From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x231.google.com (mail-oi0-x231.google.com [IPv6:2607:f8b0:4003:c06::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7675C1A1EBD for ; Thu, 22 Sep 2016 08:19:13 -0700 (PDT) Received: by mail-oi0-x231.google.com with SMTP id t83so101225445oie.3 for ; Thu, 22 Sep 2016 08:19:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=7Z6fm/tek4QVox+pTIC2d/yfyXquGs+oiHBYM1RSoZM=; b=Ix/02dljbIak895o5Ks/h5zXi9HutPm7kW9vUKXXE4N/pMDuYE5ww8iMIXi+KkZuoQ 98HFWM+p6zv8WHUhgJvPusFsx59kan1NgkdZp/7nGx6OE0hX/tMb/0r4RWt4z8S3p0zf 63AjqI/IG8JJrQaqHSm+ijOeEQfMFQVDLnC69jonq2R8EcxL2yiOIEoV0dp7xFBLl6s+ M8jwls9nFNUZ7sGzLJzL/3JhCoLO4s3HI7uXCSPLDvpccxWeob5TCjVyIYksHnUn+hsr BDYOFmfn86PO3Yp7wYiS3PT340lQhz3L5nfP2vDvyKgwXcSy+32K8sVz4oKpR3E0FO9O Lnmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=7Z6fm/tek4QVox+pTIC2d/yfyXquGs+oiHBYM1RSoZM=; b=i+LU3ZIiPnw/AsuQtnzTkr1vOqRRrZd9OYyBGh8v3g7aNhRo8dKntav8IaOVKDAqkS u3fXtWmvbfxKI8rvFHaO0kPA2cwrHx6ZWFHAncvfhZcTG281iiAHdvOwpF4tHnC6OsPU N3qvBXFuexvLenlW6gaeMzKZcBeN8NgRffFLUEAXhiYIj3b0JGfiC8blvFhCZf/p2D0g X5D0oGtV/f27Iu/dz0ELMxzA21IMSbXGiJVRtOLYKKQCgWpBMuz/k+tFRWi0PW+rffjQ 6MWerf3ubc8Sio/S1HcBukaMpYVtYjU8u48QlVYzKH++o/0ETVz9MoCRzuqaJltGCg8a WxEw== X-Gm-Message-State: AE9vXwOZY2JBilkzWSVlb+j7/F/W08CDwa8+Hh0GpEGZKVaGULzp1mWR6HyuHdtVGsqldd7MVOYts821oneiPA== X-Received: by 10.202.59.65 with SMTP id i62mr2975595oia.185.1474557552772; Thu, 22 Sep 2016 08:19:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.202.170.131 with HTTP; Thu, 22 Sep 2016 08:19:12 -0700 (PDT) In-Reply-To: References: From: valerij zaporogeci Date: Thu, 22 Sep 2016 18:19:12 +0300 Message-ID: To: Ard Biesheuvel Cc: edk2-devel Subject: Re: flat mapping vs identity mapping on ARM X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Sep 2016 15:19:13 -0000 Content-Type: text/plain; charset=UTF-8 2016-09-22 18:03 GMT+03:00, Ard Biesheuvel : > On 22 September 2016 at 15:30, valerij zaporogeci > wrote: >> In the ARM architecture, there is such a thing - "flat mapping", where >> MMU stage 1 is disabled and the mapping done is 1:1 and attributes set >> to the predefined values. > > What do you mean by 'attributes set to the predefined values' ? > I meant what is written in the section B3.2.1, short quote: "For all other accesses, when a stage 1 MMU is disabled, the assigned attributes depend on whether the access is a data access or an instruction access, as follows: Data access The stage 1 translation assigns the Strongly-Ordered memory type" ... and then, more lengthy description for instruction access. > > On ARM, you need to enable the MMU in order to enable the Dcache. > Thank you, I suspected this is for this, just wanted to be sure.