From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5715 invoked by alias); 5 Mar 2012 09:50:06 -0000 Received: (qmail 5647 invoked by uid 22791); 5 Mar 2012 09:50:05 -0000 X-SWARE-Spam-Status: No, hits=-0.7 required=5.0 tests=AWL,BAYES_00,SARE_LWSHORTT X-Spam-Check-By: sourceware.org Received: from tetra.codeconfidence.com (HELO tetra.codeconfidence.com) (94.229.66.225) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 05 Mar 2012 09:49:45 +0000 Received: from cog.dallaway.org.uk (cpc1-cmbg10-0-0-cust34.5-4.cable.virginmedia.com [81.102.132.35]) by tetra.codeconfidence.com (Postfix) with ESMTP id 6DA11234C17B; Mon, 5 Mar 2012 09:49:44 +0000 (GMT) Received: from cog.dallaway.org.uk (cog.dallaway.org.uk [127.0.0.1]) by cog.dallaway.org.uk (8.13.8/8.13.8) with ESMTP id q259nhsu006346; Mon, 5 Mar 2012 09:49:44 GMT Message-ID: <4F548C37.2090306@dallaway.org.uk> Date: Mon, 05 Mar 2012 09:50:00 -0000 From: John Dallaway User-Agent: Thunderbird 2.0.0.24 (X11/20111109) MIME-Version: 1.0 To: Tomas Frydrych CC: ecos-devel@ecos.sourceware.org Subject: Re: eCos GNU tools 4.6.2-20120125 ready for testing References: <4F106345.4080902@siva.com.mk> <4F11574D.9070002@dallaway.org.uk> <4F11AC54.7000902@siva.com.mk> <4F1CB41C.90900@jifvik.org> <4F1DA9A0.5070702@siva.com.mk> <4F1FF5AD.4010901@ecoscentric.com> <4F39887A.5050905@siva.com.mk> <4F50F700.5080902@ecoscentric.com> <4F521D6A.4010500@siva.com.mk> <4F52B2C8.4010809@schuilenburg.org> <4F53C46B.4090502@dallaway.org.uk> <4F54798C.2070700@r-finger.com> <4F547FBE.8080507@r-finger.com> In-Reply-To: <4F547FBE.8080507@r-finger.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Mailing-List: contact ecos-devel-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: ecos-devel-owner@ecos.sourceware.org X-SW-Source: 2012-03/txt/msg00011.txt.bz2 Hi Tomas Tomas Frydrych wrote: > On 05/03/12 08:30, Tomas Frydrych wrote: >> On 04/03/12 19:37, John Dallaway wrote: >>> However, this success was achieved using arm-eabi-gdb 6.8.50.20080706. >>> There does appear to be an issue with the length of the 'g' packet when >>> using the new arm-eabi-gdb 7.3.1: >>> >>>> (gdb) tar rem /dev/ttyS0 >>>> Remote debugging using /dev/ttyS0 >>>> Remote 'g' packet reply is too long: e14e000810000000000000001000000000000000000000000000000000000000000000000000000000000000fccf0d6800000000e8cf0d6895680008e24e00080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000021 >>>> (gdb) >>> We will need to look into why the packet length has apparently changed >>> for Cortex-M targets. I can connect to an ARM7 target using the new GDB >>> without problem. >> >> This is a mismatch between the number of registers a gdb server reports >> and the number that gdb expects for the given architecture. In this case >> too many registers are being reported. IIRC, there should be 8 hex >> digits for a register, so the above string seems to represent 42 >> registers instead of the 21 that Cortex-M has. Looks like a bug in the >> monitor stub code, or perhaps a work around for something broken in >> older toolchains? > > Done bit further digging around the sources, > hal/cortexm/arch/.../cortexm_stub.h:64 defines 16 gpr, 8 fp or 12 bytes > each and 2 ps registers; this adds up to the 336 bytes of the above output. Yes. It looks like the FPA registers have been dropped from the default register set for Cortex-M targets in recent GDB. In the longer term, we should add a CDL option to our GDB stub code to accommodate this change. In the short term, I will look at creating a GDB target description file that we can use to accommodate the larger register set returned by our stubs. John Dallaway eCos maintainer http://www.dallaway.org.uk/john