From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg1-x543.google.com ([2607:f8b0:4864:20::543]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fi7ht-00020n-8f for kexec@lists.infradead.org; Wed, 25 Jul 2018 00:31:10 +0000 Received: by mail-pg1-x543.google.com with SMTP id z8-v6so4013543pgu.8 for ; Tue, 24 Jul 2018 17:30:58 -0700 (PDT) Date: Wed, 25 Jul 2018 09:32:29 +0900 From: AKASHI Takahiro Subject: Re: [PATCH v4 0/2] Add capability to dump fdt blob for arm64 platforms Message-ID: <20180725003228.GB11258@linaro.org> References: <1529576678-14615-1-git-send-email-bhsharma@redhat.com> <20180709071107.GT28220@linaro.org> <20180724063110.lclgpne27o5xbws3@verge.net.au> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180724063110.lclgpne27o5xbws3@verge.net.au> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Simon Horman Cc: dyoung@redhat.com, Bhupesh Sharma , bhupesh.linux@gmail.com, kexec@lists.infradead.org, james.morse@arm.com On Tue, Jul 24, 2018 at 08:31:54AM +0200, Simon Horman wrote: > On Tue, Jul 17, 2018 at 02:13:42AM +0530, Bhupesh Sharma wrote: > > Hi Akashi, > > > > On 07/09/2018 12:41 PM, AKASHI Takahiro wrote: > > > Bhupesh, Simon, > > > > > > #I'm afraid that I gonna rehash the old discussion. > > > > > > Looking into ppc's kexec-tools code, I found that ppc version of > > > this tool has a similar feature and it saves a new dtb into a file, > > > named "debug.dtb." > > > See save_fixed_up_dtb() in kexec/arch/ppc/fixup_dtb.c > > > > > > Even if it is a debug feature, we'd better go in the same way > > > (if possible). > > > > Thanks for sharing the same. > > > > I had a look earlier also at the ppc - "debug.dtb" code in kexec-tools, but > > this is again fails to fulfill the same purpose that we are trying to > > resolve for early primary kernel crash(es) on arm64 machines, because of > > which we are not able to reach the command prompt with the primary kernel > > itself. > > > > We would need to either reach the command prompt to dump out/save the > > "debug.dtb" file when we are running the primary kernel (which is > > unfortunately not always possible wit latest kernels on some of the arm64 > > machines), Although I'm not sure how it cannot be possible, > or use some initramfs scriptware to dump out the same to some > > secondary storage device (nfs server or usb stick). > > > > So, I would still suggest to stick with the approach I proposed for now (and > > we can take a similar approach as ppc for arm64 later on) once we have > > kexec, kdump and other user-space utilities (which rely on the kexec kernel > > framework) working stably on arm64 machines (with latest upstream kernels). > > That sounds like a reasonable argument to me. > > Akashi, what do you think? it's fine to me, too. -Takahiro AKASHI _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec