From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29181 invoked by alias); 10 Jun 2005 10:34:45 -0000 Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Received: (qmail 29166 invoked by uid 22791); 10 Jun 2005 10:34:39 -0000 Received: from web53401.mail.yahoo.com (HELO web53401.mail.yahoo.com) (206.190.37.48) by sourceware.org (qpsmtpd/0.30-dev) with SMTP; Fri, 10 Jun 2005 10:34:39 +0000 Received: (qmail 10290 invoked by uid 60001); 10 Jun 2005 10:34:37 -0000 Message-ID: <20050610103437.10287.qmail@web53401.mail.yahoo.com> Received: from [192.19.199.27] by web53401.mail.yahoo.com via HTTP; Fri, 10 Jun 2005 03:34:37 PDT Date: Fri, 10 Jun 2005 10:34:00 -0000 From: Sujoy Ray To: Peter Korsgaard Cc: ecos-discuss@sources.redhat.com In-Reply-To: <9305ca41050610025175f9a8fe@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: [ECOS] IXP425 Big Endian Mode X-SW-Source: 2005-06/txt/msg00074.txt.bz2 Hello Peter, Thanks for your suggestion! I am still having one doubt - When I compare the code(pls read elf file) compiled in little endian mode with the one in big endian mode using objdump - I see that bytes are swapped. E.g a code which looks like E6000021 in little endian mode becomes 210000E6 in big endian mode. Now, during instruction fetch and decode cycle, how processor decodes this big endian instruction, when the state of the processor is in little endian? Pls note that the processor is in little endian mode and trying to execute a big-endian instruction. So, byte 0 for it will be E6 of the big endian instruction, but the correct one should be 21. I think 'am confused in some way. Please help me to come out from this confusion. Regards, Sujoy Ray. --- Peter Korsgaard wrote: > On 6/10/05, Sujoy Ray wrote: > > big-endian order. Now, I have a question - how the > > processor executes the above mentioned code, when > it > > is in little endian mode. I know for sure that > there > > is some way to do that because the code works > fine. I > > think 'am missing some basic concept - any > suggestion > > will be highly appreciated. > > big/little endian mode only matters for 8 and 16bit > accesses, and the > instructions are 32bit. > > See > http://www.intel.com/design/network/applnots/25423701.pdf > for details. > > -- > Bye, Peter Korsgaard > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss