[edk2-platforms][PATCH 5/8] Platform/RPi: Clean up and improve early memory init

["Pete Batard" <pete@akeo.ie>]

This patch improves memory initialization for the Raspberry Pi Platform by:

Using VideoCore mailbox data to reserve only the regions that are actually
mapped. Especially, besides the base RAM size, which was already set using
VideoCore data, we can set the GPU/VideoCore base address as well as the
extended RAM, which is the memory beyond 1 GB that is available on models
such as the Raspberry Pi 4 (for the 2GB or 4GB versions).

Introducing a new PcdExtendedMemoryBase PCD for the base address of the
extended memory region, which currently cannot be retrieved from VideoCore
(MBOX_GET_ARM_MEMSIZE still only returns a single region on Bcm2711).

Introducing a new RpiPlatformGetVirtualMemoryInfo() companion call to
ArmPlatformGetVirtualMemoryMap() that allows us greatly simplify the
registration of each segment in MemoryPeim() as well as making it easier
to maintain for future models.

We also fix SoC register space that should have been marked as reserved
but wasn't until now and remove the unreferenced mSystemMemoryEnd extern
in MemoryInitPeiLib.c.

Signed-off-by: Pete Batard <pete@akeo.ie>
---
 Platform/RaspberryPi/Include/Library/RPiMem.h                      |  26 +++
 Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.c   |  94 ++++----
 Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.inf |   1 +
 Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf           |   3 +
 Platform/RaspberryPi/Library/PlatformLib/RaspberryPiMem.c          | 242 +++++++++++---------
 Platform/RaspberryPi/RaspberryPi.dec                               |   1 +
 6 files changed, 210 insertions(+), 157 deletions(-)

diff --git a/Platform/RaspberryPi/Include/Library/RPiMem.h b/Platform/RaspberryPi/Include/Library/RPiMem.h
new file mode 100644
index 000000000000..0bfc697ed094
--- /dev/null
+++ b/Platform/RaspberryPi/Include/Library/RPiMem.h
@@ -0,0 +1,26 @@
+/** @file
+ *
+ *  Copyright (c) 2019, Pete Batard <pete@akeo.ie>
+ *
+ *  SPDX-License-Identifier: BSD-2-Clause-Patent
+ *
+ **/
+
+#ifndef __RPI_MEM_H__
+#define __RPI_MEM_H__
+
+#define RPI_MEM_BASIC_REGION    0
+#define RPI_MEM_RUNTIME_REGION  1
+#define RPI_MEM_RESERVED_REGION 2
+
+typedef struct {
+  CONST CHAR16*                 Name;
+  UINTN                         Type;
+} RPI_MEMORY_REGION_INFO;
+
+VOID
+RpiPlatformGetVirtualMemoryInfo (
+  IN RPI_MEMORY_REGION_INFO** MemoryInfo
+  );
+
+#endif /* __RPI_MEM_H__ */
diff --git a/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.c b/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.c
index 60cf397f8baa..3a0f7e19e993 100644
--- a/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.c
+++ b/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.c
@@ -15,8 +15,7 @@
 #include <Library/HobLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/PcdLib.h>
-
-extern UINT64 mSystemMemoryEnd;
+#include <Library/RPiMem.h>
 
