Re: [edk2-platforms][PATCH V2 1/3] IntelSiliconPkg/FirmwareBootMediaLib: Add library

["Chaganty, Rangasai V" <rangasai.v.chaganty@intel.com>]

Reviewed-by: Sai Chaganty <rangasai.v.chaganty@intel.com>

-----Original Message-----
From: Kubacki, Michael A 
Sent: Friday, October 04, 2019 10:29 AM
To: devel@edk2.groups.io
Cc: Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>; Ni, Ray <ray.ni@intel.com>
Subject: [edk2-platforms][PATCH V2 1/3] IntelSiliconPkg/FirmwareBootMediaLib: Add library

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2229

Adds a new library that is used to make system initialization decisions in the boot flow dependent upon firmware boot media.
Note that the firmware boot media is the storage media that the boot firmware is stored on. It is not the OS storage media which may be stored upon a different non-volatile storage device.

Any Intel board, platform, or silicon code that must take action conditionally based on the firmware boot media must use this library API.

Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
---
 Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec                                          |   8 +-
 Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dsc                                          |   4 +-
 Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.inf |  43 ++++++++
 Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.inf    |  38 +++++++
 Silicon/Intel/IntelSiliconPkg/Include/Library/FirmwareBootMediaLib.h                       | 106 +++++++++++++++++++
 Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.c   | 107 +++++++++++++++++++
 Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/FirmwareBootMediaLib.c         | 109 ++++++++++++++++++++
 Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.c      |  82 +++++++++++++++
 8 files changed, 495 insertions(+), 2 deletions(-)

diff --git a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
index fe5bfa0dc6..f70e3b977d 100644
--- a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
+++ b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
@@ -3,7 +3,7 @@
 #
 # This package provides common open source Intel silicon modules.
 #
-# Copyright (c) 2016 - 2018, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2016 - 2019, Intel Corporation. All rights 
+reserved.<BR>
 # SPDX-License-Identifier: BSD-2-Clause-Patent  #  ## @@ -22,6 +22,10 @@
   #
   MicrocodeFlashAccessLib|Include/Library/MicrocodeFlashAccessLib.h
 
+  ## @libraryclass  Provides services to identify the firmware boot media device.
+  #
+  FirmwareBootMediaLib|Include/Library/FirmwareBootMediaLib.h
+
 [Guids]
   ## GUID for Package token space
   # {A9F8D54E-1107-4F0A-ADD0-4587E7A4A735}
@@ -35,6 +39,8 @@
   ## Include/Guid/MicrocodeFmp.h
   gMicrocodeFmpImageTypeIdGuid      = { 0x96d4fdcd, 0x1502, 0x424d, { 0x9d, 0x4c, 0x9b, 0x12, 0xd2, 0xdc, 0xae, 0x5c } }
 
+  gFirmwareBootMediaHobGuid = { 0x8c7340ea, 0xde8b, 0x4e06, {0xa4, 
+ 0x78, 0xec, 0x8b, 0x62, 0xd7, 0xa, 0x8b } }
+
 [Ppis]
   gEdkiiVTdInfoPpiGuid = { 0x8a59fcb3, 0xf191, 0x400c, { 0x97, 0x67, 0x67, 0xaf, 0x2b, 0x25, 0x68, 0x4a } }
 
diff --git a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dsc b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dsc
index 58b5b656ef..3fb8a08b50 100644
--- a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dsc
+++ b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dsc
@@ -1,7 +1,7 @@
 ## @file
 # This package provides common open source Intel silicon modules.
 #
-# Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2017 - 2019, Intel Corporation. All rights 
+reserved.<BR>
 #
 #    SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -80,6 +80,8 @@
   IntelSiliconPkg/Feature/VTd/PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.inf
   IntelSiliconPkg/Feature/Capsule/MicrocodeUpdateDxe/MicrocodeUpdateDxe.inf
   IntelSiliconPkg/Feature/Capsule/Library/MicrocodeFlashAccessLibNull/MicrocodeFlashAccessLibNull.inf
+  
+ IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.
+ inf  
+ IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaL
+ ib.inf
 
