3 files changed, 20 insertions, 3 deletions
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index f2c7081dd..83c853485 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -272,10 +272,11 @@
   # In IA64 platforms, this value should be larger than 128KB.
   gEfiMdeModulePkgTokenSpaceGuid.PcdMaxHardwareErrorVariableSize|0x8000|UINT32|0x30000004
 
-  ## 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.
+  ## The size of reserved HwErr variable space. Note that this value must be less than or equal to PcdFlashNvStorageVariableSize
+  # In EdkII implementation, HwErr type variable is stored with common non-volatile variables in the same NV region.
+  # so the platform integrator should ensure this value is less than or equal to PcdFlashNvStorageVariableSize.
   # this value is used to guarantee the space of HwErr type variable and not populated by common variable.
-  gEfiMdeModulePkgTokenSpaceGuid.PcdHwErrStorageSize|0x8000|UINT32|0x30000006
+  gEfiMdeModulePkgTokenSpaceGuid.PcdHwErrStorageSize|0x0000|UINT32|0x30000006
 
   ## The size of volatile buffer. This buffer is used to store VOLATILE attribute variable.
   gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize|0x10000|UINT32|0x30000005
diff --git a/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c b/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
index 228d7d8cf..2da9a7c30 100644
--- a/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
+++ b/MdeModulePkg/Universal/Variable/EmuRuntimeDxe/EmuVariable.c
@@ -1314,6 +1314,14 @@ InitializeVariableStore (
   VARIABLE_STORE_HEADER *VariableStore;
 
   //
+  // Note that in EdkII variable driver implementation, Hardware Error Record type variable
+  // is stored with common variable in the same NV region. So the platform integrator should
+  // ensure that the value of PcdHwErrStorageSize is less than or equal to the value of 
+  // PcdFlashNvStorageVariableSize.
+  //
+  ASSERT (FixedPcdGet32(PcdHwErrStorageSize) <= FixedPcdGet32(PcdFlashNvStorageVariableSize));
+
+  //
   // Allocate memory for volatile variable store
   //
   VariableStore = (VARIABLE_STORE_HEADER *) AllocateRuntimePool (
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index aadda4b58..e52477784 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -2247,6 +2247,14 @@ VariableCommonInitialize (
   EfiInitializeLock(&mVariableModuleGlobal->VariableGlobal.VariableServicesLock, TPL_NOTIFY);
 
   //
+  // Note that in EdkII variable driver implementation, Hardware Error Record type variable
+  // is stored with common variable in the same NV region. So the platform integrator should
+  // ensure that the value of PcdHwErrStorageSize is less than or equal to the value of 
+  // PcdFlashNvStorageVariableSize.
+  //
+  ASSERT (FixedPcdGet32(PcdHwErrStorageSize) <= FixedPcdGet32(PcdFlashNvStorageVariableSize));
+
+  //
   // Allocate memory for volatile variable store, note that there is a scratch space to store scratch data.
   //
   ScratchSize = MAX(FixedPcdGet32(PcdMaxVariableSize), FixedPcdGet32(PcdMaxHardwareErrorVariableSize));