+size_t utf16_strnlen(const u16 *src, size_t count);
+
+/**
+ * utf16_utf8_strnlen() - length of a truncated utf-16 string after conversion
+ * to utf-8
+ *
+ * @src: utf-16 string
+ * @count: maximum number of code points to convert
+ * Return: length in bytes after conversion to utf-8 without the
+ * trailing \0. If an invalid UTF-16 sequence is hit one
+ * byte will be reserved for a replacement character.
+ */
+size_t utf16_utf8_strnlen(const u16 *src, size_t count);
+
+/**
+ * utf16_utf8_strlen() - length of a utf-16 string after conversion to utf-8
+ *
+ * @src: utf-16 string
+ * Return: length in bytes after conversion to utf-8 without the
+ * trailing \0. -1 if the utf-16 string is not valid.
+ */
+#define utf16_utf8_strlen(a) utf16_utf8_strnlen((a), SIZE_MAX)
+
+/**
+ * utf16_utf8_strncpy() - copy utf-16 string to utf-8 string
+ *
+ * @dst: destination buffer
+ * @src: source buffer
+ * @count: maximum number of code points to copy
+ * Return: -1 if the input parameters are invalid
+ */
+int utf16_utf8_strncpy(char **dst, const u16 *src, size_t count);
+
+/**
+ * utf16_utf8_strcpy() - copy utf-16 string to utf-8 string
+ *
+ * @dst: destination buffer
+ * @src: source buffer
+ * Return: -1 if the input parameters are invalid
+ */
+#define utf16_utf8_strcpy(d, s) utf16_utf8_strncpy((d), (s), SIZE_MAX)
+
+/**
+ * utf_to_lower() - convert a Unicode letter to lower case
+ *
+ * @code: letter to convert
+ * Return: lower case letter or unchanged letter
+ */
+s32 utf_to_lower(const s32 code);
+
+/**
+ * utf_to_upper() - convert a Unicode letter to upper case
+ *
+ * @code: letter to convert
+ * Return: upper case letter or unchanged letter
+ */
+s32 utf_to_upper(const s32 code);
+
+/**
+ * u16_strlen - count non-zero words
+ *
+ * This function matches wsclen() if the -fshort-wchar compiler flag is set.
+ * In the EFI context we explicitly need a function handling u16 strings.
+ *
+ * @in: null terminated u16 string
+ * ReturnValue: number of non-zero words.
+ * This is not the number of utf-16 letters!
+ */
+size_t u16_strlen(const u16 *in);
+
+/**
+ * u16_strlen - count non-zero words
+ *
+ * This function matches wscnlen_s() if the -fshort-wchar compiler flag is set.
+ * In the EFI context we explicitly need a function handling u16 strings.
+ *
+ * @in: null terminated u16 string
+ * @count: maximum number of words to count
+ * ReturnValue: number of non-zero words.
+ * This is not the number of utf-16 letters!
+ */
+size_t u16_strnlen(const u16 *in, size_t count);