diff --git a/MdePkg/Include/IndustryStandard/Tpm12.h b/MdePkg/Include/IndustryStandard/Tpm12.h
index 1d489815ca..374d3131e3 100644
--- a/MdePkg/Include/IndustryStandard/Tpm12.h
+++ b/MdePkg/Include/IndustryStandard/Tpm12.h
@@ -1,25 +1,18 @@
-/*++
-
-Copyright (c) 2005 - 2006, Intel Corporation                                                         
-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.             
-
-Module Name:
-
-  Tpm12.h
-
-Abstract:
-
+/** 
+	@file   
   TPM Specification data structures (TCG TPM Specification Version 1.2 Revision 94)
-
   See http://trustedcomputinggroup.org for latest specification updates
 
---*/
+  Copyright (c) 2006 - 2007, Intel Corporation
+  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 _TPM12_H_
 #define _TPM12_H_
diff --git a/MdePkg/Include/Library/IfrSupportLib.h b/MdePkg/Include/Library/IfrSupportLib.h
index 75c7f4785b..e3885e1db3 100644
--- a/MdePkg/Include/Library/IfrSupportLib.h
+++ b/MdePkg/Include/Library/IfrSupportLib.h
@@ -1,24 +1,17 @@
-/*++
-
-Copyright (c) 2007, Intel Corporation
-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.
-
-Module Name:
-
-  IfrSupportLibrary.h
-
-Abstract:
-
+/** @file
   The file contain all library functions and definitions for IFR opcode creation and 
-  related Form Browser utility Operations.
-
---*/
+  related Form Browser utility Operations.
+
+  Copyright (c) 2007, Intel Corporation
+  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 _IFR_SUPPORT_LIBRARY_H
 #define _IFR_SUPPORT_LIBRARY_H
diff --git a/MdePkg/Include/Library/PeiPiLib.h b/MdePkg/Include/Library/PeiPiLib.h
index a1b472ac69..c79552c597 100644
--- a/MdePkg/Include/Library/PeiPiLib.h
+++ b/MdePkg/Include/Library/PeiPiLib.h
@@ -23,7 +23,7 @@
     The function allocate the EFI_PEI_PPI_DESCRIPTOR structure and update the fields accordingly to parameter passed
     in and install the PPI.
     
-    @param  FvStart              Unique identifier of the format of the memory-mapped firmware volume. If NULL is specified,
+    @param  FvFormat             Unique identifier of the format of the memory-mapped firmware volume. If NULL is specified,
                                          EFI_FIRMWARE_FILE_SYSTEM2_GUID is used as the Format GUID.
     @param  FvInfo               Points to a buffer which allows the EFI_PEI_FIRMWARE_VOLUME_PPI to
                                          process the volume. The format of this buffer is specific to the FvFormat. For
diff --git a/MdePkg/Include/Protocol/TcgService.h b/MdePkg/Include/Protocol/TcgService.h
index ddc4eaf286..aadd701719 100644
--- a/MdePkg/Include/Protocol/TcgService.h
+++ b/MdePkg/Include/Protocol/TcgService.h
@@ -1,25 +1,17 @@
-/*++
-
-Copyright (c) 2006, Intel Corporation                                                         
-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.             
-
-Module Name:
-
-  TcgService.h
-
-Abstract:
-
+/** @file
   TCG Service Protocol as defined in TCG_EFI_Protocol_1_20_Final
-
-  See http://trustedcomputinggroup.org for the latest specification
-
---*/
+  See http://trustedcomputinggroup.org for the latest specification
+
+  Copyright (c) 2007, Intel Corporation
+  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 _TCG_SERVICE_PROTOCOL_H_
 #define _TCG_SERVICE_PROTOCOL_H_
@@ -60,6 +52,31 @@ typedef UINT32   TCG_ALGORITHM_ID;
 //
 #pragma pack (pop)
 