 [BuildOptions]
   *_*_*_CC_FLAGS = -D DISABLE_NEW_DEPRECATED_INTERFACES diff --git a/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.inf b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.inf
new file mode 100644
index 0000000000..83ed5f04af
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmm
+++ FirmwareBootMediaLib.inf
@@ -0,0 +1,43 @@
+## @file
+# Firmware Boot Media Library
+#
+# The firmware boot media device is used to make system initialization 
+decisions in the boot flow dependent # upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+# It is not the OS storage media which may be stored upon a different non-volatile storage device.
+#
+# This library contains an implementation for the DXE and SMM boot phases.
+#
+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR> # #  
+SPDX-License-Identifier: BSD-2-Clause-Patent # ##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = DxeSmmFirmwareBootMediaLib
+  FILE_GUID                      = 72F07B0B-54F5-47FD-9EDB-D796BE2B87E9
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  PI_SPECIFICATION_VERSION       = 0x0001000A
+  LIBRARY_CLASS                  = FirmwareBootMediaLib|DXE_DRIVER DXE_SMM_DRIVER DXE_RUNTIME_DRIVER UEFI_APPLICATION UEFI_DRIVER
+  CONSTRUCTOR                    = DxeSmmFirmwareBootMediaLibInit
+#
+#  VALID_ARCHITECTURES           = IA32 X64 IPF EBC
+#
+
+[Sources]
+  FirmwareBootMediaLib.c
+  DxeSmmFirmwareBootMediaLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  IntelSiliconPkg/IntelSiliconPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  HobLib
+
+[Guids]
+  gFirmwareBootMediaHobGuid       ## CONSUMES
diff --git a/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.inf b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.inf
new file mode 100644
index 0000000000..063c4027d3
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFir
+++ mwareBootMediaLib.inf
@@ -0,0 +1,38 @@
+## @file
+# Firmware Boot Media Library
+#
+# The firmware boot media device is used to make system initialization 
+decisions in the boot flow dependent # upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+# It is not the OS storage media which may be stored upon a different non-volatile storage device.
+#
+# This library contains an implementation for the PEI boot phase.
+#
+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR> # #  
+SPDX-License-Identifier: BSD-2-Clause-Patent # ##
+
+[Defines]
+  INF_VERSION          = 0x00010005
+  BASE_NAME            = PeiFirmwareBootMediaLib
+  FILE_GUID            = D3F7BD0B-3539-4F2D-AF98-EE32DBE7971F
+  MODULE_TYPE          = PEIM
+  VERSION_STRING       = 1.0
+  LIBRARY_CLASS        = FirmwareBootMediaLib
+
+[Sources]
+  FirmwareBootMediaLib.c
+  PeiFirmwareBootMediaLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  IntelSiliconPkg/IntelSiliconPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  HobLib
+
+[Guids]
+  gFirmwareBootMediaHobGuid       ## PRODUCES CONSUMES
diff --git a/Silicon/Intel/IntelSiliconPkg/Include/Library/FirmwareBootMediaLib.h b/Silicon/Intel/IntelSiliconPkg/Include/Library/FirmwareBootMediaLib.h
new file mode 100644
index 0000000000..aca9593a84
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Include/Library/FirmwareBootMediaLib
+++ .h
@@ -0,0 +1,106 @@
+/** @file
+  This library identifies the firmware boot media device.
+
+  The firmware boot media device is used to make system initialization 
+ decisions in the boot flow dependent  upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+  It is not the OS storage media which may be stored upon a different non-volatile storage device.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _FIRMWARE_BOOT_MEDIA_LIB_H_
