Subject: Re: bus.h style question
To: None <scottr@Plexus.COM>
From: Gordon W. Ross <email@example.com>
Date: 08/18/1997 11:39:59
> Date: Mon, 18 Aug 1997 10:29:38 -0500 (CDT)
> From: Scott Reynolds <scottr@Plexus.COM>
> This is a great idea, except for the hardware that is wired contrarily.
> I'm glad I don't have to deal with any of those strange ISA bridges in
> other 68K-based systems. :-)
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.