[PATCH] EmbeddedPkg: add DT platform driver to select between DT and ACPI

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

As a follow up to the changes proposed by Laszlo to make ACPI and DT
mutually exclusive on ArmVirtQemu, this patch proposes a DT platform
DXE driver that either installs the NULL protocol PlatformHasAcpiGuid,
or installs the FV embedded DTB binary as a configuration table under
the appropriate GUID, depending on a preference setting recorded as
a UEFI variable, and configurable via a HII screen. This is intended
for bare metal platforms.

The DTB binary can be embedded in the firmware image by adding the
following to the platform .fdf file:

  FILE FREEFORM = 25462CDA-221F-47DF-AC1D-259CFAA4E326 {
    SECTION RAW = SomePkg/path/to/foo.dtb
  }

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---

This depends on patch 4/12 of Laszlo's series
https://lists.01.org/pipermail/edk2-devel/2017-March/009004.html

Note to Marcin: the setup page was only tested with the generic BDS, not
the Intel BDS. This shouldn't matter in practice, since they should both
implement the prerequisite protocols, but moving to the generic BDS is
probably a good idea regardless.

 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c   | 211 ++++++++++++++++++++
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.h   |  29 +++
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf |  70 +++++++
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.uni |  27 +++
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.vfr |  57 ++++++
 EmbeddedPkg/EmbeddedPkg.dec                         |   6 +
 EmbeddedPkg/Include/Guid/DtPlatformDefaultDtbFile.h |  23 +++
 EmbeddedPkg/Include/Guid/DtPlatformFormSet.h        |  23 +++
 8 files changed, 446 insertions(+)

diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c
new file mode 100644
index 000000000000..d37a01e51d7d
--- /dev/null
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c
@@ -0,0 +1,211 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
+*
+*  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 <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+#include <Library/UefiHiiServicesLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/HiiLib.h>
+#include <Library/PcdLib.h>
+#include <Library/DxeServicesLib.h>
+
+#include "DtPlatformDxe.h"
+
+extern  UINT8                     DtPlatformHiiBin[];
+extern  UINT8                     DtPlatformDxeStrings[];
+
+typedef struct {
+  VENDOR_DEVICE_PATH              VendorDevicePath;
+  EFI_DEVICE_PATH_PROTOCOL        End;
+} HII_VENDOR_DEVICE_PATH;
+
+STATIC HII_VENDOR_DEVICE_PATH     mDtPlatformDxeVendorDevicePath = {
+  {
+    {
+      HARDWARE_DEVICE_PATH,
+      HW_VENDOR_DP,
+      {
+        (UINT8) (sizeof (VENDOR_DEVICE_PATH)),
+        (UINT8) ((sizeof (VENDOR_DEVICE_PATH)) >> 8)
+      }
+    },
+    DT_PLATFORM_FORMSET_GUID
+  },
+  {
+    END_DEVICE_PATH_TYPE,
+    END_ENTIRE_DEVICE_PATH_SUBTYPE,
+    {
+      (UINT8) (END_DEVICE_PATH_LENGTH),
+      (UINT8) ((END_DEVICE_PATH_LENGTH) >> 8)
+    }
+  }
+};
+
+STATIC
+EFI_STATUS
+InstallHiiPages (
+  VOID
+  )
+{
+  EFI_STATUS                      Status;
+  EFI_HII_HANDLE                  HiiHandle;
+  EFI_HANDLE                      DriverHandle;
+
+  DriverHandle = NULL;
+  Status = gBS->InstallMultipleProtocolInterfaces (&DriverHandle,
+                  &gEfiDevicePathProtocolGuid,
+                  &mDtPlatformDxeVendorDevicePath,
+                  NULL);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  HiiHandle = HiiAddPackages (&gDtPlatformFormSetGuid,
+                              DriverHandle,
+                              DtPlatformDxeStrings,
+                              DtPlatformHiiBin,
+                              NULL);
+
+  if (HiiHandle == NULL) {
+    gBS->UninstallMultipleProtocolInterfaces (&DriverHandle,
+                  &gEfiDevicePathProtocolGuid,
+                  &mDtPlatformDxeVendorDevicePath,
+                  NULL);
+    return EFI_OUT_OF_RESOURCES;
+  }
+  return EFI_SUCCESS;
+}
+
+/**
+  The entry point for DtPlatformDxe driver.
+
+  @param[in] ImageHandle     The image handle of the driver.
+  @param[in] SystemTable     The system table.
+
+  @retval EFI_ALREADY_STARTED     The driver already exists in system.
+  @retval EFI_OUT_OF_RESOURCES    Fail to execute entry point due to lack of
+                                  resources.
+  @retval EFI_SUCCES              All the related protocols are installed on
+                                  the driver.
+
+**/
+EFI_STATUS
+EFIAPI
+DtPlatformDxeEntryPoint (
+  IN EFI_HANDLE                   ImageHandle,
+  IN EFI_SYSTEM_TABLE             *SystemTable
+  )
+{
+  EFI_STATUS                      Status;
+  EFI_HANDLE                      DriverHandle;
+  DT_ACPI_VARSTORE_DATA           DtAcpiPref;
+  UINTN                           BufferSize;
+  VOID                            *Dtb;
+  UINTN                           DtbSize;
+  VOID                            *DtbCopy;
+
+  //
+  // Check whether a DTB blob is included in the firmware image.
+  //
+  Dtb = NULL;
+  Status = GetSectionFromAnyFv (&gDtPlatformDefaultDtbFileGuid,
+             EFI_SECTION_RAW, 0, &Dtb, &DtbSize);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_WARN, "%a: no DTB blob found, defaulting to ACPI\n",
+      __FUNCTION__));
+    DtAcpiPref.Pref = DT_ACPI_SELECT_ACPI;
+  } else {
+    //
+    // Get the current ACPI/DT preference from the AcpiDtPref variable.
+    //
+    BufferSize = sizeof (DtAcpiPref);
+    Status = gRT->GetVariable(L"DtAcpiPref", &gDtPlatformFormSetGuid, NULL,
+                    &BufferSize, &DtAcpiPref);
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_WARN, "%a: no DT/ACPI preference found, defaulting to DT\n",
+        __FUNCTION__));
+      DtAcpiPref.Pref = DT_ACPI_SELECT_DT;
+    }
+  }
+
+  if (!EFI_ERROR (Status) &&
+      DtAcpiPref.Pref != DT_ACPI_SELECT_ACPI &&
+      DtAcpiPref.Pref != DT_ACPI_SELECT_DT) {
+    DEBUG ((DEBUG_WARN, "%a: illegal value for DtAcpiPref, defaulting to DT\n",
+      __FUNCTION__));
+    DtAcpiPref.Pref = DT_ACPI_SELECT_DT;
+    Status = EFI_INVALID_PARAMETER; // trigger setvar below
+  }
+
+  //
+  // Write the newly selected default value back to the variable store.
+  //
+  if (EFI_ERROR (Status)) {
+    Status = gRT->SetVariable(L"DtAcpiPref", &gDtPlatformFormSetGuid,
+                    EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
+                    sizeof (DtAcpiPref), &DtAcpiPref);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  }
+
+  if (DtAcpiPref.Pref == DT_ACPI_SELECT_ACPI) {
+    //
+    // ACPI was selected: install the gEdkiiPlatformHasAcpiGuid GUID as a
+    // NULL protocol to unlock dispatch of ACPI related drivers.
+    //
+    DriverHandle = NULL;
+    Status = gBS->InstallMultipleProtocolInterfaces (&DriverHandle,
+                    gEdkiiPlatformHasAcpiGuid, NULL, NULL);
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_ERROR,
+        "%a: failed to install gEdkiiPlatformHasAcpiGuid as a protocol\n",
+        __FUNCTION__));
+      return Status;
+    }
+  } else if (DtAcpiPref.Pref == DT_ACPI_SELECT_DT) {
+    //
+    // DT was selected: copy the blob into newly allocated memory and install
+    // a reference to it as the FDT configuration table.
+    //
+    DtbCopy = AllocateCopyPool (DtbSize, Dtb);
+    if (DtbCopy == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+    Status = gBS->InstallConfigurationTable (&gFdtTableGuid, DtbCopy);
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_ERROR, "%a: failed to install FDT configuration table\n",
+        __FUNCTION__));
+      FreePool (DtbCopy);
+      return Status;
+    }
+  } else {
+    ASSERT (FALSE);
+  }
