> If I undestood you correctly I have tried to do the following: > > struct lan966x_ifh { > __be32 timestamp; > __be32 bypass : 1; > __be32 port : 3; > ... > }; > > But then I start to get errors from sparse: > > error: invalid bitfield specifier for type restricted __be32. Maybe look at struct iphdr. It has bitfields for the header length and the IP version. Andrew