diff --git a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.c b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.c
index e41e74964f..436df8ca96 100644
--- a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.c
+++ b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.c
@@ -1,6 +1,6 @@
 /*++
 
-Copyright (c) 2006 - 2009, Intel Corporation
+Copyright (c) 2006 - 2010, 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
@@ -56,6 +56,51 @@ EFI_DRIVER_BINDING_PROTOCOL gUnixSerialIoDriverBinding = {
   NULL
 };
 
+/**
+  Check the device path node whether it's the Flow Control node or not.
+
+  @param[in] FlowControl    The device path node to be checked.
+  
+  @retval TRUE              It's the Flow Control node.
+  @retval FALSE             It's not.
+
+**/
+BOOLEAN
+IsUartFlowControlNode (
+  IN UART_FLOW_CONTROL_DEVICE_PATH *FlowControl
+  )
+{
+  return (BOOLEAN) (
+           (DevicePathType (FlowControl) == MESSAGING_DEVICE_PATH) &&
+           (DevicePathSubType (FlowControl) == MSG_VENDOR_DP) &&
+           (CompareGuid (&FlowControl->Guid, &gEfiUartDevicePathGuid))
+           );
+}
+
+/**
+  Check the device path node whether it contains Flow Control node or not.
+
+  @param[in] DevicePath     The device path to be checked.
+  
+  @retval TRUE              It contains the Flow Control node.
+  @retval FALSE             It doesn't.
+
+**/
+BOOLEAN
+ContainsFlowControl (
+  IN EFI_DEVICE_PATH_PROTOCOL      *DevicePath
+  )
+{
+  while (!IsDevicePathEnd (DevicePath)) {
+    if (IsUartFlowControlNode ((UART_FLOW_CONTROL_DEVICE_PATH *) DevicePath)) {
+      return TRUE;
+    }
+    DevicePath = NextDevicePathNode (DevicePath);
+  }
+
+  return FALSE;
+}
+
 UINTN
 ConvertBaud2Unix (
   UINT64 BaudRate
@@ -217,10 +262,15 @@ Returns:
 
 --*/
 {
-  EFI_STATUS                Status;
-  EFI_DEVICE_PATH_PROTOCOL  *ParentDevicePath;
-  EFI_UNIX_IO_PROTOCOL      *UnixIo;
-  UART_DEVICE_PATH          *UartNode;
+  EFI_STATUS                          Status;
+  EFI_DEVICE_PATH_PROTOCOL            *ParentDevicePath;
+  EFI_UNIX_IO_PROTOCOL                *UnixIo;
+  UART_DEVICE_PATH                    *UartNode;
+  EFI_DEVICE_PATH_PROTOCOL            *DevicePath;
+  UART_FLOW_CONTROL_DEVICE_PATH       *FlowControlNode;
+  EFI_OPEN_PROTOCOL_INFORMATION_ENTRY *OpenInfoBuffer;
+  UINTN                               EntryCount;
+  UINTN                               Index;
 
   //
   // Check RemainingDevicePath validation
@@ -260,6 +310,17 @@ Returns:
       if ((UartNode->DataBits >= 6) && (UartNode->DataBits <= 8) && (UartNode->StopBits == OneFiveStopBits)) {
         goto Error;
       }
+
+      FlowControlNode = (UART_FLOW_CONTROL_DEVICE_PATH *) NextDevicePathNode (UartNode);
+      if (IsUartFlowControlNode (FlowControlNode)) {
+        //
+        // If the second node is Flow Control Node,
+        //   return error when it request other than hardware flow control.
+        //
+        if ((FlowControlNode->FlowControlMap & ~UART_FLOW_CONTROL_HARDWARE) != 0) {
+          goto Error;
+        }
+      }
     }
   }
 
@@ -275,7 +336,45 @@ Returns:
                   EFI_OPEN_PROTOCOL_BY_DRIVER
                   );
   if (Status == EFI_ALREADY_STARTED) {
-    return EFI_SUCCESS;
+    if (RemainingDevicePath == NULL || IsDevicePathEnd (RemainingDevicePath)) {
+      //
+      // If RemainingDevicePath is NULL or is the End of Device Path Node
+      //
+      return EFI_SUCCESS;
+    }
+    //
+    // When the driver has produced device path with flow control node but RemainingDevicePath only contains UART node,
+    //   return unsupported, and vice versa.
+    //
+    Status = gBS->OpenProtocolInformation (
+                    Handle,
+                    &gEfiUnixIoProtocolGuid,
+                    &OpenInfoBuffer,
+                    &EntryCount
+                    );
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+
+    for (Index = 0; Index < EntryCount; Index++) {
+      if ((OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
+        Status = gBS->OpenProtocol (
+                        OpenInfoBuffer[Index].ControllerHandle,
+                        &gEfiDevicePathProtocolGuid,
+                        (VOID **) &DevicePath,
+                        This->DriverBindingHandle,
+                        Handle,
+                        EFI_OPEN_PROTOCOL_GET_PROTOCOL
+                        );
+        if (!EFI_ERROR (Status) &&
+            (ContainsFlowControl (RemainingDevicePath) ^ ContainsFlowControl (DevicePath))) {
+          Status = EFI_UNSUPPORTED;
+        }
+        break;
+      }
+    }
+    FreePool (OpenInfoBuffer);
+    return Status;
   }
 
