From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC873C433E1 for ; Thu, 23 Jul 2020 04:26:40 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 89A0F20714 for ; Thu, 23 Jul 2020 04:26:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RUZEOzSj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89A0F20714 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jySoG-0007z2-82; Thu, 23 Jul 2020 04:26:20 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jySoE-0007yu-CV for xen-devel@lists.xenproject.org; Thu, 23 Jul 2020 04:26:18 +0000 X-Inumbo-ID: a6cccaee-cc9c-11ea-86e1-bc764e2007e4 Received: from mail-oi1-x243.google.com (unknown [2607:f8b0:4864:20::243]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id a6cccaee-cc9c-11ea-86e1-bc764e2007e4; Thu, 23 Jul 2020 04:26:17 +0000 (UTC) Received: by mail-oi1-x243.google.com with SMTP id y22so3862355oie.8 for ; Wed, 22 Jul 2020 21:26:17 -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:content-transfer-encoding; bh=1f3LnCo0UdaRCs4cl8+MGpB4N3LOBXDq4Dj60+sZTXM=; b=RUZEOzSj7C+2WImZe5BJ+O0BugpgkHuJT6ZN+4IuqoCglHBqswO/0jgHTfR66AHuLz LZyh5GifMojw9ufAJkC2u/Om2C9COFjIdcgwdcv8kxOaDXui2VpZm3QO0Ec9tbZ8TsjX 3XF5xB6wrhzwWBTOH+IHTTbDTjZJyTv7t2T0rC6FhCMqjN0dVzAxGAOVypuX0jXoK34q fU2vqMgWxwcb0LDpTdZSuRO7P33TQM7YhS56SuBcO2xDycvPj4mlqzfxsKgkBtAcQMfl cN3pbOdmtEju1ZcfnBIS2w3Pt30XpAi5flfrhYZlktNitEk9dbN8pR0BGNyYGg86SDuS 9fQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=1f3LnCo0UdaRCs4cl8+MGpB4N3LOBXDq4Dj60+sZTXM=; b=OjiuWkI4JyKkLpbTqEFn0NPHyy4R+Kt4OEeic8alKN5v7rwM8162V7MtaeCaXa/QvG /D9C3Auu3/Hlr1MGb9z1k37/VorztAtD+bUdrfO71KU1h+FmkBpftJ+62u7RdIu3YhQb b6ePxHaII4zUCicGHS6Mzox663foWasPVja/SiR7MMHMQ7kyMGWpusnYZmJX+bh12qVU wqZMhB4mXJZhYLtCgrMd7tQMZxwcZhFPi0EFr14LmweWbW8rI6MjIjJsqS3UABV0D0rj p5P6zYx2UEypY9KMzZEjVi75kt+INlu/BDeZtpQIIo79Pjlz97azSJz/HsJk/9F4LrBx msvw== X-Gm-Message-State: AOAM531ySCFhlDS6KrxjBQ65686u4Bit7i218MImI00cctAUZMJjDpCD yzMHYCO8hu3zM++uv1y6GNX4PWCgK5V4JsMdi2ttNgGL X-Google-Smtp-Source: ABdhPJw/dkBaCi0vS0quFcCdCocLIISiQuR6XZ+YlvsS1497e2gXvBvLi1A4VMxntTnwAu62VVI3OEkSPvFhV6yyqWw= X-Received: by 2002:aca:72ca:: with SMTP id p193mr2285208oic.20.1595478377022; Wed, 22 Jul 2020 21:26:17 -0700 (PDT) MIME-Version: 1.0 References: <002801d66051$90fe2300$b2fa6900$@yujala.com> In-Reply-To: <002801d66051$90fe2300$b2fa6900$@yujala.com> From: Christopher Clark Date: Wed, 22 Jul 2020 21:26:05 -0700 Message-ID: Subject: Re: Porting Xen to Jetson Nano To: Srinivas Bangalore Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Wed, Jul 22, 2020 at 10:59 AM Srinivas Bangalore wrot= e: > Dear Xen experts, > > Would greatly appreciate some hints on how to move forward with this one= =E2=80=A6 Hi Srini, I don't have any strong recommendations for you, but I do want to say that I'm very happy to see you taking this project on and I am hoping for your success. I have a newly-arrived Jetson Nano sitting on my desk here, purchased with the intention of getting Xen up and running on it, that I just haven't got to work on yet. I'm also familiar with Chris Patterson, Kyle Temkin and Ian Campbell's previous Tegra Jetson patches and it would be great to see some further progress made from those. In my recent experience with the Raspberry Pi 4, one basic observation with ARM kernel bringup is that if your device tree isn't good, your dom0 kernel can be missing the configuration it needs to use the serial port correctly and you don't get any diagnostics from it after Xen attempts to launch it, so I would just patch the right serial port config directly into your Linux kernel (eg. hardcode specific things onto the kernel command line) so you're not messing about with that any more. The other thing I would recommend is patching in some printks into the earliest part of the Xen parts of the Dom0 Linux kernel start code. Others who are more familar with Xen on ARM may have some better recommendations, but linux/arch/arm/xen/enlighten.c has a function xen_guest_init that looks like a good place to stuff some extra printks for some early proof-of-entry from your kernel, and that way you'll have some indication whether execution has actually commenced in there. I don't think you're going to get a great deal of enthusiasm on this list for Xen 4.8.5, unfortunately; most people around here work off Xen's staging branch, and I'd be surprised to hear of anyone having tried a 5.7 Linux kernel with Xen 4.8.5. I can understand why you might start there from the existing patch series though. Best of luck, Christopher