From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x242.google.com (mail-wm0-x242.google.com [IPv6:2a00:1450:400c:c09::242]) (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 C73921A1DFF for ; Fri, 2 Sep 2016 21:04:39 -0700 (PDT) Received: by mail-wm0-x242.google.com with SMTP id c133so5181827wmd.2 for ; Fri, 02 Sep 2016 21:04:39 -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=1Xr9P03z2ckRN60o0f+M58DxoZdzHTHBjpYnWBZi9Dc=; b=qfMhgcpHwc9zfReoS4WbIMI5wyT/JaoOQhyUkDL7ZWmH+A0kCwEVgooZCUidPS5Ncd VC2DwldCFVQobZczxQadlkLkXCv9g08sJ45L/41G7+02iCR7vBq3CjokXfelHuy8zinx 4HlxertnSqsDint2f1Aqn8VBvWsNKkgW7zE5399ngi38Kwl3fXzlUS/g8ehT117e0tnT jQRGxE5eVJ4vSl8rA1xQQgx8Y1Dedr8CX0bDONOPegLnOxQh5RKiT3c8q5ZD6fbBP1Cg 7vIySzupl3+Tri1k5cmJ65I2ME5N9wLq+JwiEoZtLdWtbEhbq9/26owVNxCflNUo99Fs YbGA== 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=1Xr9P03z2ckRN60o0f+M58DxoZdzHTHBjpYnWBZi9Dc=; b=eiCdRy4CQLwa3MN6QcBrQQ6MhNQdrB3ndHnoSe+ryWlbttHTlgZ59st6bNruLHOXWJ rBLBhwyJZArYgG7Z1fJovu+MCq8U5oiwUkuE4MvrRUuK+7vZoSIrGn6YwVRjKQQUpooN JQKwMNEi40KvfBSELsTSYIegaWeXcvpZbHxOqFLwAHzdA/Zow5VpVRr+G/0KcmTm94Oz d/6BQyFoKFkSC8ttRzHEFms2V2HjhlAN8X4YswoEH1tqF5oOWDS5AT7oVdm3vo+VybnB 4H9Aaz5QwEcADNiCqq/2CV7pvfb9UKvpXJ0/HIjEGb5R3LWI8OxiaydAtkZ9e7IztJLL s0hQ== X-Gm-Message-State: AE9vXwP0i3a66yq+rR8lmfBatq9SEaLt1MzHY12igsqOJiClTX5dJmkLfvdVXUzBBkhkxwEehyEn0/CS36+qVg== X-Received: by 10.28.24.73 with SMTP id 70mr6196402wmy.96.1472875478154; Fri, 02 Sep 2016 21:04:38 -0700 (PDT) MIME-Version: 1.0 Received: by 10.28.0.204 with HTTP; Fri, 2 Sep 2016 21:04:37 -0700 (PDT) In-Reply-To: References: From: Michael Zimmermann Date: Sat, 3 Sep 2016 06:04:37 +0200 Message-ID: To: Ard Biesheuvel Cc: Laszlo Ersek , "edk2-devel@lists.01.org" X-Content-Filtered-By: Mailman/MimeDel 2.1.21 Subject: Re: post-ExitBootServices memory protection of RT_Data (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: Sat, 03 Sep 2016 04:04:40 -0000 Content-Type: text/plain; charset=UTF-8 > The LinuxLoader is a poorly maintained hack, and it is badly broken on AARCH64 I'm actually just using the shutdown code from linux loader. I wrote my own, very complete loader which does definitely work in terms of correct loading and argument passing. > Does the system have an L2 cache which may need invalidation/disabling. I doubt that this is the problem because I can even load the soc vendor's linux bootloader first(to a available addr) which fully works(usb, mmc, ...). and from there I can fastboot boot linux - which then just doesn't work depending on the loading addr. I'll ask him to do more tests like reading back data, loading other stuff to that location to prevent problems linux might have with other memory locations passed by atags, etc. On Fri, Sep 2, 2016 at 11:02 PM, Ard Biesheuvel wrote: > On 2 September 2016 at 21:45, Michael Zimmermann > wrote: > > If I understand this correctly this is just some MMU feature, right? > > I'm talking about a pure ARM(with atag's) linux kernel which is not UEFI > > aware. > > > > Also the LinuxLoader disables almost everything(MMU, caches, it calls > > exitbootservices etc). > > > > I really can't explain technically what UEFI could have done to > accomplish > > this protection with the MMU being disabled. > > > > No, the kernel is entered with the MMU and caches off. The LinuxLoader > is a poorly maintained hack, and it is badly broken on AARCH64. On > ARM, however, it should still work. Does the system have an L2 cache > which may need invalidation/disabling? >