+/**
+  This service provides EFI protocol capability information, state information 
+  about the TPM, and Event Log state information.
+
+  @param  This                   Indicates the calling context
+  @param  ProtocolCapability     The callee allocates memory for a TCG_BOOT_SERVICE_CAPABILITY 
+                                 structure and fills in the fields with the EFI protocol 
+                                 capability information and the current TPM state information.
+  @param  TCGFeatureFlags        This is a pointer to the feature flags. No feature 
+                                 flags are currently defined so this parameter 
+                                 MUST be set to 0. However, in the future, 
+                                 feature flags may be defined that, for example, 
+                                 enable hash algorithm agility.
+  @param  EventLogLocation       This is a pointer to the address of the event log in memory.
+  @param  EventLogLastEntry      If the Event Log contains more than one entry, 
+                                 this is a pointer to the address of the start of 
+                                 the last entry in the event log in memory. 
+
+  @retval EFI_SUCCESS            Operation completed successfully.
+  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
+  @retval EFI_INVALID_PARAMETER  One or more of the parameters are incorrect.
+  @retval EFI_BUFFER_TOO_SMALL   The receive buffer is too small.
+  @retval EFI_NOT_FOUND          The component was not running
+
+**/
 typedef
 EFI_STATUS
 (EFIAPI *EFI_TCG_STATUS_CHECK) (
@@ -71,6 +88,23 @@ EFI_STATUS
   OUT     EFI_PHYSICAL_ADDRESS      *EventLogLastEntry
   );
 
+/**
+  This service abstracts the capability to do a hash operation on a data buffer.
+  
+  @param  This                   Indicates the calling context
+  @param  HashData               Pointer to the data buffer to be hashed
+  @param  HashDataLen            Length of the data buffer to be hashed
+  @param  AlgorithmId            Identification of the Algorithm to use for the hashing operation
+  @param  HashedDataLen          Resultant length of the hashed data
+  @param  HashedDataResult       Resultant buffer of the hashed data  
+  
+  @retval EFI_SUCCESS            Operation completed successfully.
+  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
+  @retval EFI_INVALID_PARAMETER  One or more of the parameters are incorrect.
+  @retval EFI_BUFFER_TOO_SMALL   The receive buffer is too small.
+  @retval EFI_NOT_FOUND          The component was not running
+
+**/
 typedef
 EFI_STATUS
 (EFIAPI *EFI_TCG_HASH_ALL) (
@@ -82,6 +116,25 @@ EFI_STATUS
   IN OUT  UINT8                     **HashedDataResult
   );
 
+/**
+  This service abstracts the capability to add an entry to the Event Log.
+
+  @param  This                   Indicates the calling context
+  @param  TCGLogData             Pointer to the start of the data buffer containing 
+                                 the TCG_PCR_EVENT data structure. All fields in 
+                                 this structure are properly filled by the caller.
+  @param  EventNumber            The event number of the event just logged
+  @param  Flags                  Indicate additional flags. Only one flag has been 
+                                 defined at this time, which is 0x01 and means the 
+                                 extend operation should not be performed. All 
+                                 other bits are reserved. 
+ 
+  @retval EFI_SUCCESS            Operation completed successfully.
+  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
+  @retval EFI_INVALID_PARAMETER  One or more of the parameters are incorrect.
+  @retval EFI_BUFFER_TOO_SMALL   The receive buffer is too small.
+  @retval EFI_NOT_FOUND          The component was not running
+**/
 typedef
 EFI_STATUS
 (EFIAPI *EFI_TCG_LOG_EVENT) (
@@ -91,6 +144,21 @@ EFI_STATUS
   IN      UINT32                    Flags
   );
 
