Re: Who uses hdx=bswap or hdx=swapdata?

From: Richard Zidlicky (
Date: Fri Jan 04 2002 - 17:51:58 EST

On Fri, Jan 04, 2002 at 06:20:11PM +0100, Geert Uytterhoeven wrote:
> On Fri, 4 Jan 2002, Michael Schmitz wrote:
> > > > For 2.5 would it perhaps be cleaner if we had a bswapping loop device. Sort
> > > > of very bad crypto mode ?
> > >
> > > Don't mention crypto, or Atari will come after us with the DMCA sword, claiming
> > > they deliberately implemented access control? ;-)
> >
> > Caution - I recall that on some m68k boxes we had to further byteswap
> > specific parts of the identify data or they wouldn't make sense. The IDE
> > driver will still have to be aware of these exceptions. I can't recall the
> > particulars anymore - Geert?
> That's the drive identification. It indeed shouldn't be swapped once again when
> accessing a `non-native' IDE disk.

sometimes it should, eg some of the ioctls that read data via special
commands from the drive that could also use byteswapping - ide-smart
comes to my mind.

Btw the Q40 has also byteswapped IDE bus like the atari.

We already have atapi_{input|output}_bytes bytes that does the
swapping, and m68k has {ins|outs}[wl]_swapw. Perhaps one of this
could be reused to do the bswap?

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