+
+  //
+  // No point in installing the HII pages if ACPI is the only description
+  // we have
+  //
+  if (Dtb == NULL) {
+    return EFI_SUCCESS;
+  }
+
+  return InstallHiiPages ();
+}
diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.h b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.h
new file mode 100644
index 000000000000..2fb05a0336b6
--- /dev/null
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.h
@@ -0,0 +1,29 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro Limited. All rights reserved.
+*
+*  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 __DT_PLATFORM_DXE_H__
+#define __DT_PLATFORM_DXE_H__
+
+#include <Guid/HiiPlatformSetupFormset.h>
+#include <Guid/DtPlatformFormSet.h>
+
+#define DT_ACPI_SELECT_DT       0x0
+#define DT_ACPI_SELECT_ACPI     0x1
+
+typedef struct {
+  UINT8         Pref;
+  UINT8         Reserved[3];
+} DT_ACPI_VARSTORE_DATA;
+
+#endif
diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
new file mode 100644
index 000000000000..d0a99c4ecd55
--- /dev/null
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
@@ -0,0 +1,70 @@
+## @file
+#
+#  Copyright (c) 2017, Linaro, Ltd. 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               = 0x00010019
+  BASE_NAME                 = DtPlatformDxe
+  FILE_GUID                 = FC097B3C-2EBD-4A75-A3DA-121DCAB365CC
+  MODULE_TYPE               = DXE_DRIVER
+  VERSION_STRING            = 1.0
+  ENTRY_POINT               = DtPlatformDxeEntryPoint
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES      = IA32 X64 ARM AARCH64
+#
+
+[Sources]
+  DtPlatformDxe.c
+  DtPlatformHii.vfr
+  DtPlatformHii.uni
+
+[Packages]
+  EmbeddedPkg/EmbeddedPkg.dec
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  UefiLib
+  UefiDriverEntryPoint
+  UefiBootServicesTableLib
+  UefiRuntimeServicesTableLib
+  UefiHiiServicesLib
+  MemoryAllocationLib
+  HiiLib
+  PcdLib
+  DxeServicesLib
+
+[Guids]
+  gEfiIfrTianoGuid                               ## PRODUCES            ## GUID  # HII opcode
+  ## PRODUCES                ## HII
+  ## CONSUMES                ## HII
+  gDtPlatformFormSetGuid
+  gEfiVirtualDiskGuid                            ## SOMETIMES_CONSUMES  ## GUID
+  gEfiFileInfoGuid                               ## SOMETIMES_CONSUMES  ## GUID  # Indicate the information type
+  gEdkiiPlatformHasAcpiGuid
+  gDtPlatformDefaultDtbFileGuid
+  gFdtTableGuid
+
+[Protocols]
+  gEfiHiiConfigAccessProtocolGuid                ## PRODUCES
+
+[Depex]
+  gEfiHiiDatabaseProtocolGuid         AND
+  gEfiVariableArchProtocolGuid        AND
+  gEfiVariableWriteArchProtocolGuid
diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.uni b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.uni
new file mode 100644
index 000000000000..f84069261486
--- /dev/null
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.uni
@@ -0,0 +1,27 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
+*
+*  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.
+*
+**/
+
+#langdef en-US  "English"
+
+#string STR_FORM_SET_TITLE             #language en-US "O/S Hardware Description Selection"
+#string STR_FORM_SET_TITLE_HELP        #language en-US "Press <Enter> to choose between ACPI and DT hardware descriptions."
+
+#string STR_MAIN_FORM_TITLE            #language en-US "O/S Hardware Description Selection"
+#string STR_RAM_DISK_NULL_STRING       #language en-US ""
+
+#string STR_DT_ACPI_SELECT_PROMPT      #language en-US "O/S Hardware Description"
+#string STR_DT_ACPI_SELECT_HELP        #language en-US "Select the hardware description that will be exposed to the O/S."
+
+#string STR_DT_ACPI_SELECT_DT          #language en-US "Device Tree"
+#string STR_DT_ACPI_SELECT_ACPI        #language en-US "ACPI"
diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.vfr b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.vfr
new file mode 100644
index 000000000000..d0c5463dd8f0
--- /dev/null
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformHii.vfr
@@ -0,0 +1,57 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
+*
+*  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 "DtPlatformDxe.h"
+
+//
+// EFI Variable attributes
+//
+#define EFI_VARIABLE_NON_VOLATILE       0x00000001
+#define EFI_VARIABLE_BOOTSERVICE_ACCESS 0x00000002
+#define EFI_VARIABLE_RUNTIME_ACCESS     0x00000004
+#define EFI_VARIABLE_READ_ONLY          0x00000008
+
+formset
+  guid      = DT_PLATFORM_FORMSET_GUID,
+  title     = STRING_TOKEN(STR_FORM_SET_TITLE),
+  help      = STRING_TOKEN(STR_FORM_SET_TITLE_HELP),
+  classguid = EFI_HII_PLATFORM_SETUP_FORMSET_GUID,
+
+  efivarstore DT_ACPI_VARSTORE_DATA,
+    attribute = EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_NON_VOLATILE,  // EFI variable attributes
+    name  = AcpiDtPref,
+    guid  = DT_PLATFORM_FORMSET_GUID;
+
+  form formid = 0x1000,
+    title  = STRING_TOKEN(STR_MAIN_FORM_TITLE);
+
+    oneof varid = AcpiDtPref.Pref,
+        prompt      = STRING_TOKEN(STR_DT_ACPI_SELECT_PROMPT),
+        help        = STRING_TOKEN(STR_DT_ACPI_SELECT_HELP),
+        flags       = NUMERIC_SIZE_1 | INTERACTIVE | RESET_REQUIRED,
+        option text = STRING_TOKEN(STR_DT_ACPI_SELECT_DT), value = DT_ACPI_SELECT_DT, flags = DEFAULT;
+        option text = STRING_TOKEN(STR_DT_ACPI_SELECT_ACPI), value = DT_ACPI_SELECT_ACPI, flags = 0;
+    endoneof;
+
+    subtitle text = STRING_TOKEN(STR_RAM_DISK_NULL_STRING);
+
+    guidop
+      guid = DT_PLATFORM_FORMSET_GUID,
+      datatype = DT_ACPI_VARSTORE_DATA,
+        data.Pref  = 0x0,
+    endguidop;
+
+  endform;
+
+endformset;
diff --git a/EmbeddedPkg/EmbeddedPkg.dec b/EmbeddedPkg/EmbeddedPkg.dec
index 2c2cf41103c2..c0f24422dc12 100644
--- a/EmbeddedPkg/EmbeddedPkg.dec
+++ b/EmbeddedPkg/EmbeddedPkg.dec
@@ -56,6 +56,12 @@ [Guids.common]
   gFdtHobGuid   = { 0x16958446, 0x19B7, 0x480B, { 0xB0, 0x47, 0x74, 0x85, 0xAD, 0x3F, 0x71, 0x6D } }
   gFdtVariableGuid = { 0x25a4fd4a, 0x9703, 0x4ba9, { 0xa1, 0x90, 0xb7, 0xc8, 0x4e, 0xfb, 0x3e, 0x57 } }
 
