Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753694Ab3DVB71 (ORCPT ); Sun, 21 Apr 2013 21:59:27 -0400 Received: from ozlabs.org ([203.10.76.45]:51939 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753416Ab3DVB70 (ORCPT ); Sun, 21 Apr 2013 21:59:26 -0400 From: Rusty Russell To: Pranavkumar Sawargaonkar Cc: "kvmarm\@lists.cs.columbia.edu" , linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, patches@linaro.org, linux-kernel@vger.kernel.org, Anup Patel Subject: Re: [RFC] arm64: Early printk support for virtio-mmio console devices. In-Reply-To: References: <1366264344-28025-1-git-send-email-pranavkumar@linaro.org> <87wqs02uws.fsf@rustcorp.com.au> User-Agent: Notmuch/0.14 (http://notmuchmail.org) Emacs/23.4.1 (i686-pc-linux-gnu) Date: Mon, 22 Apr 2013 10:51:13 +0930 Message-ID: <87ehe3bbsm.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1288 Lines: 30 Pranavkumar Sawargaonkar writes: > On 18 April 2013 12:21, Rusty Russell wrote: >> >> PranavkumarSawargaonkar writes: >> > From: Pranavkumar Sawargaonkar >> > >> > This patch implements early printk support for virtio-mmio console devices without using any hypercalls. >> >> This makes some sense, though not sure that early console *read* makes >> much sense. I can see the PCI version of this being useful as well. > > Read can be useful for "mach-virt" which will have only virtio console > as a console device. Then if someone wants to have UEFI or any other > boot-loader emulation, which expects user to input few things, in that > case read might become handy. But implementing virtio inside a bootloader has already been done for coreboot, for example. A bootloader probably wants a virtio block device, so a console is trivial. A single writable field for debugging makes sense. Anything more is far less certain. Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/