MdePkg DxePcdLib: Updates DxePcdLib instance comments.

Describe PCD service can’t be used at Runtime phase.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16403 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/MdePkg/Library/DxePcdLib/DxePcdLib.inf b/MdePkg/Library/DxePcdLib/DxePcdLib.inf
index dfdd41211527729b80e30459ea630dde7ec2c83b..23cd5d6e7046873cc41122d70dbe1804dcd48b6f 100644 (file)
--- a/MdePkg/Library/DxePcdLib/DxePcdLib.inf
+++ b/MdePkg/Library/DxePcdLib/DxePcdLib.inf
@@ -13,6 +13,11 @@
 # This library instance uses the PCD_PROTOCOL to handle dynamic PCD request and use\r
 # EFI_PCD_PROTOCOL to handle dynamicEx type PCD.\r
 #\r
+# Note: A driver of type DXE_RUNTIME_DRIVER and DXE_SMM_DRIVER can only use this DxePcdLib \r
+#  in their initialization without any issues to access Dynamic and DynamicEx PCD. They can't \r
+#  access Dynamic and DynamicEx PCD in the implementation of runtime services and SMI handlers.\r
+#  Because EFI_PCD_PROTOCOL is DXE protocol that is not aviable in OS runtime phase.  \r
+#\r
 # Copyright (c) 2007 - 2014, Intel Corporation. All rights reserved.<BR>\r
 #\r
 #  This program and the accompanying materials\r