+/**
+  This service is a proxy for commands to the TPM.
+
+  @param  This                        Indicates the calling context
+  @param  TpmInputParameterBlockSize  Size of the TPM input parameter block
+  @param  TpmInputParameterBlock      Pointer to the TPM input parameter block
+  @param  TpmOutputParameterBlockSize Size of the TPM output parameter block
+  @param  TpmOutputParameterBlock     Pointer to the TPM output parameter block
+
+  @retval EFI_SUCCESS            Operation completed successfully.
+  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
+  @retval EFI_INVALID_PARAMETER  One or more of the parameters are incorrect.
+  @retval EFI_BUFFER_TOO_SMALL   The receive buffer is too small.
+  @retval EFI_NOT_FOUND          The component was not running
+**/
 typedef
 EFI_STATUS
 (EFIAPI *EFI_TCG_PASS_THROUGH_TO_TPM) (
@@ -101,6 +169,29 @@ EFI_STATUS
   IN      UINT8                     *TpmOutputParameterBlock
   );
 
+/**
+  This service abstracts the capability to do a hash operation on a data buffer, extend a specific TPM PCR with the hash result, and add an entry to the Event Log
+
+  @param  This                   Indicates the calling context
+  @param  HashData               Physical address of the start of the data buffer 
+                                 to be hashed, extended, and logged.
+  @param  HashDataLen            The length, in bytes, of the buffer referenced by HashData
+  @param  AlgorithmId            Identification of the Algorithm to use for the hashing operation
+  @param  TCGLogData             The physical address of the start of the data 
+                                 buffer containing the TCG_PCR_EVENT data structure.
+  @param  EventNumber            The event number of the event just logged.
+  @param  EventLogLastEntry      Physical address of the first byte of the entry 
+                                 just placed in the Event Log. If the Event Log was 
+                                 empty when this function was called then this physical 
+                                 address will be the same as the physical address of 
+                                 the start of the Event Log.
+
+  @retval EFI_SUCCESS            Operation completed successfully.
+  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
+  @retval EFI_INVALID_PARAMETER  One or more of the parameters are incorrect.
+  @retval EFI_BUFFER_TOO_SMALL   The receive buffer is too small.
+  @retval EFI_NOT_FOUND          The component was not running
+**/
 typedef
 EFI_STATUS
 (EFIAPI *EFI_TCG_HASH_LOG_EXTEND_EVENT) (
@@ -113,6 +204,21 @@ EFI_STATUS
      OUT  EFI_PHYSICAL_ADDRESS      *EventLogLastEntry
   );
 
+/**
+  The EFI_TCG Protocol abstracts TCG activity.
+
+  @param  StatusCheck        This service provides information on the TPM.
+  @param  HashAll            This service abstracts the capability to do a hash 
+                             operation on a data buffer.
+  @param  LogEvent           This service abstracts the capability to add 
+                             an entry to the Event Log.
+  @param  PassThroughToTPM   This service provides a pass-through capability 
+                             from the caller to the system¡¯s TPM.
+  @param  HashLogExtendEvent This service abstracts the capability to do a hash 
+                             operation on a data buffer, extend a specific TPM PCR 
+                             with the hash result, and add an entry to the Event Log. 
+
+**/
 typedef struct _EFI_TCG_PROTOCOL {
   EFI_TCG_STATUS_CHECK              StatusCheck;
   EFI_TCG_HASH_ALL                  HashAll;
diff --git a/MdePkg/Include/Protocol/UsbIo.h b/MdePkg/Include/Protocol/UsbIo.h
index 7d6ce276ab..833b706847 100644
--- a/MdePkg/Include/Protocol/UsbIo.h
+++ b/MdePkg/Include/Protocol/UsbIo.h
@@ -99,10 +99,10 @@ EFI_STATUS
   @param  Request               A pointer to the USB device request that will be sent to the USB
                                 device.
   @param  Direction             Indicates the data direction.
-  @param  Data                  A pointer to the buffer of data that will be transmitted to USB
-                                device or received from USB device.
   @param  Timeout               Indicating the transfer should be completed within this time frame.
                                 The units are in milliseconds.
+  @param  Data                  A pointer to the buffer of data that will be transmitted to USB
+                                device or received from USB device.
   @param  DataLength            The size, in bytes, of the data buffer specified by Data.
   @param  Status                A pointer to the result of the USB transfer.
 
diff --git a/MdePkg/Library/DxeExtractGuidedSectionLib/DxeExtractGuidedSectionLib.c b/MdePkg/Library/DxeExtractGuidedSectionLib/DxeExtractGuidedSectionLib.c
index acffa264fe..752594484c 100644
--- a/MdePkg/Library/DxeExtractGuidedSectionLib/DxeExtractGuidedSectionLib.c
+++ b/MdePkg/Library/DxeExtractGuidedSectionLib/DxeExtractGuidedSectionLib.c
@@ -1,23 +1,16 @@
-/*++
+/** @file
+  Provide generic extract guided section functions.
 
