm property is set to one of
 * the supported hash algorithms, hash value is computed and corresponding
 * hash node property is set, for example:
 *
 * Input component image node structure:
 *
 * o image@1 (at image_noffset)
 *   | - data = [binary data]
 *   o hash@1
 *     |- algo = "sha1"
 *
 * Output component image node structure:
 *
 * o image@1 (at image_noffset)
 *   | - data = [binary data]
 *   o hash@1
 *     |- algo = "sha1"
 *     |- value = sha1(data)
 *
 * returns:
 *     0 on sucess
 *    <0 on failure
 */
int fit_image_set_hashes (void *fit, int image_noffset)
{
	const void *data;
	size_t size;
	char *algo;
	uint8_t value[FIT_MAX_HASH_LEN];
	int value_len;
	int noffset;
	int ndepth;

	/* Get image data and data length */
	if (fit_image_get_data (fit, image_noffset, &data, &size)) {
		printf ("Can't get image data/size\n");
		return -1;
	}

	/* Process all hash subnodes of the component image node */
	for (ndepth = 0, noffset = fdt_next_node (fit, image_noffset, &ndepth);
	     (noffset >= 0) && (ndepth > 0);
	     noffset = fdt_next_node (fit, noffset, &ndepth)) {
		if (ndepth == 1) {
			/* Direct child node of the component image node */

			/*
			 * Check subnode name, must be equal to "hash".
			 * Multiple hash nodes require unique unit node
			 * names, e.g. hash@1, hash@2, etc.
			 */
			if (strncmp (fit_get_name(fit, noffset, NULL),
						FIT_HASH_NODENAME,
						strlen(FIT_HASH_NODENAME)) != 0) {
				/* Not a hash subnode, skip it */
				continue;
			}

			if (fit_image_hash_get_algo (fit, noffset, &algo)) {
				printf ("Can't get hash algo property for "
					"'%s' hash node in '%s' image node\n",
					fit_get_name (fit, noffset, NULL),
					fit_get_name (fit, image_noffset, NULL));
				return -1;
			}

			if (calculate_hash (data, size, algo, value, &value_len)) {
				printf ("Unsupported hash algorithm (%s) for "
					"'%s' hash node in '%s' image node\n",
					algo, fit_get_name (fit, noffset, NULL),
					fit_get_name (fit, image_noffset, NULL));
				return -1;
			}

			if (fit_image_hash_set_value (fit, noffset, value,
							value_len)) {
				printf ("Can't set hash value for "
					"'%s' hash node in '%s' image node\n",
					fit_get_name (fit, noffset, NULL),
					fit_get_name (fit, image_noffset, NULL));
				return -1;
			}
		}
	}

	return 0;
}

/**
 * fit_image_hash_set_value - set hash value in requested has node
 * @fit: pointer to the FIT format image header
 * @noffset: hash node offset
 * @value: hash value to be set
 * @value_len: hash value length
 *
 * fit_image_hash_set_value() attempts to set hash value in a node at offset
 * given and returns operation status to the caller.
 *
 * returns
 *     0, on success
 *     -1, on failure
 */
int fit_image_hash_set_value (void *fit, int noffset, uint8_t *value,
				int value_len)
{
	int ret;

	ret = fdt_setprop (fit, noffset, FIT_VALUE_PROP, value, value_len);
	if (ret) {
		printf ("Can't set hash '%s' property for '%s' node (%s)\n",
			FIT_VALUE_PROP, fit_get_name (fit, noffset, NULL),
			fdt_strerror (ret));
		return -1;
	}

	return 0;
}
#endif /* USE_HOSTCC */

/**
 * fit_image_check_hashes - verify data intergity
 * @fit: pointer to the FIT format image header
 * @image_noffset: component image node offset
 *
 * fit_image_check_hashes() goes over component image hash nodes,
 * re-calculates each data hash and compares with the value stored in hash
 * node.
 *
 * returns:
 *     1, if all hashes are valid
 *     0, otherwise (or on error)
 */
int fit_image_check_hashes (const void *fit, int image_noffset)
{
	const void	*data;
	size_t		size;
	char		*algo;
	uint8_t		*fit_value;
	int		fit_value_len;
	uint8_t		value[FIT_MAX_HASH_LEN];
	int		value_len;
	int		noffset;
	int		ndepth;
	char		*err_msg = "";

