[Patch] AdvancedFeaturePkg/AcpiDebug: Add new AcpiDebug modules.

[Eric Dong <eric.dong@intel.com>]

Add new AcpiDebug modules which provide ACPI Debug feature.
Detail about this feature see the readme.txt in the patch.

Change-Id: Ib977ece46f3494301574b04af32282b99045f673
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Michael Kubacki <michael.a.kubacki@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Eric Dong <eric.dong@intel.com>
---
 .../AcpiDebug/AcpiDebug.asl                   | 109 ++++
 .../AdvancedFeaturePkg/AcpiDebug/AcpiDebug.c  | 485 ++++++++++++++++++
 .../AcpiDebug/AcpiDebugDxe.inf                |  63 +++
 .../AcpiDebug/AcpiDebugSmm.inf                |  65 +++
 .../AdvancedFeaturePkg/AcpiDebug/Readme.txt   |  47 ++
 .../AdvancedFeaturePkg/AdvancedFeaturePkg.dec |   6 +
 .../AdvancedFeaturePkg/AdvancedFeaturePkg.dsc |   2 +
 7 files changed, 777 insertions(+)
 create mode 100644 Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.asl
 create mode 100644 Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.c
 create mode 100644 Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugDxe.inf
 create mode 100644 Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugSmm.inf
 create mode 100644 Platform/Intel/AdvancedFeaturePkg/AcpiDebug/Readme.txt

diff --git a/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.asl b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.asl
new file mode 100644
index 0000000..62d2a1b
--- /dev/null
+++ b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.asl
@@ -0,0 +1,109 @@
+/** @file
+  Acpi Debug ASL code.
+
+Copyright (c) 2019, 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.
+
+**/
+
+DefinitionBlock (
+  "AcpiDebug.aml",
+  "SSDT",
+  2,
+  "Intel ",
+  "ADebTabl",
+  0x1000
+  )
+{
+  Scope(\)
+  {
+    //
+    // These pointers are patched during POST.
+    //
+    Name (DPTR, 0x80000000) // Address of Acpi debug memory buffer, fixed up during POST
+    Name (EPTR, 0x80000000) // End of Acpi debug memory buffer, fixed up during POST
+    Name (CPTR, 0x80000000) // Current pointer used as an index into the buffer(starts after the Acpi Debug head), fixed up during POST
+
+    //
+    // Use a Mutex to prevent multiple calls from simutaneously writing to the same memory.
+    //
+    Mutex (MMUT, 0)
+
+    //
+    // Operational region for SMI port access
+    //
+    OperationRegion (ADBP, SystemIO, 0xB2, 2)
+    Field (ADBP, ByteAcc, NoLock, Preserve)
+    {
+        B2PT, 8,
+        B3PT, 8,
+    }
+
+    //
+    // Write a string to a memory buffer
+    //
+    Method (MDBG, 1, Serialized)
+    {
+      OperationRegion (ADHD, SystemMemory, DPTR, 32) // Operation region for Acpi Debug buffer first 0x20 bytes
+      Field (ADHD, ByteAcc, NoLock, Preserve)
+      {
+        Offset (0x0),
+        ASIG, 128,      // 16 bytes is Signature
+        Offset (0x10),
+        ASIZ, 32,       // 4 bytes is buffer size
+        ACHP, 32,       // 4 bytes is current head pointer, normally is DPTR + 0x20,
+                        //   if there's SMM handler to print, then it's the starting of the info hasn't been printed yet.
