From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1adfsl-0003lF-Qq for mharc-grub-devel@gnu.org; Wed, 09 Mar 2016 10:18:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51906) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adfsf-0003kR-Tr for grub-devel@gnu.org; Wed, 09 Mar 2016 10:18:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1adfsa-00086O-Al for grub-devel@gnu.org; Wed, 09 Mar 2016 10:18:33 -0500 Received: from mail-wm0-x236.google.com ([2a00:1450:400c:c09::236]:33231) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adfsa-00086D-3E for grub-devel@gnu.org; Wed, 09 Mar 2016 10:18:28 -0500 Received: by mail-wm0-x236.google.com with SMTP id l68so197368522wml.0 for ; Wed, 09 Mar 2016 07:18:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeblueprint-co-uk.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=K0U9vrsUcqFKx1mGr6ozBXl4S7Uyja8UWshK5Rye5bQ=; b=Ou1Tl7CKWl0Hs7msW2IoOWIH43qxVilLlqCaQS7pxppsCfGNY/TJuUzeng+6Hi3+Na cnhtGBDGcOwPji/DFu7w3vUh4Y58+bVWSUFNHcChfIrj5t4nVO7owmRgBMQ4ssrfu7EA CY3sjUkVjBdKFmZW0U8iCGERdRijxukRX+6zRVuA80e6GNh6m8vHow/L8SEN9PsCuSya L1QpmR6zXMucyfmS34SPAAA9f9Vzmq8H+OwD4xgX3/D0Y6Q30Ev5401kBeWV0d+U/l0C xqF8JWOyaiGiOm7t6PfEtSFpu4qTOr6CSOMJtpzkdB2wQLBkjA1foy/HV8VBFc65G28w C/Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=K0U9vrsUcqFKx1mGr6ozBXl4S7Uyja8UWshK5Rye5bQ=; b=DHPOdRZjR+J8B7O2t7+e9JQOuTyhC6KC0iA4xTlMSvGQvd7N2MzH7f+PycyLjOJa49 FmA5m/CSX895+4XX7g+rU69UsF+s3iTl1zZEjJRnoxdHEaacaO9R/5SBKYsI8oguHlol D2SrcgujR39r3EO+R8SAA1KOgO/HZ/uuM72b38gs929a/u0X3OBwD7Bl92K8hQ+RDQgR LavVi6drmiNOchmBYKQl4J8WFy9ydhWyBwvyuexNgfTB1mnhMRog2Q7+YQaO4vqFjf7v xfqPCeVtqdVwtwP1+GTSzhhVQXHLQsheFBa4kpvPzO6IkwybgpbZlIGGeex1DqZwcMyx NZKQ== X-Gm-Message-State: AD7BkJLDoWyz6hlyLmLg2taXjYdtJ5kdC8iA1avwIfd+dHQ/mJOXZ2hnWdSyl/jymoBwgw== X-Received: by 10.28.53.134 with SMTP id c128mr26346026wma.10.1457536706473; Wed, 09 Mar 2016 07:18:26 -0800 (PST) Received: from localhost (bcdc58e5.skybroadband.com. [188.220.88.229]) by smtp.gmail.com with ESMTPSA id z6sm8843501wme.9.2016.03.09.07.18.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Mar 2016 07:18:25 -0800 (PST) Date: Wed, 9 Mar 2016 15:18:24 +0000 From: Matt Fleming To: Andrei Borzenkov Subject: Re: Bugs and tasks for 2.02[~rc1] Message-ID: <20160309151824.GA15775@codeblueprint.co.uk> References: <20160307190016.GA13163@redhat.com> <56DDE5B0.6080002@gmail.com> <56DDEB3D.4010505@gmail.com> <20160307211958.GF13163@redhat.com> <56DDF2AA.3010504@gmail.com> <20160307220132.GI13163@redhat.com> <20160308034010.GA19551@linux-dsax.tai.apac.novell.com> <56DE5BBF.5050108@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56DE5BBF.5050108@gmail.com> User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::236 Cc: The development of GNU GRUB , Colin Watson , Vladimir 'phcoder' Serbinenko X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Mar 2016 15:18:38 -0000 On Tue, 08 Mar, at 07:57:35AM, Andrei Borzenkov wrote: > >> - 64-bit kernel on 32-bit platform like Baytrail can't work > > Do you mean "32 bit EFI"? If yes, why is it a problem? The biggest issue is that there's no way right now for a boot loader to tell the kernel that it needs to use a translation layer when calling EFI services (we refer to this as the "thunk" layer in the kernel) without going via the EFI handover protocol. Obviously this could be achieved by writing the required code for GRUB but it would be largely duplicated from the existing code EFI boot stub code in the kernel. I don't think it's worth the effort. The kernel figures out when to use the thunk layer by taking note of which EFI handover offset entry point the boot loader entered from, we include both a 32-bit and 64-bit entry point when CONFIG_EFI_MIXED is enabled.