/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * EFI device path functions * * (C) Copyright 2017 Rob Clark */ #ifndef EFI_DEVICE_PATH_H #define EFI_DEVICE_PATH_H #include struct blk_desc; struct efi_load_option; struct udevice; /* * EFI_DP_END - Template end node for EFI device paths. * * Represents the terminating node of an EFI device path. * It has a type of DEVICE_PATH_TYPE_END and sub_type DEVICE_PATH_SUB_TYPE_END */ extern const struct efi_device_path EFI_DP_END; /** * efi_dp_next() - Iterate to next block in device-path * * Advance to the next node in an EFI device path. * * @dp: Pointer to the current device path node. * Return: Pointer to the next device path node, or NULL if at the end * or if input is NULL. */ struct efi_device_path *efi_dp_next(const struct efi_device_path *dp); /** * efi_dp_match() - Compare two device-paths * * Compare two device paths node by node. The comparison stops when an End * node is reached in the shorter of the two paths. This is useful, for example, * to compare a device-path representing a device with one representing a file * on that device, or a device with a parent device. * * @a: Pointer to the first device path. * @b: Pointer to the second device path. * Return: An integer less than, equal to, or greater than zero if the first * differing node in 'a' is found, respectively, to be less than, * to match, or be greater than the corresponding node in 'b'. Returns 0 * if they match up to the end of the shorter path. Compares length first, * then content. */ int efi_dp_match(const struct efi_device_path *a, const struct efi_device_path *b); /** * efi_dp_shorten() - shorten device-path * * When creating a short-boot option we want to use a device-path that is * independent of the location where the block device is plugged in. * * UsbWwi() nodes contain a serial number, hard drive paths a partition * UUID. Both should be unique. * * See UEFI spec, section 3.1.2 for "short-form device path". * * @dp: original device-path * Return: shortened device-path or NULL */ struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp); /** * efi_dp_find_obj() - find handle by device path * * If @rem is provided, the handle with the longest partial match is returned. * * @dp: device path to search * @guid: GUID of protocol that must be installed on path or NULL * @rem: pointer to receive remaining device path * Return: matching handle */ efi_handle_t efi_dp_find_obj(struct efi_device_path *dp, const efi_guid_t *guid, struct efi_device_path **rem); /** * efi_dp_last_node() - Determine the last device path node before the end node * * Iterate through the device path to find the very last node before * the terminating EFI_DP_END node. * * @dp: Pointer to the device path. * Return: Pointer to the last actual data node before the end node if it exists * otherwise NULL (e.g., if dp is NULL or only an EFI_DP_END node). */ const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp); /** * efi_dp_instance_size() - Get size of the first device path instance * * Calculate the total length of all nodes in the first instance of a * (potentially multi-instance) device path. The size of the instance-specific * end node (if any) or the final device path. The end node is not included. * * @dp: Pointer to the device path. * Return: Size in bytes of the first instance, or 0 if dp is NULL or an * EFI_DP_END node */ efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp); /** * efi_dp_size() - Get size of multi-instance device path excluding end node * * Calculate the total size of the entire device path structure, traversing * through all instances, up to but not including the final * END_ENTIRE_DEVICE_PATH node. * * @dp: Pointer to the device path. * Return: Total size in bytes of all nodes in the device path (excluding the * final EFI_DP_END node), or 0 if dp is NULL. */ efi_uintn_t efi_dp_size(const struct efi_device_path *dp); /** * efi_dp_dup() - Copy multi-instance device path * * Duplicate the given device path, including its end node(s). * The caller is responsible for freeing the allocated memory (e.g., * using efi_free()). * * @dp: Pointer to the device path to duplicate. * Return: Pointer to the newly allocated and copied device path, or NULL on * allocation failure or if dp is NULL. */ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp); /** * efi_dp_concat() - Concatenate two device paths and terminate the result * * @dp1: First device path * @dp2: Second device path * @split_end_node: * - 0 to concatenate (dp1 is assumed not to have an end node or it's ignored, * dp2 is appended, then one EFI_DP_END node) * - 1 to concatenate with end node added as separator (dp1, END_THIS_INSTANCE, * dp2, END_ENTIRE) * * Size of dp1 excluding last end node to concatenate with end node as * separator in case dp1 contains an end node (dp1 (partial), END_THIS_INSTANCE, * dp2, END_ENTIRE) * * Return: * concatenated device path or NULL. Caller must