ArmPkg: ArmStandaloneMmCoreEntryPoint: Support 18 register DIRECT_REQ2

This change added the support for using 18 registers when FF-A DIRECT_REQ2 is used to communicate with MM core. This change was tested on QEMU SBSA and booted to Windows. Signed-off-by: Kun Qin <kun.qin@microsoft.com>
microsoft · Feb 26, 2025 · a6e25dd · a6e25dd
1 parent 048c463
commit a6e25dd
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Showing 2 changed files with 32 additions and 0 deletions.
diff --git a/ArmPkg/Library/ArmStandaloneMmCoreEntryPoint/ArmStandaloneMmCoreEntryPoint.c b/ArmPkg/Library/ArmStandaloneMmCoreEntryPoint/ArmStandaloneMmCoreEntryPoint.c
@@ -730,6 +730,20 @@ SetEventCompleteSvcArgs (
           EventCompleteSvcArgs->Arg5 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg1;
           EventCompleteSvcArgs->Arg6 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg2;
           EventCompleteSvcArgs->Arg7 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg3;
+          // MU_CHANGE Starts: Add 18 register support
+          if (FixedPcdGetBool (PcdSxcUse18Registers)) {
+            EventCompleteSvcArgs->Arg8  = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg4;
+            EventCompleteSvcArgs->Arg9  = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg5;
+            EventCompleteSvcArgs->Arg10 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg6;
+            EventCompleteSvcArgs->Arg11 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg7;
+            EventCompleteSvcArgs->Arg12 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg8;
+            EventCompleteSvcArgs->Arg13 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg9;
+            EventCompleteSvcArgs->Arg14 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg10;
+            EventCompleteSvcArgs->Arg15 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg11;
+            EventCompleteSvcArgs->Arg16 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg12;
+            EventCompleteSvcArgs->Arg17 = mMiscMmCommunicateBuffer->DirectMsgArgs.Arg13;
+          }
+          // MU_CHANGE Ends
         }
       }
 
@@ -772,6 +786,21 @@ InitializeMiscMmCommunicateBuffer (
   Buffer->DirectMsgArgs.Arg1 = EventSvcArgs->Arg5;
   Buffer->DirectMsgArgs.Arg2 = EventSvcArgs->Arg6;
   Buffer->DirectMsgArgs.Arg3 = EventSvcArgs->Arg7;
+  // MU_CHANGE Starts: Add 18 register support
+  if (FixedPcdGetBool (PcdSxcUse18Registers)) {
+    Buffer->DirectMsgArgs.Arg4  = EventSvcArgs->Arg8;
+    Buffer->DirectMsgArgs.Arg5  = EventSvcArgs->Arg9;
+    Buffer->DirectMsgArgs.Arg6  = EventSvcArgs->Arg10;
+    Buffer->DirectMsgArgs.Arg7  = EventSvcArgs->Arg11;
+    Buffer->DirectMsgArgs.Arg8  = EventSvcArgs->Arg12;
+    Buffer->DirectMsgArgs.Arg9  = EventSvcArgs->Arg13;
+    Buffer->DirectMsgArgs.Arg10 = EventSvcArgs->Arg14;
+    Buffer->DirectMsgArgs.Arg11 = EventSvcArgs->Arg15;
+    Buffer->DirectMsgArgs.Arg12 = EventSvcArgs->Arg16;
+    Buffer->DirectMsgArgs.Arg13 = EventSvcArgs->Arg17;
+  }
+  // MU_CHANGE Ends
+
   CopyGuid (&Buffer->HeaderGuid, ServiceGuid);
 }
 

diff --git a/ArmPkg/Library/ArmStandaloneMmCoreEntryPoint/ArmStandaloneMmCoreEntryPoint.inf b/ArmPkg/Library/ArmStandaloneMmCoreEntryPoint/ArmStandaloneMmCoreEntryPoint.inf
@@ -64,6 +64,9 @@
 [Pcd]
   gArmTokenSpaceGuid.PcdStMmStackSize
 
+[FixedPcd]
+  gArmTokenSpaceGuid.PcdSxcUse18Registers # MU_CHANGE: Add 18 registers support
+
 #
 # This configuration fails for CLANGPDB, which does not support PIE in the GCC
 # sense. Such however is required for ARM family StandaloneMmCore