+#define _FIRMWARE_BOOT_MEDIA_LIB_H_
+
+#include <Uefi.h>
+
+typedef enum {
+  FwBootMediaSpi,
+  FwBootMediaUfs,
+  FwBootMediaEmmc,
+  FwBootMediaNvme,
+  FwBootMediaMax
+} FW_BOOT_MEDIA_TYPE;
+
+typedef struct {
+  FW_BOOT_MEDIA_TYPE BootMedia;
+} FW_BOOT_MEDIA_HOB_DATA;
+
+/**
+  Determines the current platform firmware boot media device.
+
+  @param[out] FwBootMediaType The current platform Boot Media type.
+
+  @retval     EFI_SUCCESS     The operation completed successfully.
+  @retval     EFI_NOT_FOUND   The boot media type could not be found.
+**/
+EFI_STATUS
+EFIAPI
+GetFirmwareBootMediaType (
+  OUT FW_BOOT_MEDIA_TYPE   *FwBootMediaType
+  );
+
+/**
+  Indicates whether the boot media is presently known.
+
+  Note: Very early in boot this data may not be available.
+
+  @retval TRUE        Boot media is known
+  @retval FALSE       Boot media is not known
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsKnown (
+  VOID
+  );
+
+/**
+  Determines if the platform firmware is booting from SPI.
+
+  @retval TRUE        Platform firmware is booting from SPI
+  @retval FALSE       Platform firmware is booting from a non-SPI device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsSpi (
+  VOID
+  );
+
+/**
+  Determines if the platform firmware is booting from UFS.
+
+  @retval TRUE        Platform firmware is booting from UFS
+  @retval FALSE       Platform firmware is booting from a non-UFS device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsUfs (
+  VOID
+  );
+
+/**
+  Determines if the platform firmware is booting from eMMC.
+
+  @retval TRUE        Platform firmware is booting from eMMC
+  @retval FALSE       Platform firmware is booting from a non-eMMC device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsEmmc (
+  VOID
+  );
+
+/**
+  Determines if the platform firmware is booting from NVMe.
+
+  @retval TRUE        Platform firmware is booting from NVMe.
+  @retval FALSE       Platform firmware is booting from a non-NVMe device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsNvme (
+  VOID
+  );
+
+#endif
diff --git a/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.c b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmmFirmwareBootMediaLib.c
new file mode 100644
index 0000000000..1e3876afb3
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/DxeSmm
+++ FirmwareBootMediaLib.c
@@ -0,0 +1,107 @@
+/** @file
+  This library identifies the firmware boot media device.
+
+  The firmware boot media device is used to make system initialization 
+ decisions in the boot flow dependent  upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+  It is not the OS storage media which may be stored upon a different non-volatile storage device.
+
+  This file contains implementation specific to the DXE and SMM boot phases.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/FirmwareBootMediaLib.h> #include <Library/HobLib.h>
+
+STATIC FW_BOOT_MEDIA_TYPE mFwBootMedia = FwBootMediaMax;
+
+/**
+  Determines the current platform firmware boot media device.
+
+  @param[out] FwBootMediaType The current platform Boot Media type.
+
+  @retval     EFI_SUCCESS     The operation completed successfully.
+  @retval     EFI_NOT_FOUND   The boot media type could not be found.
+**/
+EFI_STATUS
+EFIAPI
+GetFirmwareBootMediaType (
+  OUT FW_BOOT_MEDIA_TYPE   *FwBootMediaType
+  )
+{
+  if (mFwBootMedia == FwBootMediaMax) {
+    return EFI_NOT_FOUND;
+  }
+
+  *FwBootMediaType = mFwBootMedia;
+  return EFI_SUCCESS;
+}
+
+/**
+  Determines if the boot media is presently known.
+
