From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1139 invoked by alias); 4 Aug 2011 19:48:21 -0000 Received: (qmail 1129 invoked by uid 22791); 4 Aug 2011 19:48:19 -0000 X-SWARE-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 04 Aug 2011 19:48:04 +0000 Received: (qmail 3163 invoked from network); 4 Aug 2011 19:48:03 -0000 Received: from unknown (HELO digraph.polyomino.org.uk) (joseph@127.0.0.2) by mail.codesourcery.com with ESMTPA; 4 Aug 2011 19:48:03 -0000 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.72) (envelope-from ) id 1Qp3th-0008TZ-Qr; Thu, 04 Aug 2011 19:48:01 +0000 Date: Thu, 04 Aug 2011 19:48:00 -0000 From: "Joseph S. Myers" To: Pedro Alves cc: gdb-patches@sourceware.org, Yao Qi Subject: Re: [RFA 5/8] New port: TI C6x: gdb port In-Reply-To: <201108041845.35876.pedro@codesourcery.com> Message-ID: References: <4E2638A6.1070406@codesourcery.com> <201108041333.42945.pedro@codesourcery.com> <201108041845.35876.pedro@codesourcery.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-08/txt/msg00082.txt.bz2 On Thu, 4 Aug 2011, Pedro Alves wrote: > > Won't GDB need a list of how the register names correspond to DWARF > > register numbers (which are allocated for all these registers) somewhere? > > AFAICS, gdbserver only exposes A0-A15, CSR, PC, A16-A31 > B16-B31, TSR, ILC, RILC, so I assumed all other registers would be > system dependent non general purpose control registers, but it's > probably then that they are only not "user space" registers, and will > be acessible by bare metal probes/stubs? Linux programs won't access > those, right? I now browsed the ABI's dwarf section and I got that > impression. I expect most of them are bare metal only - and I don't suppose they are particularly likely to appear in debug info either, but GDB may as well know the numbers since they are assigned. Some of the others *can* however be read/written from userspace (the documentation of the MVC instruction gives details, for the documented control registers). (The default in the ABI is for control registers to be caller-save.) Looking at the list of control registers, I'd think that at least AMR, GFPGFR, GPLYA, GPLYB, FADCR, FAUCR, FMCR, SSR are plausibly relevant to userspace - userspace code using inline assembly or intrinsics, anyway - and ought to be available from gdbserver (which might of course require kernel changes to expose them to ptrace). -- Joseph S. Myers joseph@codesourcery.com