Subject: Re: bus.h style question
To: Gordon W. Ross <email@example.com>
From: Jason Thorpe <firstname.lastname@example.org>
Date: 08/19/1997 03:51:02
On Mon, 18 Aug 1997 11:39:59 -0400
"Gordon W. Ross" <email@example.com> wrote:
> Not only ISA bridges on big-endian processors present this problem.
> Look at the Sun "ie" board (Intel Ethernet on VME). It is a 16-bit
> VME board with its VME interface hard-wired to do byte swaps. This
> allows the CPU to transfer the packet payloads without swapping, but
> also implies that all the i82586 data structures appear byte-swapped!
> I'd be interested to hear if/how bus.h should deal with this...
> The VME bus has no role in the swapping. The "bus" that does the
> swapping is the on-board wiring on the Sun "ie" board. I presume
> that means knowledge of this belongs in the "ie" driver only.
What needs to happen here is that the "board-level" driver needs to know
about this and DTRT, and indirect the chipset-level through the board-level.
This is exactly how the LANCE driver works.
Jason R. Thorpe firstname.lastname@example.org
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