From 9595e3cd514b55e27b53caff0e265f92f15f4ba3 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Mon, 23 Feb 2015 16:02:55 +0000
Subject: [PATCH] ArmVirtualizationPkg/PciHostBridgeDxe: clone from
 PcAtChipsetPkg

MdeModulePkg/Bus/Pci/PciBusDxe depends on
EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL and
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL. Here we clone the driver that produces
these from PcAtChipsetPkg, with the following immediate changes:

- a new FILE_GUID is generated;

- the assembly-language Ia32 / X64 specific IoFifo "accelerators" are not
  copied, and their client code (which would be dead code anyway) is
  removed;

- UNI files are not copied: they are used in conjunction with the UEFI
  Packaging Tool (UPT), but the driver under ArmVirtualizationPkg will not
  be part of UDK.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Olivier Martin <Olivier.martin@arm.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16895 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../PciHostBridgeDxe/PciHostBridge.c          | 1200 ++++++++++
 .../PciHostBridgeDxe/PciHostBridge.h          |  495 ++++
 .../PciHostBridgeDxe/PciHostBridgeDxe.inf     |   52 +
 .../PciHostBridgeDxe/PciRootBridgeIo.c        | 2123 +++++++++++++++++
 4 files changed, 3870 insertions(+)
 create mode 100644 ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c
 create mode 100644 ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.h
 create mode 100644 ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf
 create mode 100644 ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciRootBridgeIo.c

diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c
new file mode 100644
index 0000000000..2f6ef68f1d
--- /dev/null
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c
@@ -0,0 +1,1200 @@
+/** @file
+  Provides the basic interfaces to abstract a PCI Host Bridge Resource Allocation
+
+Copyright (c) 2008 - 2013, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials are
+licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution.  The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/ 
+
+#include "PciHostBridge.h"
+
+//
+// Hard code: Root Bridge Number within the host bridge
+//            Root Bridge's attribute
+//            Root Bridge's device path
+//            Root Bridge's resource aperture
+//
+UINTN RootBridgeNumber[1] = { 1 };
+
+UINT64 RootBridgeAttribute[1][1] = { { EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM } };
+
+EFI_PCI_ROOT_BRIDGE_DEVICE_PATH mEfiPciRootBridgeDevicePath[1][1] = {
+  {
+    {
+      {
+        {
+          ACPI_DEVICE_PATH,
+          ACPI_DP,
+          {
+            (UINT8) (sizeof(ACPI_HID_DEVICE_PATH)),
+            (UINT8) ((sizeof(ACPI_HID_DEVICE_PATH)) >> 8)
+          }
+        },
+        EISA_PNP_ID(0x0A03),
+        0
+      },
+  
+      {
+        END_DEVICE_PATH_TYPE,
+        END_ENTIRE_DEVICE_PATH_SUBTYPE,
+        {
+          END_DEVICE_PATH_LENGTH,
+          0
+        }
+      }
+    }
+  }
+};
+
+PCI_ROOT_BRIDGE_RESOURCE_APERTURE  mResAperture[1][1] = {
+  {{0, 0xff, 0x80000000, 0xffffffff, 0, 0xffff}}
+};
+
+EFI_HANDLE mDriverImageHandle;
+
+PCI_HOST_BRIDGE_INSTANCE mPciHostBridgeInstanceTemplate = {
+  PCI_HOST_BRIDGE_SIGNATURE,  // Signature
+  NULL,                       // HostBridgeHandle
+  0,                          // RootBridgeNumber
+  {NULL, NULL},               // Head
+  FALSE,                      // ResourceSubiteed
+  TRUE,                       // CanRestarted
+  {
+    NotifyPhase,
+    GetNextRootBridge,
+    GetAttributes,
+    StartBusEnumeration,
+    SetBusNumbers,
+    SubmitResources,
+    GetProposedResources,
+    PreprocessController
+  }
+};
+
+//
+// Implementation
+//
+
+/**
+  Entry point of this driver
+
+  @param ImageHandle     Handle of driver image
+  @param SystemTable     Point to EFI_SYSTEM_TABLE
+
+  @retval EFI_OUT_OF_RESOURCES  Can not allocate memory resource
+  @retval EFI_DEVICE_ERROR      Can not install the protocol instance
+  @retval EFI_SUCCESS           Success to initialize the Pci host bridge.
+**/
+EFI_STATUS
+EFIAPI
+InitializePciHostBridge (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS                  Status;
+  UINTN                       Loop1;
+  UINTN                       Loop2;
+  PCI_HOST_BRIDGE_INSTANCE    *HostBridge;
+  PCI_ROOT_BRIDGE_INSTANCE    *PrivateData;
+ 
+  mDriverImageHandle = ImageHandle;
+  
+  //
+  // Create Host Bridge Device Handle
+  //
+  for (Loop1 = 0; Loop1 < HOST_BRIDGE_NUMBER; Loop1++) {
+    HostBridge = AllocateCopyPool (sizeof(PCI_HOST_BRIDGE_INSTANCE), &mPciHostBridgeInstanceTemplate);
+    if (HostBridge == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+  
+    HostBridge->RootBridgeNumber = RootBridgeNumber[Loop1];
+    InitializeListHead (&HostBridge->Head);
+
+    Status = gBS->InstallMultipleProtocolInterfaces (
+                    &HostBridge->HostBridgeHandle,              
+                    &gEfiPciHostBridgeResourceAllocationProtocolGuid, &HostBridge->ResAlloc,
+                    NULL
+                    );
+    if (EFI_ERROR (Status)) {
+      FreePool (HostBridge);
+      return EFI_DEVICE_ERROR;
+    }
+  
+    //
+    // Create Root Bridge Device Handle in this Host Bridge
+    //
+  
+    for (Loop2 = 0; Loop2 < HostBridge->RootBridgeNumber; Loop2++) {
+      PrivateData = AllocateZeroPool (sizeof(PCI_ROOT_BRIDGE_INSTANCE));
+      if (PrivateData == NULL) {
+        return EFI_OUT_OF_RESOURCES;
+      }
+
+      PrivateData->Signature = PCI_ROOT_BRIDGE_SIGNATURE;
+      PrivateData->DevicePath = (EFI_DEVICE_PATH_PROTOCOL *)&mEfiPciRootBridgeDevicePath[Loop1][Loop2];
+
+      RootBridgeConstructor (
+        &PrivateData->Io, 
+        HostBridge->HostBridgeHandle, 
+        RootBridgeAttribute[Loop1][Loop2], 
+        &mResAperture[Loop1][Loop2]
+        );
+    
+      Status = gBS->InstallMultipleProtocolInterfaces(
+                      &PrivateData->Handle,              
+                      &gEfiDevicePathProtocolGuid,      PrivateData->DevicePath,
+                      &gEfiPciRootBridgeIoProtocolGuid, &PrivateData->Io,
+                      NULL
+                      );
+      if (EFI_ERROR (Status)) {
+        FreePool(PrivateData);
+        return EFI_DEVICE_ERROR;
+      }
+ 
+      InsertTailList (&HostBridge->Head, &PrivateData->Link);
+    }
+  } 
+
+  return EFI_SUCCESS;
+}
+
+
+/**
+   These are the notifications from the PCI bus driver that it is about to enter a certain
+   phase of the PCI enumeration process.
+
+   This member function can be used to notify the host bridge driver to perform specific actions,
+   including any chipset-specific initialization, so that the chipset is ready to enter the next phase.
+   Eight notification points are defined at this time. See belows:
+   EfiPciHostBridgeBeginEnumeration       Resets the host bridge PCI apertures and internal data
+                                          structures. The PCI enumerator should issue this notification
+                                          before starting a fresh enumeration process. Enumeration cannot
+                                          be restarted after sending any other notification such as
+                                          EfiPciHostBridgeBeginBusAllocation.
+   EfiPciHostBridgeBeginBusAllocation     The bus allocation phase is about to begin. No specific action is
+                                          required here. This notification can be used to perform any
+                                          chipset-specific programming.
+   EfiPciHostBridgeEndBusAllocation       The bus allocation and bus programming phase is complete. No
+                                          specific action is required here. This notification can be used to
+                                          perform any chipset-specific programming.
+   EfiPciHostBridgeBeginResourceAllocation
+                                          The resource allocation phase is about to begin. No specific
+                                          action is required here. This notification can be used to perform
+                                          any chipset-specific programming.
+   EfiPciHostBridgeAllocateResources      Allocates resources per previously submitted requests for all the PCI
+                                          root bridges. These resource settings are returned on the next call to
+                                          GetProposedResources(). Before calling NotifyPhase() with a Phase of
+                                          EfiPciHostBridgeAllocateResource, the PCI bus enumerator is responsible
+                                          for gathering I/O and memory requests for
+                                          all the PCI root bridges and submitting these requests using
+                                          SubmitResources(). This function pads the resource amount
+                                          to suit the root bridge hardware, takes care of dependencies between
+                                          the PCI root bridges, and calls the Global Coherency Domain (GCD)
+                                          with the allocation request. In the case of padding, the allocated range
+                                          could be bigger than what was requested.
+   EfiPciHostBridgeSetResources           Programs the host bridge hardware to decode previously allocated
+                                          resources (proposed resources) for all the PCI root bridges. After the
+                                          hardware is programmed, reassigning resources will not be supported.
+                                          The bus settings are not affected.
+   EfiPciHostBridgeFreeResources          Deallocates resources that were previously allocated for all the PCI
+                                          root bridges and resets the I/O and memory apertures to their initial
+                                          state. The bus settings are not affected. If the request to allocate
+                                          resources fails, the PCI enumerator can use this notification to
+                                          deallocate previous resources, adjust the requests, and retry
+                                          allocation.
+   EfiPciHostBridgeEndResourceAllocation  The resource allocation phase is completed. No specific action is
+                                          required here. This notification can be used to perform any chipsetspecific
+                                          programming.
+
+   @param[in] This                The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in] Phase               The phase during enumeration
+
+   @retval EFI_NOT_READY          This phase cannot be entered at this time. For example, this error
+                                  is valid for a Phase of EfiPciHostBridgeAllocateResources if
+                                  SubmitResources() has not been called for one or more
+                                  PCI root bridges before this call
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error. This error is valid
+                                  for a Phase of EfiPciHostBridgeSetResources.
+   @retval EFI_INVALID_PARAMETER  Invalid phase parameter
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+                                  This error is valid for a Phase of EfiPciHostBridgeAllocateResources if the
+                                  previously submitted resource requests cannot be fulfilled or
+                                  were only partially fulfilled.
+   @retval EFI_SUCCESS            The notification was accepted without any errors.
+
+**/
+EFI_STATUS
+EFIAPI
+NotifyPhase(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PHASE    Phase
+  )
+{
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  PCI_RESOURCE_TYPE                     Index;
+  LIST_ENTRY                            *List;
+  EFI_PHYSICAL_ADDRESS                  BaseAddress;
+  UINT64                                AddrLen;
+  UINTN                                 BitsOfAlignment;
+  EFI_STATUS                            Status;
+  EFI_STATUS                            ReturnStatus;
+  
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  
+  switch (Phase) {
+
+  case EfiPciHostBridgeBeginEnumeration:
+    if (HostBridgeInstance->CanRestarted) {
+      //
+      // Reset the Each Root Bridge 
+      //
+      List = HostBridgeInstance->Head.ForwardLink;
+  
+      while (List != &HostBridgeInstance->Head) {
+        RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+        for (Index = TypeIo; Index < TypeMax; Index++) {
+          RootBridgeInstance->ResAllocNode[Index].Type      = Index;
+          RootBridgeInstance->ResAllocNode[Index].Base      = 0;
+          RootBridgeInstance->ResAllocNode[Index].Length    = 0;
+          RootBridgeInstance->ResAllocNode[Index].Status    = ResNone;
+        }
+          
+        List = List->ForwardLink;
+      }
+        
+      HostBridgeInstance->ResourceSubmited = FALSE;
+      HostBridgeInstance->CanRestarted     = TRUE;
+    } else {
+      //
+      // Can not restart
+      // 
+      return EFI_NOT_READY;
+    }  
+    break;
+
+  case EfiPciHostBridgeEndEnumeration:
+    break;
+
+  case EfiPciHostBridgeBeginBusAllocation:
+    //
+    // No specific action is required here, can perform any chipset specific programing
+    //
+    HostBridgeInstance->CanRestarted = FALSE;
+    break;
+
+  case EfiPciHostBridgeEndBusAllocation:
+    //
+    // No specific action is required here, can perform any chipset specific programing
+    //
+    //HostBridgeInstance->CanRestarted = FALSE;
+    break;
+
+  case EfiPciHostBridgeBeginResourceAllocation:
+    //
+    // No specific action is required here, can perform any chipset specific programing
+    //
+    //HostBridgeInstance->CanRestarted = FALSE;
+    break;
+
+  case EfiPciHostBridgeAllocateResources:
+    ReturnStatus = EFI_SUCCESS;
+    if (HostBridgeInstance->ResourceSubmited) {
+      //
+      // Take care of the resource dependencies between the root bridges 
+      //
+      List = HostBridgeInstance->Head.ForwardLink;
+
+      while (List != &HostBridgeInstance->Head) {
+        RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+        for (Index = TypeIo; Index < TypeBus; Index++) {
+          if (RootBridgeInstance->ResAllocNode[Index].Status != ResNone) {
+                                        
+            AddrLen = RootBridgeInstance->ResAllocNode[Index].Length;
+            
+            //
+            // Get the number of '1' in Alignment.
+            //
+            BitsOfAlignment = (UINTN) (HighBitSet64 (RootBridgeInstance->ResAllocNode[Index].Alignment) + 1);
+                                  
+            switch (Index) {
+
+              case TypeIo:  
+                //
+                // It is impossible for this chipset to align 0xFFFF for IO16
+                // So clear it
+                //
+                if (BitsOfAlignment >= 16) {
+                  BitsOfAlignment = 0;
+                }
+                  
+                Status = gDS->AllocateIoSpace (
+                                EfiGcdAllocateAnySearchBottomUp, 
+                                EfiGcdIoTypeIo, 
+                                BitsOfAlignment,
+                                AddrLen,
+                                &BaseAddress,
+                                mDriverImageHandle,
+                                NULL
+                                );
+                 
+                if (!EFI_ERROR (Status)) {
+                  RootBridgeInstance->ResAllocNode[Index].Base   = (UINTN)BaseAddress;
+                  RootBridgeInstance->ResAllocNode[Index].Status = ResAllocated; 
+                } else {
+                  ReturnStatus = Status;  
+                  if (Status != EFI_OUT_OF_RESOURCES) {
+                    RootBridgeInstance->ResAllocNode[Index].Length = 0;
+                  }
+                }
+
+                break;
+
+
+              case TypeMem32:
+                //
+                // It is impossible for this chipset to align 0xFFFFFFFF for Mem32
+                // So clear it 
+                //
+                  
+                if (BitsOfAlignment >= 32) {
+                  BitsOfAlignment = 0;
+                }
+                  
+                Status = gDS->AllocateMemorySpace (
+                                EfiGcdAllocateAnySearchBottomUp, 
+                                EfiGcdMemoryTypeMemoryMappedIo, 
+                                BitsOfAlignment,
+                                AddrLen,
+                                &BaseAddress,
+                                mDriverImageHandle,
+                                NULL
+                                );
+                  
+                if (!EFI_ERROR (Status)) {
+                  // We were able to allocate the PCI memory
+                  RootBridgeInstance->ResAllocNode[Index].Base   = (UINTN)BaseAddress;
+                  RootBridgeInstance->ResAllocNode[Index].Status = ResAllocated;
+                    
+                } else {
+                  // Not able to allocate enough PCI memory
+                  ReturnStatus = Status;  
+                    
+                  if (Status != EFI_OUT_OF_RESOURCES) {
+                    RootBridgeInstance->ResAllocNode[Index].Length = 0;
+                  } 
+                  ASSERT (FALSE);
+                }
+                break;
+                  
+              case TypePMem32:                  
+              case TypeMem64:                  
+              case TypePMem64:
+                  ReturnStatus = EFI_ABORTED;
+                  break;  
+              default:
+                ASSERT (FALSE);
+                break;
+              }; //end switch
+          }
+        }
+          
+        List = List->ForwardLink;
+      }
+        
+      return ReturnStatus;
+
+    } else {
+      return EFI_NOT_READY;
+    }
+    break;
+
+  case EfiPciHostBridgeSetResources:
+    break;
+
+  case EfiPciHostBridgeFreeResources:
+    ReturnStatus = EFI_SUCCESS;
+    List = HostBridgeInstance->Head.ForwardLink;
+    while (List != &HostBridgeInstance->Head) {
+      RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+      for (Index = TypeIo; Index < TypeBus; Index++) {
+        if (RootBridgeInstance->ResAllocNode[Index].Status == ResAllocated) {
+          AddrLen = RootBridgeInstance->ResAllocNode[Index].Length;
+          BaseAddress = RootBridgeInstance->ResAllocNode[Index].Base;
+          switch (Index) {
+
+          case TypeIo:  
+            Status = gDS->FreeIoSpace (BaseAddress, AddrLen);                
+            if (EFI_ERROR (Status)) {
+              ReturnStatus = Status;
+            }
+            break;
+
+          case TypeMem32:
+            Status = gDS->FreeMemorySpace (BaseAddress, AddrLen);
+            if (EFI_ERROR (Status)) {
+              ReturnStatus = Status;
+            }
+            break;
+
+          case TypePMem32:
+            break;
+
+          case TypeMem64:
+            break;
+
+          case TypePMem64:
+            break; 
+
+          default:
+            ASSERT (FALSE);
+            break;
+
+          }; //end switch
+          RootBridgeInstance->ResAllocNode[Index].Type      = Index;
+          RootBridgeInstance->ResAllocNode[Index].Base      = 0;
+          RootBridgeInstance->ResAllocNode[Index].Length    = 0;
+          RootBridgeInstance->ResAllocNode[Index].Status    = ResNone;
+        }
+      }
+        
+      List = List->ForwardLink;
+    }
+              
+    HostBridgeInstance->ResourceSubmited = FALSE;
+    HostBridgeInstance->CanRestarted     = TRUE;      
+    return ReturnStatus;
+
+  case EfiPciHostBridgeEndResourceAllocation:
+    HostBridgeInstance->CanRestarted = FALSE;
+    break;
+
+  default:
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  return EFI_SUCCESS;  
+}
+
+/**
+   Return the device handle of the next PCI root bridge that is associated with this Host Bridge.
