From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 42096 invoked by alias); 19 Oct 2018 21:18:47 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 42087 invoked by uid 89); 19 Oct 2018 21:18:47 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=H*c:alternative X-HELO: mail-ua1-f53.google.com Received: from mail-ua1-f53.google.com (HELO mail-ua1-f53.google.com) (209.85.222.53) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 19 Oct 2018 21:18:45 +0000 Received: by mail-ua1-f53.google.com with SMTP id i30so6451484uae.11 for ; Fri, 19 Oct 2018 14:18:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kJI5gB0evtAMpUtGpGd18BSHPAhywCrapKmGGw50jQY=; b=CyH8GF+Fwn/GDyXkw7X99l0PhbLlp6W6IdYWngFKLJPY0KgMmDFjD4FtUMFNJIZtUh pA9cw9chVM9npXttUuuWR6IqQjMETyrcLbCFeaVY6z9I4QqRYu4Mbpk7zXo0iScuAd1G asCBa494f4EgEcdCp3X4eI+Dw9TA1rQJda5tD0LWtaVnAw+7TueTOwstj8+focRLpvCn r8h9YlZQlaytQDATPDwxSoV86XXq1YN4dhpfVKRXQgGiaZ9pZl4KbRH66/L2F56PHP/W n7pLkfJHANOWrrIV7kKEEGxKgt6+RxeaexjNMMd3CwWwehQ7lbB8bGsSlkXpo9HIEWqz lt6w== MIME-Version: 1.0 References: <0eeb55ca-d4e1-4db4-e601-74ca7e1151e2@redhat.com> <11b018ef2ea200e314dbce95f424eb6c@polymtl.ca> <1b531704-d9a0-3024-5bb9-7e26d2a6fcc4@redhat.com> In-Reply-To: <1b531704-d9a0-3024-5bb9-7e26d2a6fcc4@redhat.com> From: Bill Morgan Date: Fri, 19 Oct 2018 21:18:00 -0000 Message-ID: Subject: Re: gdb ignoring vCont supported commands To: palves@redhat.com Cc: Simon Marchi , gdb@sourceware.org Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2018-10/txt/msg00042.txt.bz2 On Fri, Oct 19, 2018 at 8:40 AM Pedro Alves wrote: > On 10/09/2018 10:33 PM, Bill Morgan wrote: > > On Tue, Oct 9, 2018 at 4:16 PM Bill Morgan < > arthurwilliammorgan@gmail.com> > > wrote: > > > >> > >> > >> On Tue, Oct 9, 2018 at 4:12 PM Pedro Alves wrote: > >> > >>> On 10/09/2018 09:29 PM, Bill Morgan wrote: > >>>> On Tue, Oct 9, 2018 at 3:16 PM Simon Marchi > >>> wrote: > >>>> > >>>>> On 2018-10-09 16:12, Bill Morgan wrote: > >>>>>> I get a warning that vContSupported is unrecognized: > >>>>>> > >>>>>> Sending packet: > >>>>>> > >>>>> > >>> > $qSupported:multiprocess+;swbreak+;hwbreak+;qRelocInsn+;fork-events+;vfork-events+;exec-events+;vContSupported+;QThreadEvents+;no-resumed+#df...Ack > >>>>>> Packet received: > >>>>>> > >>>>> > >>> > PacketSize=3fff;QPassSignals+;qXfer:features:read+;qXfer:threads:read+;vContSupported > >>>>>> Packet qSupported (supported-packets) is supported > >>>>>> warning: unrecognized item "vContSupported" in "qSupported" response > >>>>> > >>>>> I believe you are missing the + after vContSupported. > >>>>> > >>>>> You are correct, I was missing the +. Thank you. > >>>> > >>>> So it is now recognizing the vContSupported, but it is still sending > >>>> vCont;s > >>>> > >>> > >>> Argh, I forgot that this only really works on ARM GNU/Linux. > >>> What is your target? > >>> > >> > >> Custom OS on ARM. > >> > >> This is what I'm reporting to GDB: > >> > >> Sending packet: $qXfer:features:read:target.xml:0,fff#7d...Ack > >> Packet received: larm > >> > >> > >> > >>> > >>> We're missing the small infrastructure change in GDB > >>> mentioned in the discussion I linked before. > >>> > >> > > What does GDB need to know about my OS for using software breakpoints for > > stepping? From looking at this document: > > > http://infocenter.arm.com/help/topic/com.arm.doc.ihi0036b/IHI0036B_bsabi.pdf > > I'd be using the ARM Architecture Procedure Call Standard and probably be > > considered Bare Metal. Although I have some ELF processes loaded and > > running, I think that should be opaque to GDB though. My stub switches > MMU > > TTB as necessary for writing the software breakpoints to memory. > > > > Could I report an existing OS to GDB? > > You could try using a --target=arm-linux-gnu GDB (or an > --enablet-targets=all) > build, and forcing GNU/Linux ABI, with "set osabi GNU/Linux". I think > that should be enough. If that works, you could also report that > automatically > in the tdesc, with: > > GNU/Linux > > Of course, that's a hack. As discussed on the other thread, GDB should > be able to fallback to software single-step automatically. > With the hack, some things might not work correctly, as GDB will be > assuming > a GNU/Linux environment in your target. But maybe it's still good enough. > > Thanks, > Pedro Alves > OK thanks Pedro. I will probably stick with the patch I posted earlier to force software stepping for now. If I have time later maybe I'll try to get a better fix in.