	/* Get image data and data length */
	if (fit_image_get_data (fit, image_noffset, &data, &size)) {
		printf ("Can't get image data/size\n");
		return 0;
	}

	/* Process all hash subnodes of the component image node */
	for (ndepth = 0, noffset = fdt_next_node (fit, image_noffset, &ndepth);
	     (noffset >= 0) && (ndepth > 0);
	     noffset = fdt_next_node (fit, noffset, &ndepth)) {
		if (ndepth == 1) {
			/* Direct child node of the component image node */

			/*
			 * Check subnode name, must be equal to "hash".
			 * Multiple hash nodes require unique unit node
			 * names, e.g. hash@1, hash@2, etc.
			 */
			if (strncmp (fit_get_name(fit, noffset, NULL),
					FIT_HASH_NODENAME,
					strlen(FIT_HASH_NODENAME)) != 0)
				continue;

			if (fit_image_hash_get_algo (fit, noffset, &algo)) {
				err_msg = " error!\nCan't get hash algo "
						"property";
				goto error;
			}
			printf ("%s", algo);

			if (fit_image_hash_get_value (fit, noffset, &fit_value,
							&fit_value_len)) {
				err_msg = " error!\nCan't get hash value "
						"property";
				goto error;
			}

			if (calculate_hash (data, size, algo, value, &value_len)) {
				err_msg = " error!\nUnsupported hash algorithm";
				goto error;
			}

			if (value_len != fit_value_len) {
				err_msg = " error !\nBad hash value len";
				goto error;
			} else if (memcmp (value, fit_value, value_len) != 0) {
				err_msg = " error!\nBad hash value";
				goto error;
			}
			printf ("+ ");
		}
	}

	return 1;

error:
	printf ("%s for '%s' hash node in '%s' image node\n",
			err_msg, fit_get_name (fit, noffset, NULL),
			fit_get_name (fit, image_noffset, NULL));
	return 0;
}

/**
 * fit_all_image_check_hashes - verify data intergity for all images
 * @fit: pointer to the FIT format image header
 *
 * fit_all_image_check_hashes() goes over all images in the FIT and
 * for every images checks if all it's hashes are valid.
 *
 * returns:
 *     1, if all hashes of all images are valid
 *     0, otherwise (or on error)
 */
int fit_all_image_check_hashes (const void *fit)
{
	int images_noffset;
	int noffset;
	int ndepth;
	int count;

	/* Find images parent node offset */
	images_noffset = fdt_path_offset (fit, FIT_IMAGES_PATH);
	if (images_noffset < 0) {
		printf ("Can't find images parent node '%s' (%s)\n",
			FIT_IMAGES_PATH, fdt_strerror (images_noffset));
		return 0;
	}

	/* Process all image subnodes, check hashes for each */
	printf ("## Checking hash(es) for FIT Image at %08lx ...\n",
		(ulong)fit);
	for (ndepth = 0, count = 0,
		noffset = fdt_next_node (fit, images_noffset, &ndepth);
		(noffset >= 0) && (ndepth > 0);
		noffset = fdt_next_node (fit, noffset, &ndepth)) {
		if (ndepth == 1) {
			/*
			 * Direct child node of the images parent node,
			 * i.e. component image node.
			 */
			printf ("   Hash(es) for Image %u (%s): ", count++,
					fit_get_name (fit, noffset, NULL));

			if (!fit_image_check_hashes (fit, noffset))
				return 0;
			printf ("\n");
		}
	}
	return 1;
}

