From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25729 invoked by alias); 3 Feb 2014 20:29:09 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 25712 invoked by uid 89); 3 Feb 2014 20:29:08 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.1 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: sesbmg20.ericsson.net Received: from sesbmg20.ericsson.net (HELO sesbmg20.ericsson.net) (193.180.251.56) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Mon, 03 Feb 2014 20:29:06 +0000 Received: from ESESSHC002.ericsson.se (Unknown_Domain [153.88.253.124]) by sesbmg20.ericsson.net (Symantec Mail Security) with SMTP id 25.0C.04249.D0CFFE25; Mon, 3 Feb 2014 21:29:01 +0100 (CET) Received: from [142.133.182.115] (153.88.183.153) by smtps.internal.ericsson.com (153.88.183.24) with Microsoft SMTP Server (TLS) id 14.2.347.0; Mon, 3 Feb 2014 21:29:00 +0100 Message-ID: <52EFFC0A.8030309@ericsson.com> Date: Mon, 03 Feb 2014 20:29:00 -0000 From: Andreas From User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: John Gilmore , Subject: Re: Clarification on what a byte is in -data-*-memory-bytes ? References: <52EC2698.1030300@ericsson.com> <201402010035.s110Z4CR025827@new.toad.com> In-Reply-To: <201402010035.s110Z4CR025827@new.toad.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2014-02/txt/msg00002.txt.bz2 (NOTE: I didn't see this previous mail reaching the GDB mailing list. Has there been some problem lately with lost messages or can there be some delay before mails hit the archives for some reason?) On 14-01-31 07:35 PM, John Gilmore wrote: >> We're developing support for a target architecture where the smallest >> addressable data type is 16-bit, i.e. the char type size is 16 bits... > > I don't think GDB has ever been ported to a machine without 8-bit bytes. > So some generalization would probably need to be added at the heart of GDB. > This is not for the faint of heart. It is complicated by the likelihood > that you are cross-debugging (a machine with 16-bit addresses probably > can't run GDB natively), so you'll be dealing with two byte sizes, > the target's and the host's. > We have ported GDB to this architecture, and you're right, the target cannot run GDB natively and it needs a stub of its own. The separation into host bytes and target bytes internally on client side might not be trivial, but we have most things working related to such 16-bit issues. > Is this a DSP? Why did someone build a processor without byte > addressing? If you are intent on using an unusual processor, you > might not get much leverage from our free tools; you might have to > write your own tools from scratch. Good luck! > Yes, the processing is on a multicore/DSP architecture. I don't know the history of the architecture that well to know the reasoning behind going for 16-bit. We are one of the very few along with some off the shelf commercial DSPs / architectures out there using something else than 8-bit, e.g. TI's C54x family and OnSemi's Belasigna 250 (24-bit audio DSPs) and even the unlikely DCPU-16 (virtual HW for the computer terminals inside the Mojang game 0x10c that won't ever be released?!). > John Gilmore > > PS: There are some free emulators that can deal with strange byte > sizes and addressing (such as in emulating ancient computers). See, > for example, http://ibm1130.org/sim which emulates a machine with > 16-bit addressing of 16-bit words. See also: > http://simh.trailing-edge.com/ I don't know of cross-debuggers for the > code that runs inside these simulators, but maybe they exist. >