+  Note: Very early in boot this data may not be available.
+
+  @retval TRUE        Boot media is known
+  @retval FALSE       Boot media is not known
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsKnown (
+  VOID
+  )
+{
+  return mFwBootMedia != FwBootMediaMax; }
+
+/**
+  The library constructor.
+
+  This constructor depends upon gFirmwareBootMediaHobGuid.
+  It should be produced by the platform in the HOB producer phase.
+
+  @param[in]  ImageHandle           The firmware allocated handle for the UEFI image.
+  @param[in]  SystemTable           A pointer to the EFI system table.
+
+  @retval     EFI_SUCCESS           The constructor executed successfully.
+  @retval     EFI_NOT_FOUND         The gFirmwareBootMediaHobGuid HOB could not be located
+                                    or the boot media type is invalid.
+**/
+EFI_STATUS
+EFIAPI
+DxeSmmFirmwareBootMediaLibInit (
+  IN EFI_HANDLE         ImageHandle,
+  IN EFI_SYSTEM_TABLE   *SystemTable
+  )
+{
+  FW_BOOT_MEDIA_HOB_DATA    *BootMediaHobData;
+  FW_BOOT_MEDIA_TYPE        BootMediaType;
+  EFI_HOB_GUID_TYPE         *GuidHobPtr;
+
+  GuidHobPtr  = GetFirstGuidHob (&gFirmwareBootMediaHobGuid);  if 
+ (GuidHobPtr == NULL) {
+    DEBUG ((DEBUG_ERROR, "The firmware boot media HOB does not exist!\n"));
+    ASSERT (GuidHobPtr != NULL);
+    return EFI_NOT_FOUND;
+  }
+
+  BootMediaHobData = (FW_BOOT_MEDIA_HOB_DATA *) GET_GUID_HOB_DATA 
+ (GuidHobPtr);  if (BootMediaHobData == NULL) {
+    return EFI_NOT_FOUND;
+  }
+
+  BootMediaType = BootMediaHobData->BootMedia;
+
+  if (BootMediaType >= FwBootMediaMax) {
+    DEBUG ((DEBUG_ERROR, "The firmware boot media HOB specifies an invalid media type.\n"));
+    return EFI_NOT_FOUND;
+  }
+
+  mFwBootMedia = BootMediaType;
+
+  return EFI_SUCCESS;
+}
diff --git a/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/FirmwareBootMediaLib.c b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/FirmwareBootMediaLib.c
new file mode 100644
index 0000000000..11a14d172d
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/Firmwa
+++ reBootMediaLib.c
@@ -0,0 +1,109 @@
+/** @file
+  This library identifies the firmware boot media device.
+
+  The firmware boot media device is used to make system initialization 
+ decisions in the boot flow dependent  upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+  It is not the OS storage media which may be stored upon a different non-volatile storage device.
+
+  This file contains library implementation common to all boot phases.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/FirmwareBootMediaLib.h>
+
+/**
+  Determines if the platform firmware is booting from SPI.
+
+  @retval TRUE        Platform firmware is booting from SPI
+  @retval FALSE       Platform firmware is booting from a non-SPI device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsSpi (
+  VOID
+  )
+{
+  EFI_STATUS          Status;
+  FW_BOOT_MEDIA_TYPE  BootMedia;
+
+  Status = GetFirmwareBootMediaType (&BootMedia);
+  if (EFI_ERROR (Status) || BootMedia != FwBootMediaSpi) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
+
+/**
+  Determines if the platform firmware is booting from UFS.
+
+  @retval TRUE        Platform firmware is booting from UFS
+  @retval FALSE       Platform firmware is booting from a non-UFS device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsUfs (
+  VOID
+  )
+{
+  EFI_STATUS          Status;
+  FW_BOOT_MEDIA_TYPE  BootMedia;
+
+  Status = GetFirmwareBootMediaType (&BootMedia);
+  if (EFI_ERROR (Status) || BootMedia != FwBootMediaUfs) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
+
+/**