   if (EFI_ERROR (Status)) {
@@ -366,21 +465,25 @@ Returns:
   EFI_UNIX_IO_PROTOCOL                *UnixIo;
   UNIX_SERIAL_IO_PRIVATE_DATA         *Private;
   UINTN                               UnixHandle;
-  UART_DEVICE_PATH                    Node;
+  UART_DEVICE_PATH                    UartNode;
   EFI_DEVICE_PATH_PROTOCOL            *ParentDevicePath;
   EFI_OPEN_PROTOCOL_INFORMATION_ENTRY *OpenInfoBuffer;
   UINTN                               EntryCount;
   UINTN                               Index;
   EFI_SERIAL_IO_PROTOCOL              *SerialIo;
   CHAR8                               AsciiDevName[1024];
-  UART_DEVICE_PATH                    *UartNode;
+  UART_DEVICE_PATH                    *Uart;
+  UINT32                              FlowControlMap;
+  UART_FLOW_CONTROL_DEVICE_PATH       *FlowControl;
+  EFI_DEVICE_PATH_PROTOCOL            *TempDevicePath;
+  UINT32                              Control;
 
   DEBUG ((EFI_D_INFO, "SerialIo drive binding start!\r\n"));
   Private   = NULL;
   UnixHandle  = -1;
 
   //
-  // Grab the protocols we need
+  // Get the Parent Device Path
   //
   Status = gBS->OpenProtocol (
                   Handle,
@@ -440,7 +543,7 @@ Returns:
 
     Status = EFI_ALREADY_STARTED;
     for (Index = 0; Index < EntryCount; Index++) {
-      if (OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) {
+      if ((OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
         Status = gBS->OpenProtocol (
                         OpenInfoBuffer[Index].ControllerHandle,
                         &gEfiSerialIoProtocolGuid,
@@ -450,16 +553,35 @@ Returns:
                         EFI_OPEN_PROTOCOL_GET_PROTOCOL
                         );
         if (!EFI_ERROR (Status)) {
-          UartNode = (UART_DEVICE_PATH *) RemainingDevicePath;
+          Uart   = (UART_DEVICE_PATH *) RemainingDevicePath;
           Status = SerialIo->SetAttributes (
-                              SerialIo,
-                              UartNode->BaudRate,
-                              SerialIo->Mode->ReceiveFifoDepth,
-                              SerialIo->Mode->Timeout,
-                              UartNode->Parity,
-                              UartNode->DataBits,
-                              UartNode->StopBits
-                              );
+                               SerialIo,
+                               Uart->BaudRate,
+                               SerialIo->Mode->ReceiveFifoDepth,
+                               SerialIo->Mode->Timeout,
+                               (EFI_PARITY_TYPE) Uart->Parity,
+                               Uart->DataBits,
+                               (EFI_STOP_BITS_TYPE) Uart->StopBits
+                               );
+
+          FlowControl = (UART_FLOW_CONTROL_DEVICE_PATH *) NextDevicePathNode (Uart);
+          if (!EFI_ERROR (Status) && IsUartFlowControlNode (FlowControl)) {
+            Status = SerialIo->GetControl (SerialIo, &Control);
+            if (!EFI_ERROR (Status)) {
+              if (FlowControl->FlowControlMap == UART_FLOW_CONTROL_HARDWARE) {
+                Control |= EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE;
+              } else {
+                Control &= ~EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE;
+              }
+              //
+              // Clear the bits that are not allowed to pass to SetControl
+              //
+              Control &= (EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY |
+                          EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE | EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE | 
+                          EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE);
+              Status = SerialIo->SetControl (SerialIo, Control);
+            }
+          }
         }
         break;
       }
@@ -469,16 +591,18 @@ Returns:
     return Status;
   }
 