+
+   This function is called multiple times to retrieve the device handles of all the PCI root bridges that
+   are associated with this PCI host bridge. Each PCI host bridge is associated with one or more PCI
+   root bridges. On each call, the handle that was returned by the previous call is passed into the
+   interface, and on output the interface returns the device handle of the next PCI root bridge. The
+   caller can use the handle to obtain the instance of the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+   for that root bridge. When there are no more PCI root bridges to report, the interface returns
+   EFI_NOT_FOUND. A PCI enumerator must enumerate the PCI root bridges in the order that they
+   are returned by this function.
+   For D945 implementation, there is only one root bridge in PCI host bridge.
+
+   @param[in]       This              The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in, out]  RootBridgeHandle  Returns the device handle of the next PCI root bridge.
+   
+   @retval EFI_SUCCESS            If parameter RootBridgeHandle = NULL, then return the first Rootbridge handle of the
+                                  specific Host bridge and return EFI_SUCCESS. 
+   @retval EFI_NOT_FOUND          Can not find the any more root bridge in specific host bridge.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not an EFI_HANDLE that was
+                                  returned on a previous call to GetNextRootBridge().
+**/
+EFI_STATUS
+EFIAPI
+GetNextRootBridge(
+  IN       EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN OUT   EFI_HANDLE                                       *RootBridgeHandle
+  )
+{
+  BOOLEAN                               NoRootBridge; 
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  
+  NoRootBridge = TRUE;
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  
+  while (List != &HostBridgeInstance->Head) {
+    NoRootBridge = FALSE;
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (*RootBridgeHandle == NULL) {
+      //
+      // Return the first Root Bridge Handle of the Host Bridge
+      //
+      *RootBridgeHandle = RootBridgeInstance->Handle;
+      return EFI_SUCCESS;
+    } else {
+      if (*RootBridgeHandle == RootBridgeInstance->Handle) {
+        //
+        // Get next if have
+        //
+        List = List->ForwardLink;
+        if (List!=&HostBridgeInstance->Head) {
+          RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+          *RootBridgeHandle = RootBridgeInstance->Handle;
+          return EFI_SUCCESS;  
+        } else {
+          return EFI_NOT_FOUND;
+        }
+      }
+    }
+      
+    List = List->ForwardLink;
+  } //end while
+  
+  if (NoRootBridge) {
+    return EFI_NOT_FOUND;
+  } else {
+    return EFI_INVALID_PARAMETER;
+  }
+}
+
+/**
+   Returns the allocation attributes of a PCI root bridge.
+
+   The function returns the allocation attributes of a specific PCI root bridge. The attributes can vary
+   from one PCI root bridge to another. These attributes are different from the decode-related
+   attributes that are returned by the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.GetAttributes() member function. The
+   RootBridgeHandle parameter is used to specify the instance of the PCI root bridge. The device
+   handles of all the root bridges that are associated with this host bridge must be obtained by calling
+   GetNextRootBridge(). The attributes are static in the sense that they do not change during or
+   after the enumeration process. The hardware may provide mechanisms to change the attributes on
+   the fly, but such changes must be completed before EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL is 
+   installed. The permitted values of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ATTRIBUTES are defined in
+   "Related Definitions" below. The caller uses these attributes to combine multiple resource requests.
+   For example, if the flag EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM is set, the PCI bus enumerator needs to 
+   include requests for the prefetchable memory in the nonprefetchable memory pool and not request any 
+   prefetchable memory.
+      Attribute                                 Description
+   ------------------------------------         ----------------------------------------------------------------------
+   EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM         If this bit is set, then the PCI root bridge does not support separate
+                                                windows for nonprefetchable and prefetchable memory. A PCI bus
+                                                driver needs to include requests for prefetchable memory in the
+                                                nonprefetchable memory pool.
+
+   EFI_PCI_HOST_BRIDGE_MEM64_DECODE             If this bit is set, then the PCI root bridge supports 64-bit memory
+                                                windows. If this bit is not set, the PCI bus driver needs to include
+                                                requests for a 64-bit memory address in the corresponding 32-bit
+                                                memory pool.
+
+   @param[in]   This               The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in]   RootBridgeHandle   The device handle of the PCI root bridge in which the caller is interested. Type
+                                   EFI_HANDLE is defined in InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param[out]  Attributes         The pointer to attribte of root bridge, it is output parameter
+   
+   @retval EFI_INVALID_PARAMETER   Attribute pointer is NULL
+   @retval EFI_INVALID_PARAMETER   RootBridgehandle is invalid.
+   @retval EFI_SUCCESS             Success to get attribute of interested root bridge.
+
+**/
+EFI_STATUS
+EFIAPI
+GetAttributes(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT UINT64                                           *Attributes
+  )
+{
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  
+  if (Attributes == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      *Attributes = RootBridgeInstance->RootBridgeAttrib;
+      return EFI_SUCCESS;
+    }
+    List = List->ForwardLink;
+  }
+  
+  //
+  // RootBridgeHandle is not an EFI_HANDLE 
+  // that was returned on a previous call to GetNextRootBridge()
+  //
+  return EFI_INVALID_PARAMETER;
+}
+
+/**
+   Sets up the specified PCI root bridge for the bus enumeration process.
+
+   This member function sets up the root bridge for bus enumeration and returns the PCI bus range
+   over which the search should be performed in ACPI 2.0 resource descriptor format.
+
+   @param[in]   This              The EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ PROTOCOL instance.
+   @param[in]   RootBridgeHandle  The PCI Root Bridge to be set up.
+   @param[out]  Configuration     Pointer to the pointer to the PCI bus resource descriptor.
+   
+   @retval EFI_INVALID_PARAMETER Invalid Root bridge's handle
+   @retval EFI_OUT_OF_RESOURCES  Fail to allocate ACPI resource descriptor tag.
+   @retval EFI_SUCCESS           Sucess to allocate ACPI resource descriptor.
+
+**/
+EFI_STATUS
+EFIAPI
+StartBusEnumeration(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT VOID                                             **Configuration
+  )
+{
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  VOID                                  *Buffer;
+  UINT8                                 *Temp;
+  UINT64                                BusStart;
+  UINT64                                BusEnd;
+  
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      //
+      // Set up the Root Bridge for Bus Enumeration
+      //
+      BusStart = RootBridgeInstance->BusBase;
+      BusEnd   = RootBridgeInstance->BusLimit;
+      //
+      // Program the Hardware(if needed) if error return EFI_DEVICE_ERROR
+      //
+      
+      Buffer = AllocatePool (sizeof(EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) + sizeof(EFI_ACPI_END_TAG_DESCRIPTOR));
+      if (Buffer == NULL) {
+        return EFI_OUT_OF_RESOURCES;
+      }
+      
+      Temp = (UINT8 *)Buffer;
+      
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->Desc = 0x8A;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->Len  = 0x2B;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->ResType = 2;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->GenFlag = 0; 
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->SpecificFlag = 0;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->AddrSpaceGranularity = 0;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->AddrRangeMin = BusStart;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->AddrRangeMax = 0;
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->AddrTranslationOffset = 0;       
+      ((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Temp)->AddrLen = BusEnd - BusStart + 1;
+      
+      Temp = Temp + sizeof(EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR);
+      ((EFI_ACPI_END_TAG_DESCRIPTOR *)Temp)->Desc = 0x79;      
+      ((EFI_ACPI_END_TAG_DESCRIPTOR *)Temp)->Checksum = 0x0;
+      
+      *Configuration = Buffer;      
+      return EFI_SUCCESS;
+    }
+    List = List->ForwardLink;
+  }
+  
+  return EFI_INVALID_PARAMETER;
+}
+
+/**
+   Programs the PCI root bridge hardware so that it decodes the specified PCI bus range.
+
+   This member function programs the specified PCI root bridge to decode the bus range that is
+   specified by the input parameter Configuration.
+   The bus range information is specified in terms of the ACPI 2.0 resource descriptor format.
+
+   @param[in] This              The EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ PROTOCOL instance
+   @param[in] RootBridgeHandle  The PCI Root Bridge whose bus range is to be programmed
+   @param[in] Configuration     The pointer to the PCI bus resource descriptor
+   
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER  Configuration is NULL.
+   @retval EFI_INVALID_PARAMETER  Configuration does not point to a valid ACPI 2.0 resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration does not include a valid ACPI 2.0 bus resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration includes valid ACPI 2.0 resource descriptors other than 
+                                  bus descriptors.
+   @retval EFI_INVALID_PARAMETER  Configuration contains one or more invalid ACPI resource descriptors.
+   @retval EFI_INVALID_PARAMETER  "Address Range Minimum" is invalid for this root bridge.
+   @retval EFI_INVALID_PARAMETER  "Address Range Length" is invalid for this root bridge.
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error.
+   @retval EFI_SUCCESS            The bus range for the PCI root bridge was programmed.
+
+**/
+EFI_STATUS
+EFIAPI
+SetBusNumbers(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_HANDLE                                       RootBridgeHandle,
+  IN VOID                                             *Configuration
+  )
+{
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  UINT8                                 *Ptr;
+  UINTN                                 BusStart;
+  UINTN                                 BusEnd;
+  UINTN                                 BusLen;
+  
+  if (Configuration == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+    
+  Ptr = Configuration;
+  
+  //
+  // Check the Configuration is valid
+  //
+  if(*Ptr != ACPI_ADDRESS_SPACE_DESCRIPTOR) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  if (((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Ptr)->ResType != 2) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Ptr += sizeof(EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR);
+  if (*Ptr != ACPI_END_TAG_DESCRIPTOR) {
+    return EFI_INVALID_PARAMETER;
+  }
+   
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  Ptr = Configuration;
+  
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      BusStart = (UINTN)((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Ptr)->AddrRangeMin;
+      BusLen = (UINTN)((EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)Ptr)->AddrLen;
+      BusEnd = BusStart + BusLen - 1;
+      
+      if (BusStart > BusEnd) {
+        return EFI_INVALID_PARAMETER;
+      }
+      
+      if ((BusStart < RootBridgeInstance->BusBase) || (BusEnd > RootBridgeInstance->BusLimit)) {
+        return EFI_INVALID_PARAMETER;
+      }
+      
+      //
+      // Update the Bus Range
+      //
+      RootBridgeInstance->ResAllocNode[TypeBus].Base   = BusStart;
+      RootBridgeInstance->ResAllocNode[TypeBus].Length = BusLen;
+      RootBridgeInstance->ResAllocNode[TypeBus].Status = ResAllocated;
+      
+      //
+      // Program the Root Bridge Hardware
+      //
+       
+      return EFI_SUCCESS;
+    }
+    
+    List = List->ForwardLink;
+  }
+  
+  return EFI_INVALID_PARAMETER;
+}
+
+
+/**
+   Submits the I/O and memory resource requirements for the specified PCI root bridge.
+
+   This function is used to submit all the I/O and memory resources that are required by the specified
+   PCI root bridge. The input parameter Configuration is used to specify the following:
+   - The various types of resources that are required
+   - The associated lengths in terms of ACPI 2.0 resource descriptor format
+
+   @param[in] This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param[in] RootBridgeHandle  The PCI root bridge whose I/O and memory resource requirements are being submitted.
+   @param[in] Configuration     The pointer to the PCI I/O and PCI memory resource descriptor.
+   
+   @retval EFI_SUCCESS            The I/O and memory resource requests for a PCI root bridge were accepted.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER  Configuration is NULL.
+   @retval EFI_INVALID_PARAMETER  Configuration does not point to a valid ACPI 2.0 resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration includes requests for one or more resource types that are 
+                                  not supported by this PCI root bridge. This error will happen if the caller 
+                                  did not combine resources according to Attributes that were returned by
+                                  GetAllocAttributes().
+   @retval EFI_INVALID_PARAMETER  Address Range Maximum" is invalid.
+   @retval EFI_INVALID_PARAMETER  "Address Range Length" is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  "Address Space Granularity" is invalid for this PCI root bridge.
