lkml.org 
[lkml]   [2007]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: __LITTLE_ENDIAN vs. __LITTLE_ENDIAN_BITFIELD
    Lennart Sorensen wrote:

    >> You're talking about byte endian. I'm talking about bit endian -- the
    >> order of bits within a byte. Software cannot know what the bit endian is,
    >> but external devices that have memory-mapped registers can know.
    >
    > The guy wiring up the hardware should connect the wires correctly.

    I'm sure they're correct, my problem is that how can my driver know what they are?

    > Doesn't the bus usually have some definition of bit order which the
    > device would have to adhere to? After all there must be address lines
    > somewhere.

    I was hoping that there would be some compile-time constant I could check that
    would give me this information.

    > Does this perhaps offer anything useful?
    > http://www.linuxjournal.com/article/6788

    Yeah, I read that article some time ago when trying to diagnose the problem I
    was seeing. It does explain the point I'm trying to make. We have a device
    that's used on two product lines: one ARM-based, and one PowerPC. The ARM is
    little-endian, and the PowerPC is big-endian. The device can support
    little-endian or big-endian data, as long as the bit-order matches the byte-order.

    For now, I'm going to have to assume that they do match.

    --
    Timur Tabi
    Linux Kernel Developer @ Freescale
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-10-09 19:59    [W:0.025 / U:0.332 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site