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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 39C44C433F5 for ; Fri, 3 Dec 2021 10:42:13 +0000 (UTC) Received: from localhost ([::1]:42034 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mt616-0006Bz-2S for qemu-devel@archiver.kernel.org; Fri, 03 Dec 2021 05:42:12 -0500 Received: from eggs.gnu.org ([209.51.188.92]:49634) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mt5zi-0005OD-UZ for qemu-devel@nongnu.org; Fri, 03 Dec 2021 05:40:46 -0500 Received: from [2a00:1450:4864:20::32b] (port=46619 helo=mail-wm1-x32b.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mt5zh-00067B-5R for qemu-devel@nongnu.org; Fri, 03 Dec 2021 05:40:46 -0500 Received: by mail-wm1-x32b.google.com with SMTP id c6-20020a05600c0ac600b0033c3aedd30aso1840379wmr.5 for ; Fri, 03 Dec 2021 02:40:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=r39zueJZ4y6n4WK8rsirZDPWZOocW9EPBCj9/4VXJDI=; b=duTzXTXol61n9D4NYm/jL+1f0986iEP9jMfng61GCXySP6GYSGUKBQMDB3g7YjnDj5 ARb4C7r+DJ5EEcbgzmHaU8woCIw6ZypP8hU/Cos0wagMElrpK4jtEUBGXv40p4BopeE3 wQ5RcHeYaOIkezX3kW28pZ8xxlO6FGwVcfT/w6hPrMveJD4o4TiXBDo7Xv4UiavXETYj 5ZL7lmQa4v2ptdAcxsqS+T0Iew/pPdJLKhfiV7K51uVyVOm0le2RmU6iXGRwl+zXol3Q I1sme+UAF/qZrkqgEZAi8Tw2ym1qGDaV7AfUf1PnY5qXYqnG7nKS4Lr3+5dzJTKg1UFu TQ/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=r39zueJZ4y6n4WK8rsirZDPWZOocW9EPBCj9/4VXJDI=; b=0OEdDUQOaysU3H0aibM+poljEKc1BvRFKDbIAsSmggiyV+AB+GVtJEqXIxI/1Ty7rn xEawbwgqoYm8bwPY8WhP4HRJZiiGpOKlVgw8kn1lpuff/02BmULwAiDT3/2TkOQUUV54 UT3g22jVtrYyQobkdE6HcD3t+uJ//yM81GTAX1Vb8jVIv0TK9qhLUoYIrdLdZCL89LhT OSi26Sqk/S/96LqEn75v1ZohIX3u44euQy06jBOFsxiUXTxdofKsDV/sAZZFZ52ObYVe cwlu3nLn+3IgXiJN0UP1qVKI8WWotsQHWNum6Ow6Q/Rb12ZPQs95RlUkwrsGzN2col0j X3HA== X-Gm-Message-State: AOAM530jDI0kkW+IWDoMMgU2yjleu5L53yhANOdHsJfD1PZ9F99SbHLF 2/Ro8WR3M2LUpayO9hZJ9SveVQ5X7ZVk05Ig85Fl4A== X-Google-Smtp-Source: ABdhPJzPPJ4xVSj3spbNgob6zF+wJ9Z/ijMMj+ljBO09M7esebCu4G1p+k6XFJoa6FkF/vP4XQoY50EWlBB71eYjWVg= X-Received: by 2002:a05:600c:3486:: with SMTP id a6mr13846418wmq.32.1638528041762; Fri, 03 Dec 2021 02:40:41 -0800 (PST) MIME-Version: 1.0 References: <20211202191446.1292125-1-clg@kaod.org> <8d21273b-0b81-5041-cfc4-704307aa37cc@kaod.org> <32012645-274e-9ee9-2d8a-a3d87c4a6bf5@csgroup.eu> <599e5aa0-d7a9-b89c-2da9-5e7c909a6064@kaod.org> <75b27dfe-cb8f-d40c-c1bd-79415264a87f@redhat.com> In-Reply-To: <75b27dfe-cb8f-d40c-c1bd-79415264a87f@redhat.com> From: Peter Maydell Date: Fri, 3 Dec 2021 10:40:30 +0000 Message-ID: Subject: Re: [PATCH] hw/ppc/ppc405_boards: Change kernel load address To: Thomas Huth Content-Type: text/plain; charset="UTF-8" X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::32b (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::32b; envelope-from=peter.maydell@linaro.org; helo=mail-wm1-x32b.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Henrique Barboza , Greg Kurz , LEROY Christophe , "qemu-devel@nongnu.org" , "qemu-ppc@nongnu.org" , =?UTF-8?Q?C=C3=A9dric_Le_Goater?= , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 3 Dec 2021 at 10:32, Thomas Huth wrote: > I guess it's an accidential NULL pointer dereference somewhere in the u-boot > code ... which will be quite hard to track down when the first page of > memory is marked as writable... :-/ Attach a target-arch gdb to the QEMU gdbstub and put a watchpoint on address zero ? (Or if you suspect something inside QEMU is doing it then run QEMU under gdb and watchpoint the host memory location corresponding to guest address 0, but that's more painful.) Nothing in the pre-kernel part of the boot process will have set up paging, so the watchpointing should be pretty reliable. -- PMM