free the returned value. */ struct efi_device_path *efi_dp_concat(const struct efi_device_path *dp1, const struct efi_device_path *dp2, size_t split_end_node); /** * efi_dp_append_node() - Append a single node to a device path * * Create a new device path by appending a given node to an existing * device path. * If the original device path @dp is NULL, a new path is created * with the given @node followed by an EFI_DP_END node. * If the @node is NULL and @dp is not NULL, the original path @dp is * duplicated. * If both @dp and @node are NULL, a path with only an EFI_DP_END node is * returned. * The caller must free the returned path (e.g., using efi_free()). * * @dp: Original device path (can be NULL). * @node: Node to append (can be NULL). * Return: New device path with the node appended, or NULL on allocation * failure. */ struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp, const struct efi_device_path *node); /** * efi_dp_create_device_node() - Create a new device path node * * Allocate and initialise the header of a new EFI device path node with the * given type, sub-type, and length. The content of the node beyond the basic * efi_device_path header is zeroed by efi_alloc. * * @type: Device path type. * @sub_type: Device path sub-type. * @length: Length of the node (must be >= sizeof(struct efi_device_path)). * Return: Pointer to the new device path node, or NULL on allocation failure * or if length is invalid. */ struct efi_device_path *efi_dp_create_device_node(const u8 type, const u8 sub_type, const u16 length); /** * efi_dp_append_instance() - Append a device path instance to another * * Concatenate two device paths, treating the second path (@dpi) as a new * instance appended to the first path (@dp). An END_THIS_INSTANCE node is * inserted between @dp and @dpi if @dp is not NULL. * If @dp is NULL, @dpi is duplicated (and terminated appropriately). * @dpi must not be NULL. * The caller is responsible for freeing the returned path (e.g., using * efi_free()). * * @dp: The base device path. If NULL, @dpi is duplicated. * @dpi: The device path instance to append. Must not be NULL. * Return: A new device path with @dpi appended as a new instance, or NULL on * error (e.g. allocation failure, @dpi is NULL). */ struct efi_device_path * efi_dp_append_instance(const struct efi_device_path *dp, const struct efi_device_path *dpi); /** * efi_dp_get_next_instance() - Extract the next dp instance * * Given a pointer to a pointer to a device path (@dp), this function extracts * the first instance from the path. It allocates a new path for this extracted * instance (including its instance-specific EFI_DP_END node). The input pointer * (*@dp) is then updated to point to the start of the next instance in the * original path, or set to NULL if no more instances remain. * The caller is responsible for freeing the returned instance path (e.g., * using efi_free()). * * @dp: On input, a pointer to a pointer to the multi-instance device path. * On output, *@dp is updated to point to the start of the next instance, * or NULL if no more instances. * @size: Optional pointer to an efi_uintn_t variable that will receive the size * of the extracted instance path (including its EFI_DP_END node). * Return: Pointer to a newly allocated device path for the extracted instance, * or NULL if no instance could be extracted or an error occurred (e.g., * allocation failure). */ struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp, efi_uintn_t *size); /** * efi_dp_is_multi_instance() - Check if a device path is multi-instance * * Traverse the device path to its end. It is considered multi-instance if an * END_THIS_INSTANCE_DEVICE_PATH node (type DEVICE_PATH_TYPE_END, sub-type * DEVICE_PATH_SUB_TYPE_INSTANCE_END) is encountered before the final * END_ENTIRE_DEVICE_PATH node. * * @dp: The device path to check. * Return: True if the device path contains multiple instances, false otherwise * (including if @dp is NULL). */ bool efi_dp_is_multi_instance(const struct efi_device_path *dp); /** * efi_dp_from_part() - Construct a dp from a partition on a block device * * Create a full device path for a specified partition on a given block device. * If the partition number @part is 0, the path is for the block device itself. * The caller is responsible for freeing the allocated memory (e.g., using * efi_free()). * * @desc: Pointer to the block device descriptor. * @part: Partition number (0 for the whole device, >0 for a specific * partition). * Return: Pointer to the newly created device path, or NULL on allocation * failure or if the device/partition is not found or invalid. */ struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part); /** * efi_dp_part_node() - Create a device node for a block device partition * * Creates a single device path node representing a specific partition * (e.g., HardDrivePath or CDROMPath, depending on desc->part_type). * It does not create the full path from