-Copyright (c) 2007, Intel Corporation
-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
+  Copyright (c) 2007, Intel Corporation<BR>
+  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.
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
-Module Name:
-
-  DxeExtractGuidedSectionLib.c
-
-Abstract:
-
-  Provide generic extract guided section functions. 
-
---*/
+**/
 
 #include <PiDxe.h>
 
diff --git a/MdePkg/Library/PeiExtractGuidedSectionLib/PeiExtractGuidedSectionLib.c b/MdePkg/Library/PeiExtractGuidedSectionLib/PeiExtractGuidedSectionLib.c
index a360d59d85..aa6c2fa33e 100644
--- a/MdePkg/Library/PeiExtractGuidedSectionLib/PeiExtractGuidedSectionLib.c
+++ b/MdePkg/Library/PeiExtractGuidedSectionLib/PeiExtractGuidedSectionLib.c
@@ -1,23 +1,16 @@
-/*++
+/** @file
+  Provide generic extract guided section functions.
 
-Copyright (c) 2007, Intel Corporation
-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
+  Copyright (c) 2007, Intel Corporation<BR>
+  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.
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
-Module Name:
-
-  PeiExtractGuidedSectionLib.c
-
-Abstract:
-
-  Provide generic extract guided section functions. 
-
---*/
+**/
 
 #include <PiPei.h>
 
diff --git a/MdePkg/Library/PeiPiLib/PeiPiLib.c b/MdePkg/Library/PeiPiLib/PeiPiLib.c
index d1e8611365..3030b1cd7f 100644
--- a/MdePkg/Library/PeiPiLib/PeiPiLib.c
+++ b/MdePkg/Library/PeiPiLib/PeiPiLib.c
@@ -32,6 +32,27 @@ CONST EFI_PEI_FIRMWARE_VOLUME_INFO_PPI mFvInfoPpiTemplate = {
   NULL //ParentFileName;
 };
 
+/**
+    Install a EFI_PEI_FIRMWARE_VOLUME_INFO PPI to inform PEI core about the existence of a new Firmware Volume.
+  
+    The function allocate the EFI_PEI_PPI_DESCRIPTOR structure and update the fields accordingly to parameter passed
+    in and install the PPI.
+    
+    @param  FvFormat             Unique identifier of the format of the memory-mapped firmware volume. If NULL is specified,
+                                         EFI_FIRMWARE_FILE_SYSTEM2_GUID is used as the Format GUID.
+    @param  FvInfo               Points to a buffer which allows the EFI_PEI_FIRMWARE_VOLUME_PPI to
+                                         process the volume. The format of this buffer is specific to the FvFormat. For
+                                         memory-mapped firmware volumes, this typically points to the first byte of the
+                                         firmware volume.
+    @param  FvInfoSize          Size of the data provided by FvInfo. For memory-mapped firmware volumes, this is
+                                         typically the size of the firmware volume.
+    @param  ParentFvName, ParentFileName      If the firmware volume originally came from a firmware file, then these point to the
+                                          parent firmware volume name and firmware volume file. If it did not originally come
+                                          from a firmware file, these should be NULL
+  
+    @retval  VOID
+  
+**/
 VOID
 EFIAPI
 PiLibInstallFvInfoPpi (
diff --git a/MdePkg/Library/UefiScsiLib/UefiScsiLib.c b/MdePkg/Library/UefiScsiLib/UefiScsiLib.c
index 6eb21dd878..5ac34334d0 100644
--- a/MdePkg/Library/UefiScsiLib/UefiScsiLib.c
+++ b/MdePkg/Library/UefiScsiLib/UefiScsiLib.c
@@ -25,8 +25,10 @@
 