+  Determines if the platform firmware is booting from eMMC.
+
+  @retval TRUE        Platform firmware is booting from eMMC
+  @retval FALSE       Platform firmware is booting from a non-eMMC device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsEmmc (
+  VOID
+  )
+{
+  EFI_STATUS          Status;
+  FW_BOOT_MEDIA_TYPE  BootMedia;
+
+  Status = GetFirmwareBootMediaType (&BootMedia);
+  if (EFI_ERROR (Status) || BootMedia != FwBootMediaEmmc) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
+
+/**
+  Determines if the platform firmware is booting from NVMe.
+
+  @retval TRUE        Platform firmware is booting from NVMe.
+  @retval FALSE       Platform firmware is booting from a non-NVMe device or the boot media is unknown
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsNvme (
+  VOID
+  )
+{
+  EFI_STATUS          Status;
+  FW_BOOT_MEDIA_TYPE  BootMedia;
+
+  Status = GetFirmwareBootMediaType (&BootMedia);
+  if (EFI_ERROR (Status) || BootMedia != FwBootMediaNvme) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
diff --git a/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.c b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFirmwareBootMediaLib.c
new file mode 100644
index 0000000000..14478e0dbe
--- /dev/null
+++ b/Silicon/Intel/IntelSiliconPkg/Library/PeiDxeSmmBootMediaLib/PeiFir
+++ mwareBootMediaLib.c
@@ -0,0 +1,82 @@
+/** @file
+  This library identifies the firmware boot media device.
+
+  The firmware boot media device is used to make system initialization 
+ decisions in the boot flow dependent  upon firmware boot media. Note that the firmware boot media is the storage media that the boot firmware is stored on.
+  It is not the OS storage media which may be stored upon a different non-volatile storage device.
+
+  This file contains implementation specific to the PEI boot phase.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/FirmwareBootMediaLib.h> #include <Library/HobLib.h>
+
+/**
+  Determines the current platform firmware boot media device.
+
+  @param[out] FwBootMediaType The current platform Boot Media type.
+
+  @retval     EFI_SUCCESS     The operation completed successfully.
+  @retval     EFI_NOT_FOUND   The boot media type could not be found.
+**/
+EFI_STATUS
+EFIAPI
+GetFirmwareBootMediaType (
+  OUT FW_BOOT_MEDIA_TYPE   *FwBootMediaType
+  )
+{
+  FW_BOOT_MEDIA_HOB_DATA    *BootMediaHobData;
+  EFI_HOB_GUID_TYPE         *GuidHobPtr;
+
+  GuidHobPtr  = GetFirstGuidHob (&gFirmwareBootMediaHobGuid);  if 
+ (GuidHobPtr == NULL) {
+      DEBUG ((DEBUG_ERROR, "The firmware boot media HOB does not exist!\n"));
+      ASSERT (GuidHobPtr != NULL);
+      return EFI_NOT_FOUND;
+  }
+
+  BootMediaHobData = (FW_BOOT_MEDIA_HOB_DATA *) GET_GUID_HOB_DATA 
+ (GuidHobPtr);  if (BootMediaHobData == NULL) {
+    return EFI_NOT_FOUND;
+  }
+
+  if (BootMediaHobData->BootMedia >= FwBootMediaMax) {
+    DEBUG ((DEBUG_ERROR, "The firmware boot media HOB specifies an invalid media type.\n"));
+    return EFI_NOT_FOUND;
+  }
+  *FwBootMediaType = BootMediaHobData->BootMedia;
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Determines if the boot media is presently known.
+
+  Note: Very early in boot this data may not be available.
+
+  @retval TRUE        Boot media is known
+  @retval FALSE       Boot media is not known
+**/
+BOOLEAN
+EFIAPI
+FirmwareBootMediaIsKnown (
+  VOID
+  )
+{
+  EFI_STATUS          Status;
+  FW_BOOT_MEDIA_TYPE  BootMedia;
+
+  BootMedia = FwBootMediaMax;
+  Status = GetFirmwareBootMediaType (&BootMedia);
+  if (EFI_ERROR (Status) || BootMedia == FwBootMediaMax) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
--
2.16.2.windows.1