 VOID
 BuildMemoryTypeInformationHob (
@@ -39,23 +38,32 @@ InitMmu (
   }
 }
 
+STATIC
+VOID
+AddBasicMemoryRegion (
+  IN ARM_MEMORY_REGION_DESCRIPTOR *Desc
+)
+{
+  BuildResourceDescriptorHob (
+    EFI_RESOURCE_SYSTEM_MEMORY,
+    EFI_RESOURCE_ATTRIBUTE_PRESENT |
+    EFI_RESOURCE_ATTRIBUTE_INITIALIZED |
+    EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |
+    EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
+    EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |
+    EFI_RESOURCE_ATTRIBUTE_TESTED,
+    Desc->PhysicalBase,
+    Desc->Length
+  );
+}
+
 STATIC
 VOID
 AddRuntimeServicesRegion (
   IN ARM_MEMORY_REGION_DESCRIPTOR *Desc
 )
 {
-  BuildResourceDescriptorHob (
-    EFI_RESOURCE_SYSTEM_MEMORY,
-    EFI_RESOURCE_ATTRIBUTE_PRESENT |
-    EFI_RESOURCE_ATTRIBUTE_INITIALIZED |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_TESTED,
-    Desc->PhysicalBase,
-    Desc->Length
-  );
+  AddBasicMemoryRegion (Desc);
 
   BuildMemoryAllocationHob (
     Desc->PhysicalBase,
@@ -70,17 +78,7 @@ AddReservedMemoryRegion (
   IN ARM_MEMORY_REGION_DESCRIPTOR *Desc
   )
 {
-  BuildResourceDescriptorHob (
-    EFI_RESOURCE_SYSTEM_MEMORY,
-    EFI_RESOURCE_ATTRIBUTE_PRESENT |
-    EFI_RESOURCE_ATTRIBUTE_INITIALIZED |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_TESTED,
-    Desc->PhysicalBase,
-    Desc->Length
-  );
+  AddBasicMemoryRegion (Desc);
 
   BuildMemoryAllocationHob (
     Desc->PhysicalBase,
@@ -89,6 +87,12 @@ AddReservedMemoryRegion (
   );
 }
 
+void (*AddRegion[]) (IN ARM_MEMORY_REGION_DESCRIPTOR *Desc) = {
+  AddBasicMemoryRegion,
+  AddRuntimeServicesRegion,
+  AddReservedMemoryRegion,
+  };
+
 /*++
 
 Routine Description:
@@ -113,36 +117,28 @@ MemoryPeim (
   )
 {
   ARM_MEMORY_REGION_DESCRIPTOR *MemoryTable;
+  RPI_MEMORY_REGION_INFO       *MemoryInfo;
+  UINTN                        Index;
 
   // Get Virtual Memory Map from the Platform Library
   ArmPlatformGetVirtualMemoryMap (&MemoryTable);
 
-  // Ensure PcdSystemMemorySize has been set
-  ASSERT (PcdGet64 (PcdSystemMemorySize) != 0);
+  // Get additional info not provided by MemoryTable
+  RpiPlatformGetVirtualMemoryInfo (&MemoryInfo);
 
-  // FD without variable store
-  AddReservedMemoryRegion (&MemoryTable[0]);
-
-  // Variable store.
-  AddRuntimeServicesRegion (&MemoryTable[1]);
-
-  // Trusted Firmware region
-  AddReservedMemoryRegion (&MemoryTable[2]);
-
-  // Usable memory.
-  BuildResourceDescriptorHob (
-    EFI_RESOURCE_SYSTEM_MEMORY,
-    EFI_RESOURCE_ATTRIBUTE_PRESENT |
-    EFI_RESOURCE_ATTRIBUTE_INITIALIZED |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |
-    EFI_RESOURCE_ATTRIBUTE_TESTED,
-    MemoryTable[3].PhysicalBase,
-    MemoryTable[3].Length
-  );
-
-  AddReservedMemoryRegion (&MemoryTable[4]);
+  // Register each memory region
+  for (Index = 0; MemoryTable[Index].Length != 0; Index++) {
+    ASSERT (MemoryInfo[Index].Type < ARRAY_SIZE (AddRegion));
+    DEBUG ((DEBUG_INFO, "%s:\n"
+      "\tPhysicalBase: 0x%lX\n"
+      "\tVirtualBase: 0x%lX\n"
+      "\tLength: 0x%lX\n",
+      MemoryInfo[Index].Name,
+      MemoryTable[Index].PhysicalBase,
+      MemoryTable[Index].VirtualBase,
+      MemoryTable[Index].Length));
+    AddRegion[MemoryInfo[Index].Type] (&MemoryTable[Index]);
+  }
 
