/*
   * EFI device path from u-boot device-model mapping
   *
   * (C) Copyright 2017 Rob Clark
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #define LOG_CATEGORY LOGL_ERR
  
  #include <common.h>
  #include <blk.h>
  #include <dm.h>
  #include <usb.h>
  #include <mmc.h>
  #include <efi_loader.h>
  #include <inttypes.h>
  #include <part.h>
  
  /* template END node: */
  static const struct efi_device_path END = {
  	.type     = DEVICE_PATH_TYPE_END,
  	.sub_type = DEVICE_PATH_SUB_TYPE_END,
  	.length   = sizeof(END),
  };
  
  #define U_BOOT_GUID \
  	EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
  		 0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
  
  /* template ROOT node: */
  static const struct efi_device_path_vendor ROOT = {
  	.dp = {
  		.type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
  		.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
  		.length   = sizeof(ROOT),
  	},
  	.guid = U_BOOT_GUID,
  };
  
  #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  /*
   * Determine if an MMC device is an SD card.
   *
   * @desc	block device descriptor
   * @return	true if the device is an SD card
   */
  static bool is_sd(struct blk_desc *desc)
  {
  	struct mmc *mmc = find_mmc_device(desc->devnum);
  
  	if (!mmc)
  		return false;
  
  	return IS_SD(mmc) != 0U;
  }
  #endif
  
  static void *dp_alloc(size_t sz)
  {
  	void *buf;
  
  	if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
  	    EFI_SUCCESS) {
  		debug("EFI: ERROR: out of memory in %s
  ", __func__);
  		return NULL;
  	}
  
  	return buf;
  }
  
  /*
   * Iterate to next block in device-path, terminating (returning NULL)
   * at /End* node.
   */
  struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  {
  	if (dp == NULL)
  		return NULL;
  	if (dp->type == DEVICE_PATH_TYPE_END)
  		return NULL;
  	dp = ((void *)dp) + dp->length;
  	if (dp->type == DEVICE_PATH_TYPE_END)
  		return NULL;
  	return (struct efi_device_path *)dp;
  }
  
  /*
   * Compare two device-paths, stopping when the shorter of the two hits
   * an End* node.  This is useful to, for example, compare a device-path
   * representing a device with one representing a file on the device, or
   * a device with a parent device.
   */
  int efi_dp_match(const struct efi_device_path *a,
  		 const struct efi_device_path *b)
  {
  	while (1) {
  		int ret;
  
  		ret = memcmp(&a->length, &b->length, sizeof(a->length));
  		if (ret)
  			return ret;
  
  		ret = memcmp(a, b, a->length);
  		if (ret)
  			return ret;
  
  		a = efi_dp_next(a);
  		b = efi_dp_next(b);
  
  		if (!a || !b)
  			return 0;
  	}
  }
  
  /*
   * See UEFI spec (section 3.1.2, about short-form device-paths..
   * tl;dr: we can have a device-path that starts with a USB WWID
   * or USB Class node, and a few other cases which don't encode
   * the full device path with bus hierarchy:
   *
   *   - MESSAGING:USB_WWID
   *   - MESSAGING:USB_CLASS
   *   - MEDIA:FILE_PATH
   *   - MEDIA:HARD_DRIVE
   *   - MESSAGING:URI
   */
  static struct efi_device_path *shorten_path(struct efi_device_path *dp)
  {
  	while (dp) {
  		/*
  		 * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
  		 * in practice fallback.efi just uses MEDIA:HARD_DRIVE
  		 * so not sure when we would see these other cases.
  		 */
  		if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
  		    EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
  		    EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
  			return dp;
  
  		dp = efi_dp_next(dp);
  	}
  
  	return dp;
  }
  
  static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
  				   struct efi_device_path **rem)
  {
  	struct efi_object *efiobj;
  	unsigned int dp_size = efi_dp_size(dp);
  
  	list_for_each_entry(efiobj, &efi_obj_list, link) {
  		struct efi_handler *handler;
  		struct efi_device_path *obj_dp;
  		efi_status_t ret;
  
