MdeModulePkg/BM: Make it look like current BootMngr

MdeModulePkg/Library/BootManagerUiLib/BootManager.c

@@ -484,6 +484,7 @@ UpdateBootManager (
   BOOLEAN                       IsLegacyOption;
   BOOLEAN                       NeedEndOp;
   UINTN                         MaxLen;
+  UINTN                         OptionCount = 0;
 
   DeviceType = (UINT16) -1;
 
@@ -526,6 +527,7 @@ UpdateBootManager (
   EndLabel = (EFI_IFR_GUID_LABEL *) HiiCreateGuidOpCode (EndOpCodeHandle, &gEfiIfrTianoGuid, NULL, sizeof (EFI_IFR_GUID_LABEL));
   EndLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
   EndLabel->Number       = LABEL_BOOT_OPTION_END;
+
   mKeyInput = 0;
   NeedEndOp = FALSE;
   for (Index = 0; Index < BootOptionCount; Index++) {
@@ -541,6 +543,8 @@ UpdateBootManager (
       continue;
     }
 
+    OptionCount++;
+
     //
     // Group the legacy boot option in the sub title created dynamically
     //
@@ -596,6 +600,10 @@ UpdateBootManager (
       );
   }
 
+  if (OptionCount == 0) {
+    HiiCreateSubTitleOpCode (StartOpCodeHandle, STRING_TOKEN (STR_NO_BOOTABLE_MEDIA), 0, 0, 0);
+  }
+
   if (NeedEndOp) {
     HiiCreateEndOpCode (StartOpCodeHandle);
   }