   // Build Memory Allocation Hob
   InitMmu (MemoryTable);
diff --git a/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.inf b/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.inf
index 0084c010936d..d39210c7a4f1 100644
--- a/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.inf
+++ b/Platform/RaspberryPi/Library/MemoryInitPeiLib/MemoryInitPeiLib.inf
@@ -24,6 +24,7 @@ [Packages]
   EmbeddedPkg/EmbeddedPkg.dec
   ArmPkg/ArmPkg.dec
   ArmPlatformPkg/ArmPlatformPkg.dec
+  Platform/RaspberryPi/RaspberryPi.dec
 
 [LibraryClasses]
   DebugLib
diff --git a/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf b/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf
index 85462febdd8d..c0e2a75451c3 100644
--- a/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf
+++ b/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf
@@ -22,6 +22,7 @@ [Packages]
   EmbeddedPkg/EmbeddedPkg.dec
   ArmPkg/ArmPkg.dec
   ArmPlatformPkg/ArmPlatformPkg.dec
+  Silicon/Broadcom/Bcm27xx/Bcm27xx.dec
   Silicon/Broadcom/Bcm283x/Bcm283x.dec
   Platform/RaspberryPi/RaspberryPi.dec
 
@@ -50,10 +51,12 @@ [FixedPcd]
   gEmbeddedTokenSpaceGuid.PcdDmaDeviceOffset
   gArmTokenSpaceGuid.PcdSystemMemoryBase
   gArmTokenSpaceGuid.PcdSystemMemorySize
+  gRaspberryPiTokenSpaceGuid.PcdExtendedMemoryBase
   gRaspberryPiTokenSpaceGuid.PcdNvStorageEventLogSize
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
+  gBcm27xxTokenSpaceGuid.PcdBcm27xxRegistersAddress
   gBcm283xTokenSpaceGuid.PcdBcm283xRegistersAddress
 
 [Ppis]
diff --git a/Platform/RaspberryPi/Library/PlatformLib/RaspberryPiMem.c b/Platform/RaspberryPi/Library/PlatformLib/RaspberryPiMem.c
index 2bfd3f020a6e..1a6a13b9591b 100644
--- a/Platform/RaspberryPi/Library/PlatformLib/RaspberryPiMem.c
+++ b/Platform/RaspberryPi/Library/PlatformLib/RaspberryPiMem.c
@@ -1,7 +1,9 @@
 /** @file
  *
+ *  Copyright (c) 2019, Pete Batard <pete@akeo.ie>
  *  Copyright (c) 2017-2018, Andrey Warkentin <andrey.warkentin@gmail.com>
  *  Copyright (c) 2014, Linaro Limited. All rights reserved.
+ *  Copyright (c) 2013-2018, ARM Limited. All rights reserved.
  *
  *  SPDX-License-Identifier: BSD-2-Clause-Patent
  *
@@ -9,8 +11,11 @@
 
 #include <Library/ArmPlatformLib.h>
 #include <Library/DebugLib.h>
-#include <IndustryStandard/Bcm2836.h>
 #include <Library/PcdLib.h>
+#include <Library/RPiMem.h>
+#include <Library/MemoryAllocationLib.h>
+#include <IndustryStandard/Bcm2711.h>
+#include <IndustryStandard/Bcm2836.h>
 
 UINT64 mSystemMemoryBase;
 extern UINT64 mSystemMemoryEnd;
@@ -18,6 +23,13 @@ UINT64 mVideoCoreBase;
 UINT64 mVideoCoreSize;
 UINT32 mBoardRevision;
 