+        ACTP, 32,       // 4 bytes is current tail pointer, is the same as CPTR
+        SMIN, 8,        // 1 byte of SMI Number for trigger callback
+        WRAP, 8,        // 1 byte of wrap status
+        SMMV, 8,        // 1 byte of SMM version status
+        TRUN, 8         // 1 byte of truncate status
+      }
+
+      Store (Acquire (MMUT, 1000), Local0) // save Acquire result so we can check for Mutex acquired
+      If (LEqual (Local0, Zero)) // check for Mutex acquired
+      {
+        OperationRegion (ABLK, SystemMemory, CPTR, 32) // Operation region to allow writes to ACPI debug buffer
+        Field (ABLK, ByteAcc, NoLock, Preserve)
+        {
+          Offset (0x0),
+          AAAA, 256 // 32 bytes is max size for string or data
+        }
+        ToHexString (Arg0, Local1) // convert argument to Hexadecimal String
+        Store (0, TRUN)
+        If (LGreaterEqual (SizeOf (Local1), 32))
+        {
+          Store (1, TRUN) // the input from ASL >= 32
+        }
+        Mid (Local1, 0, 31, AAAA) // extract the input to current buffer
+
+        Add (CPTR, 32, CPTR) // advance current pointer to next string location in memory buffer
+        If (LGreaterEqual (CPTR, EPTR) ) // check for end of 64kb Acpi debug buffer
+        {
+          Add (DPTR, 32, CPTR) // wrap around to beginning of buffer if the end has been reached
+          Store (1, WRAP)
+        }
+        Store (CPTR, ACTP)
+
+        If (SMMV)
+        {
+          //
+          // Triggle the SMI to print
+          //
+          Store (SMIN, B2PT)
+        }
+        Release (MMUT)
+      }
+
+      Return (Local0) // return error code indicating whether Mutex was acquired
+    }
+
+  } // End Scope
+} // End SSDT
+
diff --git a/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.c b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.c
new file mode 100644
index 0000000..ce9b59d
--- /dev/null
+++ b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebug.c
@@ -0,0 +1,485 @@
+/** @file
+  Smbios basic entry point.
+
+Copyright (c) 2019, 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 that 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 <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/DxeServicesLib.h>
+#include <Protocol/AcpiTable.h>
+#include <IndustryStandard/Acpi.h>
+
+#include <Protocol/SmmBase2.h>
+#include <Protocol/SmmEndOfDxe.h>
+#include <Protocol/SmmSwDispatch2.h>
+
+#define ACPI_DEBUG_STR      "INTEL ACPI DEBUG"
+
+//
+// ASL NAME structure
+//
+#pragma pack(1)
+typedef struct {
+  UINT8  NameOp;            // Byte [0]=0x08:NameOp.
+  UINT32 NameString;        // Byte [4:1]=Name of object.
+  UINT8  DWordPrefix;       // Byte [5]=0x0C:DWord Prefix.
+  UINT32 Value;             // 0 ; Value of named object.
+} NAME_LAYOUT;
+#pragma pack()
+
+#pragma pack(1)
+typedef struct {
+  UINT8  Signature[16];     // "INTEL ACPI DEBUG"
+  UINT32 BufferSize;        // Total size of Acpi Debug buffer including header structure
+  UINT32 Head;              // Current buffer pointer for SMM to print out
+  UINT32 Tail;              // Current buffer pointer for ASL to input
+  UINT8  SmiTrigger;        // Value to trigger the SMI via B2 port
+  UINT8  Wrap;              // If current Tail < Head
+  UINT8  SmmVersion;        // If SMM version
+  UINT8  Truncate;          // If the input from ASL > MAX_BUFFER_SIZE
+} ACPI_DEBUG_HEAD;
+#pragma pack()
+
+#define AD_SIZE             sizeof (ACPI_DEBUG_HEAD) // This is 0x20
+
+#define MAX_BUFFER_SIZE     32
+
+UINT32                      mBufferEnd = 0;
+ACPI_DEBUG_HEAD             *mAcpiDebug = NULL;
+
+EFI_SMM_SYSTEM_TABLE2       *mSmst = NULL;
+
+/**
+  Patch and load ACPI table.
+
+  @param[in] AcpiDebugAddress   Address of Acpi debug memory buffer.
+  @param[in] BufferIndex        Index that starts after the Acpi Debug head.
+  @param[in] BufferEnd          End of Acpi debug memory buffer.