  		ret = efi_search_protocol(efiobj->handle,
  					  &efi_guid_device_path, &handler);
  		if (ret != EFI_SUCCESS)
  			continue;
  		obj_dp = handler->protocol_interface;
  
  		do {
  			if (efi_dp_match(dp, obj_dp) == 0) {
  				if (rem) {
  					/*
  					 * Allow partial matches, but inform
  					 * the caller.
  					 */
  					*rem = ((void *)dp) +
  						efi_dp_size(obj_dp);
  					return efiobj;
  				} else {
  					/* Only return on exact matches */
  					if (efi_dp_size(obj_dp) == dp_size)
  						return efiobj;
  				}
  			}
  
  			obj_dp = shorten_path(efi_dp_next(obj_dp));
  		} while (short_path && obj_dp);
  	}
  
  	return NULL;
  }
  
  /*
   * Find an efiobj from device-path, if 'rem' is not NULL, returns the
   * remaining part of the device path after the matched object.
   */
  struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
  				   struct efi_device_path **rem)
  {
  	struct efi_object *efiobj;
  
  	/* Search for an exact match first */
  	efiobj = find_obj(dp, false, NULL);
  
  	/* Then for a fuzzy match */
  	if (!efiobj)
  		efiobj = find_obj(dp, false, rem);
  
  	/* And now for a fuzzy short match */
  	if (!efiobj)
  		efiobj = find_obj(dp, true, rem);
  
  	return efiobj;
  }
  
  /*
   * Determine the last device path node that is not the end node.
   *
   * @dp		device path
   * @return	last node before the end node if it exists
   *		otherwise NULL
   */
  const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
  {
  	struct efi_device_path *ret;
  
  	if (!dp || dp->type == DEVICE_PATH_TYPE_END)
  		return NULL;
  	while (dp) {
  		ret = (struct efi_device_path *)dp;
  		dp = efi_dp_next(dp);
  	}
  	return ret;
  }
  
  /* return size not including End node: */
  unsigned efi_dp_size(const struct efi_device_path *dp)
  {
  	unsigned sz = 0;
  
  	while (dp) {
  		sz += dp->length;
  		dp = efi_dp_next(dp);
  	}
  
  	return sz;
  }
  
  struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
  {
  	struct efi_device_path *ndp;
  	unsigned sz = efi_dp_size(dp) + sizeof(END);
  
  	if (!dp)
  		return NULL;
  
  	ndp = dp_alloc(sz);
  	if (!ndp)
  		return NULL;
  	memcpy(ndp, dp, sz);
  
  	return ndp;
  }
  
  struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
  				      const struct efi_device_path *dp2)
  {
  	struct efi_device_path *ret;
  
  	if (!dp1) {
  		ret = efi_dp_dup(dp2);
  	} else if (!dp2) {
  		ret = efi_dp_dup(dp1);
  	} else {
  		/* both dp1 and dp2 are non-null */
  		unsigned sz1 = efi_dp_size(dp1);
  		unsigned sz2 = efi_dp_size(dp2);
  		void *p = dp_alloc(sz1 + sz2 + sizeof(END));
  		if (!p)
  			return NULL;
  		memcpy(p, dp1, sz1);
  		memcpy(p + sz1, dp2, sz2);
  		memcpy(p + sz1 + sz2, &END, sizeof(END));
  		ret = p;
  	}
  
  	return ret;
  }
  
  struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
  					   const struct efi_device_path *node)
  {
  	struct efi_device_path *ret;
  
  	if (!node && !dp) {
  		ret = efi_dp_dup(&END);
  	} else if (!node) {
  		ret = efi_dp_dup(dp);
  	} else if (!dp) {
  		unsigned sz = node->length;
  		void *p = dp_alloc(sz + sizeof(END));
  		if (!p)
  			return NULL;
  		memcpy(p, node, sz);
  		memcpy(p + sz, &END, sizeof(END));
  		ret = p;
  	} else {
  		/* both dp and node are non-null */
  		unsigned sz = efi_dp_size(dp);
  		void *p = dp_alloc(sz + node->length + sizeof(END));
  		if (!p)
  			return NULL;
  		memcpy(p, dp, sz);
  		memcpy(p + sz, node, node->length);
  		memcpy(p + sz + node->length, &END, sizeof(END));
  		ret = p;
  	}
  
