diff --git a/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFv.inf b/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFv.inf
index c3580859ff..4248ace658 100644
--- a/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFv.inf
+++ b/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFv.inf
@@ -30,6 +30,7 @@
 
 [LibraryClasses]
   ArmSvcLib
+  ArmFfaLib
   BaseLib
   BaseMemoryLib
   DebugLib
diff --git a/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFvb.c b/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFvb.c
index 19252698b2..8b9946a0e1 100644
--- a/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFvb.c
+++ b/Drivers/OpTee/OpteeRpmbPkg/OpTeeRpmbFvb.c
@@ -7,7 +7,7 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
-#include <Library/ArmSvcLib.h>
+#include <Library/ArmFfaLib.h>
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
@@ -27,12 +27,11 @@
 // Since the FFA autodiscovery mechanism is not yet implemented we are
 // hardcoding the ID values for the two operations OP-TEE currently supports
 //
-// mMemMgrId is used to set the page permissions after relocating the executable
 // mStorageId is used to access the RPMB partition via OP-TEE
 // In both cases the return value is located in x3. Once the autodiscovery mechanism
 // is in place, we'll have to account for an error value in x2 as well, handling
 // the autodiscovery failed scenario
-STATIC CONST UINT16 mMemMgrId = 3U;
+//
 STATIC CONST UINT16 mStorageId = 4U;
 
 STATIC MEM_INSTANCE mInstance;
@@ -63,48 +62,31 @@ ReadWriteRpmb (
   IN UINTN Offset
   )
 {
-  ARM_SVC_ARGS  SvcArgs;
-  EFI_STATUS    Status;
-
-  ZeroMem (&SvcArgs, sizeof (SvcArgs));
-
-  SvcArgs.Arg0 = ARM_SVC_ID_FFA_MSG_SEND_DIRECT_REQ;
-  SvcArgs.Arg1 = mStorageId;
-  SvcArgs.Arg2 = 0;
-  SvcArgs.Arg3 = SvcAct;
-  SvcArgs.Arg4 = Addr;
-  SvcArgs.Arg5 = NumBytes;
-  SvcArgs.Arg6 = Offset;
-
-  ArmCallSvc (&SvcArgs);
-  if (SvcArgs.Arg3) {
-    DEBUG ((DEBUG_ERROR, "%a: Svc Call 0x%08x Addr: 0x%08x len: 0x%x Offset: 0x%x failed with 0x%x\n",
-      __func__, SvcAct, Addr, NumBytes, Offset, SvcArgs.Arg3));
-  }
+  EFI_STATUS        Status;
+  DIRECT_MSG_ARGS   StorageArgs;
 
-  switch (SvcArgs.Arg3) {
-  case ARM_SVC_SPM_RET_SUCCESS:
-    Status = EFI_SUCCESS;
-    break;
+  ZeroMem (&StorageArgs, sizeof (StorageArgs));
 
-  case ARM_SVC_SPM_RET_NOT_SUPPORTED:
-    Status = EFI_UNSUPPORTED;
-    break;
+  StorageArgs.Arg0 = SvcAct;
+  StorageArgs.Arg1 = Addr;
+  StorageArgs.Arg2 = NumBytes;
+  StorageArgs.Arg3 = Offset;
 
-  case ARM_SVC_SPM_RET_INVALID_PARAMS:
-    Status = EFI_INVALID_PARAMETER;
-    break;
-
-  case ARM_SVC_SPM_RET_DENIED:
-    Status = EFI_ACCESS_DENIED;
-    break;
+  Status = ArmFfaLibMsgDirectReq (
+             mStorageId,
+             0,
+             &StorageArgs
+             );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to call ffa direct message request.\n", __func__));
+    return Status;
+  }
 
-  case ARM_SVC_SPM_RET_NO_MEMORY:
-    Status = EFI_OUT_OF_RESOURCES;
-    break;
+  Status = FfaStatusToEfiStatus (StorageArgs.Arg0);
 
-  default:
-    Status = EFI_ACCESS_DENIED;
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: SvcAct(0x%08x), Addr(0x%08x), NumBytes(0x%x), Offset(0x%x) failed with 0x%x\n",
+      __func__, SvcAct, Addr, NumBytes, Offset, StorageArgs.Arg0));
   }
 
   return Status;