/**
 * fit_image_check_os - check whether image node is of a given os type
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @os: requested image os
 *
 * fit_image_check_os() reads image os property and compares its numeric
 * id with the requested os. Comparison result is returned to the caller.
 *
 * returns:
 *     1 if image is of given os type
 *     0 otherwise (or on error)
 */
int fit_image_check_os (const void *fit, int noffset, uint8_t os)
{
	uint8_t image_os;

	if (fit_image_get_os (fit, noffset, &image_os))
		return 0;
	return (os == image_os);
}

/**
 * fit_image_check_arch - check whether image node is of a given arch
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @arch: requested imagearch
 *
 * fit_image_check_arch() reads image arch property and compares its numeric
 * id with the requested arch. Comparison result is returned to the caller.
 *
 * returns:
 *     1 if image is of given arch
 *     0 otherwise (or on error)
 */
int fit_image_check_arch (const void *fit, int noffset, uint8_t arch)
{
	uint8_t image_arch;

	if (fit_image_get_arch (fit, noffset, &image_arch))
		return 0;
	return (arch == image_arch);
}

/**
 * fit_image_check_type - check whether image node is of a given type
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @type: requested image type
 *
 * fit_image_check_type() reads image type property and compares its numeric
 * id with the requested type. Comparison result is returned to the caller.
 *
 * returns:
 *     1 if image is of given type
 *     0 otherwise (or on error)
 */
int fit_image_check_type (const void *fit, int noffset, uint8_t type)
{
	uint8_t image_type;

	if (fit_image_get_type (fit, noffset, &image_type))
		return 0;
	return (type == image_type);
}

/**
 * fit_image_check_comp - check whether image node uses given compression
 * @fit: pointer to the FIT format image header
 * @noffset: component image node offset
 * @comp: requested image compression type
 *
 * fit_image_check_comp() reads image compression property and compares its
 * numeric id with the requested compression type. Comparison result is
 * returned to the caller.
 *
 * returns:
 *     1 if image uses requested compression
 *     0 otherwise (or on error)
 */
int fit_image_check_comp (const void *fit, int noffset, uint8_t comp)
{
	uint8_t image_comp;

	if (fit_image_get_comp (fit, noffset, &image_comp))
		return 0;
	return (comp == image_comp);
}

/**
 * fit_check_format - sanity check FIT image format
 * @fit: pointer to the FIT format image header
 *
 * fit_check_format() runs a basic sanity FIT image verification.
 * Routine checks for mandatory properties, nodes, etc.
 *
 * returns:
 *     1, on success
 *     0, on failure
 */
int fit_check_format (const void *fit)
{
	/* mandatory / node 'description' property */
	if (fdt_getprop (fit, 0, FIT_DESC_PROP, NULL) == NULL) {
		debug ("Wrong FIT format: no description\n");
		return 0;
	}

#if defined(CONFIG_TIMESTAMP) || defined(CONFIG_CMD_DATE) || defined(USE_HOSTCC)
	/* mandatory / node 'timestamp' property */
	if (fdt_getprop (fit, 0, FIT_TIMESTAMP_PROP, NULL) == NULL) {
		debug ("Wrong FIT format: no timestamp\n");
		return 0;
	}
#endif

	/* mandatory subimages parent '/images' node */
	if (fdt_path_offset (fit, FIT_IMAGES_PATH) < 0) {
		debug ("Wrong FIT format: no images parent node\n");
		return 0;
	}

	return 1;
}

/**
 * fit_conf_get_node - get node offset for configuration of a given unit name
 * @fit: pointer to the FIT format image header
 * @conf_uname: configuration node unit name
 *
 * fit_conf_get_node() finds a configuration (withing the '/configurations'
 * parant node) of a provided unit name. If configuration is found its node offset
 * is returned to the caller.
 *
 * When NULL is provided in second argument fit_conf_get_node() will search
 * for a default configuration node instead. Default configuration node unit name
 * is retrived from FIT_DEFAULT_PROP property of the '/configurations' node.
 *
 * returns:
 *     configuration node offset when found (>=0)
 *     negative number on failure (FDT_ERR_* code)
 */
int fit_conf_get_node (const void *fit, const char *conf_uname)
{
	int noffset, confs_noffset;
	int len;

