+/**
+ * @internal
+ * Map a particular resource from a file.
+ *
+ * @param requested_addr
+ * The starting address for the new mapping range.
+ * @param fd
+ * The file descriptor.
+ * @param offset
+ * The offset for the mapping range.
+ * @param size
+ * The size for the mapping range.
+ * @param additional_flags
+ * The additional flags for the mapping range.
+ * @return
+ * - On success, the function returns a pointer to the mapped area.
+ * - On error, the value MAP_FAILED is returned.
+ */
+void *pci_map_resource(void *requested_addr, int fd, off_t offset,
+ size_t size, int additional_flags);
+
+/**
+ * @internal
+ * Unmap a particular resource.
+ *
+ * @param requested_addr
+ * The address for the unmapping range.
+ * @param size
+ * The size for the unmapping range.
+ */
+void pci_unmap_resource(void *requested_addr, size_t size);
+