From mboxrd@z Thu Jan 1 00:00:00 1970 From: schen@mvista.com (Steve Chen) Date: Tue, 06 Oct 2009 07:56:14 -0500 Subject: ARM1176 register writes are in reverse? In-Reply-To: References: Message-ID: <1254833774.3153.52.camel@linux-1lbu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 2009-10-06 at 17:40 +0530, Nicholas Van Orton wrote: > Hi, > > I noticed that register writes to ARM1176 need to be in the reverse > order. That is, lets say I need to write 0xABCD to a register. But in > the actual write using __raw_writel() the value needs to be changed to > 0xCDAB. Why is this so? The Davinci or OMAP on the other hand for > example, which is an ARM 926 does not need any such manipulation. Why > is the ARM1176 an exception? > Are you working with TI Puma5? I suspect that reverse order is probably due to specific hardware endianness implementation rather than generic difference between ARM1176 and ARM926. Regards, Steve