Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758318Ab3HMSwV (ORCPT ); Tue, 13 Aug 2013 14:52:21 -0400 Received: from terminus.zytor.com ([198.137.202.10]:35612 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757615Ab3HMSwS (ORCPT ); Tue, 13 Aug 2013 14:52:18 -0400 Message-ID: <520A8054.1030108@zytor.com> Date: Tue, 13 Aug 2013 11:52:04 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: James Bottomley CC: Ingo Molnar , Thomas Gleixner , Linus Torvalds , "linux-efi@vger.kernel.org" , Linux Kernel Mailing List , Matt Fleming Subject: Re: RFC: default CONFIG_EFI_STUB=y References: <52050985.9070107@zytor.com> <1376062345.2087.16.camel@dabdike.int.hansenpartnership.com> <52050D03.4030805@zytor.com> <520A7B48.3020304@zytor.com> <1376419410.3467.67.camel@dabdike.int.hansenpartnership.com> In-Reply-To: <1376419410.3467.67.camel@dabdike.int.hansenpartnership.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1290 Lines: 31 On 08/13/2013 11:43 AM, James Bottomley wrote: >> James, does this address your concerns? > > You mean for globally enabling CONFIG_EFI on x86? not really for 32 > bit, you say above it's pretty much unusable; I'd prefer just to enable > it for 64 bit. As you said in your original post "since EFI now is a > significant percentage of all systems" but you actually mean EFI64 ... > EFI32 is a pretty insignificant percentage of all systems. For better or worse, there will be more. > Can we actually boot a 32 bit kernel on an EFI64 system? The last time > I tried on my Secure Boot SDV it wouldn't work; the problem is getting > someting in the transfer of control path to boot the processor back to > 32 bit mode. We can boot with a bootloader in "skip stub" mode; no runtime services yet. We are working on making it possible to boot via a EFI stub in assisted mode (still needing a bootloader, but with the boot stub in the kernel.) Runtime services will be the last piece, obviously, but even that looks reasonably doable. -hpa -- 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/