+
+**/
+EFI_STATUS
+EFIAPI
+SubmitResources(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_HANDLE                                       RootBridgeHandle,
+  IN VOID                                             *Configuration
+  )
+{
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  UINT8                                 *Temp;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR     *Ptr;
+  UINT64                                AddrLen;
+  UINT64                                Alignment;
+  
+  //
+  // Check the input parameter: Configuration
+  //
+  if (Configuration == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  Temp = (UINT8 *)Configuration;
+  while ( *Temp == 0x8A) { 
+    Temp += sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) ;
+  }
+  if (*Temp != 0x79) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  Temp = (UINT8 *)Configuration;
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      while ( *Temp == 0x8A) {
+        Ptr = (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *) Temp ;
+
+        //
+        // Check Address Length
+        //
+        if (Ptr->AddrLen > 0xffffffff) {
+          return EFI_INVALID_PARAMETER;
+        }
+
+        //
+        // Check address range alignment
+        //
+        if (Ptr->AddrRangeMax >= 0xffffffff || Ptr->AddrRangeMax != (GetPowerOfTwo64 (Ptr->AddrRangeMax + 1) - 1)) {
+          return EFI_INVALID_PARAMETER;
+        }
+        
+        switch (Ptr->ResType) {
+
+        case 0:
+            
+          //
+          // Check invalid Address Sapce Granularity
+          //
+          if (Ptr->AddrSpaceGranularity != 32) {
+            return EFI_INVALID_PARAMETER;
+          }
+            
+          //
+          // check the memory resource request is supported by PCI root bridge
+          //
+          if (RootBridgeInstance->RootBridgeAttrib == EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM &&
+               Ptr->SpecificFlag == 0x06) {
+            return EFI_INVALID_PARAMETER;
+          }
+            
+          AddrLen = Ptr->AddrLen;
+          Alignment = Ptr->AddrRangeMax;
+          if (Ptr->AddrSpaceGranularity == 32) {
+            if (Ptr->SpecificFlag == 0x06) {
+              //
+              // Apply from GCD
+              //
+              RootBridgeInstance->ResAllocNode[TypePMem32].Status = ResSubmitted;
+            } else {
+              RootBridgeInstance->ResAllocNode[TypeMem32].Length = AddrLen;
+              RootBridgeInstance->ResAllocNode[TypeMem32].Alignment = Alignment;
+              RootBridgeInstance->ResAllocNode[TypeMem32].Status = ResRequested; 
+              HostBridgeInstance->ResourceSubmited = TRUE;
+            }
+          }
+
+          if (Ptr->AddrSpaceGranularity == 64) {
+            if (Ptr->SpecificFlag == 0x06) {
+              RootBridgeInstance->ResAllocNode[TypePMem64].Status = ResSubmitted;
+            } else {
+              RootBridgeInstance->ResAllocNode[TypeMem64].Status = ResSubmitted;
+            }
+          }
+          break;
+
+        case 1:
+          AddrLen = (UINTN) Ptr->AddrLen;
+          Alignment = (UINTN) Ptr->AddrRangeMax;
+          RootBridgeInstance->ResAllocNode[TypeIo].Length  = AddrLen;
+          RootBridgeInstance->ResAllocNode[TypeIo].Alignment = Alignment;
+          RootBridgeInstance->ResAllocNode[TypeIo].Status  = ResRequested;
+          HostBridgeInstance->ResourceSubmited = TRUE; 
+          break;
+
+        default:
+            break;
+        };
+    
+        Temp += sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) ;
+      } 
+      
+      return EFI_SUCCESS;
+    }
+    
+    List = List->ForwardLink;
+  }
+  
+  return EFI_INVALID_PARAMETER;
+}
+
+/**
+   Returns the proposed resource settings for the specified PCI root bridge.
+
+   This member function returns the proposed resource settings for the specified PCI root bridge. The
+   proposed resource settings are prepared when NotifyPhase() is called with a Phase of
+   EfiPciHostBridgeAllocateResources. The output parameter Configuration
+   specifies the following:
+   - The various types of resources, excluding bus resources, that are allocated
+   - The associated lengths in terms of ACPI 2.0 resource descriptor format
+
+   @param[in]  This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param[in]  RootBridgeHandle  The PCI root bridge handle. Type EFI_HANDLE is defined in InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param[out] Configuration     The pointer to the pointer to the PCI I/O and memory resource descriptor.
+   
+   @retval EFI_SUCCESS            The requested parameters were returned.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+GetProposedResources(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT VOID                                             **Configuration
+  )
+{
+  LIST_ENTRY                            *List; 
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  UINTN                                 Index;
+  UINTN                                 Number; 
+  VOID                                  *Buffer; 
+  UINT8                                 *Temp;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR     *Ptr;
+  UINT64                                ResStatus;
+    
+  Buffer = NULL;
+  Number = 0;
+  //
+  // Get the Host Bridge Instance from the resource allocation protocol
+  //
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+  
+  //
+  // Enumerate the root bridges in this host bridge
+  //
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      for (Index = 0; Index < TypeBus; Index ++) {
+        if (RootBridgeInstance->ResAllocNode[Index].Status != ResNone) {
+          Number ++;
+        }  
+      }
+      
+      if (Number ==  0) {
+        return EFI_INVALID_PARAMETER;
+      }
+
+      Buffer = AllocateZeroPool (Number * sizeof(EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) + sizeof(EFI_ACPI_END_TAG_DESCRIPTOR));
+      if (Buffer == NULL) {
+        return EFI_OUT_OF_RESOURCES;
+      }
+      
+      Temp = Buffer;
+      for (Index = 0; Index < TypeBus; Index ++) {
+        if (RootBridgeInstance->ResAllocNode[Index].Status != ResNone) {
+          Ptr = (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *) Temp ;
+          ResStatus = RootBridgeInstance->ResAllocNode[Index].Status;
+          
+          switch (Index) {
+
+          case TypeIo:
+            //
+            // Io
+            //
+            Ptr->Desc = 0x8A;
+            Ptr->Len  = 0x2B;
+            Ptr->ResType = 1;
+            Ptr->GenFlag = 0; 
+            Ptr->SpecificFlag = 0;
+            Ptr->AddrRangeMin = RootBridgeInstance->ResAllocNode[Index].Base;
+            Ptr->AddrRangeMax = 0;
+            Ptr->AddrTranslationOffset = \
+                 (ResStatus == ResAllocated) ? EFI_RESOURCE_SATISFIED : EFI_RESOURCE_LESS;
+            Ptr->AddrLen = RootBridgeInstance->ResAllocNode[Index].Length;
+            break;
+
+          case TypeMem32:
+            //
+            // Memory 32
+            // 
+            Ptr->Desc = 0x8A;
+            Ptr->Len  = 0x2B;
+            Ptr->ResType = 0;
+            Ptr->GenFlag = 0; 
+            Ptr->SpecificFlag = 0;
+            Ptr->AddrSpaceGranularity = 32;
+            Ptr->AddrRangeMin = RootBridgeInstance->ResAllocNode[Index].Base;
+            Ptr->AddrRangeMax = 0;
+            Ptr->AddrTranslationOffset = \
+                 (ResStatus == ResAllocated) ? EFI_RESOURCE_SATISFIED : EFI_RESOURCE_LESS;              
+            Ptr->AddrLen = RootBridgeInstance->ResAllocNode[Index].Length;
+            break;
+
+          case TypePMem32:
+            //
+            // Prefetch memory 32
+            //
+            Ptr->Desc = 0x8A;
+            Ptr->Len  = 0x2B;
+            Ptr->ResType = 0;
+            Ptr->GenFlag = 0; 
+            Ptr->SpecificFlag = 6;
+            Ptr->AddrSpaceGranularity = 32;
+            Ptr->AddrRangeMin = 0;
+            Ptr->AddrRangeMax = 0;
+            Ptr->AddrTranslationOffset = EFI_RESOURCE_NONEXISTENT;       
+            Ptr->AddrLen = 0;
+            break;
+
+          case TypeMem64:
+            //
+            // Memory 64
+            //
+            Ptr->Desc = 0x8A;
+            Ptr->Len  = 0x2B;
+            Ptr->ResType = 0;
+            Ptr->GenFlag = 0; 
+            Ptr->SpecificFlag = 0;
+            Ptr->AddrSpaceGranularity = 64;
+            Ptr->AddrRangeMin = 0;
+            Ptr->AddrRangeMax = 0;
+            Ptr->AddrTranslationOffset = EFI_RESOURCE_NONEXISTENT;       
+            Ptr->AddrLen = 0;
+            break;
+
+          case TypePMem64:
+            //
+            // Prefetch memory 64
+            //
+            Ptr->Desc = 0x8A;
+            Ptr->Len  = 0x2B;
+            Ptr->ResType = 0;
+            Ptr->GenFlag = 0; 
+            Ptr->SpecificFlag = 6;
+            Ptr->AddrSpaceGranularity = 64;
+            Ptr->AddrRangeMin = 0;
+            Ptr->AddrRangeMax = 0;
+            Ptr->AddrTranslationOffset = EFI_RESOURCE_NONEXISTENT;       
+            Ptr->AddrLen = 0;
+            break;
+          };
+          
+          Temp += sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR);
+        }  
+      }
+      
+      ((EFI_ACPI_END_TAG_DESCRIPTOR *)Temp)->Desc = 0x79;      
+      ((EFI_ACPI_END_TAG_DESCRIPTOR *)Temp)->Checksum = 0x0;
+      
+      *Configuration = Buffer;      
+       
+      return EFI_SUCCESS;
+    }
+    
+    List = List->ForwardLink;
+  }
+  
+  return EFI_INVALID_PARAMETER;
+}
+
+/**
+   Provides the hooks from the PCI bus driver to every PCI controller (device/function) at various
+   stages of the PCI enumeration process that allow the host bridge driver to preinitialize individual
+   PCI controllers before enumeration.
+
+   This function is called during the PCI enumeration process. No specific action is expected from this
+   member function. It allows the host bridge driver to preinitialize individual PCI controllers before
+   enumeration.
+
+   @param This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param RootBridgeHandle  The associated PCI root bridge handle. Type EFI_HANDLE is defined in
+                            InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param PciAddress        The address of the PCI device on the PCI bus. This address can be passed to the
+                            EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL member functions to access the PCI
+                            configuration space of the device. See Table 12-1 in the UEFI 2.0 Specification for
+                            the definition of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS.
+   @param Phase             The phase of the PCI device enumeration. 
+   
+   @retval EFI_SUCCESS              The requested parameters were returned.
+   @retval EFI_INVALID_PARAMETER    RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER    Phase is not a valid phase that is defined in
+                                    EFI_PCI_CONTROLLER_RESOURCE_ALLOCATION_PHASE.
+   @retval EFI_DEVICE_ERROR         Programming failed due to a hardware error. The PCI enumerator should
+                                    not enumerate this device, including its child devices if it is a PCI-to-PCI
+                                    bridge.
+
+**/
+EFI_STATUS
+EFIAPI
+PreprocessController (
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL          *This,
+  IN  EFI_HANDLE                                                RootBridgeHandle,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS               PciAddress,
+  IN  EFI_PCI_CONTROLLER_RESOURCE_ALLOCATION_PHASE              Phase
+  )
+{
+  PCI_HOST_BRIDGE_INSTANCE              *HostBridgeInstance;
+  PCI_ROOT_BRIDGE_INSTANCE              *RootBridgeInstance;
+  LIST_ENTRY                            *List; 
+
+  HostBridgeInstance = INSTANCE_FROM_RESOURCE_ALLOCATION_THIS (This);
+  List = HostBridgeInstance->Head.ForwardLink;
+
+  //
+  // Enumerate the root bridges in this host bridge
+  //
+  while (List != &HostBridgeInstance->Head) {
+    RootBridgeInstance = DRIVER_INSTANCE_FROM_LIST_ENTRY (List);
+    if (RootBridgeHandle == RootBridgeInstance->Handle) {
+      break;
+    }
+    List = List->ForwardLink;
+  }
+  if (List == &HostBridgeInstance->Head) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((UINT32)Phase > EfiPciBeforeResourceCollection) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  return EFI_SUCCESS;
+}
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.h b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.h
new file mode 100644
index 0000000000..f9ef7d8c1c
--- /dev/null
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.h
@@ -0,0 +1,495 @@
+/** @file
+  The Header file of the Pci Host Bridge Driver 
+
+  Copyright (c) 2008 - 2010, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials are
+  licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+  
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/ 
+
+#ifndef _PCI_HOST_BRIDGE_H_
+#define _PCI_HOST_BRIDGE_H_
+
+#include <PiDxe.h>
+
+#include <IndustryStandard/Pci.h>
+#include <IndustryStandard/Acpi.h>
+
+#include <Protocol/PciHostBridgeResourceAllocation.h>
+#include <Protocol/PciRootBridgeIo.h>
+#include <Protocol/Metronome.h>
+#include <Protocol/DevicePath.h>
+
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/IoLib.h>
+#include <Library/PciLib.h>
+
+//
+// Hard code the host bridge number in the platform.
+// In this chipset, there is only one host bridge.
+//
+#define HOST_BRIDGE_NUMBER  1
+
+#define MAX_PCI_DEVICE_NUMBER      31
+#define MAX_PCI_FUNCTION_NUMBER    7
+#define MAX_PCI_REG_ADDRESS        0xFF
+
+typedef enum {
+  IoOperation,
+  MemOperation,
+  PciOperation
+} OPERATION_TYPE;
+
+#define PCI_HOST_BRIDGE_SIGNATURE  SIGNATURE_32('e', 'h', 's', 't')
+typedef struct {
+  UINTN                                             Signature;
+  EFI_HANDLE                                        HostBridgeHandle;
+  UINTN                                             RootBridgeNumber;
+  LIST_ENTRY                                        Head;
+  BOOLEAN                                           ResourceSubmited;  
+  BOOLEAN                                           CanRestarted;  
+  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL  ResAlloc;
+} PCI_HOST_BRIDGE_INSTANCE;
+
+#define INSTANCE_FROM_RESOURCE_ALLOCATION_THIS(a) \
+  CR(a, PCI_HOST_BRIDGE_INSTANCE, ResAlloc, PCI_HOST_BRIDGE_SIGNATURE)
+  
+//
+//  HostBridge Resource Allocation interface
+//
+
+/**
+   These are the notifications from the PCI bus driver that it is about to enter a certain
+   phase of the PCI enumeration process.
+
+   This member function can be used to notify the host bridge driver to perform specific actions,
+   including any chipset-specific initialization, so that the chipset is ready to enter the next phase.
+   Eight notification points are defined at this time. See belows:
+   EfiPciHostBridgeBeginEnumeration       Resets the host bridge PCI apertures and internal data
+                                          structures. The PCI enumerator should issue this notification
+                                          before starting a fresh enumeration process. Enumeration cannot
+                                          be restarted after sending any other notification such as
+                                          EfiPciHostBridgeBeginBusAllocation.
+   EfiPciHostBridgeBeginBusAllocation     The bus allocation phase is about to begin. No specific action is
+                                          required here. This notification can be used to perform any
+                                          chipset-specific programming.
+   EfiPciHostBridgeEndBusAllocation       The bus allocation and bus programming phase is complete. No
+                                          specific action is required here. This notification can be used to
+                                          perform any chipset-specific programming.
+   EfiPciHostBridgeBeginResourceAllocation
+                                          The resource allocation phase is about to begin. No specific
+                                          action is required here. This notification can be used to perform
+                                          any chipset-specific programming.
+   EfiPciHostBridgeAllocateResources      Allocates resources per previously submitted requests for all the PCI
+                                          root bridges. These resource settings are returned on the next call to
+                                          GetProposedResources(). Before calling NotifyPhase() with a Phase of
+                                          EfiPciHostBridgeAllocateResource, the PCI bus enumerator is responsible
+                                          for gathering I/O and memory requests for
+                                          all the PCI root bridges and submitting these requests using
+                                          SubmitResources(). This function pads the resource amount
+                                          to suit the root bridge hardware, takes care of dependencies between
+                                          the PCI root bridges, and calls the Global Coherency Domain (GCD)
+                                          with the allocation request. In the case of padding, the allocated range
+                                          could be bigger than what was requested.
+   EfiPciHostBridgeSetResources           Programs the host bridge hardware to decode previously allocated
+                                          resources (proposed resources) for all the PCI root bridges. After the
+                                          hardware is programmed, reassigning resources will not be supported.
+                                          The bus settings are not affected.
+   EfiPciHostBridgeFreeResources          Deallocates resources that were previously allocated for all the PCI
+                                          root bridges and resets the I/O and memory apertures to their initial
+                                          state. The bus settings are not affected. If the request to allocate
+                                          resources fails, the PCI enumerator can use this notification to
+                                          deallocate previous resources, adjust the requests, and retry
+                                          allocation.
+   EfiPciHostBridgeEndResourceAllocation  The resource allocation phase is completed. No specific action is
+                                          required here. This notification can be used to perform any chipsetspecific
+                                          programming.
+
+   @param[in] This                The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in] Phase               The phase during enumeration
+
+   @retval EFI_NOT_READY          This phase cannot be entered at this time. For example, this error
+                                  is valid for a Phase of EfiPciHostBridgeAllocateResources if
+                                  SubmitResources() has not been called for one or more
+                                  PCI root bridges before this call
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error. This error is valid
+                                  for a Phase of EfiPciHostBridgeSetResources.
+   @retval EFI_INVALID_PARAMETER  Invalid phase parameter
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+                                  This error is valid for a Phase of EfiPciHostBridgeAllocateResources if the
+                                  previously submitted resource requests cannot be fulfilled or
+                                  were only partially fulfilled.
+   @retval EFI_SUCCESS            The notification was accepted without any errors.
+
+**/
+EFI_STATUS
+EFIAPI
+NotifyPhase(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PHASE    Phase
+  );
+
+/**
+   Return the device handle of the next PCI root bridge that is associated with this Host Bridge.