	confs_noffset = fdt_path_offset (fit, FIT_CONFS_PATH);
	if (confs_noffset < 0) {
		debug ("Can't find configurations parent node '%s' (%s)\n",
			FIT_CONFS_PATH, fdt_strerror (confs_noffset));
		return confs_noffset;
	}

	if (conf_uname == NULL) {
		/* get configuration unit name from the default property */
		debug ("No configuration specified, trying default...\n");
		conf_uname = (char *)fdt_getprop (fit, confs_noffset, FIT_DEFAULT_PROP, &len);
		if (conf_uname == NULL) {
			fit_get_debug (fit, confs_noffset, FIT_DEFAULT_PROP, len);
			return len;
		}
		debug ("Found default configuration: '%s'\n", conf_uname);
	}

	noffset = fdt_subnode_offset (fit, confs_noffset, conf_uname);
	if (noffset < 0) {
		debug ("Can't get node offset for configuration unit name: '%s' (%s)\n",
			conf_uname, fdt_strerror (noffset));
	}

	return noffset;
}

static int __fit_conf_get_prop_node (const void *fit, int noffset,
		const char *prop_name)
{
	char *uname;
	int len;

	/* get kernel image unit name from configuration kernel property */
	uname = (char *)fdt_getprop (fit, noffset, prop_name, &len);
	if (uname == NULL)
		return len;

	return fit_image_get_node (fit, uname);
}

/**
 * fit_conf_get_kernel_node - get kernel image node offset that corresponds to
 * a given configuration
 * @fit: pointer to the FIT format image header
 * @noffset: configuration node offset
 *
 * fit_conf_get_kernel_node() retrives kernel image node unit name from
 * configuration FIT_KERNEL_PROP property and translates it to the node
 * offset.
 *
 * returns:
 *     image node offset when found (>=0)
 *     negative number on failure (FDT_ERR_* code)
 */
int fit_conf_get_kernel_node (const void *fit, int noffset)
{
	return __fit_conf_get_prop_node (fit, noffset, FIT_KERNEL_PROP);
}

/**
 * fit_conf_get_ramdisk_node - get ramdisk image node offset that corresponds to
 * a given configuration
 * @fit: pointer to the FIT format image header
 * @noffset: configuration node offset
 *
 * fit_conf_get_ramdisk_node() retrives ramdisk image node unit name from
 * configuration FIT_KERNEL_PROP property and translates it to the node
 * offset.
 *
 * returns:
 *     image node offset when found (>=0)
 *     negative number on failure (FDT_ERR_* code)
 */
int fit_conf_get_ramdisk_node (const void *fit, int noffset)
{
	return __fit_conf_get_prop_node (fit, noffset, FIT_RAMDISK_PROP);
}

/**
 * fit_conf_get_fdt_node - get fdt image node offset that corresponds to
 * a given configuration
 * @fit: pointer to the FIT format image header
 * @noffset: configuration node offset
 *
 * fit_conf_get_fdt_node() retrives fdt image node unit name from
 * configuration FIT_KERNEL_PROP property and translates it to the node
 * offset.
 *
 * returns:
 *     image node offset when found (>=0)
 *     negative number on failure (FDT_ERR_* code)
 */
int fit_conf_get_fdt_node (const void *fit, int noffset)
{
	return __fit_conf_get_prop_node (fit, noffset, FIT_FDT_PROP);
}

/**
 * fit_conf_print - prints out the FIT configuration details
 * @fit: pointer to the FIT format image header
 * @noffset: offset of the configuration node
 * @p: pointer to prefix string
 *
 * fit_conf_print() lists all mandatory properies for the processed
 * configuration node.
 *
 * returns:
 *     no returned results
 */
void fit_conf_print (const void *fit, int noffset, const char *p)
{