Converting Endianess on a bit field structure

Question

I need to convert a bit-field structure from little-endian to big-endia architecture. What is the best way to do that, as there will be issues in byte boundaries, if I simply sw

Answer 1

Processor endianness is unrelated to bit field ordering. It's quite possible to have two compilers on the same computer use opposite ordering for bitfields. So, given this:

union {
    unsigned char x;
    struct {
        unsigned char b1 : 1;
        unsigned char b2 : 7;
    };
} abc;
abc.x = 0;
abc.b1 = 1;
printf( "%02x\n", abc.x );

Unless you happen to have detailed documentation, the only way to know whether that will print out 01 or 80 is to try it.