+
+   This function is called multiple times to retrieve the device handles of all the PCI root bridges that
+   are associated with this PCI host bridge. Each PCI host bridge is associated with one or more PCI
+   root bridges. On each call, the handle that was returned by the previous call is passed into the
+   interface, and on output the interface returns the device handle of the next PCI root bridge. The
+   caller can use the handle to obtain the instance of the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+   for that root bridge. When there are no more PCI root bridges to report, the interface returns
+   EFI_NOT_FOUND. A PCI enumerator must enumerate the PCI root bridges in the order that they
+   are returned by this function.
+   For D945 implementation, there is only one root bridge in PCI host bridge.
+
+   @param[in]       This              The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in, out]  RootBridgeHandle  Returns the device handle of the next PCI root bridge.
+   
+   @retval EFI_SUCCESS            If parameter RootBridgeHandle = NULL, then return the first Rootbridge handle of the
+                                  specific Host bridge and return EFI_SUCCESS. 
+   @retval EFI_NOT_FOUND          Can not find the any more root bridge in specific host bridge.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not an EFI_HANDLE that was
+                                  returned on a previous call to GetNextRootBridge().
+**/
+EFI_STATUS
+EFIAPI
+GetNextRootBridge(
+  IN       EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN OUT   EFI_HANDLE                                       *RootBridgeHandle
+  );
+  
+/**
+   Returns the allocation attributes of a PCI root bridge.
+
+   The function returns the allocation attributes of a specific PCI root bridge. The attributes can vary
+   from one PCI root bridge to another. These attributes are different from the decode-related
+   attributes that are returned by the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.GetAttributes() member function. The
+   RootBridgeHandle parameter is used to specify the instance of the PCI root bridge. The device
+   handles of all the root bridges that are associated with this host bridge must be obtained by calling
+   GetNextRootBridge(). The attributes are static in the sense that they do not change during or
+   after the enumeration process. The hardware may provide mechanisms to change the attributes on
+   the fly, but such changes must be completed before EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL is 
+   installed. The permitted values of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ATTRIBUTES are defined in
+   "Related Definitions" below. The caller uses these attributes to combine multiple resource requests.
+   For example, if the flag EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM is set, the PCI bus enumerator needs to 
+   include requests for the prefetchable memory in the nonprefetchable memory pool and not request any 
+   prefetchable memory.
+      Attribute                                 Description
+   ------------------------------------         ----------------------------------------------------------------------
+   EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM         If this bit is set, then the PCI root bridge does not support separate
+                                                windows for nonprefetchable and prefetchable memory. A PCI bus
+                                                driver needs to include requests for prefetchable memory in the
+                                                nonprefetchable memory pool.
+
+   EFI_PCI_HOST_BRIDGE_MEM64_DECODE             If this bit is set, then the PCI root bridge supports 64-bit memory
+                                                windows. If this bit is not set, the PCI bus driver needs to include
+                                                requests for a 64-bit memory address in the corresponding 32-bit
+                                                memory pool.
+
+   @param[in]   This               The instance pointer of EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
+   @param[in]   RootBridgeHandle   The device handle of the PCI root bridge in which the caller is interested. Type
+                                   EFI_HANDLE is defined in InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param[out]  Attributes         The pointer to attribte of root bridge, it is output parameter
+   
+   @retval EFI_INVALID_PARAMETER   Attribute pointer is NULL
+   @retval EFI_INVALID_PARAMETER   RootBridgehandle is invalid.
+   @retval EFI_SUCCESS             Success to get attribute of interested root bridge.
+
+**/  
+EFI_STATUS
+EFIAPI
+GetAttributes(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT UINT64                                           *Attributes
+  );
+  
+/**
+   Sets up the specified PCI root bridge for the bus enumeration process.
+
+   This member function sets up the root bridge for bus enumeration and returns the PCI bus range
+   over which the search should be performed in ACPI 2.0 resource descriptor format.
+
+   @param[in]   This              The EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ PROTOCOL instance.
+   @param[in]   RootBridgeHandle  The PCI Root Bridge to be set up.
+   @param[out]  Configuration     Pointer to the pointer to the PCI bus resource descriptor.
+   
+   @retval EFI_INVALID_PARAMETER Invalid Root bridge's handle
+   @retval EFI_OUT_OF_RESOURCES  Fail to allocate ACPI resource descriptor tag.
+   @retval EFI_SUCCESS           Sucess to allocate ACPI resource descriptor.
+
+**/
+EFI_STATUS
+EFIAPI
+StartBusEnumeration(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT VOID                                             **Configuration
+  );
+  
+/**
+   Programs the PCI root bridge hardware so that it decodes the specified PCI bus range.
+
+   This member function programs the specified PCI root bridge to decode the bus range that is
+   specified by the input parameter Configuration.
+   The bus range information is specified in terms of the ACPI 2.0 resource descriptor format.
+
+   @param[in] This              The EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_ PROTOCOL instance
+   @param[in] RootBridgeHandle  The PCI Root Bridge whose bus range is to be programmed
+   @param[in] Configuration     The pointer to the PCI bus resource descriptor
+   
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER  Configuration is NULL.
+   @retval EFI_INVALID_PARAMETER  Configuration does not point to a valid ACPI 2.0 resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration does not include a valid ACPI 2.0 bus resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration includes valid ACPI 2.0 resource descriptors other than 
+                                  bus descriptors.
+   @retval EFI_INVALID_PARAMETER  Configuration contains one or more invalid ACPI resource descriptors.
+   @retval EFI_INVALID_PARAMETER  "Address Range Minimum" is invalid for this root bridge.
+   @retval EFI_INVALID_PARAMETER  "Address Range Length" is invalid for this root bridge.
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error.
+   @retval EFI_SUCCESS            The bus range for the PCI root bridge was programmed.
+
+**/
+EFI_STATUS
+EFIAPI
+SetBusNumbers(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_HANDLE                                       RootBridgeHandle,
+  IN VOID                                             *Configuration
+  );
+  
+/**
+   Submits the I/O and memory resource requirements for the specified PCI root bridge.
+
+   This function is used to submit all the I/O and memory resources that are required by the specified
+   PCI root bridge. The input parameter Configuration is used to specify the following:
+   - The various types of resources that are required
+   - The associated lengths in terms of ACPI 2.0 resource descriptor format
+
+   @param[in] This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param[in] RootBridgeHandle  The PCI root bridge whose I/O and memory resource requirements are being submitted.
+   @param[in] Configuration     The pointer to the PCI I/O and PCI memory resource descriptor.
+   
+   @retval EFI_SUCCESS            The I/O and memory resource requests for a PCI root bridge were accepted.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER  Configuration is NULL.
+   @retval EFI_INVALID_PARAMETER  Configuration does not point to a valid ACPI 2.0 resource descriptor.
+   @retval EFI_INVALID_PARAMETER  Configuration includes requests for one or more resource types that are 
+                                  not supported by this PCI root bridge. This error will happen if the caller 
+                                  did not combine resources according to Attributes that were returned by
+                                  GetAllocAttributes().
+   @retval EFI_INVALID_PARAMETER  Address Range Maximum" is invalid.
+   @retval EFI_INVALID_PARAMETER  "Address Range Length" is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  "Address Space Granularity" is invalid for this PCI root bridge.
+
+**/
+EFI_STATUS
+EFIAPI
+SubmitResources(
+  IN EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN EFI_HANDLE                                       RootBridgeHandle,
+  IN VOID                                             *Configuration
+  );
+  
+/**
+   Returns the proposed resource settings for the specified PCI root bridge.
+
+   This member function returns the proposed resource settings for the specified PCI root bridge. The
+   proposed resource settings are prepared when NotifyPhase() is called with a Phase of
+   EfiPciHostBridgeAllocateResources. The output parameter Configuration
+   specifies the following:
+   - The various types of resources, excluding bus resources, that are allocated
+   - The associated lengths in terms of ACPI 2.0 resource descriptor format
+
+   @param[in]  This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param[in]  RootBridgeHandle  The PCI root bridge handle. Type EFI_HANDLE is defined in InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param[out] Configuration     The pointer to the pointer to the PCI I/O and memory resource descriptor.
+   
+   @retval EFI_SUCCESS            The requested parameters were returned.
+   @retval EFI_INVALID_PARAMETER  RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_DEVICE_ERROR       Programming failed due to a hardware error.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+GetProposedResources(
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL *This,
+  IN  EFI_HANDLE                                       RootBridgeHandle,
+  OUT VOID                                             **Configuration
+  );
+
+/**
+   Provides the hooks from the PCI bus driver to every PCI controller (device/function) at various
+   stages of the PCI enumeration process that allow the host bridge driver to preinitialize individual
+   PCI controllers before enumeration.
+
+   This function is called during the PCI enumeration process. No specific action is expected from this
+   member function. It allows the host bridge driver to preinitialize individual PCI controllers before
+   enumeration.
+
+   @param This              Pointer to the EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL instance.
+   @param RootBridgeHandle  The associated PCI root bridge handle. Type EFI_HANDLE is defined in
+                            InstallProtocolInterface() in the UEFI 2.0 Specification.
+   @param PciAddress        The address of the PCI device on the PCI bus. This address can be passed to the
+                            EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL member functions to access the PCI
+                            configuration space of the device. See Table 12-1 in the UEFI 2.0 Specification for
+                            the definition of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS.
+   @param Phase             The phase of the PCI device enumeration. 
+   
+   @retval EFI_SUCCESS              The requested parameters were returned.
+   @retval EFI_INVALID_PARAMETER    RootBridgeHandle is not a valid root bridge handle.
+   @retval EFI_INVALID_PARAMETER    Phase is not a valid phase that is defined in
+                                    EFI_PCI_CONTROLLER_RESOURCE_ALLOCATION_PHASE.
+   @retval EFI_DEVICE_ERROR         Programming failed due to a hardware error. The PCI enumerator should
+                                    not enumerate this device, including its child devices if it is a PCI-to-PCI
+                                    bridge.
+
+**/
+EFI_STATUS
+EFIAPI
+PreprocessController (
+  IN  EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL  *This,
+  IN  EFI_HANDLE                                        RootBridgeHandle,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS       PciAddress,
+  IN  EFI_PCI_CONTROLLER_RESOURCE_ALLOCATION_PHASE      Phase
+  );
+
+
+//
+// Define resource status constant 
+//
+#define EFI_RESOURCE_NONEXISTENT   0xFFFFFFFFFFFFFFFFULL
+#define EFI_RESOURCE_LESS          0xFFFFFFFFFFFFFFFEULL
+
+
+//
+// Driver Instance Data Prototypes
+//
+
+typedef struct {
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation;
+  UINTN                                      NumberOfBytes;
+  UINTN                                      NumberOfPages;
+  EFI_PHYSICAL_ADDRESS                       HostAddress;
+  EFI_PHYSICAL_ADDRESS                       MappedHostAddress;
+} MAP_INFO;
+
+typedef struct {
+  ACPI_HID_DEVICE_PATH              AcpiDevicePath;
+  EFI_DEVICE_PATH_PROTOCOL          EndDevicePath;
+} EFI_PCI_ROOT_BRIDGE_DEVICE_PATH;
+
+typedef struct {
+  UINT64          BusBase;
+  UINT64          BusLimit;     
+  
+  UINT64          MemBase;     
+  UINT64          MemLimit;    
+  
+  UINT64          IoBase; 
+  UINT64          IoLimit;     
+} PCI_ROOT_BRIDGE_RESOURCE_APERTURE;
+
+typedef enum {
+  TypeIo = 0,
+  TypeMem32,
+  TypePMem32,
+  TypeMem64,
+  TypePMem64,
+  TypeBus,
+  TypeMax
+} PCI_RESOURCE_TYPE;
+
+typedef enum {
+  ResNone = 0,
+  ResSubmitted,
+  ResRequested,
+  ResAllocated,
+  ResStatusMax
+} RES_STATUS;
+
+typedef struct {
+  PCI_RESOURCE_TYPE Type;
+  UINT64            Base;
+  UINT64            Length;
+  UINT64            Alignment;
+  RES_STATUS        Status;
+} PCI_RES_NODE;
+
+#define PCI_ROOT_BRIDGE_SIGNATURE  SIGNATURE_32('e', '2', 'p', 'b')
+
+typedef struct {
+  UINT32                 Signature;
+  LIST_ENTRY             Link;
+  EFI_HANDLE             Handle;
+  UINT64                 RootBridgeAttrib;
+  UINT64                 Attributes;
+  UINT64                 Supports;
+  
+  //
+  // Specific for this memory controller: Bus, I/O, Mem
+  //
+  PCI_RES_NODE           ResAllocNode[6];
+  
+  //
+  // Addressing for Memory and I/O and Bus arrange
+  //
+  UINT64                 BusBase;
+  UINT64                 MemBase;     
+  UINT64                 IoBase; 
+  UINT64                 BusLimit;     
+  UINT64                 MemLimit;    
+  UINT64                 IoLimit;     
+
+  EFI_DEVICE_PATH_PROTOCOL                *DevicePath;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL         Io;
+
+} PCI_ROOT_BRIDGE_INSTANCE;
+
+
+//
+// Driver Instance Data Macros
+//
+#define DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(a) \
+  CR(a, PCI_ROOT_BRIDGE_INSTANCE, Io, PCI_ROOT_BRIDGE_SIGNATURE)
+
+
+#define DRIVER_INSTANCE_FROM_LIST_ENTRY(a) \
+  CR(a, PCI_ROOT_BRIDGE_INSTANCE, Link, PCI_ROOT_BRIDGE_SIGNATURE)
+
+/**
+
+  Construct the Pci Root Bridge Io protocol
+
+  @param Protocol         Point to protocol instance
+  @param HostBridgeHandle Handle of host bridge
+  @param Attri            Attribute of host bridge
+  @param ResAperture      ResourceAperture for host bridge
+
+  @retval EFI_SUCCESS Success to initialize the Pci Root Bridge.
+
+**/
+EFI_STATUS
+RootBridgeConstructor (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL    *Protocol,
+  IN EFI_HANDLE                         HostBridgeHandle,
+  IN UINT64                             Attri,
+  IN PCI_ROOT_BRIDGE_RESOURCE_APERTURE  *ResAperture
+  );
+
+#endif
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf
new file mode 100644
index 0000000000..4d5bb9ca14
--- /dev/null
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf
@@ -0,0 +1,52 @@
+## @file
+#  The basic interfaces implementation to a single segment PCI Host Bridge driver.
+#
+#  Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution.  The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = PciHostBridge
+  FILE_GUID                      = 9f609346-37cb-4eb7-801f-f55099373998
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+
+  ENTRY_POINT                    = InitializePciHostBridge
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  UefiDriverEntryPoint
+  UefiBootServicesTableLib
+  DxeServicesTableLib
+  UefiLib
+  MemoryAllocationLib
+  BaseMemoryLib
+  BaseLib
+  DebugLib
+  DevicePathLib
+  IoLib
+  PciLib
+
+[Sources]
+  PciHostBridge.c
+  PciRootBridgeIo.c
+  PciHostBridge.h
+
+[Protocols]
+  gEfiPciHostBridgeResourceAllocationProtocolGuid       ## PRODUCES
+  gEfiPciRootBridgeIoProtocolGuid                       ## PRODUCES
+  gEfiMetronomeArchProtocolGuid                         ## CONSUMES
+  gEfiDevicePathProtocolGuid                            ## PRODUCES
+
+[depex]
+  gEfiMetronomeArchProtocolGuid
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciRootBridgeIo.c b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciRootBridgeIo.c
new file mode 100644
index 0000000000..7c35e85c63
--- /dev/null
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciRootBridgeIo.c
@@ -0,0 +1,2123 @@
+/** @file
+  PCI Root Bridge Io Protocol implementation
+
+Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials are
+licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution.  The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/ 
+
+#include "PciHostBridge.h"
+
+typedef struct {
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR     SpaceDesp[TypeMax];
+  EFI_ACPI_END_TAG_DESCRIPTOR           EndDesp;
+} RESOURCE_CONFIGURATION;
+
+RESOURCE_CONFIGURATION Configuration = {
+  {{0x8A, 0x2B, 1, 0, 0, 0, 0, 0, 0, 0},
+  {0x8A, 0x2B, 0, 0, 0, 32, 0, 0, 0, 0}, 
+  {0x8A, 0x2B, 0, 0, 6, 32, 0, 0, 0, 0},
+  {0x8A, 0x2B, 0, 0, 0, 64, 0, 0, 0, 0},
+  {0x8A, 0x2B, 0, 0, 6, 64, 0, 0, 0, 0},
+  {0x8A, 0x2B, 2, 0, 0, 0, 0, 0, 0, 0}},
+  {0x79, 0}
+};
+
+//
+// Protocol Member Function Prototypes
+//
+
+/**
+   Polls an address in memory mapped I/O space until an exit condition is met, or 
+   a timeout occurs. 
