On 2018-07-03 08:14, Kalle Valo wrote: > Pkshih <[email protected]> writes: > >> On Fri, 2018-06-29 at 10:30 +0300, Kalle Valo wrote: >>> Pkshih <[email protected]> writes: >>> >>> > On Tue, 2018-05-29 at 08:18 +0300, Kalle Valo wrote: >>> >> <[email protected]> writes: >>> >> >>> > >>> > Because C2H data is little endian order, the struct will look like >>> > struct foo { >>> > #ifdef __LITTLE_ENDIAN >>> > u8 bar:4; >>> > u8 koo:4; >>> > #else >>> > u8 koo:4; >>> > u8 bar:4; >>> > #endif >>> > } >>> >>> With u8 you don't need endian check, right? I would assume that with >>> both little and big endian bar and koo would be in the same place. >> >> I think u8 with bitfield would be different between little and big endian >> machines. > > To me that does not make any sense, I have never heard about bit > endianness any of the devices I have worked on. Unfortunately, the order in which these fields are laid out is different between big and little endian, even when only dealing with u8. That alone is a strong reason to avoid bitfields entirely for anything shared between the host and something else.
- Felix
