X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdeModulePkg%2FMdeModulePkg.dec;h=a5e348f95bb7e4975ad8bbc77d6d4e850b023693;hb=4376a6f27300b7f710947ccf5df53f45a556d970;hp=366a4be8d905b41a7946b23f1a3c616c9e21119d;hpb=f6f910dd125144707e3516bbb517b8ec7a388c06;p=mirror_edk2.git

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 366a4be8d9..a5e348f95b 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -268,21 +268,32 @@
   ## Maximum PPI count is supported by PeiCore's PPI database.
   gEfiMdeModulePkgTokenSpaceGuid.PcdPeiCoreMaxPpiSupported|64|UINT32|0x00010033
   
-  ## Size of the NV variable range.
+  ## Size of the NV variable range. Note that this value should less than or equal to PcdFlashNvStorageFtwSpareSize
+  # The root cause is that variable driver will use FTW protocol to reclaim variable region.
+  # If the length of variable region is larger than FTW spare size, it means the whole variable region can not
+  # be reflushed through the manner of fault tolerant write. 
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize|0x0|UINT32|0x30000002
   
-  ## Maximum allowable size of a common type variable, that is, non-hardware error type variable.
+  ## The maximum size of single common variable, that is non-HwErr type varible.
   gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize|0x400|UINT32|0x30000003
   
-  ## Maximum allowable size of a single hardware error record variable.
+  ## The maximum size of single hardware error record variable.
+  # In IA32/X64 platforms, this value should be larger than 1KB.
+  # In IA64 platforms, this value should be larger than 128KB.
   gEfiMdeModulePkgTokenSpaceGuid.PcdMaxHardwareErrorVariableSize|0x8000|UINT32|0x30000004
   
-  ## Size of allocated memory for volatile variable store. Variables are stored in such region and 
-  #  total length of all variables should not larger than this value.
-  ##
+  ## The size of reserved HwErr variable space. This space is located at NV variable range.
+  # HwErr type variable is stored with common non-volatile variables in NV region.
+  # this value is used to guarantee the space of HwErr type variable and not populated by common variable.
+  gEfiMdeModulePkgTokenSpaceGuid.PcdHwErrStorageSize|0x8000|UINT32|0x30000006
+
+  ## The size of volatile buffer. This buffer is used to store VOLATILE attribute variable.
   gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize|0x10000|UINT32|0x30000005
-   
-  ## Size of the FTW spare block range.
+
+  ## Size of the FTW spare block range. Note that this value should larger than PcdFlashNvStorageVariableSize
+  # The root cause is that variable driver will use FTW protocol to reclaim variable region.
+  # If the length of variable region is larger than FTW spare size, it means the whole variable region can not
+  # be reflushed through the manner of fault tolerant write.
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize|0x0|UINT32|0x30000014
     
   ## Size of the FTW working block range.