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Re: Big and little endian issue
- To: Mailing List Recipients <email@example.com>
- Subject: Re: Big and little endian issue
- From: "chefren" <firstname.lastname@example.org>
- Date: Tue, 28 Apr 1998 01:08:27 +0200
- In-reply-to: <199804271532.IAA23882@cherbourg.eng.efi.com>
- Posted-Date: Tue, 28 Apr 1998 01:07:01 +0200 (MET DST)
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- Resent-Date: Mon, 27 Apr 1998 17:53:54 -0700
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On 27 Apr 98 at 8:32, Philip Ronzone wrote:
> An IDE or SCSI controller has no knowledge of, and doesn't care,
> and COULDN'T care even if it wanted to, whether the data to/from
> the disk is BE, LE, mixed, or all ASCII text.
> Since it doesn't know, how in the heck can it justify changing
> byte ordering?
> So, without the context, without any knowledge, just HOW can
> "that lowest level of software may just want to tell the intermediate
> device to swap bytes" be reasonable?
Without knowledge it wouldn't do anything at all. Knowledge
is information and that information needs passed to an
information processing element before something can happen.
If the controller gets knowledge because a command is
passed to it that command might have a higher level just
because there is an option bit "swap data". The controller
would have more functionality that can be used inteligently
by higher layers that can use more powerful commands for
This seems like a classic software-hardware clash. The
hardware guys cannot immagine how their bridge itself could
swap bytes and because they cannot immagine it they don't
want to pass control to software guys. If the hardware of
all PCI controllers would have a standard BE/LE swap bit
the software guys could write drivers and get rid of the
whole problem in a very short time.
Would such a bit have cost more than a $0.01 for each
PCI interface??? And aren't there things of $0.10 that
better could have been left out?