the root, only the partition-specific * node. The caller is responsible for freeing the allocated memory (e.g., * using efi_free()). * * @desc: Pointer to the block device descriptor. * @part: Partition number (must be > 0 and correspond to a valid partition on * the device). * Return: Pointer to the new device path node for the partition, or NULL on * allocation * failure or error in getting partition information. */ struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part); /** * efi_dp_from_file() - append file path node to device path. * * @dp: device path or NULL * @path: file path or NULL * Return: device path or NULL in case of an error */ struct efi_device_path *efi_dp_from_file(const struct efi_device_path *dp, const char *path); /** * efi_dp_from_uart() - Create a device path for a UART device. * * Construct a device path representing the system's default UART, * typically based on the U-Boot device model root and a UART messaging node. * The caller is responsible for freeing the allocated memory (e.g., using * efi_free()). * * Return: Pointer to the new UART device path, or NULL on allocation failure. */ struct efi_device_path *efi_dp_from_uart(void); /** * efi_dp_from_eth() - Create a device path for an Ethernet device * * Construct a device path representing the given device. The caller is * responsible for freeing the allocated memory (e.g. using efi_free()) * * @dev: UCLASS_ETH device to process * * Return: Pointer to the new Ethernet device path, or NULL on allocation * failure */ struct efi_device_path *efi_dp_from_eth(struct udevice *dev); /** * efi_dp_from_mem() - Construct a device-path for a memory-mapped region * * Create an EFI device path representing a specific memory region, defined * by its type, start address, and size. * The caller is responsible for freeing the allocated memory (e.g., * using efi_free()). * * @memory_type: EFI memory type (e.g., EFI_RESERVED_MEMORY_TYPE). * @start_address: Starting address of the memory region. * @size: Size of the memory region in bytes. * Return: Pointer to the new memory device path, or NULL on allocation failure */ struct efi_device_path *efi_dp_from_mem(u32 memory_type, u64 start_address, size_t size); /** * efi_dp_split_file_path() - split of relative file path from device path * * Given a device path indicating a file on a device, separate the device * path in two: the device path of the actual device and the file path * relative to this device. * * @full_path: device path including device and file path * @device_path: path of the device * @file_path: relative path of the file or NULL if there is none * Return: status code */ 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); /** * efi_dp_from_name() - convert U-Boot device and file path to device path * * @dev: U-Boot device, e.g. 'mmc' * @devnr: U-Boot device number, e.g. 1 for 'mmc:1' * @path: file path relative to U-Boot device, may be NULL * @device: pointer to receive device path of the device * @file: pointer to receive device path for the file * Return: status code */ efi_status_t efi_dp_from_name(const char *dev, const char *devnr, const char *path, struct efi_device_path **device, struct efi_device_path **file); /** * efi_dp_check_length() - check length of a device path * * @dp: pointer to device path * @maxlen: maximum length of the device path * Return: * * length of the device path if it is less or equal @maxlen * * -1 if the device path is longer then @maxlen * * -1 if a device path node has a length of less than 4 * * -EINVAL if maxlen exceeds SSIZE_MAX */ ssize_t efi_dp_check_length(const struct efi_device_path *dp, const size_t maxlen); /** * efi_dp_from_lo() - get device-path from load option * * The load options in U-Boot may contain multiple concatenated device-paths. * The first device-path indicates the EFI binary to execute. Subsequent * device-paths start with a VenMedia node where the GUID identifies the * function (initrd or fdt). * * @lo: EFI load option containing a valid device path * @guid: GUID identifying device-path or NULL for the EFI binary * * Return: * device path excluding the matched VenMedia node or NULL. * Caller must free the returned value. */ struct efi_device_path *efi_dp_from_lo(struct efi_load_option *lo, const efi_guid_t *guid); /** * search_gpt_dp_node() - search gpt device path node * * @device_path: device path * * Return: pointer to the gpt device path node */ struct efi_device_path *search_gpt_dp_node(struct efi_device_path *device_path); /** * efi_dp_from_http() - set device path from http * * Set the device path to an IPv4 path as provided by efi_dp_from_ipv4 * concatenated with a device path of subtype DEVICE_PATH_SUB_TYPE_MSG_URI, * and an EFI_DP_END node. * * @server: URI of remote server * @dev: net udevice * Return: pointer to HTTP device path, NULL on error */ struct efi_device_path *efi_dp_from_http(const char *server, struct udevice *dev); #endif /* EFI_DEVICE_PATH_H */