efi_loader: Separate device path into its own header
These functions are useful for the EFI app. As a first step towards
making these available outside lib/efi_loader, create a separate header
file and include it where needed. Add proper comments to the functions,
since many are missing at present.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/efi_device_path.h b/include/efi_device_path.h
new file mode 100644
index 0000000..d179a55
--- /dev/null
+++ b/include/efi_device_path.h
@@ -0,0 +1,420 @@
+/* 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 <efi.h>
+
+struct blk_desc;
+struct efi_load_option;
+struct udevice;
+
+/*
+ * 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 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 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 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 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 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 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 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 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 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 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 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 */
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 8f9f2bc..b3beda5 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -9,6 +9,7 @@
#define _EFI_LOADER_H 1
#include <blk.h>
+#include <efi_device_path.h>
#include <event.h>
#include <log.h>
#include <part_efi.h>
@@ -935,66 +936,10 @@
#define EFI_LOADER_BOUNCE_BUFFER_SIZE (64 * 1024 * 1024)
#endif
-/* shorten device path */
-struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp);
-struct efi_device_path *efi_dp_next(const struct efi_device_path *dp);
-int efi_dp_match(const struct efi_device_path *a,
- const struct efi_device_path *b);
-efi_handle_t efi_dp_find_obj(struct efi_device_path *dp,
- const efi_guid_t *guid,
- struct efi_device_path **rem);
-/* get size of the first device path instance excluding end node */
-efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp);
-/* size of multi-instance device path excluding end node */
-efi_uintn_t efi_dp_size(const struct efi_device_path *dp);
-struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp);
-struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
- const struct efi_device_path *node);
-/* Create a device path node of given type, sub-type, length */
-struct efi_device_path *efi_dp_create_device_node(const u8 type,
- const u8 sub_type,
- const u16 length);
-/* Append device path instance */
-struct efi_device_path *efi_dp_append_instance(
- const struct efi_device_path *dp,
- const struct efi_device_path *dpi);
-/* Get next device path instance */
-struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
- efi_uintn_t *size);
-/* Check if a device path contains muliple instances */
-bool efi_dp_is_multi_instance(const struct efi_device_path *dp);
-
-struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part);
-/* Create a device node for a block device partition. */
-struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part);
-struct efi_device_path *efi_dp_from_file(const struct efi_device_path *dp,
- const char *path);
-struct efi_device_path *efi_dp_from_eth(struct udevice *dev);
-struct efi_device_path *efi_dp_from_http(const char *server, struct udevice *dev);
-struct efi_device_path *efi_dp_from_mem(uint32_t mem_type,
- uint64_t start_address,
- size_t size);
-/* Determine the last device path node that is not the end node. */
-const struct efi_device_path *efi_dp_last_node(
- const struct efi_device_path *dp);
-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 *efi_dp_from_uart(void);
-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);
-ssize_t efi_dp_check_length(const struct efi_device_path *dp,
- const size_t maxlen);
-
#define EFI_DP_TYPE(_dp, _type, _subtype) \
(((_dp)->type == DEVICE_PATH_TYPE_##_type) && \
((_dp)->sub_type == DEVICE_PATH_SUB_TYPE_##_subtype))
-/* template END node: */
-extern const struct efi_device_path END;
-
/* Indicate supported runtime services */
efi_status_t efi_init_runtime_supported(void);