Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933482AbaFINS5 (ORCPT ); Mon, 9 Jun 2014 09:18:57 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:39564 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932403AbaFINS4 (ORCPT ); Mon, 9 Jun 2014 09:18:56 -0400 MIME-Version: 1.0 X-Originating-IP: [5.67.212.210] In-Reply-To: <20140609125427.GA16256@redhat.com> References: <1402140380-15377-1-git-send-email-matt@console-pimps.org> <20140609125427.GA16256@redhat.com> Date: Mon, 9 Jun 2014 14:18:54 +0100 Message-ID: Subject: Re: [PATCH] x86/boot: EFI_MIXED should not prohibit loading above 4G From: Matt Fleming To: Vivek Goyal Cc: "H. Peter Anvin" , LKML , linux-efi@vger.kernel.org, Matt Fleming , Dave Young Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9 June 2014 13:54, Vivek Goyal wrote: > Hi Matt, > > So with new kexec syscall I have written 64bit bzImage loader. For now > I would like to detect this situation and disable loading and once > 32bit loader gets implemented it can take care of loading bzImage below > 4G. What situation do you want to detect? You want to detect when it's impossible to load a kernel above 4G in the kexec path because you're booting with 32-bit EFI firmware? > So how do I find out if EFI is 32bit. efi_enabled(EFI_64BIT) will tell you that, but you probably also want to check that EFI runtime services are actually usable with efi_enabled(EFI_RUNTIME_SERVICES) since if they're not, you'll never call into the firmware so it doesn't matter where you load the kernel (this may happen with "noefi" kernel parameter). -- 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/