+
+// The total number of descriptors, including the final "end-of-table" descriptor.
+#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS 10
+
+STATIC BOOLEAN                  VirtualMemoryInfoInitialized = FALSE;
+STATIC RPI_MEMORY_REGION_INFO   VirtualMemoryInfo[MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS];
+
 #define VariablesSize (FixedPcdGet32(PcdFlashNvStorageVariableSize) +   \
                        FixedPcdGet32(PcdFlashNvStorageFtwWorkingSize) + \
                        FixedPcdGet32(PcdFlashNvStorageFtwSpareSize) +  \
@@ -29,49 +41,6 @@ UINT32 mBoardRevision;
 
 #define ATFBase (FixedPcdGet64(PcdFdBaseAddress) + FixedPcdGet32(PcdFdSize))
 
-STATIC ARM_MEMORY_REGION_DESCRIPTOR RaspberryPiMemoryRegionDescriptor[] = {
-  {
-    /* Firmware Volume. */
-    FixedPcdGet64 (PcdFdBaseAddress), FixedPcdGet64 (PcdFdBaseAddress),
-    FixedPcdGet32 (PcdFdSize) - VariablesSize,
-    ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK
-  },
-  {
-    /* Variables Volume. */
-    VariablesBase, VariablesBase,
-    VariablesSize,
-    ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK
-  },
-  {
-    /* ATF reserved RAM. */
-    ATFBase, ATFBase,
-    FixedPcdGet64 (PcdSystemMemoryBase) - ATFBase,
-    ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK
-  },
-  {
-    /* System RAM. */
-    FixedPcdGet64 (PcdSystemMemoryBase), FixedPcdGet64 (PcdSystemMemoryBase),
-    0,
-    ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK
-  },
-  {
-    /* Reserved GPU RAM. */
-    0,
-    0,
-    0,
-    ARM_MEMORY_REGION_ATTRIBUTE_DEVICE
-  },
-  {
-    /* SOC registers. */
-    BCM2836_SOC_REGISTERS,
-    BCM2836_SOC_REGISTERS,
-    BCM2836_SOC_REGISTER_LENGTH,
-    ARM_MEMORY_REGION_ATTRIBUTE_DEVICE
-  },
-  {
-  }
-};
-
 /**
   Return the Virtual Memory Map of your platform
 
@@ -89,6 +58,11 @@ ArmPlatformGetVirtualMemoryMap (
   IN ARM_MEMORY_REGION_DESCRIPTOR** VirtualMemoryMap
   )
 {
+  UINTN                         Index = 0;
+  UINTN                         GpuIndex;
+  INT64                         ExtendedMemorySize;
+  ARM_MEMORY_REGION_DESCRIPTOR  *VirtualMemoryTable;
+
   // Early output of the info we got from VideoCore can prove valuable.
   DEBUG ((DEBUG_INFO, "Board Rev: 0x%lX\n", mBoardRevision));
   DEBUG ((DEBUG_INFO, "Base RAM : 0x%ll08X (Size 0x%ll08X)\n", mSystemMemoryBase, mSystemMemoryEnd + 1));
@@ -97,68 +71,120 @@ ArmPlatformGetVirtualMemoryMap (
   ASSERT (mSystemMemoryBase == 0);
   ASSERT (VirtualMemoryMap != NULL);
 
