Timur Tabi <timur@freescale.com> writes:

quoted text
> I'm writing a driver that talks to hardware that has a shift register.
> The register can be shifted either left or right, so all the bits
> obviously have to be in order, but it can be either order.

Bit addressing is strictly internal to the cpu, the smallest unit that
the cpu can address externally is a byte.  The only place where bit
order matters on the C level is in a bitfield that is overlayed over a
block of memory, but this is not visible outside the cpu.

quoted text
> What I want to do is to have the driver detect when byte-endianness
> doesn't match bit-endianness when it writes the the word to a
> memory-mapped device.

The bit mapping on your device is strictly internal to the device and
has nothing to do with bit order on the C level.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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"And now for something completely different."
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