+int pb_protocol_serialise_device(const struct device *dev,
+ char *buf, int buf_len);
+int pb_protocol_serialise_boot_option(const struct boot_option *opt,
+ char *buf, int buf_len);
+int pb_protocol_serialise_boot_command(const struct boot_command *boot,
+ char *buf, int buf_len);
+int pb_protocol_serialise_boot_status(const struct boot_status *status,
+ char *buf, int buf_len);