+
+   This function provides a standard way to poll a PCI memory location. A PCI memory read
+   operation is performed at the PCI memory address specified by Address for the width specified
+   by Width. The result of this PCI memory read operation is stored in Result. This PCI memory
+   read operation is repeated until either a timeout of Delay 100 ns units has expired, or (Result &
+   Mask) is equal to Value.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The base address of the memory operations. The caller is
+                          responsible for aligning Address if required.
+   @param[in]   Mask      Mask used for the polling criteria. Bytes above Width in Mask
+                          are ignored. The bits in the bytes below Width which are zero in
+                          Mask are ignored when polling the memory address.
+   @param[in]   Value     The comparison value used for the polling exit criteria.
+   @param[in]   Delay     The number of 100 ns units to poll. Note that timer available may
+                          be of poorer granularity.
+   @param[out]  Result    Pointer to the last value read from the memory location.
+   
+   @retval EFI_SUCCESS            The last data returned from the access matched the poll exit criteria.
+   @retval EFI_INVALID_PARAMETER  Width is invalid.
+   @retval EFI_INVALID_PARAMETER  Result is NULL.
+   @retval EFI_TIMEOUT            Delay expired before a match occurred.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPollMem ( 
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN  UINT64                                 Address,
+  IN  UINT64                                 Mask,
+  IN  UINT64                                 Value,
+  IN  UINT64                                 Delay,
+  OUT UINT64                                 *Result
+  );
+  
+/**
+   Reads from the I/O space of a PCI Root Bridge. Returns when either the polling exit criteria is
+   satisfied or after a defined duration.
+
+   This function provides a standard way to poll a PCI I/O location. A PCI I/O read operation is
+   performed at the PCI I/O address specified by Address for the width specified by Width.
+   The result of this PCI I/O read operation is stored in Result. This PCI I/O read operation is
+   repeated until either a timeout of Delay 100 ns units has expired, or (Result & Mask) is equal
+   to Value.
+
+   @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in] Width     Signifies the width of the I/O operations.
+   @param[in] Address   The base address of the I/O operations. The caller is responsible
+                        for aligning Address if required.
+   @param[in] Mask      Mask used for the polling criteria. Bytes above Width in Mask
+                        are ignored. The bits in the bytes below Width which are zero in
+                        Mask are ignored when polling the I/O address.
+   @param[in] Value     The comparison value used for the polling exit criteria.
+   @param[in] Delay     The number of 100 ns units to poll. Note that timer available may
+                        be of poorer granularity.
+   @param[out] Result   Pointer to the last value read from the memory location.
+   
+   @retval EFI_SUCCESS            The last data returned from the access matched the poll exit criteria.
+   @retval EFI_INVALID_PARAMETER  Width is invalid.
+   @retval EFI_INVALID_PARAMETER  Result is NULL.
+   @retval EFI_TIMEOUT            Delay expired before a match occurred.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPollIo ( 
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN  UINT64                                 Address,
+  IN  UINT64                                 Mask,
+  IN  UINT64                                 Value,
+  IN  UINT64                                 Delay,
+  OUT UINT64                                 *Result
+  );
+  
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space.
+
+   The Mem.Read(), and Mem.Write() functions enable a driver to access PCI controller
+   registers in the PCI root bridge memory space.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI Root Bridge on a platform might require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operation.
+   @param[in]   Address   The base address of the memory operation. The caller is
+                          responsible for aligning the Address if required.
+   @param[in]   Count     The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at Address.
+   @param[out]  Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMemRead (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  OUT    VOID                                   *Buffer
+  );
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space.
+
+   The Mem.Read(), and Mem.Write() functions enable a driver to access PCI controller
+   registers in the PCI root bridge memory space.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI Root Bridge on a platform might require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operation.
+   @param[in]   Address   The base address of the memory operation. The caller is
+                          responsible for aligning the Address if required.
+   @param[in]   Count     The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at Address.
+   @param[in]   Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMemWrite (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  IN     VOID                                   *Buffer
+  );
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge I/O space.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width       Signifies the width of the memory operations.
+   @param[in]   UserAddress The base address of the I/O operation. The caller is responsible for
+                            aligning the Address if required.
+   @param[in]   Count       The number of I/O operations to perform. Bytes moved is Width
+                            size * Count, starting at Address.
+   @param[out]  UserBuffer  For read operations, the destination buffer to store the results. For
+                            write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS              The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoIoRead (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 UserAddress,
+  IN     UINTN                                  Count,
+  OUT    VOID                                   *UserBuffer
+  );
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge I/O space.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width       Signifies the width of the memory operations.
+   @param[in]   UserAddress The base address of the I/O operation. The caller is responsible for
+                            aligning the Address if required.
+   @param[in]   Count       The number of I/O operations to perform. Bytes moved is Width
+                            size * Count, starting at Address.
+   @param[in]   UserBuffer  For read operations, the destination buffer to store the results. For
+                            write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS              The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoIoWrite (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 UserAddress,
+  IN     UINTN                                  Count,
+  IN     VOID                                   *UserBuffer
+  );
+
+/**
+   Enables a PCI driver to copy one region of PCI root bridge memory space to another region of PCI
+   root bridge memory space.
+
+   The CopyMem() function enables a PCI driver to copy one region of PCI root bridge memory
+   space to another region of PCI root bridge memory space. This is especially useful for video scroll
+   operation on a memory mapped video buffer.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI root bridge on a platform might require.
+
+   @param[in] This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
+   @param[in] Width       Signifies the width of the memory operations.
+   @param[in] DestAddress The destination address of the memory operation. The caller is
+                          responsible for aligning the DestAddress if required.
+   @param[in] SrcAddress  The source address of the memory operation. The caller is
+                          responsible for aligning the SrcAddress if required.
+   @param[in] Count       The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at DestAddress and SrcAddress.
+   
+   @retval  EFI_SUCCESS             The data was copied from one memory region to another memory region.
+   @retval  EFI_INVALID_PARAMETER   Width is invalid for this PCI root bridge.
+   @retval  EFI_OUT_OF_RESOURCES    The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoCopyMem (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 DestAddress,
+  IN     UINT64                                 SrcAddress,
+  IN     UINTN                                  Count
+  );
+
+/**
+   Enables a PCI driver to access PCI controller registers in a PCI root bridge's configuration space.
+
+   The Pci.Read() and Pci.Write() functions enable a driver to access PCI configuration
+   registers for a PCI controller.
+   The PCI Configuration operations are carried out exactly as requested. The caller is responsible for
+   any alignment and PCI configuration width issues that a PCI Root Bridge on a platform might
+   require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count     The number of PCI configuration operations to perform. Bytes
+                          moved is Width size * Count, starting at Address.
+   @param[out]  Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPciRead (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  OUT    VOID                                   *Buffer
+  );
+
+/**
+   Enables a PCI driver to access PCI controller registers in a PCI root bridge's configuration space.
+
+   The Pci.Read() and Pci.Write() functions enable a driver to access PCI configuration
+   registers for a PCI controller.
+   The PCI Configuration operations are carried out exactly as requested. The caller is responsible for
+   any alignment and PCI configuration width issues that a PCI Root Bridge on a platform might
+   require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count     The number of PCI configuration operations to perform. Bytes
+                          moved is Width size * Count, starting at Address.
+   @param[in]   Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPciWrite (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  IN     VOID                                   *Buffer
+  );
+
+/**
+   Provides the PCI controller-specific addresses required to access system memory from a
+   DMA bus master.
+
+   The Map() function provides the PCI controller specific addresses needed to access system
+   memory. This function is used to map system memory for PCI bus master DMA accesses.
+
+   @param[in]       This            A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]       Operation       Indicates if the bus master is going to read or write to system memory.
+   @param[in]       HostAddress     The system memory address to map to the PCI controller.
+   @param[in, out]  NumberOfBytes   On input the number of bytes to map. On output the number of bytes that were mapped.
+   @param[out]      DeviceAddress   The resulting map address for the bus master PCI controller to use
+                                    to access the system memory's HostAddress.
+   @param[out]      Mapping         The value to pass to Unmap() when the bus master DMA operation is complete.
+   
+   @retval EFI_SUCCESS            The range was mapped for the returned NumberOfBytes.
+   @retval EFI_INVALID_PARAMETER  Operation is invalid.
+   @retval EFI_INVALID_PARAMETER  HostAddress is NULL.
+   @retval EFI_INVALID_PARAMETER  NumberOfBytes is NULL.
+   @retval EFI_INVALID_PARAMETER  DeviceAddress is NULL.
+   @retval EFI_INVALID_PARAMETER  Mapping is NULL.
+   @retval EFI_UNSUPPORTED        The HostAddress cannot be mapped as a common buffer.
+   @retval EFI_DEVICE_ERROR       The system hardware could not map the requested address.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMap (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
+  IN     VOID                                       *HostAddress,
+  IN OUT UINTN                                      *NumberOfBytes,
+  OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
+  OUT    VOID                                       **Mapping
+  );
+
+/**
+   Completes the Map() operation and releases any corresponding resources.
+
+   The Unmap() function completes the Map() operation and releases any corresponding resources.
+   If the operation was an EfiPciOperationBusMasterWrite or
+   EfiPciOperationBusMasterWrite64, the data is committed to the target system memory.
+   Any resources used for the mapping are freed.  
+
+   @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in] Mapping   The mapping value returned from Map().
+   
+   @retval EFI_SUCCESS            The range was unmapped.
+   @retval EFI_INVALID_PARAMETER  Mapping is not a value that was returned by Map().
+   @retval EFI_DEVICE_ERROR       The data was not committed to the target system memory.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoUnmap (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN  VOID                             *Mapping
+  );
+
+/**
+   Allocates pages that are suitable for an EfiPciOperationBusMasterCommonBuffer or
+   EfiPciOperationBusMasterCommonBuffer64 mapping.
+  
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Type        This parameter is not used and must be ignored.
+   @param MemoryType  The type of memory to allocate, EfiBootServicesData or EfiRuntimeServicesData.
+   @param Pages       The number of pages to allocate.
+   @param HostAddress A pointer to store the base system memory address of the allocated range.
+   @param Attributes  The requested bit mask of attributes for the allocated range. Only
+                      the attributes EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE, EFI_PCI_ATTRIBUTE_MEMORY_CACHED, 
+                      and EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE may be used with this function.
+   
+   @retval EFI_SUCCESS            The requested memory pages were allocated.
+   @retval EFI_INVALID_PARAMETER  MemoryType is invalid.
+   @retval EFI_INVALID_PARAMETER  HostAddress is NULL.
+   @retval EFI_UNSUPPORTED        Attributes is unsupported. The only legal attribute bits are
+                                  MEMORY_WRITE_COMBINE, MEMORY_CACHED, and DUAL_ADDRESS_CYCLE.
+   @retval EFI_OUT_OF_RESOURCES   The memory pages could not be allocated.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoAllocateBuffer (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN  EFI_ALLOCATE_TYPE                Type,
+  IN  EFI_MEMORY_TYPE                  MemoryType,
+  IN  UINTN                            Pages,
+  OUT VOID                             **HostAddress,
+  IN  UINT64                           Attributes
+  );
+
+/**
+   Frees memory that was allocated with AllocateBuffer().
+
+   The FreeBuffer() function frees memory that was allocated with AllocateBuffer().
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Pages       The number of pages to free.
+   @param HostAddress The base system memory address of the allocated range.
+   
+   @retval EFI_SUCCESS            The requested memory pages were freed.
+   @retval EFI_INVALID_PARAMETER  The memory range specified by HostAddress and Pages
+                                  was not allocated with AllocateBuffer().
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoFreeBuffer (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN  UINTN                            Pages,
+  OUT VOID                             *HostAddress
+  );
+
+/**
+   Flushes all PCI posted write transactions from a PCI host bridge to system memory.
+
+   The Flush() function flushes any PCI posted write transactions from a PCI host bridge to system
+   memory. Posted write transactions are generated by PCI bus masters when they perform write
+   transactions to target addresses in system memory.
+   This function does not flush posted write transactions from any PCI bridges. A PCI controller
+   specific action must be taken to guarantee that the posted write transactions have been flushed from
+   the PCI controller and from all the PCI bridges into the PCI host bridge. This is typically done with
+   a PCI read transaction from the PCI controller prior to calling Flush().
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   
+   @retval EFI_SUCCESS        The PCI posted write transactions were flushed from the PCI host
+                              bridge to system memory.
+   @retval EFI_DEVICE_ERROR   The PCI posted write transactions were not flushed from the PCI
+                              host bridge due to a hardware error.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoFlush (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This
+  );
+
+/**
+   Gets the attributes that a PCI root bridge supports setting with SetAttributes(), and the
+   attributes that a PCI root bridge is currently using.  
+
+   The GetAttributes() function returns the mask of attributes that this PCI root bridge supports
+   and the mask of attributes that the PCI root bridge is currently using.
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Supported   A pointer to the mask of attributes that this PCI root bridge
+                      supports setting with SetAttributes().
+   @param Attributes  A pointer to the mask of attributes that this PCI root bridge is
+                      currently using.
+   
+   @retval  EFI_SUCCESS           If Supports is not NULL, then the attributes that the PCI root
+                                  bridge supports is returned in Supports. If Attributes is
+                                  not NULL, then the attributes that the PCI root bridge is currently
+                                  using is returned in Attributes.
+   @retval  EFI_INVALID_PARAMETER Both Supports and Attributes are NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoGetAttributes (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  OUT UINT64                           *Supported,
+  OUT UINT64                           *Attributes
+  );
+
+/**
+   Sets attributes for a resource range on a PCI root bridge.
+
+   The SetAttributes() function sets the attributes specified in Attributes for the PCI root
+   bridge on the resource range specified by ResourceBase and ResourceLength. Since the
+   granularity of setting these attributes may vary from resource type to resource type, and from
+   platform to platform, the actual resource range and the one passed in by the caller may differ. As a
+   result, this function may set the attributes specified by Attributes on a larger resource range
+   than the caller requested. The actual range is returned in ResourceBase and
+   ResourceLength. The caller is responsible for verifying that the actual range for which the
+   attributes were set is acceptable.
+
+   @param[in]       This            A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]       Attributes      The mask of attributes to set. If the attribute bit
+                                    MEMORY_WRITE_COMBINE, MEMORY_CACHED, or
+                                    MEMORY_DISABLE is set, then the resource range is specified by
+                                    ResourceBase and ResourceLength. If
+                                    MEMORY_WRITE_COMBINE, MEMORY_CACHED, and
+                                    MEMORY_DISABLE are not set, then ResourceBase and
+                                    ResourceLength are ignored, and may be NULL.
+   @param[in, out]  ResourceBase    A pointer to the base address of the resource range to be modified
+                                    by the attributes specified by Attributes.
+   @param[in, out]  ResourceLength  A pointer to the length of the resource range to be modified by the
+                                    attributes specified by Attributes.
+   
+   @retval  EFI_SUCCESS     The current configuration of this PCI root bridge was returned in Resources.
+   @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge could not be retrieved.
+   @retval  EFI_INVALID_PARAMETER Invalid pointer of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoSetAttributes (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN     UINT64                           Attributes,
+  IN OUT UINT64                           *ResourceBase,
+  IN OUT UINT64                           *ResourceLength 
+  ); 
+
+/**
+   Retrieves the current resource settings of this PCI root bridge in the form of a set of ACPI 2.0
+   resource descriptors.