  	return ret;
  }
  
  #ifdef CONFIG_DM
  /* size of device-path not including END node for device and all parents
   * up to the root device.
   */
  static unsigned dp_size(struct udevice *dev)
  {
  	if (!dev || !dev->driver)
  		return sizeof(ROOT);
  
  	switch (dev->driver->id) {
  	case UCLASS_ROOT:
  	case UCLASS_SIMPLE_BUS:
  		/* stop traversing parents at this point: */
  		return sizeof(ROOT);
  	case UCLASS_ETH:
  		return dp_size(dev->parent) +
  			sizeof(struct efi_device_path_mac_addr);
  #ifdef CONFIG_BLK
  	case UCLASS_BLK:
  		switch (dev->parent->uclass->uc_drv->id) {
  #ifdef CONFIG_IDE
  		case UCLASS_IDE:
  			return dp_size(dev->parent) +
  				sizeof(struct efi_device_path_atapi);
  #endif
  #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
  		case UCLASS_SCSI:
  			return dp_size(dev->parent) +
  				sizeof(struct efi_device_path_scsi);
  #endif
  #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  		case UCLASS_MMC:
  			return dp_size(dev->parent) +
  				sizeof(struct efi_device_path_sd_mmc_path);
  #endif
  		default:
  			return dp_size(dev->parent);
  		}
  #endif
  #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  	case UCLASS_MMC:
  		return dp_size(dev->parent) +
  			sizeof(struct efi_device_path_sd_mmc_path);
  #endif
  	case UCLASS_MASS_STORAGE:
  	case UCLASS_USB_HUB:
  		return dp_size(dev->parent) +
  			sizeof(struct efi_device_path_usb_class);
  	default:
  		/* just skip over unknown classes: */
  		return dp_size(dev->parent);
  	}
  }
  
  /*
   * Recursively build a device path.
   *
   * @buf		pointer to the end of the device path
   * @dev		device
   * @return	pointer to the end of the device path
   */
  static void *dp_fill(void *buf, struct udevice *dev)
  {
  	if (!dev || !dev->driver)
  		return buf;
  
  	switch (dev->driver->id) {
  	case UCLASS_ROOT:
  	case UCLASS_SIMPLE_BUS: {
  		/* stop traversing parents at this point: */
  		struct efi_device_path_vendor *vdp = buf;
  		*vdp = ROOT;
  		return &vdp[1];
  	}
  #ifdef CONFIG_DM_ETH
  	case UCLASS_ETH: {
  		struct efi_device_path_mac_addr *dp =
  			dp_fill(buf, dev->parent);
  		struct eth_pdata *pdata = dev->platdata;
  
  		dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  		dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
  		dp->dp.length = sizeof(*dp);
  		memset(&dp->mac, 0, sizeof(dp->mac));
  		/* We only support IPv4 */
  		memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
  		/* Ethernet */
  		dp->if_type = 1;
  		return &dp[1];
  	}
  #endif
  #ifdef CONFIG_BLK
  	case UCLASS_BLK:
  		switch (dev->parent->uclass->uc_drv->id) {
  #ifdef CONFIG_IDE
  		case UCLASS_IDE: {
  			struct efi_device_path_atapi *dp =
  			dp_fill(buf, dev->parent);
  			struct blk_desc *desc = dev_get_uclass_platdata(dev);
  
  			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
  			dp->dp.length = sizeof(*dp);
  			dp->logical_unit_number = desc->devnum;
  			dp->primary_secondary = IDE_BUS(desc->devnum);
  			dp->slave_master = desc->devnum %
  				(CONFIG_SYS_IDE_MAXDEVICE /
  				 CONFIG_SYS_IDE_MAXBUS);
  			return &dp[1];
  			}
  #endif
  #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
  		case UCLASS_SCSI: {
  			struct efi_device_path_scsi *dp =
  				dp_fill(buf, dev->parent);
  			struct blk_desc *desc = dev_get_uclass_platdata(dev);
  
