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 D36A1E7108E for ; Thu, 21 Sep 2023 15:35:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qjLhc-0001yF-Gc; Thu, 21 Sep 2023 11:34:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qjLha-0001y5-G5 for qemu-devel@nongnu.org; Thu, 21 Sep 2023 11:34:50 -0400 Received: from mail-ed1-x52d.google.com ([2a00:1450:4864:20::52d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qjLhY-0000xa-Su for qemu-devel@nongnu.org; Thu, 21 Sep 2023 11:34:50 -0400 Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-530ce262ab2so1220498a12.1 for ; Thu, 21 Sep 2023 08:34:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1695310487; x=1695915287; darn=nongnu.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=vrnpursJUmK4b5ucv9p1aLhIFHikMQ4PmzLXpkRJ7mQ=; b=MBlnIZluKL2aaArMMVFu33YnL5UwO1heLvmx2jSPqqUnse3G1Doi/JWWQGKMq3dbyl CAalrvdjXITGyQL/9WvjRURRfxOiqesghEgigwHIZF+V/igKeJ3+xWwuy0ZOxRU513lX OXwK3uXSji1NsqR5NuFh9rxfFsZTCLFYS0lZCXLKyBs/p6/pmENhWW6bvQY7oTJIGDo4 rs0aRQxY53y+7a3y+YlZ1IafJq5nQhiagrhEkZtTzOGc3oK9DPL0hHRMjqYp3ptmWDeD CFe694TBO+YSbvAEIcd8GMTJ9zA4rpXpEyj1cdJRbP/s6RFIxJlE1CJBq5Tgu/zxlYuM Cn8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695310487; x=1695915287; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=vrnpursJUmK4b5ucv9p1aLhIFHikMQ4PmzLXpkRJ7mQ=; b=hMHxuBNkyUYzviwY8zpRhtaZaZRnmOMTpw7Zw1Tc9G50wE0+SwlRSdpZ0Atc9QW53z P/q8tZ9oKzvq1X1bR12HuL+sQbWFoo9gymdGTkGl92xT93yrH/45uvPa4kbn1P6N1y62 BZDlcv8dQUu7+q+0aDIe2iPMbAq7Urg+X9GaJNzH9G8uCVRC+yRRIkqLrCTmJVfDN5kt 6jzhc4g/aIZc9CFXkCwBIIX58MvVGcERpU3f9aTjPMUsmGR4XIF4MKKEtpmEqSFKgIL1 OYdMnRr6ay/GhOceNIfronfqq4H68kEzbuEl/v2djVEF6usoTfaU5LyVGpnpxvi6Vlsg RG3g== X-Gm-Message-State: AOJu0YynNWeWPObf0rGnWW+t9jkA/yzibn89DJdmfc5mSSeobEcNXCAk vpYUXSQ9dkaEqV7ozxihacPoROq8x/57/5j9gobAOA== X-Google-Smtp-Source: AGHT+IEwhSs3RR1HnAlbDw/MAxwRgMgT87bR+FVZT6N32waSAp/z7gudW7kART65XX6xJVAQ7R/ZhtT5cH3ZeBD3ut8= X-Received: by 2002:aa7:ca46:0:b0:523:2e30:aaee with SMTP id j6-20020aa7ca46000000b005232e30aaeemr4755630edt.32.1695310486673; Thu, 21 Sep 2023 08:34:46 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Peter Maydell Date: Thu, 21 Sep 2023 16:34:27 +0100 Message-ID: Subject: Re: EDK2 ArmVirtQemu behaviour with multiple UARTs To: Gerd Hoffmann Cc: QEMU Developers , devel@edk2.groups.io, Leif Lindholm , Ard Biesheuvel , Sami Mujawar Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::52d; envelope-from=peter.maydell@linaro.org; helo=mail-ed1-x52d.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, 21 Sept 2023 at 16:26, Gerd Hoffmann wrote: > > On Thu, Sep 21, 2023 at 11:50:20AM +0100, Peter Maydell wrote: > > Hi; I've been looking again at a very long standing missing feature in > > the QEMU virt board, which is that we only have one UART. One of the > > things that has stalled this in the past has been the odd behaviour of > > EDK2 if the DTB that QEMU passes it describes two UARTs. > > Note that edk2 recently got support for virtio-serial, so you can use > that for the console and leave the uart for debug logging. The prebuild > edk2 binaries in qemu have been updated days ago and these already > support for virtio-serial.. As long as EDK2 does something sensible when the DTB says "two UARTs here and here" and it also finds a virtio-serial PCI device, I don't mind what exactly it does. The problem here is more that EDK2 currently does strange things when told that the hardware is present, rather than that anybody specifically wants EDK2 to use multiple serial outputs. Though given there's no way to say in the DTB "use a PCI card for your console" I think the virtio-serial approach is likely to be awkward for users in practice. -- PMM