+
+   There are only two resource descriptor types from the ACPI Specification that may be used to
+   describe the current resources allocated to a PCI root bridge. These are the QWORD Address
+   Space Descriptor (ACPI 2.0 Section 6.4.3.5.1), and the End Tag (ACPI 2.0 Section 6.4.2.8). The
+   QWORD Address Space Descriptor can describe memory, I/O, and bus number ranges for dynamic
+   or fixed resources. The configuration of a PCI root bridge is described with one or more QWORD
+   Address Space Descriptors followed by an End Tag.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[out]  Resources   A pointer to the ACPI 2.0 resource descriptors that describe the
+                            current configuration of this PCI root bridge. The storage for the
+                            ACPI 2.0 resource descriptors is allocated by this function. The
+                            caller must treat the return buffer as read-only data, and the buffer
+                            must not be freed by the caller.
+   
+   @retval  EFI_SUCCESS     The current configuration of this PCI root bridge was returned in Resources.
+   @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge could not be retrieved.
+   @retval  EFI_INVALID_PARAMETER Invalid pointer of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoConfiguration (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  OUT    VOID                             **Resources
+  );
+
+//
+// Memory Controller Pci Root Bridge Io Module Variables
+//
+EFI_METRONOME_ARCH_PROTOCOL *mMetronome;
+
+//
+// Lookup table for increment values based on transfer widths
+//
+UINT8 mInStride[] = {
+  1, // EfiPciWidthUint8
+  2, // EfiPciWidthUint16
+  4, // EfiPciWidthUint32
+  8, // EfiPciWidthUint64
+  0, // EfiPciWidthFifoUint8
+  0, // EfiPciWidthFifoUint16
+  0, // EfiPciWidthFifoUint32
+  0, // EfiPciWidthFifoUint64
+  1, // EfiPciWidthFillUint8
+  2, // EfiPciWidthFillUint16
+  4, // EfiPciWidthFillUint32
+  8  // EfiPciWidthFillUint64
+};
+
+//
+// Lookup table for increment values based on transfer widths
+//
+UINT8 mOutStride[] = {
+  1, // EfiPciWidthUint8
+  2, // EfiPciWidthUint16
+  4, // EfiPciWidthUint32
+  8, // EfiPciWidthUint64
+  1, // EfiPciWidthFifoUint8
+  2, // EfiPciWidthFifoUint16
+  4, // EfiPciWidthFifoUint32
+  8, // EfiPciWidthFifoUint64
+  0, // EfiPciWidthFillUint8
+  0, // EfiPciWidthFillUint16
+  0, // EfiPciWidthFillUint32
+  0  // EfiPciWidthFillUint64
+};
+
+/**
+
+  Construct the Pci Root Bridge Io protocol
+
+  @param Protocol         Point to protocol instance
+  @param HostBridgeHandle Handle of host bridge
+  @param Attri            Attribute of host bridge
+  @param ResAperture      ResourceAperture for host bridge
+
+  @retval EFI_SUCCESS Success to initialize the Pci Root Bridge.
+
+**/
+EFI_STATUS
+RootBridgeConstructor (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL    *Protocol,
+  IN EFI_HANDLE                         HostBridgeHandle,
+  IN UINT64                             Attri,
+  IN PCI_ROOT_BRIDGE_RESOURCE_APERTURE  *ResAperture
+  )
+{
+  EFI_STATUS                        Status;
+  PCI_ROOT_BRIDGE_INSTANCE          *PrivateData;
+  PCI_RESOURCE_TYPE                 Index;
+
+  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (Protocol);
+
+  //
+  // The host to pci bridge, the host memory and io addresses are
+  // direct mapped to pci addresses, so no need translate, set bases to 0.
+  //
+  PrivateData->MemBase = ResAperture->MemBase;
+  PrivateData->IoBase  = ResAperture->IoBase;
+
+  //
+  // The host bridge only supports 32bit addressing for memory
+  // and standard IA32 16bit io
+  //
+  PrivateData->MemLimit = ResAperture->MemLimit;
+  PrivateData->IoLimit  = ResAperture->IoLimit;
+
+  //
+  // Bus Aperture for this Root Bridge (Possible Range)
+  //
+  PrivateData->BusBase  = ResAperture->BusBase;
+  PrivateData->BusLimit = ResAperture->BusLimit;
+  
+  //
+  // Specific for this chipset
+  //
+  for (Index = TypeIo; Index < TypeMax; Index++) {
+    PrivateData->ResAllocNode[Index].Type      = Index;
+    PrivateData->ResAllocNode[Index].Base      = 0;
+    PrivateData->ResAllocNode[Index].Length    = 0;
+    PrivateData->ResAllocNode[Index].Status    = ResNone;
+  }
+  
+  PrivateData->RootBridgeAttrib = Attri;
+  
+  PrivateData->Supports    = EFI_PCI_ATTRIBUTE_IDE_PRIMARY_IO | EFI_PCI_ATTRIBUTE_IDE_SECONDARY_IO | \
+                             EFI_PCI_ATTRIBUTE_ISA_IO_16 | EFI_PCI_ATTRIBUTE_ISA_MOTHERBOARD_IO | \
+                             EFI_PCI_ATTRIBUTE_VGA_MEMORY | \
+                             EFI_PCI_ATTRIBUTE_VGA_IO_16  | EFI_PCI_ATTRIBUTE_VGA_PALETTE_IO_16;
+  PrivateData->Attributes  = PrivateData->Supports;
+
+  Protocol->ParentHandle   = HostBridgeHandle;
+  
+  Protocol->PollMem        = RootBridgeIoPollMem;
+  Protocol->PollIo         = RootBridgeIoPollIo;
+
+  Protocol->Mem.Read       = RootBridgeIoMemRead;
+  Protocol->Mem.Write      = RootBridgeIoMemWrite;
+
+  Protocol->Io.Read        = RootBridgeIoIoRead;
+  Protocol->Io.Write       = RootBridgeIoIoWrite;
+
+  Protocol->CopyMem        = RootBridgeIoCopyMem;
+
+  Protocol->Pci.Read       = RootBridgeIoPciRead;
+  Protocol->Pci.Write      = RootBridgeIoPciWrite;
+
+  Protocol->Map            = RootBridgeIoMap;
+  Protocol->Unmap          = RootBridgeIoUnmap;
+
+  Protocol->AllocateBuffer = RootBridgeIoAllocateBuffer;
+  Protocol->FreeBuffer     = RootBridgeIoFreeBuffer;
+
+  Protocol->Flush          = RootBridgeIoFlush;
+
+  Protocol->GetAttributes  = RootBridgeIoGetAttributes;
+  Protocol->SetAttributes  = RootBridgeIoSetAttributes;
+
+  Protocol->Configuration  = RootBridgeIoConfiguration;
+
+  Protocol->SegmentNumber  = 0;
+
+  Status = gBS->LocateProtocol (&gEfiMetronomeArchProtocolGuid, NULL, (VOID **)&mMetronome);
+  ASSERT_EFI_ERROR (Status);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Check parameters for IO,MMIO,PCI read/write services of PCI Root Bridge IO.
+
+  The I/O operations are carried out exactly as requested. The caller is responsible 
+  for satisfying any alignment and I/O width restrictions that a PI System on a 
+  platform might require. For example on some platforms, width requests of 
+  EfiCpuIoWidthUint64 do not work. Misaligned buffers, on the other hand, will 
+  be handled by the driver.
+  
+  @param[in] This           A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+  @param[in] OperationType  I/O operation type: IO/MMIO/PCI.
+  @param[in] Width          Signifies the width of the I/O or Memory operation.
+  @param[in] Address        The base address of the I/O operation. 
+  @param[in] Count          The number of I/O operations to perform. The number of  
+                            bytes moved is Width size * Count, starting at Address.
+  @param[in] Buffer         For read operations, the destination buffer to store the results.
+                            For write operations, the source buffer from which to write data.
+
+  @retval EFI_SUCCESS            The parameters for this request pass the checks.
+  @retval EFI_INVALID_PARAMETER  Width is invalid for this PI system.
+  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+  @retval EFI_UNSUPPORTED        The Buffer is not aligned for the given Width.
+  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
+                                 and Count is not valid for this PI system.
+
+**/
+EFI_STATUS
+RootBridgeIoCheckParameter (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN OPERATION_TYPE                         OperationType,
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN UINT64                                 Address,
+  IN UINTN                                  Count,
+  IN VOID                                   *Buffer
+  )
+{
+  PCI_ROOT_BRIDGE_INSTANCE                     *PrivateData;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS  *PciRbAddr;
+  UINT64                                       MaxCount;
+  UINT64                                       Base;
+  UINT64                                       Limit;
+
+  //
+  // Check to see if Buffer is NULL
+  //
+  if (Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Check to see if Width is in the valid range
+  //
+  if ((UINT32)Width >= EfiPciWidthMaximum) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // For FIFO type, the target address won't increase during the access,
+  // so treat Count as 1
+  //
+  if (Width >= EfiPciWidthFifoUint8 && Width <= EfiPciWidthFifoUint64) {
+    Count = 1;
+  }
+
+  //
+  // Check to see if Width is in the valid range for I/O Port operations
+  //
+  Width = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
+  if ((OperationType != MemOperation) && (Width == EfiPciWidthUint64)) {
+    ASSERT (FALSE);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Check to see if Address is aligned
+  //
+  if ((Address & (UINT64)(mInStride[Width] - 1)) != 0) {
+    return EFI_UNSUPPORTED;
+  }
+
+  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (This);
+
+  //
+  // Check to see if any address associated with this transfer exceeds the maximum 
+  // allowed address.  The maximum address implied by the parameters passed in is
+  // Address + Size * Count.  If the following condition is met, then the transfer
+  // is not supported.
+  //
+  //    Address + Size * Count > Limit + 1
+  //
+  // Since Limit can be the maximum integer value supported by the CPU and Count 
+  // can also be the maximum integer value supported by the CPU, this range
+  // check must be adjusted to avoid all oveflow conditions.
+  //   
+  // The following form of the range check is equivalent but assumes that 
+  // Limit is of the form (2^n - 1).
+  //
+  if (OperationType == IoOperation) {
+    Base = PrivateData->IoBase;
+    Limit = PrivateData->IoLimit;
+  } else if (OperationType == MemOperation) {
+    Base = PrivateData->MemBase;
+    Limit = PrivateData->MemLimit;
+  } else {
+    PciRbAddr = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS*) &Address;
+    if (PciRbAddr->Bus < PrivateData->BusBase || PciRbAddr->Bus > PrivateData->BusLimit) {
+      return EFI_INVALID_PARAMETER;
+    }
+
+    if (PciRbAddr->Device > MAX_PCI_DEVICE_NUMBER || PciRbAddr->Function > MAX_PCI_FUNCTION_NUMBER) {
+      return EFI_INVALID_PARAMETER;
+    }
+
+    if (PciRbAddr->ExtendedRegister != 0) {
+      Address = PciRbAddr->ExtendedRegister;
+    } else {
+      Address = PciRbAddr->Register;
+    }
+    Base = 0;
+    Limit = MAX_PCI_REG_ADDRESS;
+  }
+
+  if (Address < Base) {
+      return EFI_INVALID_PARAMETER;
+  }
+
+  if (Count == 0) {
+    if (Address > Limit) {
+      return EFI_UNSUPPORTED;
+    }
+  } else {  
+    MaxCount = RShiftU64 (Limit, Width);
+    if (MaxCount < (Count - 1)) {
+      return EFI_UNSUPPORTED;
+    }
+    if (Address > LShiftU64 (MaxCount - Count + 1, Width)) {
+      return EFI_UNSUPPORTED;
+    }
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+   Internal help function for read and write memory space.
+
+   @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Write         Switch value for Read or Write.
+   @param[in]   Width         Signifies the width of the memory operations.
+   @param[in]   UserAddress   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count         The number of PCI configuration operations to perform. Bytes
+                              moved is Width size * Count, starting at Address.
+   @param[in, out] UserBuffer For read operations, the destination buffer to store the results. For
+                              write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+RootBridgeIoMemRW (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     BOOLEAN                                Write,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  IN OUT VOID                                   *Buffer
+  )
+{
+  EFI_STATUS                             Status;
+  UINT8                                  InStride;
+  UINT8                                  OutStride;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  OperationWidth;
+  UINT8                                  *Uint8Buffer;
+
+  Status = RootBridgeIoCheckParameter (This, MemOperation, Width, Address, Count, Buffer);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  InStride = mInStride[Width];
+  OutStride = mOutStride[Width];
+  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
+  for (Uint8Buffer = Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
+    if (Write) {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          MmioWrite8 ((UINTN)Address, *Uint8Buffer);
+          break;
+        case EfiPciWidthUint16:
+          MmioWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
+          break;
+        case EfiPciWidthUint32:
+          MmioWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
+          break;
+        case EfiPciWidthUint64:
+          MmioWrite64 ((UINTN)Address, *((UINT64 *)Uint8Buffer));
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    } else {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          *Uint8Buffer = MmioRead8 ((UINTN)Address);
+          break;
+        case EfiPciWidthUint16:
+          *((UINT16 *)Uint8Buffer) = MmioRead16 ((UINTN)Address);
+          break;
+        case EfiPciWidthUint32:
+          *((UINT32 *)Uint8Buffer) = MmioRead32 ((UINTN)Address);
+          break;
+        case EfiPciWidthUint64:
+          *((UINT64 *)Uint8Buffer) = MmioRead64 ((UINTN)Address);
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    }
+  }
+  return EFI_SUCCESS;  
+}
+
+/**
+   Internal help function for read and write IO space.
+
+   @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Write         Switch value for Read or Write.
+   @param[in]   Width         Signifies the width of the memory operations.
+   @param[in]   UserAddress   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count         The number of PCI configuration operations to perform. Bytes
+                              moved is Width size * Count, starting at Address.
+   @param[in, out] UserBuffer For read operations, the destination buffer to store the results. For
+                              write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+RootBridgeIoIoRW (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     BOOLEAN                                Write,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  IN OUT VOID                                   *Buffer
+  )
+{
+  EFI_STATUS                             Status;
+  UINT8                                  InStride;
+  UINT8                                  OutStride;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  OperationWidth;
+  UINT8                                  *Uint8Buffer;
+
+  Status = RootBridgeIoCheckParameter (This, IoOperation, Width, Address, Count, Buffer);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  InStride = mInStride[Width];
+  OutStride = mOutStride[Width];
+  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
+
+  for (Uint8Buffer = Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
+    if (Write) {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          IoWrite8 ((UINTN)Address, *Uint8Buffer);
+          break;
+        case EfiPciWidthUint16:
+          IoWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
+          break;
+        case EfiPciWidthUint32:
+          IoWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    } else {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          *Uint8Buffer = IoRead8 ((UINTN)Address);
+          break;
+        case EfiPciWidthUint16:
+          *((UINT16 *)Uint8Buffer) = IoRead16 ((UINTN)Address);
+          break;
+        case EfiPciWidthUint32:
+          *((UINT32 *)Uint8Buffer) = IoRead32 ((UINTN)Address);
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    }
+  }
+  return EFI_SUCCESS;
+}
+
+/**
+   Internal help function for read and write PCI configuration space.
+
+   @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Write         Switch value for Read or Write.
+   @param[in]   Width         Signifies the width of the memory operations.
+   @param[in]   UserAddress   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count         The number of PCI configuration operations to perform. Bytes
+                              moved is Width size * Count, starting at Address.
