From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1604 invoked by alias); 21 May 2003 16:38:07 -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 1550 invoked from network); 21 May 2003 16:38:06 -0000 Received: from unknown (HELO localhost.redhat.com) (207.219.125.131) by sources.redhat.com with SMTP; 21 May 2003 16:38:06 -0000 Received: from redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 4005C2B2F; Wed, 21 May 2003 12:04:35 -0400 (EDT) Message-ID: <3ECBA393.9020904@redhat.com> Date: Wed, 21 May 2003 16:38:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030223 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Daniel Jacobowitz Cc: cgd@broadcom.com, kevinb@redhat.com, gdb-patches@sources.redhat.com Subject: Re: [WIP/RFC] MIPS registers overhaul References: <1030516230550.ZM12582@localhost.localdomain> <1030517004052.ZM13153@localhost.localdomain> <3ECA9587.4090407@redhat.com> <3ECB9C8F.1060706@redhat.com> <20030521154134.GA7667@nevyn.them.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-05/txt/msg00388.txt.bz2 >> That came out wrong. >> >> I think a GDB debugging a remote 64 bit MIPS ISA should always expect 64 >> bit GPRs and 64 bit FPRs when the ISA is 64 bits, regardless of the ABI. >> >> It is quite legitimate, for instance, for GDB to do something as sick-o >> as clearing the FR bit and then resume the thread. The register >> save/restore code needs to correctly handle this - be it reject the >> operation or ``do the right thing''. > > > But when using rda or gdbserver to debug an o32 application, then for > all intents and purposes we are debugging a 32-bit ISA. The kernel > will not allow us to change the FR bit. The app will never see 64-bit > registers. The 32-bit protocol makes more sense here IMO. From GDB's view point, the ISA is 64 bit. The fact that a specific remote debug agent choses to use 32 bit registers is a limitation of that debug agent / kernel. An embedded target, and I'm pretty sure IRIX 6.5, for instance, don't do that. Andrew