+  FlowControl    = NULL;
+  FlowControlMap = 0;
   if (RemainingDevicePath == NULL) {
     //
     // Build the device path by appending the UART node to the ParentDevicePath
     // from the UnixIo handle. The Uart setings are zero here, since
     // SetAttribute() will update them to match the default setings.
     //
-    ZeroMem (&Node, sizeof (UART_DEVICE_PATH));
-    Node.Header.Type     = MESSAGING_DEVICE_PATH;
-    Node.Header.SubType  = MSG_UART_DP;
-    SetDevicePathNodeLength ((EFI_DEVICE_PATH_PROTOCOL *) &Node, sizeof (UART_DEVICE_PATH));
+    ZeroMem (&UartNode, sizeof (UART_DEVICE_PATH));
+    UartNode.Header.Type     = MESSAGING_DEVICE_PATH;
+    UartNode.Header.SubType  = MSG_UART_DP;
+    SetDevicePathNodeLength ((EFI_DEVICE_PATH_PROTOCOL *) &UartNode, sizeof (UART_DEVICE_PATH));
 
   } else if (!IsDevicePathEnd (RemainingDevicePath)) {
     //
@@ -490,7 +614,13 @@ Returns:
     // already checked to make sure the RemainingDevicePath contains settings
     // that we can support.
     //
-    CopyMem (&Node, RemainingDevicePath, sizeof (UART_DEVICE_PATH));
+    CopyMem (&UartNode, RemainingDevicePath, sizeof (UART_DEVICE_PATH));
+    FlowControl = (UART_FLOW_CONTROL_DEVICE_PATH *) NextDevicePathNode (RemainingDevicePath);
+    if (IsUartFlowControlNode (FlowControl)) {
+      FlowControlMap = FlowControl->FlowControlMap;
+    } else {
+      FlowControl    = NULL;
+    }
 
   } else {
     //
@@ -536,12 +666,12 @@ Returns:
 
   Private->SoftwareLoopbackEnable = FALSE;
   Private->HardwareLoopbackEnable = FALSE;
-  Private->HardwareFlowControl    = FALSE;
+  Private->HardwareFlowControl    = (BOOLEAN) (FlowControlMap == UART_FLOW_CONTROL_HARDWARE);
   Private->Fifo.First             = 0;
   Private->Fifo.Last              = 0;
   Private->Fifo.Surplus           = SERIAL_MAX_BUFFER_SIZE;
 
-  CopyMem (&Private->UartDevicePath, &Node, sizeof (UART_DEVICE_PATH));
+  CopyMem (&Private->UartDevicePath, &UartNode, sizeof (UART_DEVICE_PATH));
 
   AddUnicodeString (
     "eng",
@@ -570,6 +700,19 @@ Returns:
                           ParentDevicePath,
                           (EFI_DEVICE_PATH_PROTOCOL *) &Private->UartDevicePath
                           );
+  //
+  // Only produce the FlowControl node when remaining device path has it
+  //
+  if (FlowControl != NULL) {
+    TempDevicePath = Private->DevicePath;
+    if (TempDevicePath != NULL) {
+      Private->DevicePath = AppendDevicePathNode (
+                              TempDevicePath,
+                              (EFI_DEVICE_PATH_PROTOCOL *) FlowControl
+                              );
+      FreePool (TempDevicePath);
+    }
+  }
   if (Private->DevicePath == NULL) {
     Status = EFI_OUT_OF_RESOURCES;
     goto Error;
@@ -876,8 +1019,8 @@ Returns:
 {
   EFI_STATUS                    Status;
   UNIX_SERIAL_IO_PRIVATE_DATA   *Private;
+  UART_DEVICE_PATH              *Uart;
   EFI_TPL                       Tpl;
-  EFI_DEVICE_PATH_PROTOCOL      *NewDevicePath;
 
   Tpl     = gBS->RaiseTPL (TPL_NOTIFY);
   Private = UNIX_SERIAL_IO_PRIVATE_DATA_FROM_THIS (This);
@@ -977,9 +1120,10 @@ Returns:
                         &Private->UnixTermios
                         )) {
     DEBUG ((EFI_D_INFO, "Fail to set options for serial device!\r\n"));
+    gBS->RestoreTPL (Tpl);
     return EFI_DEVICE_ERROR;
   }
-  
+
   //
   //  Update mode
   //
@@ -989,6 +1133,7 @@ Returns:
   Private->SerialIoMode.Parity            = Parity;
   Private->SerialIoMode.DataBits          = DataBits;
   Private->SerialIoMode.StopBits          = StopBits;
+
   //
   // See if Device Path Node has actually changed
   //
@@ -1008,37 +1153,25 @@ Returns:
   Private->UartDevicePath.Parity    = (UINT8) Parity;
   Private->UartDevicePath.StopBits  = (UINT8) StopBits;
 