   @param[in]     ScsiIo             A pointer to SCSI IO protocol.
   @param[in]     Timeout            The length of timeout period.
-  @param[out]    SenseData          A pointer to output sense data.
-  @param[out]    SenseDataLength    The length of output sense data.
+  @param[in out] SenseData          A pointer to the sense data that 
+                                    was generated by the execution of the SCSI Request Packet.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
 
@@ -40,7 +42,7 @@
                                 queued.
   @retval EFI_DEVICE_ERROR      A device error occurred while attempting to send 
                                 the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER The contents of CommandPacket are invalid, or ScsiIo is NULL.  
   @retval EFI_UNSUPPORTED       The command described by the SCSI Request Packet
                                 is not supported by the SCSI initiator(i.e., SCSI 
                                 Host Controller).
@@ -52,8 +54,8 @@ EFI_STATUS
 ScsiTestUnitReadyCommand (
   IN  EFI_SCSI_IO_PROTOCOL  *ScsiIo,
   IN  UINT64                Timeout,
-  OUT VOID                  *SenseData,
-  OUT UINT8                 *SenseDataLength,
+  IN OUT VOID               *SenseData,
+  IN OUT UINT8              *SenseDataLength,
   OUT UINT8                 *HostAdapterStatus,
   OUT UINT8                 *TargetStatus
   )
@@ -65,6 +67,13 @@ ScsiTestUnitReadyCommand (
   EFI_STATUS                      Status;
   UINT8                           Cdb[6];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
 
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 6);
@@ -103,10 +112,11 @@ ScsiTestUnitReadyCommand (
   @param[in]     ScsiIo             SCSI IO Protocol to use
   @param[in]     Timeout            The length of timeout period.
   @param[out]    SenseData          A pointer to output sense data.
-  @param[in,out] SenseDataLength    The length of output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
-  @param[in,out] InquirydataBuffer  A pointer to inquiry data buffer.
+  @param[in]     InquirydataBuffer  A pointer to inquiry data buffer.
   @param[in,out] InquiryDataLength  The length of inquiry data buffer.
   @param[in]     EnableVitalProductData  Boolean to enable Vital Product Data.
 
@@ -120,7 +130,7 @@ ScsiTestUnitReadyCommand (
                           queued.
   @retval EFI_DEVICE_ERROR  A device error occurred while attempting to send 
                             the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER The contents of CommandPacket are invalid, or ScsiIo is NULL.
   @retval EFI_UNSUPPORTED The command described by the SCSI Request Packet
                           is not supported by the SCSI initiator(i.e., SCSI 
                           Host Controller).
@@ -136,7 +146,7 @@ ScsiInquiryCommand (
   IN OUT UINT8              *SenseDataLength,
   OUT UINT8                 *HostAdapterStatus,
   OUT UINT8                 *TargetStatus,
-  IN OUT VOID               *InquiryDataBuffer,
+  IN VOID                   *InquiryDataBuffer,
   IN OUT UINT32             *InquiryDataLength,
   IN  BOOLEAN               EnableVitalProductData
   )
@@ -148,6 +158,15 @@ ScsiInquiryCommand (
   EFI_STATUS                      Status;
   UINT8                           Cdb[6];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  ASSERT (InquiryDataLength != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 6);
 
@@ -192,7 +211,8 @@ ScsiInquiryCommand (
   @param[in]     ScsiIo             A pointer to SCSI IO protocol.
   @param[in]     Timeout            The length of timeout period.
   @param[out]    SenseData          A pointer to output sense data.
-  @param[in,out] SenseDataLength    The length of output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
   @param[in]     DataBuffer         A pointer to input data buffer.
@@ -211,7 +231,7 @@ ScsiInquiryCommand (
                                     queued.
   @retval EFI_DEVICE_ERROR          A device error occurred while attempting to send 
                                     the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid, or ScsiIo is NULL.  
   @retval EFI_UNSUPPORTED           The command described by the SCSI Request Packet
                                     is not supported by the SCSI initiator(i.e., SCSI 
                                     Host Controller).
@@ -241,6 +261,15 @@ ScsiModeSense10Command (
   EFI_STATUS                      Status;
   UINT8                           Cdb[10];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  ASSERT (DataLength != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 10);
 