+
+**/
+VOID
+PatchAndLoadAcpiTable (
+  IN ACPI_DEBUG_HEAD            *AcpiDebugAddress,
+  IN UINT32                     BufferIndex,
+  IN UINT32                     BufferEnd
+  )
+{
+  EFI_STATUS                    Status;
+  EFI_ACPI_TABLE_PROTOCOL       *AcpiTable;
+  UINTN                         Size;
+  EFI_ACPI_DESCRIPTION_HEADER   *TableHeader;
+  UINTN                         TableKey;
+  UINT8                         *CurrPtr;
+  UINT32                        *Signature;
+  NAME_LAYOUT                   *NamePtr;
+  UINT8                         UpdateCounter;
+
+  Status = GetSectionFromFv (
+             &gEfiCallerIdGuid,
+             EFI_SECTION_RAW,
+             0,
+             (VOID **) &TableHeader,
+             &Size
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // This is Acpi Debug SSDT. Acpi Debug should be enabled if we reach here so load the table.
+  //
+  ASSERT (((EFI_ACPI_DESCRIPTION_HEADER *) TableHeader)->OemTableId == SIGNATURE_64 ('A', 'D', 'e', 'b', 'T', 'a', 'b', 'l'));
+
+  //
+  // Patch some pointers for the ASL code before loading the SSDT.
+  //
+
+  //
+  // Count pointer updates, so we can stop after all three pointers are patched.
+  //
+  UpdateCounter = 1;
+  for (CurrPtr = (UINT8 *) TableHeader; CurrPtr <= ((UINT8 *) TableHeader + TableHeader->Length) && UpdateCounter < 4; CurrPtr++) {
+    Signature = (UINT32 *) (CurrPtr + 1);
+    //
+    // patch DPTR (address of Acpi debug memory buffer)
+    //
+    if ((*CurrPtr == AML_NAME_OP) && *Signature == SIGNATURE_32 ('D', 'P', 'T', 'R')) {
+      NamePtr = (NAME_LAYOUT *) CurrPtr;
+      NamePtr->Value  = (UINT32) (UINTN) AcpiDebugAddress;
+      UpdateCounter++;
+    }
+    //
+    // patch EPTR (end of Acpi debug memory buffer)
+    //
+    if ((*CurrPtr == AML_NAME_OP) && *Signature == SIGNATURE_32 ('E', 'P', 'T', 'R')) {
+      NamePtr = (NAME_LAYOUT *) CurrPtr;
+      NamePtr->Value  = BufferEnd;
+      UpdateCounter++;
+    }
+    //
+    // patch CPTR (used as an index that starts after the Acpi Debug head)
+    //
+    if ((*CurrPtr == AML_NAME_OP) && *Signature == SIGNATURE_32 ('C', 'P', 'T', 'R')) {
+      NamePtr = (NAME_LAYOUT *) CurrPtr;
+      NamePtr->Value  = BufferIndex;
+      UpdateCounter++;
+    }
+  }
+
+  //
+  // Add the table
+  //
+  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **)&AcpiTable);
+  ASSERT_EFI_ERROR (Status);
+
+  TableKey = 0;
+  Status = AcpiTable->InstallAcpiTable (
+                        AcpiTable,
+                        TableHeader,
+                        Size,
+                        &TableKey
+                        );
+  ASSERT_EFI_ERROR (Status);
+
+  gBS->FreePool (TableHeader);
+  return ;
+}
+
+/**
+  Allocate Acpi Debug memory.
+
+  @param[out] BufferSize    Pointer to Acpi debug memory buffer size.
+
+  @return Address of Acpi debug memory buffer. 0 if PcdAcpiDebugEnable is FALSE.
+
+**/
+EFI_PHYSICAL_ADDRESS
+AllocateAcpiDebugMemory (
+  OUT UINT32           *BufferSize
+  )
+{
+  EFI_STATUS           Status;
+  EFI_PHYSICAL_ADDRESS AcpiDebugAddress;
+
+  AcpiDebugAddress = 0;
+  *BufferSize = 0;
+
+  if (PcdGetBool (PcdAcpiDebugEnable)) {
+    //
+    // Reserve memory to store Acpi Debug data.
