From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754735Ab2CRMKH (ORCPT ); Sun, 18 Mar 2012 08:10:07 -0400 Received: from caibbdcaaaaf.dreamhost.com ([208.113.200.5]:33907 "EHLO homiemail-a50.g.dreamhost.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751581Ab2CRMKF (ORCPT ); Sun, 18 Mar 2012 08:10:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=shealevy.com; h=message-id:date :from:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; q=dns; s=shealevy.com; b=PLVGTBM2PYjFxkJxRkRfVkATcp9abxPMaJ1wxl4vRbJZTh62xdA6hUHX07Zrb SIUN8B6oIwnAx+xB1x+MCO+ruWlF1Qvy5pA+8lb28D5rT0u/3LYkp2Gs8ST99p9b n3EcRQcyC35YOmKL/w3dL12L294LMIH5ewmUV++2wiLbYQ= Message-ID: <4F65D09B.4050807@shealevy.com> Date: Sun, 18 Mar 2012 08:10:03 -0400 From: Shea Levy User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 To: Matt Fleming CC: "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: EFI Boot Stub Early Console References: <4F5E46EA.7020602@shealevy.com> <4F5E47E4.2070303@shealevy.com> <4F5E74A0.60001@zytor.com> <4F5E761B.7010608@shealevy.com> <4F5E775D.7080702@zytor.com> <4F648DD3.3000405@shealevy.com> <1332069701.4041.42.camel@mfleming-mobl1.ger.corp.intel.com> In-Reply-To: <1332069701.4041.42.camel@mfleming-mobl1.ger.corp.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matt, On 3/18/12 7:21 AM, Matt Fleming wrote: > I don't think you'll need to use the graphics protocols, you should > just be able to put something together using the 'output_string' > function from the EFI simple text output protocol, e.g. something like > this, https://lkml.org/lkml/2012/3/16/193 From the UEFI 2.3.1 spec: > Prior to a call to ExitBootServices(), all of the fields of the EFI > System Table are valid. After an operating system has taken control of > the platform with a call to ExitBootServices(), only the Hdr, > FirmwareVendor, FirmwareRevision, RuntimeServices, > NumberOfTableEntries, and ConfigurationTable fields are valid. Doesn't this mean that ConOut can't be used for the earlyprintk, since any bootloader (including the bootstub) will call ExitBootServices() before any printk'ing actually happens?? Or am I misunderstanding the spec somehow? I suppose I could just try it and see what happens... Cheers, Shea