-  RaspberryPiMemoryRegionDescriptor[3].Length = mSystemMemoryEnd + 1 -
-    FixedPcdGet64 (PcdSystemMemoryBase);
-
-  RaspberryPiMemoryRegionDescriptor[4].PhysicalBase =
-    RaspberryPiMemoryRegionDescriptor[3].PhysicalBase +
-    RaspberryPiMemoryRegionDescriptor[3].Length;
-
-  RaspberryPiMemoryRegionDescriptor[4].VirtualBase =
-    RaspberryPiMemoryRegionDescriptor[4].PhysicalBase;
-
-  RaspberryPiMemoryRegionDescriptor[4].Length =
-    RaspberryPiMemoryRegionDescriptor[5].PhysicalBase -
-    RaspberryPiMemoryRegionDescriptor[4].PhysicalBase;
-
-  DEBUG ((DEBUG_INFO, "FD:\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[0].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[0].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[0].Length +
-    RaspberryPiMemoryRegionDescriptor[1].Length));
-
-  DEBUG ((DEBUG_INFO, "Variables (part of FD):\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[1].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[1].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[1].Length));
-
-  DEBUG ((DEBUG_INFO, "ATF RAM:\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[2].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[2].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[2].Length));
-
-  DEBUG ((DEBUG_INFO, "System RAM:\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[3].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[3].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[3].Length));
-
-  DEBUG ((DEBUG_INFO, "GPU Reserved:\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[4].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[4].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[4].Length));
-
-  DEBUG ((DEBUG_INFO, "SoC reserved:\n"
-    "\tPhysicalBase: 0x%lX\n"
-    "\tVirtualBase: 0x%lX\n"
-    "\tLength: 0x%lX\n",
-    RaspberryPiMemoryRegionDescriptor[5].PhysicalBase,
-    RaspberryPiMemoryRegionDescriptor[5].VirtualBase,
-    RaspberryPiMemoryRegionDescriptor[5].Length));
-
-  *VirtualMemoryMap = RaspberryPiMemoryRegionDescriptor;
+  VirtualMemoryTable = (ARM_MEMORY_REGION_DESCRIPTOR*)AllocatePages
+                       (EFI_SIZE_TO_PAGES (sizeof (ARM_MEMORY_REGION_DESCRIPTOR) *
+                       MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS));
+  if (VirtualMemoryTable == NULL) {
+    return;
+  }
+
+
+  // Firmware Volume
+  VirtualMemoryTable[Index].PhysicalBase    = FixedPcdGet64 (PcdFdBaseAddress);
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = FixedPcdGet32 (PcdFdSize) - VariablesSize;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_RESERVED_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"FD";
+
+  // Variable Volume
+  VirtualMemoryTable[Index].PhysicalBase    = VariablesBase;
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = VariablesSize;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_RUNTIME_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"FD Variables";
+
+  // TF-A reserved RAM
+  VirtualMemoryTable[Index].PhysicalBase    = ATFBase;
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = FixedPcdGet64 (PcdSystemMemoryBase) - ATFBase;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_RESERVED_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"TF-A RAM";
+
+  // Base System RAM
+  VirtualMemoryTable[Index].PhysicalBase    = FixedPcdGet64 (PcdSystemMemoryBase);
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = mSystemMemoryEnd + 1 - FixedPcdGet64 (PcdSystemMemoryBase);
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_BASIC_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"Base System RAM";
+
+  // GPU Reserved
+  GpuIndex = Index;
+  VirtualMemoryTable[Index].PhysicalBase    = mVideoCoreBase;