+    //
+    AcpiDebugAddress = 0xFFFFFFFF;
+    Status = gBS->AllocatePages (
+                    AllocateMaxAddress,
+                    EfiReservedMemoryType,
+                    EFI_SIZE_TO_PAGES (PcdGet32 (PcdAcpiDebugBufferSize)),
+                    &AcpiDebugAddress
+                    );
+    ASSERT_EFI_ERROR(Status);
+
+    DEBUG ((DEBUG_INFO, "AcpiDebugAddress - 0x%08x\n", AcpiDebugAddress));
+
+    Status = PcdSet32S (PcdAcpiDebugAddress, (UINT32) AcpiDebugAddress);
+    ASSERT_EFI_ERROR(Status);
+    *BufferSize = PcdGet32 (PcdAcpiDebugBufferSize);
+  }
+
+  return AcpiDebugAddress;
+}
+
+/**
+  Acpi Debug EndOfDxe notification.
+
+  @param[in] Event      Event whose notification function is being invoked.
+  @param[in] Context    Pointer to the notification function's context.
+
+**/
+VOID
+EFIAPI
+AcpiDebugEndOfDxeNotification (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  UINT32        BufferSize;
+  UINT32        BufferIndex;
+
+  mAcpiDebug = (ACPI_DEBUG_HEAD *) (UINTN) AllocateAcpiDebugMemory (&BufferSize);
+  if (mAcpiDebug != NULL) {
+    //
+    // Init ACPI DEBUG buffer to lower case 'x'.
+    //
+    SetMem ((VOID *) mAcpiDebug, BufferSize, 0x78);
+
+    //
+    // Clear header of AD_SIZE bytes.
+    //
+    ZeroMem ((VOID *) mAcpiDebug, AD_SIZE);
+
+    //
+    // Write a signature to the first line of the buffer, "INTEL ACPI DEBUG".
+    //
+    CopyMem ((VOID *) mAcpiDebug, ACPI_DEBUG_STR, sizeof (ACPI_DEBUG_STR) - 1);
+
+    BufferIndex = (UINT32) (UINTN) mAcpiDebug;
+    mBufferEnd = BufferIndex + BufferSize;
+
+    //
+    // Leave the Index after the Acpi Debug head.
+    //
+    BufferIndex += AD_SIZE;
+
+    //
+    // Patch and Load the SSDT ACPI Tables.
+    //
+    PatchAndLoadAcpiTable (mAcpiDebug, BufferIndex, mBufferEnd);
+
+    mAcpiDebug->Head = BufferIndex;
+    mAcpiDebug->Tail = BufferIndex;
+    mAcpiDebug->BufferSize = BufferSize;
+  }
+
+  //
+  // Close event, so it will not be invoked again.
+  //
+  gBS->CloseEvent (Event);
+
+  return ;
+}
+
+/**
+  Initialize ACPI Debug.
+
+  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
+  @param[in] SystemTable    A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The driver initializes correctly.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeAcpiDebugDxe (
+  IN EFI_HANDLE         ImageHandle,
+  IN EFI_SYSTEM_TABLE   *SystemTable
+  )
+{
+  EFI_STATUS            Status;
+  EFI_EVENT             EndOfDxeEvent;
+
+  //
+  // Register EndOfDxe notification
+  // that point could ensure the Acpi Debug related PCDs initialized.
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  AcpiDebugEndOfDxeNotification,
+                  NULL,
+                  &gEfiEndOfDxeEventGroupGuid,
+                  &EndOfDxeEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Software SMI callback for ACPI Debug which is called from ACPI method.
+
+  @param[in]      DispatchHandle    The unique handle assigned to this handler by SmiHandlerRegister().
+  @param[in]      Context           Points to an optional handler context which was specified when the
+                                    handler was registered.
+  @param[in, out] CommBuffer        A pointer to a collection of data in memory that will
+                                    be conveyed from a non-SMM environment into an SMM environment.
+  @param[in, out] CommBufferSize    The size of the CommBuffer.