  			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
  			dp->dp.length = sizeof(*dp);
  			dp->logical_unit_number = desc->lun;
  			dp->target_id = desc->target;
  			return &dp[1];
  			}
  #endif
  #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  		case UCLASS_MMC: {
  			struct efi_device_path_sd_mmc_path *sddp =
  				dp_fill(buf, dev->parent);
  			struct blk_desc *desc = dev_get_uclass_platdata(dev);
  
  			sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  			sddp->dp.sub_type = is_sd(desc) ?
  				DEVICE_PATH_SUB_TYPE_MSG_SD :
  				DEVICE_PATH_SUB_TYPE_MSG_MMC;
  			sddp->dp.length   = sizeof(*sddp);
  			sddp->slot_number = dev->seq;
  			return &sddp[1];
  			}
  #endif
  		default:
  			debug("%s(%u) %s: unhandled parent class: %s (%u)
  ",
  			      __FILE__, __LINE__, __func__,
  			      dev->name, dev->parent->uclass->uc_drv->id);
  			return dp_fill(buf, dev->parent);
  		}
  #endif
  #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  	case UCLASS_MMC: {
  		struct efi_device_path_sd_mmc_path *sddp =
  			dp_fill(buf, dev->parent);
  		struct mmc *mmc = mmc_get_mmc_dev(dev);
  		struct blk_desc *desc = mmc_get_blk_desc(mmc);
  
  		sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  		sddp->dp.sub_type = is_sd(desc) ?
  			DEVICE_PATH_SUB_TYPE_MSG_SD :
  			DEVICE_PATH_SUB_TYPE_MSG_MMC;
  		sddp->dp.length   = sizeof(*sddp);
  		sddp->slot_number = dev->seq;
  
  		return &sddp[1];
  	}
  #endif
  	case UCLASS_MASS_STORAGE:
  	case UCLASS_USB_HUB: {
  		struct efi_device_path_usb_class *udp =
  			dp_fill(buf, dev->parent);
  		struct usb_device *udev = dev_get_parent_priv(dev);
  		struct usb_device_descriptor *desc = &udev->descriptor;
  
  		udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  		udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
  		udp->dp.length   = sizeof(*udp);
  		udp->vendor_id   = desc->idVendor;
  		udp->product_id  = desc->idProduct;
  		udp->device_class    = desc->bDeviceClass;
  		udp->device_subclass = desc->bDeviceSubClass;
  		udp->device_protocol = desc->bDeviceProtocol;
  
  		return &udp[1];
  	}
  	default:
  		debug("%s(%u) %s: unhandled device class: %s (%u)
  ",
  		      __FILE__, __LINE__, __func__,
  		      dev->name, dev->driver->id);
  		return dp_fill(buf, dev->parent);
  	}
  }
  
  /* Construct a device-path from a device: */
  struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
  {
  	void *buf, *start;
  
  	start = buf = dp_alloc(dp_size(dev) + sizeof(END));
  	if (!buf)
  		return NULL;
  	buf = dp_fill(buf, dev);
  	*((struct efi_device_path *)buf) = END;
  
  	return start;
  }
  #endif
  
  static unsigned dp_part_size(struct blk_desc *desc, int part)
  {
  	unsigned dpsize;
  
  #ifdef CONFIG_BLK
  	{
  		struct udevice *dev;
  		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
  
  		if (ret)
  			dev = desc->bdev->parent;
  		dpsize = dp_size(dev);
  	}
  #else
  	dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
  #endif
  
  	if (part == 0) /* the actual disk, not a partition */
  		return dpsize;
  
  	if (desc->part_type == PART_TYPE_ISO)
  		dpsize += sizeof(struct efi_device_path_cdrom_path);
  	else
  		dpsize += sizeof(struct efi_device_path_hard_drive_path);
  