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = mVideoCoreSize;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_RESERVED_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"GPU Reserved";
+
+  // Compute the amount of extended RAM available on this platform
+  ExtendedMemorySize = SIZE_256MB;
+  ExtendedMemorySize <<= (mBoardRevision >> 20) & 0x07;
+  ExtendedMemorySize -= SIZE_1GB;
+  if (ExtendedMemorySize > 0) {
+    VirtualMemoryTable[Index].PhysicalBase  = FixedPcdGet64 (PcdExtendedMemoryBase);
+    VirtualMemoryTable[Index].VirtualBase   = VirtualMemoryTable[Index].PhysicalBase;
+    VirtualMemoryTable[Index].Length        = ExtendedMemorySize;
+    VirtualMemoryTable[Index].Attributes    = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+    VirtualMemoryInfo[Index].Type           = RPI_MEM_BASIC_REGION;
+    VirtualMemoryInfo[Index++].Name         = L"Extended System RAM";
+  }
+
+  // Extended SoC registers (PCIe, genet, ...)
+  if (BCM2711_SOC_REGISTERS > 0) {
+    VirtualMemoryTable[Index].PhysicalBase  = BCM2711_SOC_REGISTERS;
+    VirtualMemoryTable[Index].VirtualBase   = VirtualMemoryTable[Index].PhysicalBase;
+    VirtualMemoryTable[Index].Length        = BCM2711_SOC_REGISTER_LENGTH;
+    VirtualMemoryTable[Index].Attributes    = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+    VirtualMemoryInfo[Index].Type           = RPI_MEM_RESERVED_REGION;
+    VirtualMemoryInfo[Index++].Name         = L"SoC Reserved (27xx)";
+  }
+
+  // Base SoC registers
+  VirtualMemoryTable[Index].PhysicalBase    = BCM2836_SOC_REGISTERS;
+  // On the Pi 3 the SoC registers may overlap VideoCore => fix this
+  if (VirtualMemoryTable[GpuIndex].PhysicalBase + VirtualMemoryTable[GpuIndex].Length > VirtualMemoryTable[Index].PhysicalBase) {
+    VirtualMemoryTable[GpuIndex].Length = VirtualMemoryTable[Index].PhysicalBase - VirtualMemoryTable[GpuIndex].PhysicalBase;
+  }
+  VirtualMemoryTable[Index].VirtualBase     = VirtualMemoryTable[Index].PhysicalBase;
+  VirtualMemoryTable[Index].Length          = BCM2836_SOC_REGISTER_LENGTH;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  VirtualMemoryInfo[Index].Type             = RPI_MEM_RESERVED_REGION;
+  VirtualMemoryInfo[Index++].Name           = L"SoC Reserved (283x)";
+
+  // End of Table
+  VirtualMemoryTable[Index].PhysicalBase    = 0;
+  VirtualMemoryTable[Index].VirtualBase     = 0;
+  VirtualMemoryTable[Index].Length          = 0;
+  VirtualMemoryTable[Index++].Attributes    = (ARM_MEMORY_REGION_ATTRIBUTES)0;
+
+  ASSERT(Index <= MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS);
+
+  *VirtualMemoryMap = VirtualMemoryTable;
+  VirtualMemoryInfoInitialized = TRUE;
+}
+
+/**
+  Return additional memory info not populated by the above call.
+
+  This call should follow the one to ArmPlatformGetVirtualMemoryMap ().
+
+**/
+VOID
+RpiPlatformGetVirtualMemoryInfo (
+  IN RPI_MEMORY_REGION_INFO** MemoryInfo
+  )
+{
+  ASSERT (VirtualMemoryInfo != NULL);
+
+  if (!VirtualMemoryInfoInitialized) {
+    DEBUG ((DEBUG_ERROR,
+      "ArmPlatformGetVirtualMemoryMap must be called before RpiPlatformGetVirtualMemoryInfo.\n"));
+    return;
+  }
+
+  *MemoryInfo = VirtualMemoryInfo;
 }
diff --git a/Platform/RaspberryPi/RaspberryPi.dec b/Platform/RaspberryPi/RaspberryPi.dec
index 3e9171eccb13..c7e17350544a 100644
--- a/Platform/RaspberryPi/RaspberryPi.dec
+++ b/Platform/RaspberryPi/RaspberryPi.dec
@@ -42,6 +42,7 @@ [PcdsFixedAtBuild.common]
   gRaspberryPiTokenSpaceGuid.PcdNvStorageVariableBase|0x0|UINT32|0x00000005
   gRaspberryPiTokenSpaceGuid.PcdNvStorageFtwSpareBase|0x0|UINT32|0x00000006
   gRaspberryPiTokenSpaceGuid.PcdNvStorageFtwWorkingBase|0x0|UINT32|0x00000007
+  gRaspberryPiTokenSpaceGuid.PcdExtendedMemoryBase|0x0|UINT32|0x00000008
 
 [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
   gRaspberryPiTokenSpaceGuid.PcdCpuClock|0|UINT32|0x0000000d
-- 
2.21.0.windows.1