+
+  @retval EFI_SUCCESS               The interrupt was handled successfully.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiDebugSmmCallback (
+  IN EFI_HANDLE     DispatchHandle,
+  IN CONST VOID     *Context,
+  IN OUT VOID       *CommBuffer,
+  IN OUT UINTN      *CommBufferSize
+  )
+{
+  UINT8             Buffer[MAX_BUFFER_SIZE];
+
+  //
+  // Validate the fields in mAcpiDebug to ensure there is no harm to SMI handler.
+  // mAcpiDebug is below 4GB and the start address of whole buffer.
+  //
+  if ((mAcpiDebug->BufferSize != (mBufferEnd - (UINT32) (UINTN) mAcpiDebug)) ||
+      (mAcpiDebug->Head < (UINT32) ((UINTN) mAcpiDebug + AD_SIZE)) ||
+      (mAcpiDebug->Head > mBufferEnd) ||
+      (mAcpiDebug->Tail < (UINT32) ((UINTN) mAcpiDebug + AD_SIZE)) ||
+      (mAcpiDebug->Tail > mBufferEnd)) {
+    //
+    // If some fields in mAcpiDebug are invaid, return directly.
+    //
+    return EFI_SUCCESS;
+  }
+
+  if (!(BOOLEAN)mAcpiDebug->Wrap && ((mAcpiDebug->Head >= (UINT32) ((UINTN) mAcpiDebug + AD_SIZE))
+    && (mAcpiDebug->Head < mAcpiDebug->Tail))){
+    //
+    // If curent ----- buffer + 020
+    //                 ...
+    //                 ... Head
+    //                 ... Data for SMM print
+    //                 ... Tail
+    //                 ... Vacant for ASL input
+    //           ----- buffer end
+    //
+    // skip NULL block
+    //
+    while ((*(CHAR8 *) (UINTN) mAcpiDebug->Head == '\0') && (mAcpiDebug->Head < mAcpiDebug->Tail)) {
+      mAcpiDebug->Head ++;
+    }
+
+    if (mAcpiDebug->Head < mAcpiDebug->Tail){
+      ZeroMem (Buffer, MAX_BUFFER_SIZE);
+      AsciiStrnCpyS ((CHAR8 *) Buffer, MAX_BUFFER_SIZE, (CHAR8 *) (UINTN) mAcpiDebug->Head, MAX_BUFFER_SIZE - 1);
+
+      DEBUG ((DEBUG_INFO | DEBUG_ERROR, "%a%a\n", Buffer, (BOOLEAN)mAcpiDebug->Truncate ? "..." : ""));
+      mAcpiDebug->Head += MAX_BUFFER_SIZE;
+
+      if (mAcpiDebug->Head >= (mAcpiDebug->Tail)){
+        //
+        // When head == tail, we do nothing in handler.
+        //
+        mAcpiDebug->Head = mAcpiDebug->Tail;
+      }
+    }
+  } else if ((BOOLEAN)mAcpiDebug->Wrap && ((mAcpiDebug->Head > mAcpiDebug->Tail)
+    && (mAcpiDebug->Head < (UINT32) ((UINTN) mAcpiDebug + mAcpiDebug->BufferSize)))){
+    //
+    // If curent ----- buffer + 020
+    //                 ... Tail
+    //                 ... Vacant for ASL input
+    //                 ... Head
+    //                 ... Data for SMM print
+    //           ----- buffer end
+    //
+    while((*(CHAR8 *) (UINTN) mAcpiDebug->Head == '\0') && (mAcpiDebug->Head < (UINT32) ((UINTN) mAcpiDebug + mAcpiDebug->BufferSize))) {
+      mAcpiDebug->Head ++;
+    }
+    if (mAcpiDebug->Head < (UINT32) ((UINTN) mAcpiDebug + mAcpiDebug->BufferSize)){
+      ZeroMem (Buffer, MAX_BUFFER_SIZE);
+      AsciiStrnCpyS ((CHAR8 *) Buffer, MAX_BUFFER_SIZE, (CHAR8 *) (UINTN) mAcpiDebug->Head, MAX_BUFFER_SIZE - 1);
+      DEBUG ((DEBUG_INFO | DEBUG_ERROR, "%a%a\n", Buffer, (BOOLEAN)mAcpiDebug->Truncate ? "..." : ""));
+      mAcpiDebug->Head += MAX_BUFFER_SIZE;
+
+      if (mAcpiDebug->Head >= (UINT32) ((UINTN) mAcpiDebug + mAcpiDebug->BufferSize)) {
+        //
+        // We met end of buffer.