@@ -278,19 +307,14 @@ ScsiModeSense10Command (
 
 /**
   Function to submit SCSI request sense command.
-  ScsiIo               - A pointer to SCSI IO protocol.
-  Timeout              - The length of timeout period.
-  SenseData            - A pointer to output sense data.
-  SenseDataLength      - The length of output sense data.
-  HostAdapterStatus    - The status of Host Adapter.
-  TargetStatus         - The status of the target.
 
-  @param[in]     ScsiIo             SCSI IO Protocol to use
-  @param[in]     Timeout            TODO:
-  @param[out]    SenseData          TODO:
-  @param[in,out] SenseDataLength    TODO:
-  @param[out]    HostAdapterStatus  TODO:
-  @param[out]    TargetStatus       TODO:
+  @param[in]     ScsiIo             A pointer to SCSI IO protocol.
+  @param[in]     Timeout            The length of timeout period.
+  @param[in]     SenseData          A pointer to output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
+  @param[out]    HostAdapterStatus  The status of Host Adapter.
+  @param[out]    TargetStatus       The status of the target.
 
   @retval EFI_SUCCESS        Valid data returned
   @retval EFI_SUCCESS        The status of the unit is tested successfully.
@@ -303,7 +327,7 @@ ScsiModeSense10Command (
                                     queued.
   @retval EFI_DEVICE_ERROR          A device error occurred while attempting to send 
                                     the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid, or ScsiIo is NULL.
   @retval EFI_UNSUPPORTED           The command described by the SCSI Request Packet
                                     is not supported by the SCSI initiator(i.e., SCSI 
                                     Host Controller).
@@ -328,6 +352,14 @@ ScsiRequestSenseCommand (
   EFI_STATUS                      Status;
   UINT8                           Cdb[6];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 6);
 
@@ -366,7 +398,8 @@ ScsiRequestSenseCommand (
   @param[in]     ScsiIo             A pointer to SCSI IO protocol.
   @param[in]     Timeout            The length of timeout period.
   @param[out]    SenseData          A pointer to output sense data.
-  @param[in,out] SenseDataLength    The length of output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
   @param[out]    DataBuffer         A pointer to a data buffer.
@@ -383,7 +416,7 @@ ScsiRequestSenseCommand (
                                       queued.
   @retval  EFI_DEVICE_ERROR           A device error occurred while attempting to send 
                                       the SCSI Request Packet.
-  @retval  EFI_INVALID_PARAMETER      The contents of CommandPacket are invalid.  
+  @retval  EFI_INVALID_PARAMETER      The contents of CommandPacket are invalid, or ScsiIo is NULL.
   @retval  EFI_UNSUPPORTED            The command described by the SCSI Request Packet
                                       is not supported by the SCSI initiator(i.e., SCSI 
                                       Host Controller).
@@ -411,6 +444,15 @@ ScsiReadCapacityCommand (
   EFI_STATUS                      Status;
   UINT8                           Cdb[10];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  ASSERT (DataLength != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 10);
 
@@ -457,7 +499,8 @@ ScsiReadCapacityCommand (
   @param[in]     ScsiIo             A pointer to SCSI IO protocol.
   @param[in]     Timeout            The length of timeout period.
   @param[out]    SenseData          A pointer to output sense data.
-  @param[in,out] SenseDataLength    The length of output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
   @param[out]    DataBuffer         Read 10 command data.
@@ -475,7 +518,7 @@ ScsiReadCapacityCommand (
                                     queued.
   @retval EFI_DEVICE_ERROR          A device error occurred while attempting to send 
                                     the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid, or ScsiIo is NULL.
   @retval EFI_UNSUPPORTED           The command described by the SCSI Request Packet
                                     is not supported by the SCSI initiator(i.e., SCSI 
                                     Host Controller).
@@ -504,6 +547,15 @@ ScsiRead10Command (
   EFI_STATUS                      Status;
   UINT8                           Cdb[10];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  ASSERT (DataLength != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 10);
 