  	return dpsize;
  }
  
  /*
   * Create a device node for a block device partition.
   *
   * @buf		buffer to which the device path is wirtten
   * @desc	block device descriptor
   * @part	partition number, 0 identifies a block device
   */
  static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
  {
  	disk_partition_t info;
  
  	part_get_info(desc, part, &info);
  
  	if (desc->part_type == PART_TYPE_ISO) {
  		struct efi_device_path_cdrom_path *cddp = buf;
  
  		cddp->boot_entry = part;
  		cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
  		cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
  		cddp->dp.length = sizeof(*cddp);
  		cddp->partition_start = info.start;
  		cddp->partition_end = info.size;
  
  		buf = &cddp[1];
  	} else {
  		struct efi_device_path_hard_drive_path *hddp = buf;
  
  		hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
  		hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
  		hddp->dp.length = sizeof(*hddp);
  		hddp->partition_number = part;
  		hddp->partition_start = info.start;
  		hddp->partition_end = info.size;
  		if (desc->part_type == PART_TYPE_EFI)
  			hddp->partmap_type = 2;
  		else
  			hddp->partmap_type = 1;
  
  		switch (desc->sig_type) {
  		case SIG_TYPE_NONE:
  		default:
  			hddp->signature_type = 0;
  			memset(hddp->partition_signature, 0,
  			       sizeof(hddp->partition_signature));
  			break;
  		case SIG_TYPE_MBR:
  			hddp->signature_type = 1;
  			memset(hddp->partition_signature, 0,
  			       sizeof(hddp->partition_signature));
  			memcpy(hddp->partition_signature, &desc->mbr_sig,
  			       sizeof(desc->mbr_sig));
  			break;
  		case SIG_TYPE_GUID:
  			hddp->signature_type = 2;
  			memcpy(hddp->partition_signature, &desc->guid_sig,
  			       sizeof(hddp->partition_signature));
  			break;
  		}
  
  		buf = &hddp[1];
  	}
  
  	return buf;
  }
  
  /*
   * Create a device path for a block device or one of its partitions.
   *
   * @buf		buffer to which the device path is wirtten
   * @desc	block device descriptor
   * @part	partition number, 0 identifies a block device
   */
  static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
  {
  #ifdef CONFIG_BLK
  	{
  		struct udevice *dev;
  		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
  
  		if (ret)
  			dev = desc->bdev->parent;
  		buf = dp_fill(buf, dev);
  	}
  #else
  	/*
  	 * We *could* make a more accurate path, by looking at if_type
  	 * and handling all the different cases like we do for non-
  	 * legacy (ie CONFIG_BLK=y) case.  But most important thing
  	 * is just to have a unique device-path for if_type+devnum.
  	 * So map things to a fictitious USB device.
  	 */
  	struct efi_device_path_usb *udp;
  
  	memcpy(buf, &ROOT, sizeof(ROOT));
  	buf += sizeof(ROOT);
  
  	udp = buf;
  	udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  	udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
  	udp->dp.length = sizeof(*udp);
  	udp->parent_port_number = desc->if_type;
  	udp->usb_interface = desc->devnum;
  	buf = &udp[1];
  #endif
  
  	if (part == 0) /* the actual disk, not a partition */
  		return buf;
  
  	return dp_part_node(buf, desc, part);
  }
  
  /* Construct a device-path from a partition on a blk device: */
  struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
  {
  	void *buf, *start;
  
  	start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
  	if (!buf)
  		return NULL;
  
  	buf = dp_part_fill(buf, desc, part);
  
  	*((struct efi_device_path *)buf) = END;
  
  	return start;
  }
  
  /*
   * Create a device node for a block device partition.
   *
   * @buf		buffer to which the device path is wirtten
   * @desc	block device descriptor
   * @part	partition number, 0 identifies a block device
   */
  struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
  {
  	efi_uintn_t dpsize;
  	void *buf;
  
  	if (desc->part_type == PART_TYPE_ISO)
  		dpsize = sizeof(struct efi_device_path_cdrom_path);
  	else
  		dpsize = sizeof(struct efi_device_path_hard_drive_path);
  	buf = dp_alloc(dpsize);
  
  	dp_part_node(buf, desc, part);
  
  	return buf;
  }
  
  /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
  static void path_to_uefi(u16 *uefi, const char *path)
  {
  	while (*path) {
  		char c = *(path++);
  		if (c == '/')
  			c = '\\';
  		*(uefi++) = c;
  	}
  	*uefi = '\0';
  }
  
