From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29515 invoked by alias); 23 May 2003 19:02:50 -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 23040 invoked from network); 23 May 2003 18:44:45 -0000 Received: from unknown (HELO crack.them.org) (146.82.138.56) by sources.redhat.com with SMTP; 23 May 2003 18:44:45 -0000 Received: from nevyn.them.org ([66.93.61.169] ident=mail) by crack.them.org with asmtp (Exim 3.12 #1 (Debian)) id 19JHXY-0004h5-00; Fri, 23 May 2003 13:45:16 -0500 Received: from drow by nevyn.them.org with local (Exim 3.36 #1 (Debian)) id 19JHWy-00025R-00; Fri, 23 May 2003 14:44:40 -0400 Date: Fri, 23 May 2003 19:02:00 -0000 From: Daniel Jacobowitz To: Andrew Cagney Cc: Kevin Buettner , cgd@broadcom.com, gdb-patches@sources.redhat.com Subject: Re: [WIP/RFC] MIPS registers overhaul Message-ID: <20030523184439.GA7928@nevyn.them.org> Mail-Followup-To: Andrew Cagney , Kevin Buettner , cgd@broadcom.com, gdb-patches@sources.redhat.com References: <3ECA9587.4090407@redhat.com> <3ECB9C8F.1060706@redhat.com> <20030521154134.GA7667@nevyn.them.org> <3ECBA393.9020904@redhat.com> <20030521165816.GA8784@nevyn.them.org> <1030521183234.ZM31903@localhost.localdomain> <3ECBD034.3080504@redhat.com> <20030522003151.GA15642@nevyn.them.org> <3ECE66BD.7060700@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ECE66BD.7060700@redhat.com> User-Agent: Mutt/1.5.1i X-SW-Source: 2003-05/txt/msg00465.txt.bz2 On Fri, May 23, 2003 at 02:21:49PM -0400, Andrew Cagney wrote: > > >>Er, it's the same deal as for SPARC. If GDB is built against the 64 bit > >>debug interface, it can debug both 32 and 64 bit applications. This is > >>the debuggers view, not the program being run's view. > > > > > >But the point is that the debugger's view of a 32-bit application on > >MIPS is of a 32-bit ISA. That's all that's available. You get 32-bit > >registers from the kernel. > > That isn't true. CF the embedded case. The ISA can be 64 bits, but the > ABI 32 bits. This argument is becomming circular. I'm not talking about the embedded case! I never said that we should always use a 32-bit protocol when debugging a 32-bit ABI. I said that in this case, using rda or gdbserver on a hosted system, it doesn't make any sense to use the 64-bit protocol. > GDB has to make a choice. Either hack the tdep code so that it tries to > get the user, register, and target ABIs to all line up, or select an > underlying canonical ISA and expect targets to map their register values > onto that. Selecting a definitive 64 bit ISA means that the tdep code > works in all cases - the target is made responsibile for resolving self > inflicted esoteric edge cases. Then why have the 32-bit protocol at all, besides compatibility with existing stubs? Just waste the transfer time for the unused bits all the time. > Note here that the self inflicting esoteric target is remote.c, it is > still tied to the register cache at the hip :-( -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer