From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <sigmaepsilon92@gmail.com>
Received: from mail-ua0-x22e.google.com (mail-ua0-x22e.google.com
 [IPv6:2607:f8b0:400c:c08::22e])
 (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 6A481803D6
 for <edk2-devel@ml01.01.org>; Mon, 20 Mar 2017 09:06:50 -0700 (PDT)
Received: by mail-ua0-x22e.google.com with SMTP id q7so78435571uaf.2
 for <edk2-devel@ml01.01.org>; Mon, 20 Mar 2017 09:06:50 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
 h=mime-version:from:date:message-id:subject:to;
 bh=FpUTL00uFlhp9QfgPHbl3i4+xThUz34ej6nbVpXKpTI=;
 b=fAUH3cQI7h5E3JpmP9NpsGZ/qccWVk7yUVxBppv+JVjGKL9DNUGDoTJe/Mj+TrvDbg
 szIZ/9oorU4d9p7Q7ktMhOMT9sdD9wfcITBuiUSNmLV7kI5yh0CumMcrH+EEPA+VgPWH
 FG4DN3ea6nFjONP5eFmL3sIxSQu0/dxZAIUliJRyJu/Gi85RYXfmAOEQhYBwz6zaz2Wh
 1ZRz9DjsfQYtiEAgnv9zUl7au/MkWj3DdqWgoyZNiGG4G12sm8V10Xr52DIQWZAPmATr
 LwsgXf2Cp5QLjCbLjpKMXvx3D1s/3TzlNKoxAljlrBUNnR8kf/c188xBiuDtRa6WmFnK
 6WGw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:mime-version:from:date:message-id:subject:to;
 bh=FpUTL00uFlhp9QfgPHbl3i4+xThUz34ej6nbVpXKpTI=;
 b=Jq0qHTzYJ+msn3426QX2GoiSf63hxw+1p4r4noGNYcYDAx3rigT3Tth8fJsWjy7DQ/
 TQly2ae/Y0pWkkOCUZVp7EUOVbAglJu0fGtQb8ZccnjFNyBhONR3/n+25ZVBq84gRKX2
 bPidps5NNAGRgNF1R4hsINv8K7FGcVcDkmzkGZ36p1vfkeN2PkAgGgOq+QSEkXF2QfwF
 TcPZdSqXyAa8tHQS5l6gSAZaqB1GmzdC3pQuy/jKmElYK1zIKn8MIWOnR48sj40u/IZU
 WuTrakuzet7mvr9MbGIomgh04bqo2iInVRN5xHWFDCBr0Z2uZFvIW3VOjdQjnJi9So/B
 wMZw==
X-Gm-Message-State: AFeK/H3mvxb5N1n0260eyJf0sTCdCwYXvxBOdI59M5A0z72QDqPyQBX9Ke8JdTn7pEr4ub7wx/ocqHvKjcyX5w==
X-Received: by 10.176.2.71 with SMTP id 65mr10680152uas.155.1490026009275;
 Mon, 20 Mar 2017 09:06:49 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.31.171.80 with HTTP; Mon, 20 Mar 2017 09:06:48 -0700 (PDT)
From: Michael Zimmermann <sigmaepsilon92@gmail.com>
Date: Mon, 20 Mar 2017 17:06:48 +0100
Message-ID: <CAN9vWDJhYWarrabhGbEcY3L_R0hc_SAR4GWUrwBt=kUWgiQaZA@mail.gmail.com>
To: "edk2-devel@lists.01.org" <edk2-devel@ml01.01.org>,
 Laszlo Ersek <lersek@redhat.com>, 
 Ard Biesheuvel <ard.biesheuvel@linaro.org>,
 Leif Lindholm <leif.lindholm@linaro.org>, 
 Yonghong Zhu <yonghong.zhu@intel.com>, Liming Gao <liming.gao@intel.com>
Subject: visibility pf PcdSet
X-BeenThere: edk2-devel@lists.01.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: EDK II Development  <edk2-devel.lists.01.org>
List-Unsubscribe: <https://lists.01.org/mailman/options/edk2-devel>,
 <mailto:edk2-devel-request@lists.01.org?subject=unsubscribe>
List-Archive: <http://lists.01.org/pipermail/edk2-devel/>
List-Post: <mailto:edk2-devel@lists.01.org>
List-Help: <mailto:edk2-devel-request@lists.01.org?subject=help>
List-Subscribe: <https://lists.01.org/mailman/listinfo/edk2-devel>,
 <mailto:edk2-devel-request@lists.01.org?subject=subscribe>
X-List-Received-Date: Mon, 20 Mar 2017 16:06:50 -0000
Content-Type: text/plain; charset=UTF-8

Do I understand correctly, that a PcdSet on a 'PcdsPatchableInModule'
is only visible to the current module?(SEC, driver, application, ...)
Because I've tested this and a PcdSet on
gArmTokenSpaceGuid.PcdSystemMemoryBase inisde PrePi is not visible
inside a DXE_DRIVER - which means that for everyone else the value is
still 0x0.

If this is the case and I don't have some platform bug, then there is
probably a bug in ArmVirtPkg's HighMemDxe where this Pcd is used in a
DXE_DRIVER:
https://github.com/tianocore/edk2/blob/76874be3d411bf8daac051718e20932e0bf97d70/ArmVirtPkg/HighMemDxe/HighMemDxe.c#L70
It doesn't cause anything bad but it would show 'Failed to add System
RAM @ START - END (Access Denied)' after calling AddMemorySpace for
memory which has already been registered.

Thanks
Michael