[PATCH 2/3] MdePkg/MdeModule: Add support for RuntimeServicesSupported variable

["Jeff Brasen" <jbrasen@nvidia.com>]

Add support for new global variable defined in the UEFI 2.8
specification. This provides a bitmask of which calls are
implemented by the firmware during runtime services.

Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
---
 .../Library/VarCheckUefiLib/VarCheckUefiLibNullClass.c        | 11 +++++++++++
 MdePkg/Include/Guid/GlobalVariable.h                          |  7 +++++++
 2 files changed, 18 insertions(+)

diff --git a/MdeModulePkg/Library/VarCheckUefiLib/VarCheckUefiLibNullClass.c b/MdeModulePkg/Library/VarCheckUefiLib/VarCheckUefiLibNullClass.c
index e3bf04a..4264892 100644
--- a/MdeModulePkg/Library/VarCheckUefiLib/VarCheckUefiLibNullClass.c
+++ b/MdeModulePkg/Library/VarCheckUefiLib/VarCheckUefiLibNullClass.c
@@ -553,6 +553,17 @@ UEFI_DEFINED_VARIABLE_ENTRY mGlobalVariableList[] = {
     },
     NULL
   },
+  {
+    EFI_RUNTIME_SERVICES_SUPPORTED_VARIABLE_NAME,
+    {
+      VAR_CHECK_VARIABLE_PROPERTY_REVISION,
+      VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY,
+      VARIABLE_ATTRIBUTE_BS_RT,
+      sizeof (UINT16),
+      sizeof (UINT16)
+    },
+    NULL
+  },
 };
 
 UEFI_DEFINED_VARIABLE_ENTRY mGlobalVariableList2[] = {
diff --git a/MdePkg/Include/Guid/GlobalVariable.h b/MdePkg/Include/Guid/GlobalVariable.h
index 7abc103..06a8a12 100644
--- a/MdePkg/Include/Guid/GlobalVariable.h
+++ b/MdePkg/Include/Guid/GlobalVariable.h
@@ -182,5 +182,12 @@ extern EFI_GUID gEfiGlobalVariableGuid;
 /// Its attribute is BS+RT.
 ///
 #define EFI_VENDOR_KEYS_VARIABLE_NAME               L"VendorKeys"
+///
+/// Bitmask of which calls are implemented by the firmware during runtime services.
+/// RT access is required only if GetVariable() is implemented by runtime services.
+/// Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_RUNTIME_SERVICES_SUPPORTED_VARIABLE_NAME  L"RuntimeServicesSupported"
 
 #endif
-- 
2.7.4