diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c
index 5921533a81..f75a5c4fc5 100644
--- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c
+++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c
@@ -685,7 +685,8 @@ ResourceConflict (
 
   for (Link = GetFirstNode (&HostBridge->RootBridges), Descriptor = Resources; !IsNull (&HostBridge->RootBridges, Link); Link = GetNextNode (&HostBridge->RootBridges, Link)) {
     RootBridge = ROOT_BRIDGE_FROM_LINK (Link);
-    for (Index = TypeIo; Index < TypeMax; Index++) {
+    // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+    for (Index = PCI_RESOURCE_TYPE_ENUM_START; Index < TypeMax; Index++) {
       ResAllocNode = &RootBridge->ResAllocNode[Index];
 
       Descriptor->Desc         = ACPI_ADDRESS_SPACE_DESCRIPTOR;
@@ -928,7 +929,8 @@ NotifyPhase (
         RootBridge = ROOT_BRIDGE_FROM_LINK (Link);
         DEBUG ((DEBUG_INFO, " RootBridge: %s\n", RootBridge->DevicePathStr));
 
-        for (Index1 = TypeIo; Index1 < TypeBus; Index1++) {
+        // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+        for (Index1 = PCI_RESOURCE_TYPE_ENUM_START; Index1 < TypeBus; Index1++) {
           if (RootBridge->ResAllocNode[Index1].Status == ResNone) {
             ResNodeHandled[Index1] = TRUE;
           } else {
@@ -937,7 +939,8 @@ NotifyPhase (
             //
             MaxAlignment = 0;
             Index        = TypeMax;
-            for (Index2 = TypeIo; Index2 < TypeBus; Index2++) {
+            // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+            for (Index2 = PCI_RESOURCE_TYPE_ENUM_START; Index2 < TypeBus; Index2++) {
               if (ResNodeHandled[Index2]) {
                 continue;
               }
@@ -1142,7 +1145,8 @@ NotifyPhase (
            )
       {
         RootBridge = ROOT_BRIDGE_FROM_LINK (Link);
-        for (Index = TypeIo; Index < TypeBus; Index++) {
+        // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+        for (Index = PCI_RESOURCE_TYPE_ENUM_START; Index < TypeBus; Index++) {
           if (RootBridge->ResAllocNode[Index].Status == ResAllocated) {
             switch (Index) {
               case TypeIo:
@@ -1642,7 +1646,8 @@ GetProposedResources (
       }
 
       Descriptor = (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Buffer;
-      for (Index = 0; Index < TypeBus; Index++) {
+      // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+      for (Index = PCI_RESOURCE_TYPE_ENUM_START; Index < TypeBus; Index++) {
         ResStatus = RootBridge->ResAllocNode[Index].Status;
         if (ResStatus != ResNone) {
           Descriptor->Desc    = ACPI_ADDRESS_SPACE_DESCRIPTOR;
diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostResource.h b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostResource.h
index 772f4b513f..572abc0c80 100644
--- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostResource.h
+++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostResource.h
@@ -24,6 +24,16 @@ typedef enum {
   TypeMax
 } PCI_RESOURCE_TYPE;
 
+// MU_CHANGE begin
+// Only processor type X64 has IO resource
+#if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)
+
+#define PCI_RESOURCE_TYPE_ENUM_START  TypeIo
+#else
+#define PCI_RESOURCE_TYPE_ENUM_START  TypeMem32
+#endif
+// MU_CHANGE end
+
 typedef enum {
   ResNone,
   ResSubmitted,
diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
index 216f797deb..b03d107f8f 100644
--- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
+++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
@@ -226,7 +226,8 @@ CreateRootBridge (
   CopyMem (&RootBridge->PMem, &Bridge->PMem, sizeof (PCI_ROOT_BRIDGE_APERTURE));
   CopyMem (&RootBridge->PMemAbove4G, &Bridge->PMemAbove4G, sizeof (PCI_ROOT_BRIDGE_APERTURE));
 
-  for (Index = TypeIo; Index < TypeMax; Index++) {
+  // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+  for (Index = PCI_RESOURCE_TYPE_ENUM_START; Index < TypeMax; Index++) {
     switch (Index) {
       case TypeBus:
         Aperture = &RootBridge->Bus;
@@ -1940,7 +1941,8 @@ RootBridgeIoConfiguration (
     TypeMax * sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) + sizeof (EFI_ACPI_END_TAG_DESCRIPTOR)
     );
   Descriptor = RootBridge->ConfigBuffer;
-  for (Index = TypeIo; Index < TypeMax; Index++) {
+  // MU_CHANGE - PCI_RESOURCE_TYPE_ENUM_START
+  for (Index = PCI_RESOURCE_TYPE_ENUM_START; Index < TypeMax; Index++) {
     ResAllocNode = &RootBridge->ResAllocNode[Index];
 
     if (ResAllocNode->Status != ResAllocated) {