+/**
+ * Format a register requirements information into a string.
+ * @param buf The string where to put it to.
+ * @param len The size of @p buf.
+ * @param req The requirements structure to format.
+ * @return A pointer to buf.
+ */
+extern char *arch_register_req_format(char *buf, size_t len, const arch_register_req_t *req);
+
+