Refine comments for PCD PEIM/driver.

[mirror_edk2.git] / MdeModulePkg / Universal / PCD / Pei / Pcd.inf

diff --git a/MdeModulePkg/Universal/PCD/Pei/Pcd.inf b/MdeModulePkg/Universal/PCD/Pei/Pcd.inf
index 075e16aeb4deb12b5ff555593b17569aab354352..fc392909113bb02bd6108e33cb658c8d22e57787 100644 (file)
--- a/MdeModulePkg/Universal/PCD/Pei/Pcd.inf
+++ b/MdeModulePkg/Universal/PCD/Pei/Pcd.inf
@@ -1,6 +1,14 @@
 #/** @file\r
 # PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service.\r
 #\r
+# There are two PCD PPIs as follows:\r
+#   1) PCD_PPI \r
+#      It is EDKII implementation which support Dynamic/DynamicEx Pcds.\r
+#   2) EFI_PEI_PCD_PPI\r
+#      It is defined by PI specification 1.2, Vol 3 which only support dynamicEx \r
+#      type Pcd.\r
+# For dynamicEx type PCD, it is compatible between PCD_PPI and EFI_PEI_PCD_PPI.\r
+#\r
 # ////////////////////////////////////////////////////////////////////////////////\r
 # //                                                                            //\r
 # //                      Introduction of PCD database                          //\r