From mboxrd@z Thu Jan  1 00:00:00 1970
Reply-To: <acurtis@onz.com>
From: "Allen Curtis" <acurtis@onz.com>
To: "Matt Porter" <porter@cox.net>,
	"Laurent Mohin" <laurent.mohin@acterna.com>
Cc: "Stefan Roese" <stefan.roese@esd-electronics.com>,
	"Michael Meriin" <Michael@KSWaves.com>,
	<linuxppc-embedded@lists.linuxppc.org>
Subject: RE: How to change endian attribute for a memory region
Date: Tue, 15 Oct 2002 07:35:40 -0700
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> > By the way, I really studied the chip and if I want to be able to manage
> > both 8 bpp and 16 bpp mode, I need to be able to change the endianness
> > attribute of the memory region.
>
> Why wouldn't you access video memory via a sthbrx instruction (writew)?

Right!
writew() - assumes that you are talking to a peripheral and all peripherals
must be little endian , thank you PCI.

__raw_writew() - accesses the memory in the native format which is
big-endian in your case.


To answer your other question:
You can not set an attribute on a memory region within the memory controller
to force the hardware to handle this for you on a region by region basis.
The chip's endianness may be configurable. This is an exercise let to the
programmer.  :(


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