From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22127 invoked by alias); 17 May 2003 00:41:00 -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 22120 invoked from network); 17 May 2003 00:41:00 -0000 Received: from unknown (HELO mx1.redhat.com) (66.187.233.31) by sources.redhat.com with SMTP; 17 May 2003 00:41:00 -0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.11.6/8.11.6) with ESMTP id h4H0f0H21948 for ; Fri, 16 May 2003 20:41:00 -0400 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [172.16.52.156]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h4H0exI09989; Fri, 16 May 2003 20:40:59 -0400 Received: from localhost.localdomain (vpn50-3.rdu.redhat.com [172.16.50.3]) by pobox.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h4H0ewo15721; Fri, 16 May 2003 20:40:58 -0400 Received: (from kev@localhost) by localhost.localdomain (8.11.6/8.11.6) id h4H0eqm13154; Fri, 16 May 2003 17:40:52 -0700 Date: Sat, 17 May 2003 00:41:00 -0000 From: Kevin Buettner Message-Id: <1030517004052.ZM13153@localhost.localdomain> In-Reply-To: cgd@broadcom.com "Re: [WIP/RFC] MIPS registers overhaul" (May 16, 4:24pm) References: <1030510002453.ZM3880@localhost.localdomain> <3EBD6131.30209@redhat.com> <1030514220025.ZM10373@localhost.localdomain> <3EC461C1.1080104@redhat.com> <1030516230550.ZM12582@localhost.localdomain> To: cgd@broadcom.com, kevinb@redhat.com Subject: Re: [WIP/RFC] MIPS registers overhaul Cc: ac131313@redhat.com, gdb-patches@sources.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-05/txt/msg00299.txt.bz2 On May 16, 4:24pm, cgd@broadcom.com wrote: > At Fri, 16 May 2003 23:06:50 +0000 (UTC), "Kevin Buettner" wrote: > > On May 16, 3:50pm, cgd@broadcom.com wrote: > > > > > another reasonable way (but less efficient on a 64-bit part with a > > > 64-bit FPU) would be: > > > > > > 0: > > > 1: > > > > This is how the mips64 o32 rda transfers the FP registers. > > Hmm. > > OK, then, well, how do we ("gdb") tell the difference, since for o32 > binaries it's reasonable to use either o32 RDA or (one might think) > n32 RDA? Unfortunately, it isn't reasonable to use an ABI-specific RDA to debug an application which uses a different ABI. It might kind of, sort of work some of the time, but there are various things that won't work. You've just identified one of the problems. Another one (and it's a doozie) is that thread debugging won't work due to the ABI specific libthread_db.so library that's dlopen'd by RDA. A native GDB (assuming that we did the necessary work to port it to mips64-linux) would have the same problem. We've kicked around some ideas for fixing this problem in the past. The only idea that I've found compelling is from Alex Oliva (and perhaps others) who suggested that it may be best for a "native" gdb to spawn an ABI-specific rda or gdbserver and connect to it automatically. Kevin