+   @param[in, out] UserBuffer For read operations, the destination buffer to store the results. For
+                              write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+RootBridgeIoPciRW (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN BOOLEAN                                Write,
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN UINT64                                 Address,
+  IN UINTN                                  Count,
+  IN OUT VOID                               *Buffer
+  )
+{
+  EFI_STATUS                                   Status;
+  UINT8                                        InStride;
+  UINT8                                        OutStride;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH        OperationWidth;
+  UINT8                                        *Uint8Buffer;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS  *PciRbAddr;
+  UINTN                                        PcieRegAddr;
+
+  Status = RootBridgeIoCheckParameter (This, PciOperation, Width, Address, Count, Buffer);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  PciRbAddr = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS*) &Address;
+
+  PcieRegAddr = (UINTN) PCI_LIB_ADDRESS (
+                          PciRbAddr->Bus,
+                          PciRbAddr->Device,
+                          PciRbAddr->Function,
+                          (PciRbAddr->ExtendedRegister != 0) ? \
+                            PciRbAddr->ExtendedRegister :
+                            PciRbAddr->Register
+                          );
+
+  InStride = mInStride[Width];
+  OutStride = mOutStride[Width];
+  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
+  for (Uint8Buffer = Buffer; Count > 0; PcieRegAddr += InStride, Uint8Buffer += OutStride, Count--) {
+    if (Write) {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          PciWrite8 (PcieRegAddr, *Uint8Buffer);
+          break;
+        case EfiPciWidthUint16:
+          PciWrite16 (PcieRegAddr, *((UINT16 *)Uint8Buffer));
+          break;
+        case EfiPciWidthUint32:
+          PciWrite32 (PcieRegAddr, *((UINT32 *)Uint8Buffer));
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    } else {
+      switch (OperationWidth) {
+        case EfiPciWidthUint8:
+          *Uint8Buffer = PciRead8 (PcieRegAddr);
+          break;
+        case EfiPciWidthUint16:
+          *((UINT16 *)Uint8Buffer) = PciRead16 (PcieRegAddr);
+          break;
+        case EfiPciWidthUint32:
+          *((UINT32 *)Uint8Buffer) = PciRead32 (PcieRegAddr);
+          break;
+        default:
+          //
+          // The RootBridgeIoCheckParameter call above will ensure that this
+          // path is not taken.
+          //
+          ASSERT (FALSE);
+          break;
+      }
+    }
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+   Polls an address in memory mapped I/O space until an exit condition is met, or 
+   a timeout occurs. 
+
+   This function provides a standard way to poll a PCI memory location. A PCI memory read
+   operation is performed at the PCI memory address specified by Address for the width specified
+   by Width. The result of this PCI memory read operation is stored in Result. This PCI memory
+   read operation is repeated until either a timeout of Delay 100 ns units has expired, or (Result &
+   Mask) is equal to Value.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The base address of the memory operations. The caller is
+                          responsible for aligning Address if required.
+   @param[in]   Mask      Mask used for the polling criteria. Bytes above Width in Mask
+                          are ignored. The bits in the bytes below Width which are zero in
+                          Mask are ignored when polling the memory address.
+   @param[in]   Value     The comparison value used for the polling exit criteria.
+   @param[in]   Delay     The number of 100 ns units to poll. Note that timer available may
+                          be of poorer granularity.
+   @param[out]  Result    Pointer to the last value read from the memory location.
+   
+   @retval EFI_SUCCESS            The last data returned from the access matched the poll exit criteria.
+   @retval EFI_INVALID_PARAMETER  Width is invalid.
+   @retval EFI_INVALID_PARAMETER  Result is NULL.
+   @retval EFI_TIMEOUT            Delay expired before a match occurred.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPollMem ( 
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN  UINT64                                 Address,
+  IN  UINT64                                 Mask,
+  IN  UINT64                                 Value,
+  IN  UINT64                                 Delay,
+  OUT UINT64                                 *Result
+  )
+{
+  EFI_STATUS  Status;
+  UINT64      NumberOfTicks;
+  UINT32      Remainder;
+
+  if (Result == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((UINT32)Width > EfiPciWidthUint64) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // No matter what, always do a single poll.
+  //
+  Status = This->Mem.Read (This, Width, Address, 1, Result);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }    
+  if ((*Result & Mask) == Value) {
+    return EFI_SUCCESS;
+  }
+
+  if (Delay == 0) {
+    return EFI_SUCCESS;
+  
+  } else {
+
+    //
+    // Determine the proper # of metronome ticks to wait for polling the
+    // location.  The nuber of ticks is Roundup (Delay / mMetronome->TickPeriod)+1
+    // The "+1" to account for the possibility of the first tick being short
+    // because we started in the middle of a tick.
+    //
+    // BugBug: overriding mMetronome->TickPeriod with UINT32 until Metronome
+    // protocol definition is updated.
+    //
+    NumberOfTicks = DivU64x32Remainder (Delay, (UINT32) mMetronome->TickPeriod, &Remainder);
+    if (Remainder != 0) {
+      NumberOfTicks += 1;
+    }
+    NumberOfTicks += 1;
+  
+    while (NumberOfTicks != 0) {
+
+      mMetronome->WaitForTick (mMetronome, 1);
+    
+      Status = This->Mem.Read (This, Width, Address, 1, Result);
+      if (EFI_ERROR (Status)) {
+        return Status;
+      }
+    
+      if ((*Result & Mask) == Value) {
+        return EFI_SUCCESS;
+      }
+
+      NumberOfTicks -= 1;
+    }
+  }
+  return EFI_TIMEOUT;
+}
+  
+/**
+   Reads from the I/O space of a PCI Root Bridge. Returns when either the polling exit criteria is
+   satisfied or after a defined duration.
+
+   This function provides a standard way to poll a PCI I/O location. A PCI I/O read operation is
+   performed at the PCI I/O address specified by Address for the width specified by Width.
+   The result of this PCI I/O read operation is stored in Result. This PCI I/O read operation is
+   repeated until either a timeout of Delay 100 ns units has expired, or (Result & Mask) is equal
+   to Value.
+
+   @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in] Width     Signifies the width of the I/O operations.
+   @param[in] Address   The base address of the I/O operations. The caller is responsible
+                        for aligning Address if required.
+   @param[in] Mask      Mask used for the polling criteria. Bytes above Width in Mask
+                        are ignored. The bits in the bytes below Width which are zero in
+                        Mask are ignored when polling the I/O address.
+   @param[in] Value     The comparison value used for the polling exit criteria.
+   @param[in] Delay     The number of 100 ns units to poll. Note that timer available may
+                        be of poorer granularity.
+   @param[out] Result   Pointer to the last value read from the memory location.
+   
+   @retval EFI_SUCCESS            The last data returned from the access matched the poll exit criteria.
+   @retval EFI_INVALID_PARAMETER  Width is invalid.
+   @retval EFI_INVALID_PARAMETER  Result is NULL.
+   @retval EFI_TIMEOUT            Delay expired before a match occurred.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPollIo ( 
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN  UINT64                                 Address,
+  IN  UINT64                                 Mask,
+  IN  UINT64                                 Value,
+  IN  UINT64                                 Delay,
+  OUT UINT64                                 *Result
+  )
+{
+  EFI_STATUS  Status;
+  UINT64      NumberOfTicks;
+  UINT32      Remainder;
+
+  //
+  // No matter what, always do a single poll.
+  //
+
+  if (Result == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((UINT32)Width > EfiPciWidthUint64) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  Status = This->Io.Read (This, Width, Address, 1, Result);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }    
+  if ((*Result & Mask) == Value) {
+    return EFI_SUCCESS;
+  }
+
+  if (Delay == 0) {
+    return EFI_SUCCESS;
+  
+  } else {
+
+    //
+    // Determine the proper # of metronome ticks to wait for polling the
+    // location.  The number of ticks is Roundup (Delay / mMetronome->TickPeriod)+1
+    // The "+1" to account for the possibility of the first tick being short
+    // because we started in the middle of a tick.
+    //
+    NumberOfTicks = DivU64x32Remainder (Delay, (UINT32)mMetronome->TickPeriod, &Remainder);
+    if (Remainder != 0) {
+      NumberOfTicks += 1;
+    }
+    NumberOfTicks += 1;
+  
+    while (NumberOfTicks != 0) {
+
+      mMetronome->WaitForTick (mMetronome, 1);
+    
+      Status = This->Io.Read (This, Width, Address, 1, Result);
+      if (EFI_ERROR (Status)) {
+        return Status;
+      }
+    
+      if ((*Result & Mask) == Value) {
+        return EFI_SUCCESS;
+      }
+
+      NumberOfTicks -= 1;
+    }
+  }
+  return EFI_TIMEOUT;
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space.
+
+   The Mem.Read(), and Mem.Write() functions enable a driver to access PCI controller
+   registers in the PCI root bridge memory space.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI Root Bridge on a platform might require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operation.
+   @param[in]   Address   The base address of the memory operation. The caller is
+                          responsible for aligning the Address if required.
+   @param[in]   Count     The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at Address.
+   @param[out]  Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMemRead (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  OUT    VOID                                   *Buffer
+  )
+{
+  return RootBridgeIoMemRW (This, FALSE, Width, Address, Count, Buffer);
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space.
+
+   The Mem.Read(), and Mem.Write() functions enable a driver to access PCI controller
+   registers in the PCI root bridge memory space.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI Root Bridge on a platform might require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operation.
+   @param[in]   Address   The base address of the memory operation. The caller is
+                          responsible for aligning the Address if required.
+   @param[in]   Count     The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at Address.
+   @param[in]   Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMemWrite (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  IN     VOID                                   *Buffer
+  )
+{
+  return RootBridgeIoMemRW (This, TRUE, Width, Address, Count, Buffer);  
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge I/O space.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width       Signifies the width of the memory operations.
+   @param[in]   Address     The base address of the I/O operation. The caller is responsible for
+                            aligning the Address if required.
+   @param[in]   Count       The number of I/O operations to perform. Bytes moved is Width
+                            size * Count, starting at Address.
+   @param[out]  Buffer      For read operations, the destination buffer to store the results. For
+                            write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS              The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoIoRead (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT64                                 Address,
+  IN     UINTN                                  Count,
+  OUT    VOID                                   *Buffer
+  )
+{
+  return RootBridgeIoIoRW (This, FALSE, Width, Address, Count, Buffer);  
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in the PCI root bridge I/O space.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width       Signifies the width of the memory operations.
+   @param[in]   Address     The base address of the I/O operation. The caller is responsible for
+                            aligning the Address if required.
+   @param[in]   Count       The number of I/O operations to perform. Bytes moved is Width
+                            size * Count, starting at Address.
+   @param[in]   Buffer       For read operations, the destination buffer to store the results. For
+                            write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS              The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER    Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoIoWrite (
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL         *This,
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH   Width,
+  IN       UINT64                                  Address,
+  IN       UINTN                                   Count,
+  IN       VOID                                    *Buffer
+  )
+{
+  return RootBridgeIoIoRW (This, TRUE, Width, Address, Count, Buffer);  
+}
+
+/**
+   Enables a PCI driver to copy one region of PCI root bridge memory space to another region of PCI
+   root bridge memory space.
+
+   The CopyMem() function enables a PCI driver to copy one region of PCI root bridge memory
+   space to another region of PCI root bridge memory space. This is especially useful for video scroll
+   operation on a memory mapped video buffer.
+   The memory operations are carried out exactly as requested. The caller is responsible for satisfying
+   any alignment and memory width restrictions that a PCI root bridge on a platform might require.
+
+   @param[in] This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
+   @param[in] Width       Signifies the width of the memory operations.
+   @param[in] DestAddress The destination address of the memory operation. The caller is
+                          responsible for aligning the DestAddress if required.
+   @param[in] SrcAddress  The source address of the memory operation. The caller is
+                          responsible for aligning the SrcAddress if required.
+   @param[in] Count       The number of memory operations to perform. Bytes moved is
+                          Width size * Count, starting at DestAddress and SrcAddress.
+   
+   @retval  EFI_SUCCESS             The data was copied from one memory region to another memory region.
+   @retval  EFI_INVALID_PARAMETER   Width is invalid for this PCI root bridge.
+   @retval  EFI_OUT_OF_RESOURCES    The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoCopyMem (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL              *This,
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH        Width,
+  IN UINT64                                       DestAddress,
+  IN UINT64                                       SrcAddress,
+  IN UINTN                                        Count
+  )
+{
+  EFI_STATUS  Status;
+  BOOLEAN     Direction;
+  UINTN       Stride;
+  UINTN       Index;
+  UINT64      Result;
+
+  if ((UINT32)Width > EfiPciWidthUint64) {
+    return EFI_INVALID_PARAMETER;
+  }    
+
+  if (DestAddress == SrcAddress) {
+    return EFI_SUCCESS;
+  }
+
+  Stride = (UINTN)(1 << Width);
+
+  Direction = TRUE;
+  if ((DestAddress > SrcAddress) && (DestAddress < (SrcAddress + Count * Stride))) {
+    Direction   = FALSE;
+    SrcAddress  = SrcAddress  + (Count-1) * Stride;
+    DestAddress = DestAddress + (Count-1) * Stride;
+  }
+
+  for (Index = 0;Index < Count;Index++) {
+    Status = RootBridgeIoMemRead (
+               This,
+               Width,
+               SrcAddress,
+               1,
+               &Result
+               );
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+    Status = RootBridgeIoMemWrite (
+               This,
+               Width,
+               DestAddress,
+               1,
+               &Result
+               );
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+    if (Direction) {
+      SrcAddress  += Stride;
+      DestAddress += Stride;
+    } else {
+      SrcAddress  -= Stride;
+      DestAddress -= Stride;
+    }
+  }
+  return EFI_SUCCESS;
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in a PCI root bridge's configuration space.
+
+   The Pci.Read() and Pci.Write() functions enable a driver to access PCI configuration
+   registers for a PCI controller.
+   The PCI Configuration operations are carried out exactly as requested. The caller is responsible for
+   any alignment and PCI configuration width issues that a PCI Root Bridge on a platform might
+   require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count     The number of PCI configuration operations to perform. Bytes
+                          moved is Width size * Count, starting at Address.
+   @param[out]  Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPciRead (
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN       UINT64                                 Address,
+  IN       UINTN                                  Count,
+  OUT      VOID                                   *Buffer
+  )
+{
+  return RootBridgeIoPciRW (This, FALSE, Width, Address, Count, Buffer);
+}
+
+/**
+   Enables a PCI driver to access PCI controller registers in a PCI root bridge's configuration space.
+
+   The Pci.Read() and Pci.Write() functions enable a driver to access PCI configuration
+   registers for a PCI controller.
+   The PCI Configuration operations are carried out exactly as requested. The caller is responsible for
+   any alignment and PCI configuration width issues that a PCI Root Bridge on a platform might
+   require.
+
+   @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]   Width     Signifies the width of the memory operations.
+   @param[in]   Address   The address within the PCI configuration space for the PCI controller.
+   @param[in]   Count     The number of PCI configuration operations to perform. Bytes
+                          moved is Width size * Count, starting at Address.
+   @param[in]   Buffer    For read operations, the destination buffer to store the results. For
+                          write operations, the source buffer to write data from.
+   
+   @retval EFI_SUCCESS            The data was read from or written to the PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.
+   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoPciWrite (
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
+  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
+  IN       UINT64                                 Address,
+  IN       UINTN                                  Count,
+  IN       VOID                                   *Buffer
+  )
+{
+  return RootBridgeIoPciRW (This, TRUE, Width, Address, Count, Buffer);
+}
+
+/**
+   Provides the PCI controller-specific addresses required to access system memory from a
+   DMA bus master.
+
+   The Map() function provides the PCI controller specific addresses needed to access system
+   memory. This function is used to map system memory for PCI bus master DMA accesses.
+
+   @param[in]       This            A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]       Operation       Indicates if the bus master is going to read or write to system memory.
+   @param[in]       HostAddress     The system memory address to map to the PCI controller.
+   @param[in, out]  NumberOfBytes   On input the number of bytes to map. On output the number of bytes that were mapped.
+   @param[out]      DeviceAddress   The resulting map address for the bus master PCI controller to use
+                                    to access the system memory's HostAddress.
+   @param[out]      Mapping         The value to pass to Unmap() when the bus master DMA operation is complete.
+   
+   @retval EFI_SUCCESS            The range was mapped for the returned NumberOfBytes.
+   @retval EFI_INVALID_PARAMETER  Operation is invalid.
+   @retval EFI_INVALID_PARAMETER  HostAddress is NULL.