+  # HII form set GUID for DtPlatformDxe driver
+  gDtPlatformFormSetGuid = { 0x2b7a240d, 0xd5ad, 0x4fd6, { 0xbe, 0x1c, 0xdf, 0xa4, 0x41, 0x5f, 0x55, 0x26 } }
+
+  # File GUID for default DTB image embedded in the firmware volume
+  gDtPlatformDefaultDtbFileGuid = { 0x25462cda, 0x221f, 0x47df, { 0xac, 0x1d, 0x25, 0x9c, 0xfa, 0xa4, 0xe3, 0x26 } }
+
 [Protocols.common]
   gHardwareInterruptProtocolGuid =  { 0x2890B3EA, 0x053D, 0x1643, { 0xAD, 0x0C, 0xD6, 0x48, 0x08, 0xDA, 0x3F, 0xF1 } }
   gEfiDebugSupportPeriodicCallbackProtocolGuid = { 0x9546e07c, 0x2cbb, 0x4c88, { 0x98, 0x6c, 0xcd, 0x34, 0x10, 0x86, 0xf0, 0x44 } }
diff --git a/EmbeddedPkg/Include/Guid/DtPlatformDefaultDtbFile.h b/EmbeddedPkg/Include/Guid/DtPlatformDefaultDtbFile.h
new file mode 100644
index 000000000000..98099ae68d6d
--- /dev/null
+++ b/EmbeddedPkg/Include/Guid/DtPlatformDefaultDtbFile.h
@@ -0,0 +1,23 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro Limited. All rights reserved.
+*
+*  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 __DT_PLATFORM_DEFAULT_DTB_FILE_H__
+#define __DT_PLATFORM_DEFAULT_DTB_FILE_H__
+
+#define DT_PLATFORM_DEFAULT_DTB_FILE_GUID  \
+  { 0x2b7a240d, 0xd5ad, 0x4fd6, { 0xbe, 0x1c, 0xdf, 0xa4, 0x41, 0x5f, 0x55, 0x26 } }
+
+extern EFI_GUID gDtPlatformDefaultDtbFileGuid;
+
+#endif
diff --git a/EmbeddedPkg/Include/Guid/DtPlatformFormSet.h b/EmbeddedPkg/Include/Guid/DtPlatformFormSet.h
new file mode 100644
index 000000000000..71e3e7ebf7f3
--- /dev/null
+++ b/EmbeddedPkg/Include/Guid/DtPlatformFormSet.h
@@ -0,0 +1,23 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro Limited. All rights reserved.
+*
+*  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 __DT_PLATFORM_FORMSET_H__
+#define __DT_PLATFORM_FORMSET_H__
+
+#define DT_PLATFORM_FORMSET_GUID  \
+  { 0x2b7a240d, 0xd5ad, 0x4fd6, { 0xbe, 0x1c, 0xdf, 0xa4, 0x41, 0x5f, 0x55, 0x26 } }
+
+extern EFI_GUID gDtPlatformFormSetGuid;
+
+#endif
-- 
2.9.3