  /*
   * If desc is NULL, this creates a path with only the file component,
   * otherwise it creates a full path with both device and file components
   */
  struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
  		const char *path)
  {
  	struct efi_device_path_file_path *fp;
  	void *buf, *start;
  	unsigned dpsize = 0, fpsize;
  
  	if (desc)
  		dpsize = dp_part_size(desc, part);
  
  	fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
  	dpsize += fpsize;
  
  	start = buf = dp_alloc(dpsize + sizeof(END));
  	if (!buf)
  		return NULL;
  
  	if (desc)
  		buf = dp_part_fill(buf, desc, part);
  
  	/* add file-path: */
  	fp = buf;
  	fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
  	fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
  	fp->dp.length = fpsize;
  	path_to_uefi(fp->str, path);
  	buf += fpsize;
  
  	*((struct efi_device_path *)buf) = END;
  
  	return start;
  }
  
  #ifdef CONFIG_CMD_NET
  struct efi_device_path *efi_dp_from_eth(void)
  {
  	struct efi_device_path_mac_addr *ndp;
  	void *buf, *start;
  	unsigned dpsize = 0;
  
  	assert(eth_get_dev());
  
  #ifdef CONFIG_DM_ETH
  	dpsize += dp_size(eth_get_dev());
  #else
  	dpsize += sizeof(ROOT);
  #endif
  	dpsize += sizeof(*ndp);
  
  	start = buf = dp_alloc(dpsize + sizeof(END));
  	if (!buf)
  		return NULL;
  
  #ifdef CONFIG_DM_ETH
  	buf = dp_fill(buf, eth_get_dev());
  #else
  	memcpy(buf, &ROOT, sizeof(ROOT));
  	buf += sizeof(ROOT);
  #endif
  
  	ndp = buf;
  	ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
  	ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
  	ndp->dp.length = sizeof(*ndp);
  	memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
  	buf = &ndp[1];
  
  	*((struct efi_device_path *)buf) = END;
  
  	return start;
  }
  #endif
  
  /* Construct a device-path for memory-mapped image */
  struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
  					uint64_t start_address,
  					uint64_t end_address)
  {
  	struct efi_device_path_memory *mdp;
  	void *buf, *start;
  
  	start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
  	if (!buf)
  		return NULL;
  
  	mdp = buf;
  	mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
  	mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
  	mdp->dp.length = sizeof(*mdp);
  	mdp->memory_type = memory_type;
  	mdp->start_address = start_address;
  	mdp->end_address = end_address;
  	buf = &mdp[1];
  
  	*((struct efi_device_path *)buf) = END;
  
  	return start;
  }
  
  /*
   * Helper to split a full device path (containing both device and file
   * parts) into it's constituent parts.
   */
  efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
  				    struct efi_device_path **device_path,
  				    struct efi_device_path **file_path)
  {
  	struct efi_device_path *p, *dp, *fp;
  
  	*device_path = NULL;
  	*file_path = NULL;
  	dp = efi_dp_dup(full_path);
  	if (!dp)
  		return EFI_OUT_OF_RESOURCES;
  	p = dp;
  	while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
  		p = efi_dp_next(p);
  		if (!p)
  			return EFI_OUT_OF_RESOURCES;
  	}
  	fp = efi_dp_dup(p);
  	if (!fp)
  		return EFI_OUT_OF_RESOURCES;
  	p->type = DEVICE_PATH_TYPE_END;
  	p->sub_type = DEVICE_PATH_SUB_TYPE_END;
  	p->length = sizeof(*p);
  
  	*device_path = dp;
  	*file_path = fp;
  	return EFI_SUCCESS;
  }