+   @retval EFI_INVALID_PARAMETER  NumberOfBytes is NULL.
+   @retval EFI_INVALID_PARAMETER  DeviceAddress is NULL.
+   @retval EFI_INVALID_PARAMETER  Mapping is NULL.
+   @retval EFI_UNSUPPORTED        The HostAddress cannot be mapped as a common buffer.
+   @retval EFI_DEVICE_ERROR       The system hardware could not map the requested address.
+   @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoMap (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
+  IN     VOID                                       *HostAddress,
+  IN OUT UINTN                                      *NumberOfBytes,
+  OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
+  OUT    VOID                                       **Mapping
+  )
+{
+  EFI_STATUS            Status;
+  EFI_PHYSICAL_ADDRESS  PhysicalAddress;
+  MAP_INFO              *MapInfo;
+
+  if (HostAddress == NULL || NumberOfBytes == NULL || DeviceAddress == NULL || Mapping == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+  
+  //
+  // Initialize the return values to their defaults
+  //
+  *Mapping = NULL;
+
+  //
+  // Make sure that Operation is valid
+  //
+  if ((UINT32)Operation >= EfiPciOperationMaximum) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Most PCAT like chipsets can not handle performing DMA above 4GB.
+  // If any part of the DMA transfer being mapped is above 4GB, then
+  // map the DMA transfer to a buffer below 4GB.
+  //
+  PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
+  if ((PhysicalAddress + *NumberOfBytes) > 0x100000000ULL) {
+
+    //
+    // Common Buffer operations can not be remapped.  If the common buffer
+    // if above 4GB, then it is not possible to generate a mapping, so return 
+    // an error.
+    //
+    if (Operation == EfiPciOperationBusMasterCommonBuffer || Operation == EfiPciOperationBusMasterCommonBuffer64) {
+      return EFI_UNSUPPORTED;
+    }
+
+    //
+    // Allocate a MAP_INFO structure to remember the mapping when Unmap() is
+    // called later.
+    //
+    Status = gBS->AllocatePool (
+                    EfiBootServicesData, 
+                    sizeof(MAP_INFO), 
+                    (VOID **)&MapInfo
+                    );
+    if (EFI_ERROR (Status)) {
+      *NumberOfBytes = 0;
+      return Status;
+    }
+
+    //
+    // Return a pointer to the MAP_INFO structure in Mapping
+    //
+    *Mapping = MapInfo;
+
+    //
+    // Initialize the MAP_INFO structure
+    //
+    MapInfo->Operation         = Operation;
+    MapInfo->NumberOfBytes     = *NumberOfBytes;
+    MapInfo->NumberOfPages     = EFI_SIZE_TO_PAGES(*NumberOfBytes);
+    MapInfo->HostAddress       = PhysicalAddress;
+    MapInfo->MappedHostAddress = 0x00000000ffffffff;
+
+    //
+    // Allocate a buffer below 4GB to map the transfer to.
+    //
+    Status = gBS->AllocatePages (
+                    AllocateMaxAddress, 
+                    EfiBootServicesData, 
+                    MapInfo->NumberOfPages,
+                    &MapInfo->MappedHostAddress
+                    );
+    if (EFI_ERROR (Status)) {
+      gBS->FreePool (MapInfo);
+      *NumberOfBytes = 0;
+      return Status;
+    }
+
+    //
+    // If this is a read operation from the Bus Master's point of view,
+    // then copy the contents of the real buffer into the mapped buffer
+    // so the Bus Master can read the contents of the real buffer.
+    //
+    if (Operation == EfiPciOperationBusMasterRead || Operation == EfiPciOperationBusMasterRead64) {
+      CopyMem (
+        (VOID *)(UINTN)MapInfo->MappedHostAddress, 
+        (VOID *)(UINTN)MapInfo->HostAddress,
+        MapInfo->NumberOfBytes
+        );
+    }
+
+    //
+    // The DeviceAddress is the address of the maped buffer below 4GB
+    //
+    *DeviceAddress = MapInfo->MappedHostAddress;
+  } else {
+    //
+    // The transfer is below 4GB, so the DeviceAddress is simply the HostAddress
+    //
+    *DeviceAddress = PhysicalAddress;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+   Completes the Map() operation and releases any corresponding resources.
+
+   The Unmap() function completes the Map() operation and releases any corresponding resources.
+   If the operation was an EfiPciOperationBusMasterWrite or
+   EfiPciOperationBusMasterWrite64, the data is committed to the target system memory.
+   Any resources used for the mapping are freed.  
+
+   @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in] Mapping   The mapping value returned from Map().
+   
+   @retval EFI_SUCCESS            The range was unmapped.
+   @retval EFI_INVALID_PARAMETER  Mapping is not a value that was returned by Map().
+   @retval EFI_DEVICE_ERROR       The data was not committed to the target system memory.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoUnmap (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN VOID                             *Mapping
+  )
+{
+  MAP_INFO    *MapInfo;
+
+  //
+  // See if the Map() operation associated with this Unmap() required a mapping buffer.
+  // If a mapping buffer was not required, then this function simply returns EFI_SUCCESS.
+  //
+  if (Mapping != NULL) {
+    //
+    // Get the MAP_INFO structure from Mapping
+    //
+    MapInfo = (MAP_INFO *)Mapping;
+
+    //
+    // If this is a write operation from the Bus Master's point of view,
+    // then copy the contents of the mapped buffer into the real buffer
+    // so the processor can read the contents of the real buffer.
+    //
+    if (MapInfo->Operation == EfiPciOperationBusMasterWrite || MapInfo->Operation == EfiPciOperationBusMasterWrite64) {
+      CopyMem (
+        (VOID *)(UINTN)MapInfo->HostAddress, 
+        (VOID *)(UINTN)MapInfo->MappedHostAddress,
+        MapInfo->NumberOfBytes
+        );
+    }
+
+    //
+    // Free the mapped buffer and the MAP_INFO structure.
+    //
+    gBS->FreePages (MapInfo->MappedHostAddress, MapInfo->NumberOfPages);
+    gBS->FreePool (Mapping);
+  }
+  return EFI_SUCCESS;
+}
+
+/**
+   Allocates pages that are suitable for an EfiPciOperationBusMasterCommonBuffer or
+   EfiPciOperationBusMasterCommonBuffer64 mapping.
+  
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Type        This parameter is not used and must be ignored.
+   @param MemoryType  The type of memory to allocate, EfiBootServicesData or EfiRuntimeServicesData.
+   @param Pages       The number of pages to allocate.
+   @param HostAddress A pointer to store the base system memory address of the allocated range.
+   @param Attributes  The requested bit mask of attributes for the allocated range. Only
+                      the attributes EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE, EFI_PCI_ATTRIBUTE_MEMORY_CACHED, 
+                      and EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE may be used with this function.
+   
+   @retval EFI_SUCCESS            The requested memory pages were allocated.
+   @retval EFI_INVALID_PARAMETER  MemoryType is invalid.
+   @retval EFI_INVALID_PARAMETER  HostAddress is NULL.
+   @retval EFI_UNSUPPORTED        Attributes is unsupported. The only legal attribute bits are
+                                  MEMORY_WRITE_COMBINE, MEMORY_CACHED, and DUAL_ADDRESS_CYCLE.
+   @retval EFI_OUT_OF_RESOURCES   The memory pages could not be allocated.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoAllocateBuffer (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN  EFI_ALLOCATE_TYPE                Type,
+  IN  EFI_MEMORY_TYPE                  MemoryType,
+  IN  UINTN                            Pages,
+  OUT VOID                             **HostAddress,
+  IN  UINT64                           Attributes
+  )
+{
+  EFI_STATUS            Status;
+  EFI_PHYSICAL_ADDRESS  PhysicalAddress;
+
+  //
+  // Validate Attributes
+  //
+  if ((Attributes & EFI_PCI_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER) != 0) {
+    return EFI_UNSUPPORTED;
+  }
+
+  //
+  // Check for invalid inputs
+  //
+  if (HostAddress == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+ 
+  //
+  // The only valid memory types are EfiBootServicesData and EfiRuntimeServicesData
+  //
+  if (MemoryType != EfiBootServicesData && MemoryType != EfiRuntimeServicesData) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Limit allocations to memory below 4GB
+  //
+  PhysicalAddress = (EFI_PHYSICAL_ADDRESS)(0xffffffff);
+
+  Status = gBS->AllocatePages (AllocateMaxAddress, MemoryType, Pages, &PhysicalAddress);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  *HostAddress = (VOID *)(UINTN)PhysicalAddress;
+
+  return EFI_SUCCESS;
+}
+
+/**
+   Frees memory that was allocated with AllocateBuffer().
+
+   The FreeBuffer() function frees memory that was allocated with AllocateBuffer().
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Pages       The number of pages to free.
+   @param HostAddress The base system memory address of the allocated range.
+   
+   @retval EFI_SUCCESS            The requested memory pages were freed.
+   @retval EFI_INVALID_PARAMETER  The memory range specified by HostAddress and Pages
+                                  was not allocated with AllocateBuffer().
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoFreeBuffer (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN  UINTN                            Pages,
+  OUT VOID                             *HostAddress
+  )
+{
+  return gBS->FreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress, Pages);
+}
+
+/**
+   Flushes all PCI posted write transactions from a PCI host bridge to system memory.
+
+   The Flush() function flushes any PCI posted write transactions from a PCI host bridge to system
+   memory. Posted write transactions are generated by PCI bus masters when they perform write
+   transactions to target addresses in system memory.
+   This function does not flush posted write transactions from any PCI bridges. A PCI controller
+   specific action must be taken to guarantee that the posted write transactions have been flushed from
+   the PCI controller and from all the PCI bridges into the PCI host bridge. This is typically done with
+   a PCI read transaction from the PCI controller prior to calling Flush().
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   
+   @retval EFI_SUCCESS        The PCI posted write transactions were flushed from the PCI host
+                              bridge to system memory.
+   @retval EFI_DEVICE_ERROR   The PCI posted write transactions were not flushed from the PCI
+                              host bridge due to a hardware error.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoFlush (
+  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL           *This
+  )
+{
+  //
+  // not supported yet
+  //
+  return EFI_SUCCESS;
+}
+
+/**
+   Gets the attributes that a PCI root bridge supports setting with SetAttributes(), and the
+   attributes that a PCI root bridge is currently using.  
+
+   The GetAttributes() function returns the mask of attributes that this PCI root bridge supports
+   and the mask of attributes that the PCI root bridge is currently using.
+
+   @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param Supported   A pointer to the mask of attributes that this PCI root bridge
+                      supports setting with SetAttributes().
+   @param Attributes  A pointer to the mask of attributes that this PCI root bridge is
+                      currently using.
+   
+   @retval  EFI_SUCCESS           If Supports is not NULL, then the attributes that the PCI root
+                                  bridge supports is returned in Supports. If Attributes is
+                                  not NULL, then the attributes that the PCI root bridge is currently
+                                  using is returned in Attributes.
+   @retval  EFI_INVALID_PARAMETER Both Supports and Attributes are NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoGetAttributes (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  OUT UINT64                           *Supported,
+  OUT UINT64                           *Attributes
+  )
+{
+  PCI_ROOT_BRIDGE_INSTANCE *PrivateData;
+
+  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(This);
+
+  if (Attributes == NULL && Supported == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Set the return value for Supported and Attributes
+  //
+  if (Supported != NULL) {
+    *Supported  = PrivateData->Supports; 
+  }
+
+  if (Attributes != NULL) {
+    *Attributes = PrivateData->Attributes;
+  }
+  
+  return EFI_SUCCESS;
+}
+
+/**
+   Sets attributes for a resource range on a PCI root bridge.
+
+   The SetAttributes() function sets the attributes specified in Attributes for the PCI root
+   bridge on the resource range specified by ResourceBase and ResourceLength. Since the
+   granularity of setting these attributes may vary from resource type to resource type, and from
+   platform to platform, the actual resource range and the one passed in by the caller may differ. As a
+   result, this function may set the attributes specified by Attributes on a larger resource range
+   than the caller requested. The actual range is returned in ResourceBase and
+   ResourceLength. The caller is responsible for verifying that the actual range for which the
+   attributes were set is acceptable.
+
+   @param[in]       This            A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[in]       Attributes      The mask of attributes to set. If the attribute bit
+                                    MEMORY_WRITE_COMBINE, MEMORY_CACHED, or
+                                    MEMORY_DISABLE is set, then the resource range is specified by
+                                    ResourceBase and ResourceLength. If
+                                    MEMORY_WRITE_COMBINE, MEMORY_CACHED, and
+                                    MEMORY_DISABLE are not set, then ResourceBase and
+                                    ResourceLength are ignored, and may be NULL.
+   @param[in, out]  ResourceBase    A pointer to the base address of the resource range to be modified
+                                    by the attributes specified by Attributes.
+   @param[in, out]  ResourceLength  A pointer to the length of the resource range to be modified by the
+                                    attributes specified by Attributes.
+   
+   @retval  EFI_SUCCESS     The current configuration of this PCI root bridge was returned in Resources.
+   @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge could not be retrieved.
+   @retval  EFI_INVALID_PARAMETER Invalid pointer of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoSetAttributes (
+  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
+  IN     UINT64                           Attributes,
+  IN OUT UINT64                           *ResourceBase,
+  IN OUT UINT64                           *ResourceLength 
+  )
+{
+  PCI_ROOT_BRIDGE_INSTANCE            *PrivateData;
+  
+  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(This);
+  
+  if (Attributes != 0) {
+    if ((Attributes & (~(PrivateData->Supports))) != 0) {
+      return EFI_UNSUPPORTED;
+    }
+  }
+  
+  //
+  // This is a generic driver for a PC-AT class system.  It does not have any
+  // chipset specific knowlegde, so none of the attributes can be set or 
+  // cleared.  Any attempt to set attribute that are already set will succeed, 
+  // and any attempt to set an attribute that is not supported will fail.
+  //
+  if (Attributes & (~PrivateData->Attributes)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+   Retrieves the current resource settings of this PCI root bridge in the form of a set of ACPI 2.0
+   resource descriptors.
+
+   There are only two resource descriptor types from the ACPI Specification that may be used to
+   describe the current resources allocated to a PCI root bridge. These are the QWORD Address
+   Space Descriptor (ACPI 2.0 Section 6.4.3.5.1), and the End Tag (ACPI 2.0 Section 6.4.2.8). The
+   QWORD Address Space Descriptor can describe memory, I/O, and bus number ranges for dynamic
+   or fixed resources. The configuration of a PCI root bridge is described with one or more QWORD
+   Address Space Descriptors followed by an End Tag.
+
+   @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
+   @param[out]  Resources   A pointer to the ACPI 2.0 resource descriptors that describe the
+                            current configuration of this PCI root bridge. The storage for the
+                            ACPI 2.0 resource descriptors is allocated by this function. The
+                            caller must treat the return buffer as read-only data, and the buffer
+                            must not be freed by the caller.
+   
+   @retval  EFI_SUCCESS     The current configuration of this PCI root bridge was returned in Resources.
+   @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge could not be retrieved.
+   @retval  EFI_INVALID_PARAMETER Invalid pointer of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
+
+**/
+EFI_STATUS
+EFIAPI
+RootBridgeIoConfiguration (
+  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL     *This,
+  OUT VOID                                **Resources
+  )
+{
+  PCI_ROOT_BRIDGE_INSTANCE              *PrivateData;
+  UINTN                                 Index;
+
+  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (This);
+  
+  for (Index = 0; Index < TypeMax; Index++) {
+    if (PrivateData->ResAllocNode[Index].Status == ResAllocated) {
+      Configuration.SpaceDesp[Index].AddrRangeMin = PrivateData->ResAllocNode[Index].Base;
+      Configuration.SpaceDesp[Index].AddrRangeMax = PrivateData->ResAllocNode[Index].Base + PrivateData->ResAllocNode[Index].Length - 1;
+      Configuration.SpaceDesp[Index].AddrLen      = PrivateData->ResAllocNode[Index].Length;
+    }  
+  }  
+    
+  *Resources = &Configuration;      
+  return EFI_SUCCESS;
+}
+