From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21255 invoked by alias); 29 Apr 2002 17:23:48 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 21233 invoked from network); 29 Apr 2002 17:23:45 -0000 Received: from unknown (HELO beta.dmz-eu.st.com) (164.129.1.35) by sources.redhat.com with SMTP; 29 Apr 2002 17:23:45 -0000 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with SMTP id D0A964EF1; Mon, 29 Apr 2002 17:23:43 +0000 (GMT) Received: by zeta.dmz-eu.st.com (STMicroelectronics, from userid 0) id 9F80C61BD; Mon, 29 Apr 2002 17:23:43 +0000 (GMT) Received: from thistle.bri.st.com (localhost [127.0.0.1]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id DD3F81845; Mon, 29 Apr 2002 17:23:42 +0000 (GMT) Received: from [164.129.8.14] (helo=masterwort) by thistle.bristol.st.com with esmtp (Exim 3.03 #5) id 172EsH-00007v-00; Mon, 29 Apr 2002 18:23:41 +0100 Received: from [164.129.14.84] (helo=st.com) by masterwort with asmtp (Exim 3.22 #1) id 172EsH-0005zp-00; Mon, 29 Apr 2002 18:23:41 +0100 Message-ID: <3CCD81CD.CBAC3A62@st.com> Date: Mon, 29 Apr 2002 10:23:00 -0000 From: Joern Rennecke Reply-To: joern.rennecke@st.com Organization: SuperH UK Ltd. X-Accept-Language: en MIME-Version: 1.0 To: ac131313@cygnus.com Cc: bje@redhat.com, gdb-patches@sources.redhat.com Subject: Re: SH5 simulator contribution References: <15451.47633.743434.331956@scooby.brisbane.redhat.com> <3C5F55F3.2030807@cygnus.com> <15455.24394.87381.934711@scooby.brisbane.redhat.com> <3C5F66BB.50001@cygnus.com> <15455.31263.847272.160235@scooby.brisbane.redhat.com> <3C6008DF.5020702@cygnus.com> <15456.16085.191791.112025@scooby.brisbane.redhat.com> <3C6088B3.7080702@cygnus.com> <3CB6AD19.CCDD835A@st.com> <3CB70F11.6010609@cygnus.com> <3CBA940B.B99F0E4C@st.com> <3CBF73A3.2090409@cygnus.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2002-04/txt/msg01127.txt.bz2 ac131313@cygnus.com wrote: > > > So I don't see that you gain anything by unifying the numbering scheme > >> > in the gdb <-> sim interface, as it would be at odds with the interface > >> > to gcc and the hardware interfaces. > > > >> > >> Formalizing would be a better word. So that GDB and the SIM can agree > >> on the register numbers and their sizes without needing to know the > >> others internals. > > > > > > They only need to know if the program is for an sh5 or an earlier processor. > > This information is readily available from the elf flags (the lower five bits > Having just looked at a different target (similar problem), I think > having a single file that assigns different number ranges to the sh4 vs > sh64 registers would be best. That would make it easy to detect things > like trying to fetch an SH64 register from the SH4 sim. Using the current raw / pseudo-register distinction, that would lead to funny artifacts: the sh and sh64 raw registers would all come first, and only then the can the pseudo registers follow. In regcache.c:fetch_register / store_register, you added this comment: /* NOTE: cagney/2001-12-04: Legacy targets were using fetch/store pseudo-register as a way of handling registers that needed to be constructed from one or more raw registers. New targets instead use gdbarch register read/write. */ I suppose I could handle all the pseudos in sim_fetch_register / sim_store_register, but then the hardware interfaces would break. So maybe for the pre-sh5 targets, we should continue to use a relatively low raw register threshold so that the pseudo registers can immediately follow; The sh64 simulator can use a higher threshold that makes the sh4 pseudos into registers that are read/stored with sim_read_register / sim_store_register, i.e. eventuially via sh64_fetch_register / sh64_store_register. Then the sh1..sh4 register numbers can be used for the compact registers, too. -- -------------------------- SuperH 2430 Aztec West / Almondsbury / BRISTOL / BS32 4AQ T:+44 1454 462330