-struct bus_header {
- uint8_t endian;
- uint8_t type;
- uint8_t flags;
- uint8_t version;
- uint32_t body_size;
-
- /* Note that what the bus spec calls "serial" we'll call
- "cookie" instead, because we don't want to imply that the
- cookie was in any way monotonically increasing. */
- uint32_t serial;
- uint32_t fields_size;
-} _packed_;
-