+        //
+        mAcpiDebug->Wrap = 0;
+        mAcpiDebug->Head = (UINT32) ((UINTN) mAcpiDebug + AD_SIZE);
+      }
+    }
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Acpi Debug SmmEndOfDxe notification.
+
+  @param[in] Protocol   Points to the protocol's unique identifier.
+  @param[in] Interface  Points to the interface instance.
+  @param[in] Handle     The handle on which the interface was installed.
+
+  @retval EFI_SUCCESS   Notification runs successfully.
+
+ **/
+EFI_STATUS
+EFIAPI
+AcpiDebugSmmEndOfDxeNotification (
+  IN CONST EFI_GUID     *Protocol,
+  IN VOID               *Interface,
+  IN EFI_HANDLE         Handle
+  )
+{
+  EFI_STATUS                        Status;
+  EFI_SMM_SW_DISPATCH2_PROTOCOL     *SwDispatch;
+  EFI_SMM_SW_REGISTER_CONTEXT       SwContext;
+  EFI_HANDLE                        SwHandle;
+
+  AcpiDebugEndOfDxeNotification (NULL, NULL);
+
+  if (mAcpiDebug != NULL) {
+    //
+    // Get the Sw dispatch protocol and register SMI callback function.
+    //
+    SwDispatch = NULL;
+    Status = mSmst->SmmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID **) &SwDispatch);
+    ASSERT_EFI_ERROR (Status);
+    SwContext.SwSmiInputValue = (UINTN) -1;
+    Status = SwDispatch->Register (SwDispatch, AcpiDebugSmmCallback, &SwContext, &SwHandle);
+    ASSERT_EFI_ERROR (Status);
+    mAcpiDebug->SmiTrigger = (UINT8) SwContext.SwSmiInputValue;
+    mAcpiDebug->SmmVersion = 1;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Initialize ACPI Debug.
+
+  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
+  @param[in] SystemTable    A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The driver initializes correctly.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeAcpiDebugSmm (
+  IN EFI_HANDLE         ImageHandle,
+  IN EFI_SYSTEM_TABLE   *SystemTable
+  )
+{
+  EFI_STATUS                Status;
+  VOID                      *Registration;
+  EFI_SMM_BASE2_PROTOCOL    *SmmBase2;
+  BOOLEAN                   InSmm;
+
+  Status = gBS->LocateProtocol (&gEfiSmmBase2ProtocolGuid, NULL, (VOID **) &SmmBase2);
+  ASSERT_EFI_ERROR (Status);
+  Status = SmmBase2->InSmm (SmmBase2, &InSmm);
+  ASSERT_EFI_ERROR (Status);
+  ASSERT (InSmm);
+  Status = SmmBase2->GetSmstLocation (SmmBase2, &mSmst);
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Register SmmEndOfDxe notification
+  // that point could ensure the Acpi Debug related PCDs initialized.
+  //
+  Registration = NULL;
+  Status = mSmst->SmmRegisterProtocolNotify (
+                    &gEfiSmmEndOfDxeProtocolGuid,
+                    AcpiDebugSmmEndOfDxeNotification,
+                    &Registration
+                    );
+  ASSERT_EFI_ERROR (Status);
+
+  return EFI_SUCCESS;
+}
+
diff --git a/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugDxe.inf b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugDxe.inf
new file mode 100644
index 0000000..edfca5e
--- /dev/null
+++ b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugDxe.inf
@@ -0,0 +1,63 @@
+### @file
+# Component description file for Smbios Misc module.