@@ -548,7 +600,8 @@ ScsiRead10Command (
   @param[in]     ScsiIo             SCSI IO Protocol to use
   @param[in]     Timeout            The length of timeout period.
   @param[out]    SenseData          A pointer to output sense data.
-  @param[in,out] SenseDataLength    The length of output sense data.
+  @param[in out] SenseDataLength    On input, the length in bytes of the SenseData buffer. On
+                                    output, the number of bytes written to the SenseData buffer.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
   @param[out]    DataBuffer         A pointer to a data buffer.
@@ -566,7 +619,7 @@ ScsiRead10Command (
                                     queued.
   @retval EFI_DEVICE_ERROR          A device error occurred while attempting to send 
                                     the SCSI Request Packet.
-  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid.  
+  @retval EFI_INVALID_PARAMETER     The contents of CommandPacket are invalid, or ScsiIo is NULL.
   @retval EFI_UNSUPPORTED           The command described by the SCSI Request Packet
                                     is not supported by the SCSI initiator(i.e., SCSI 
                                     Host Controller).
@@ -595,6 +648,15 @@ ScsiWrite10Command (
   EFI_STATUS                      Status;
   UINT8                           Cdb[10];
 
+  ASSERT (SenseDataLength != NULL);
+  ASSERT (HostAdapterStatus != NULL);
+  ASSERT (TargetStatus != NULL);
+  ASSERT (DataLength != NULL);
+  
+  if (ScsiIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&CommandPacket, sizeof (EFI_SCSI_IO_SCSI_REQUEST_PACKET));
   ZeroMem (Cdb, 10);
 
diff --git a/MdePkg/Library/UefiUsbLib/Hid.c b/MdePkg/Library/UefiUsbLib/Hid.c
index 7c0ee14284..9391574fe0 100644
--- a/MdePkg/Library/UefiUsbLib/Hid.c
+++ b/MdePkg/Library/UefiUsbLib/Hid.c
@@ -38,6 +38,10 @@ UsbGetHidDescriptor (
   UINT32                  Status;
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
+  
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
 
   Request.RequestType = 0x81;
   Request.Request     = 0x06;
@@ -88,6 +92,9 @@ UsbGetReportDescriptor (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -137,6 +144,9 @@ UsbGetProtocolRequest (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -187,6 +197,9 @@ UsbSetProtocolRequest (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -238,6 +251,9 @@ UsbSetIdleRequest (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -287,7 +303,10 @@ UsbGetIdleRequest (
   UINT32                  Status;
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
-
+  
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -344,6 +363,9 @@ UsbSetReportRequest (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
@@ -399,6 +421,9 @@ UsbGetReportRequest (
   EFI_STATUS              Result;
   EFI_USB_DEVICE_REQUEST  Request;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
   //
   // Fill Device request packet
   //
diff --git a/MdePkg/Library/UefiUsbLib/UsbDxeLib.c b/MdePkg/Library/UefiUsbLib/UsbDxeLib.c
index 90b0fd3ea5..a1d61d52bf 100644
--- a/MdePkg/Library/UefiUsbLib/UsbDxeLib.c
+++ b/MdePkg/Library/UefiUsbLib/UsbDxeLib.c
@@ -527,6 +527,10 @@ UsbClearEndpointHalt (
   EFI_USB_INTERFACE_DESCRIPTOR  InterfaceDescriptor;
   UINT8                         Index;
 
+  if (UsbIo == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
   ZeroMem (&EndpointDescriptor, sizeof (EFI_USB_ENDPOINT_DESCRIPTOR));
   //
   // First seach the endpoint descriptor for that endpoint addr