diff --git a/BaseTools/Source/C/DevicePath/DevicePath.c b/BaseTools/Source/C/DevicePath/DevicePath.c
index 956bbffb5f..356f5f7e24 100644
--- a/BaseTools/Source/C/DevicePath/DevicePath.c
+++ b/BaseTools/Source/C/DevicePath/DevicePath.c
@@ -25,7 +25,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define UTILITY_MAJOR_VERSION 0
 #define UTILITY_MINOR_VERSION 1
 
-EFI_GUID gEfiDebugPortDevicePathGuid = DEVICE_PATH_MESSAGING_DEBUGPORT;
+EFI_GUID gEfiDebugPortProtocolGuid = DEVICE_PATH_MESSAGING_DEBUGPORT;
 EFI_GUID gEfiPcAnsiGuid = EFI_PC_ANSI_GUID;
 EFI_GUID gEfiVT100Guid = EFI_VT_100_GUID;
 EFI_GUID gEfiVT100PlusGuid = EFI_VT_100_PLUS_GUID;
diff --git a/BaseTools/Source/C/DevicePath/DevicePathFromText.c b/BaseTools/Source/C/DevicePath/DevicePathFromText.c
index bb74e2e170..555efa1acd 100644
--- a/BaseTools/Source/C/DevicePath/DevicePathFromText.c
+++ b/BaseTools/Source/C/DevicePath/DevicePathFromText.c
@@ -764,7 +764,16 @@ DevPathFromTextAcpiExp (
                                                   );
 
   AcpiEx->HID = EisaIdFromText (HIDStr);
-  AcpiEx->CID = EisaIdFromText (CIDStr);
+  //
+  // According to UEFI spec, the CID parametr is optional and has a default value of 0.
+  // So when the CID parametr is not specified or specified as 0 in the text device node.
+  // Set the CID to 0 in the ACPI extension device path structure.
+  //
+  if (*CIDStr == L'\0' || *CIDStr == L'0') {
+    AcpiEx->CID = 0;
+  } else {
+    AcpiEx->CID = EisaIdFromText (CIDStr);
+  }
   AcpiEx->UID = 0;
 
   AsciiStr = (CHAR8 *) ((UINT8 *)AcpiEx + sizeof (ACPI_EXTENDED_HID_DEVICE_PATH));
@@ -1603,15 +1612,15 @@ DevPathFromTextDebugPort (
    CHAR16 *TextDeviceNode
   )
 {
-  VENDOR_DEFINED_MESSAGING_DEVICE_PATH  *Vend;
+  VENDOR_DEVICE_PATH  *Vend;
 
-  Vend = (VENDOR_DEFINED_MESSAGING_DEVICE_PATH *) CreateDeviceNode (
+  Vend = (VENDOR_DEVICE_PATH *) CreateDeviceNode (
                                                     MESSAGING_DEVICE_PATH,
                                                     MSG_VENDOR_DP,
-                                                    (UINT16) sizeof (VENDOR_DEFINED_MESSAGING_DEVICE_PATH)
+                                                    (UINT16) sizeof (VENDOR_DEVICE_PATH)
                                                     );
 
-  CopyGuid (&Vend->Guid, &gEfiDebugPortDevicePathGuid);
+  CopyGuid (&Vend->Guid, &gEfiDebugPortProtocolGuid);
 
   return (EFI_DEVICE_PATH_PROTOCOL *) Vend;
 }
@@ -1906,22 +1915,42 @@ ConvertFromTextUsbClass (
   PIDStr      = GetNextParamStr (&TextDeviceNode);
   if (UsbClassText->ClassExist) {
     ClassStr = GetNextParamStr (&TextDeviceNode);
-    UsbClass->DeviceClass = (UINT8) Strtoi (ClassStr);
+    if (*ClassStr == L'\0') {
+      UsbClass->DeviceClass = 0xFF;
+    } else {
+      UsbClass->DeviceClass = (UINT8) Strtoi (ClassStr);
+    }
   } else {
     UsbClass->DeviceClass = UsbClassText->Class;
   }
   if (UsbClassText->SubClassExist) {
     SubClassStr = GetNextParamStr (&TextDeviceNode);
-    UsbClass->DeviceSubClass = (UINT8) Strtoi (SubClassStr);
+    if (*SubClassStr == L'\0') {
+      UsbClass->DeviceSubClass = 0xFF;
+    } else {
+      UsbClass->DeviceSubClass = (UINT8) Strtoi (SubClassStr);
+    }
   } else {
     UsbClass->DeviceSubClass = UsbClassText->SubClass;
   }
 
   ProtocolStr = GetNextParamStr (&TextDeviceNode);
 
-  UsbClass->VendorId        = (UINT16) Strtoi (VIDStr);
-  UsbClass->ProductId       = (UINT16) Strtoi (PIDStr);
-  UsbClass->DeviceProtocol  = (UINT8) Strtoi (ProtocolStr);
+  if (*VIDStr == L'\0') {
+    UsbClass->VendorId        = 0xFFFF;
+  } else {
+    UsbClass->VendorId        = (UINT16) Strtoi (VIDStr);
+  }
+  if (*PIDStr == L'\0') {
+    UsbClass->ProductId       = 0xFFFF;
+  } else {
+    UsbClass->ProductId       = (UINT16) Strtoi (PIDStr);
+  }
+  if (*ProtocolStr == L'\0') {
+    UsbClass->DeviceProtocol  = 0xFF;
+  } else {
+    UsbClass->DeviceProtocol  = (UINT8) Strtoi (ProtocolStr);
+  }
 
   return (EFI_DEVICE_PATH_PROTOCOL *) UsbClass;
 }
@@ -3261,7 +3290,15 @@ DevPathFromTextSata (
                                 (UINT16) sizeof (SATA_DEVICE_PATH)
                                 );
   Sata->HBAPortNumber            = (UINT16) Strtoi (Param1);
-  Sata->PortMultiplierPortNumber = (UINT16) Strtoi (Param2);
+
+  //
+  // According to UEFI spec, if PMPN is not provided, the default is 0xFFFF
+  //
+  if (*Param2 == L'\0' ) {
+    Sata->PortMultiplierPortNumber = 0xFFFF;
+  } else {
+    Sata->PortMultiplierPortNumber = (UINT16) Strtoi (Param2);
+  }
   Sata->Lun                      = (UINT16) Strtoi (Param3);
 
   return (EFI_DEVICE_PATH_PROTOCOL *) Sata;
diff --git a/BaseTools/Source/C/Include/Protocol/DevicePath.h b/BaseTools/Source/C/Include/Protocol/DevicePath.h
index 68bb37e479..0295582cbd 100644
--- a/BaseTools/Source/C/Include/Protocol/DevicePath.h
+++ b/BaseTools/Source/C/Include/Protocol/DevicePath.h
@@ -1380,7 +1380,7 @@ extern EFI_GUID  gEfiDebugPortVariableGuid;
 // DebugPort device path definitions...
 //
 #define DEVICE_PATH_MESSAGING_DEBUGPORT EFI_DEBUGPORT_PROTOCOL_GUID
-extern EFI_GUID  gEfiDebugPortDevicePathGuid;
+extern EFI_GUID  gEfiDebugPortProtocolGuid;
 
 typedef struct {
   EFI_DEVICE_PATH_PROTOCOL  Header;