+#
+# Copyright (c) 2019, 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                      = AcpiDebugDxe
+  FILE_GUID                      = EC98FF95-242C-4513-B1BC-69FA24111C58
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = InitializeAcpiDebugDxe
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 IPF
+#
+
+[LibraryClasses]
+  BaseLib
+  BaseMemoryLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  DebugLib
+  PcdLib
+  DxeServicesLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  AdvancedFeaturePkg/AdvancedFeaturePkg.dec
+
+[Pcd]
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugEnable      ## CONSUMES
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugBufferSize  ## CONSUMES
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugAddress     ## PRODUCES
+
+[Sources]
+  AcpiDebug.c
+  AcpiDebug.asl
+
+[Protocols]
+  gEfiAcpiTableProtocolGuid         ## CONSUMES
+  gEfiSmmBase2ProtocolGuid          ## CONSUMES # only for SMM version
+  gEfiSmmSwDispatch2ProtocolGuid    ## CONSUMES # only for SMM version
+  gEfiSmmEndOfDxeProtocolGuid       ## NOTIFY # only for SMM version
+
+[Guids]
+  gEfiEndOfDxeEventGroupGuid        ## CONSUMES ## Event
+
+[Depex]
+  gEfiAcpiTableProtocolGuid
+
diff --git a/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugSmm.inf b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugSmm.inf
new file mode 100644
index 0000000..f0cbfb1
--- /dev/null
+++ b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/AcpiDebugSmm.inf
@@ -0,0 +1,65 @@
+### @file
+# Component description file for Smbios Misc module.
+#
+# Copyright (c) 2019, 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                      = AcpiDebugSmm
+  FILE_GUID                      = 9069C144-0A7E-41ef-9C07-418BCA9BF939
+  MODULE_TYPE                    = DXE_SMM_DRIVER
+  VERSION_STRING                 = 1.0
+  PI_SPECIFICATION_VERSION       = 0x0001000A
+  ENTRY_POINT                    = InitializeAcpiDebugSmm
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 IPF
+#
+
+[LibraryClasses]
+  BaseLib
+  BaseMemoryLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  DebugLib
+  PcdLib
+  DxeServicesLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  AdvancedFeaturePkg/AdvancedFeaturePkg.dec
+
+[Pcd]
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugEnable      ## CONSUMES
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugBufferSize  ## CONSUMES
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugAddress     ## PRODUCES
+
+[Sources]
+  AcpiDebug.c
+  AcpiDebug.asl
+
+[Protocols]
+  gEfiAcpiTableProtocolGuid         ## CONSUMES
+  gEfiSmmBase2ProtocolGuid          ## CONSUMES
+  gEfiSmmSwDispatch2ProtocolGuid    ## CONSUMES
+  gEfiSmmEndOfDxeProtocolGuid       ## NOTIFY
+
+[Guids]
+  gEfiEndOfDxeEventGroupGuid        ## CONSUMES ## Event # only for DXE version
+
+[Depex]
+  gEfiAcpiTableProtocolGuid AND
+  gEfiSmmBase2ProtocolGuid AND
+  gEfiSmmSwDispatch2ProtocolGuid
diff --git a/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/Readme.txt b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/Readme.txt
new file mode 100644
index 0000000..65ed5b3
--- /dev/null
+++ b/Platform/Intel/AdvancedFeaturePkg/AcpiDebug/Readme.txt
@@ -0,0 +1,47 @@
+ACPI Debug feature - an alternative to Port 80 and WinDBG
+
+How it works:
+  Acpi Debug does this:
+  Opens a 64kb memory buffer during POST.
+  Patches the buffer address in SSDT ASL code.
+  Displays the address in SETUP for user reference.
+  Write strings or numbers to the buffer from ASL code with the ADBG method.
+
+How to use it:
+  Enable the feature in SETUP->Advanced->ACPI DEBUG, and confirm gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugEnable is TRUE.
+  The ACPI ASL code must be instrumented with the debug method.
