Re: [Qemu-devel] [PATCH] pcnet32 driver change, please test

[M. Warner Losh]

In message: <address@hidden>
            Paul Brook <address@hidden> writes:
: > : I find this curious...  C99 (6.7.2.1) says "the allocation order of
: > : bit-fields within a unit (high-order to low-order or low-order to
: > : high-order) is implementation defined".  I can't see any requirement
: > : for this, so is it just convention that bitfields on big endian systems
: > : start from the most significant bit, and those on little endian systems
: > : start from the least significant bit?  (My thinking is that endianness
: > : usually refers to byte ordering and not so much bit ordering.)
: >
: > This is a convention that goes back a very long ways.  It was this way
: > in the mid 1980's, and has remained true through today.  I've
: > personally observed this to be the case on many different MIPS
: > compilers, ARM compilers and SPARC compilers over the years.
: 
: I'm fairly sure I've seen targets that use other bitfield orderings, though I 
: can't remember offhand what they were.

None of them are supported by FreeBSD and/or NetBSD...

Warner