Re: [PATCH 5/5] falconide/q40ide: add ->atapi_*put_bytes and->ata_*put_data methods

From: Mikael Pettersson
Date: Tue Apr 01 2008 - 04:33:27 EST


Alan Cox writes:
> > Sorry for the mess in core code - ist there any other way for only driveid
> > and packet data getting swapped? And can we actually use the device mapper
> > to byte-swap the root partition?
>
> Device Mapper can certainly support that if needed - I don't think it has
> a swab target currently but byteswapped is just a very bad crypto
> algorithm so you can use dm crypt target as a reference. Might not be a
> bad idea just to make the media shareable.
>
> The only other way I can see to do it would be to split the ATA transfer
> functions into two sets one for media data and one for other stuff - but
> then how do you handle iso9660 cd ?

I had a brief look at this a little while ago, as I was looking at
the hacks Debian applies to make 2.6.x IDE work on Atari/ARAnym.
As I understood it the problem was some IDENTIFY command which needed
to not byteswap (the hack byteswaps a second time). Can't the driver
inspect the command type and choose whether to swap or not?

I had a grand plan of writing a pata_falconide libata driver, but
ran out of steam :-(
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