+  Strings up to 32 characters (shorter strings will be padded with Zero's, longer strings will be truncated)
+  Examples:
+    ADBG("This is a test.")
+    ADBG(Arg0)
+
+  DXE version: The bios engineer will read the strings from the buffer on the target machine with read/write memory utility.
+  SMM version: Check debug serial that would show debug strings.
+
+  Sample code for ADBG:
+    External (MDBG, MethodObj)
+    Method (ADBG, 1, Serialized)
+    {
+      If (CondRefOf (MDBG)) // Check if ACPI Debug SSDT is loaded
+      {
+        Return (MDBG (Arg0))
+      }
+      Return (0)
+    }
+
+  Sample code for Setup Pages
+    oneof varid   = SETUP_DATA.AcpiDebug,
+      prompt      = STRING_TOKEN(STR_ACPI_DEBUG_PROMPT),
+      help        = STRING_TOKEN(STR_ACPI_DEBUG_HELP),
+      option text = STRING_TOKEN(STR_DISABLED), value = 0, flags = DEFAULT | MANUFACTURING | RESET_REQUIRED;
+      option text = STRING_TOKEN(STR_ENABLED), value = 1, flags = RESET_REQUIRED;
+    endoneof;
+
+    suppressif ideqval SETUP_DATA.AcpiDebug == 0;
+      text
+        help  = STRING_TOKEN(STR_ACPI_DEBUG_ADDRESS_HELP),
+        text  = STRING_TOKEN(STR_ACPI_DEBUG_ADDRESS_NAME),
+        text  = STRING_TOKEN(STR_ACPI_DEBUG_ADDRESS_VALUE),
+        flags = 0,
+        key   = 0;
+    endif;
\ No newline at end of file
diff --git a/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dec b/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dec
index fb27647..e09facd 100644
--- a/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dec
+++ b/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dec
@@ -146,11 +146,17 @@ gAdvancedFeaturePkgTokenSpaceGuid         =  {0xa8514688, 0x6693, 0x4ab5, {0xaa,
 
 [PcdsFixedAtBuild]
   gAdvancedFeaturePkgTokenSpaceGuid.PcdMaxSOLChannels|0x3|UINT8|0x40000009
+  ## This PCD specifies AcpiDebug feature is enable/disable.
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugEnable|FALSE|BOOLEAN|0x00000012
+  ## This PCD specifies AcpiDebug buffer size.
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugBufferSize|0x10000|UINT32|0x00000013
 
 [PcdsDynamic, PcdsDynamicEx]
   gAdvancedFeaturePkgTokenSpaceGuid.PcdIpmiIoBaseAddress|0xCA2|UINT16|0x90000022
   gAdvancedFeaturePkgTokenSpaceGuid.PcdFRB2EnabledFlag|TRUE|BOOLEAN|0x10000030
   gAdvancedFeaturePkgTokenSpaceGuid.PcdFRBTimeoutValue|360|UINT16|0x10000040
+  ## This PCD specifies AcpiDebug buffer address
+  gAdvancedFeaturePkgTokenSpaceGuid.PcdAcpiDebugAddress|0|UINT32|0x00000014
 
 [PcdsFeatureFlag]
   gAdvancedFeaturePkgTokenSpaceGuid.PcdNetworkEnable          |FALSE|BOOLEAN|0xF00000A1
diff --git a/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dsc b/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dsc
index 4fcf9ac..1ec1b13 100644
--- a/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dsc
+++ b/Platform/Intel/AdvancedFeaturePkg/AdvancedFeaturePkg.dsc
@@ -155,3 +155,5 @@
   AdvancedFeaturePkg/Ipmi/BmcElog/BmcElog.inf
   AdvancedFeaturePkg/Ipmi/BmcAcpi/BmcAcpi.inf
 
+  AdvancedFeaturePkg/AcpiDebug/AcpiDebugDxe.inf
+  AdvancedFeaturePkg/AcpiDebug/AcpiDebugSmm.inf
\ No newline at end of file
-- 
2.21.0.windows.1