-  NewDevicePath = AppendDevicePathNode (
-                    Private->ParentDevicePath,
-                    (EFI_DEVICE_PATH_PROTOCOL *) &Private->UartDevicePath
-                    );
-  if (NewDevicePath == NULL) {
-    gBS->RestoreTPL (Tpl);
-    return EFI_DEVICE_ERROR;
-  }
-
+  Status = EFI_SUCCESS;
   if (Private->Handle != NULL) {
+    Uart = (UART_DEVICE_PATH *) (
+             (UINTN) Private->DevicePath
+             + GetDevicePathSize (Private->ParentDevicePath)
+             - END_DEVICE_PATH_LENGTH
+             );
+    CopyMem (Uart, &Private->UartDevicePath, sizeof (UART_DEVICE_PATH));
     Status = gBS->ReinstallProtocolInterface (
                     Private->Handle,
                     &gEfiDevicePathProtocolGuid,
                     Private->DevicePath,
-                    NewDevicePath
+                    Private->DevicePath
                     );
-    if (EFI_ERROR (Status)) {
-      gBS->RestoreTPL (Tpl);
-      return Status;
-    }
   }
 
-  if (Private->DevicePath != NULL) {
-    FreePool (Private->DevicePath);
-  }
-
-  Private->DevicePath = NewDevicePath;
-
   gBS->RestoreTPL (Tpl);
 
-  return EFI_SUCCESS;
+  return Status;
 }
 
 EFI_STATUS
@@ -1066,17 +1199,28 @@ Returns:
 
 --*/
 {
-  UNIX_SERIAL_IO_PRIVATE_DATA *Private;
-  UINTN                       Result;
-  UINTN                       Status;
-  struct termios              Options;
-  EFI_TPL                     Tpl;
+  UNIX_SERIAL_IO_PRIVATE_DATA   *Private;
+  UINTN                         Result;
+  UINTN                         IoStatus;
+  struct termios                Options;
+  EFI_TPL                       Tpl;
+  UART_FLOW_CONTROL_DEVICE_PATH *FlowControl;
+  EFI_STATUS                    Status;
+
+  //
+  // first determine the parameter is invalid
+  //
+  if (Control & (~(EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY |
+                   EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE | EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE | 
+                   EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE))) {
+    return EFI_UNSUPPORTED;
+  }
 
   Tpl     = gBS->RaiseTPL (TPL_NOTIFY);
 
   Private = UNIX_SERIAL_IO_PRIVATE_DATA_FROM_THIS (This);
 
-  Result  = Private->UnixThunk->IoCtl (Private->UnixHandle, TIOCMGET, &Status);
+  Result  = Private->UnixThunk->IoCtl (Private->UnixHandle, TIOCMGET, &IoStatus);
 
   if (Result == -1) {
     Private->UnixThunk->Perror ("SerialSetControl");
@@ -1108,7 +1252,7 @@ Returns:
     Private->HardwareLoopbackEnable = TRUE;
   }
 
-  Result  = Private->UnixThunk->IoCtl (Private->UnixHandle, TIOCMSET, &Status);
+  Result  = Private->UnixThunk->IoCtl (Private->UnixHandle, TIOCMSET, &IoStatus);
 
   if (Result == -1) {
     Private->UnixThunk->Perror ("SerialSetControl");
@@ -1116,9 +1260,32 @@ Returns:
     return EFI_DEVICE_ERROR;
   }
 
+  Status = EFI_SUCCESS;
+  if (Private->Handle != NULL) {
+    FlowControl = (UART_FLOW_CONTROL_DEVICE_PATH *) (
+                    (UINTN) Private->DevicePath
+                    + GetDevicePathSize (Private->ParentDevicePath)
+                    - END_DEVICE_PATH_LENGTH
+                    + sizeof (UART_DEVICE_PATH)
+                    );
+    if (IsUartFlowControlNode (FlowControl) &&
+        ((FlowControl->FlowControlMap == UART_FLOW_CONTROL_HARDWARE) ^ Private->HardwareFlowControl)) {
+      //
+      // Flow Control setting is changed, need to reinstall device path protocol
+      //
+      FlowControl->FlowControlMap = Private->HardwareFlowControl ? UART_FLOW_CONTROL_HARDWARE : 0;
+      Status = gBS->ReinstallProtocolInterface (
+                      Private->Handle,
+                      &gEfiDevicePathProtocolGuid,
+                      Private->DevicePath,
+                      Private->DevicePath
+                      );
+    }
+  }
+
   gBS->RestoreTPL (Tpl);
 
-  return EFI_SUCCESS;
+  return Status;
 }
 
 EFI_STATUS
diff --git a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.h b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.h
index bcd8018e4c..d392f95e80 100644
--- a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.h
+++ b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.h
@@ -120,12 +120,15 @@ extern EFI_COMPONENT_NAME_PROTOCOL  gUnixSerialIoComponentName;
 #define SERIAL_PARITY_DEFAULT   DefaultParity
 #define SERIAL_STOPBITS_DEFAULT DefaultStopBits
 
-#define SERIAL_CONTROL_MASK     (EFI_SERIAL_CLEAR_TO_SEND       | \
-                                 EFI_SERIAL_DATA_SET_READY      | \
-                                 EFI_SERIAL_RING_INDICATE       | \
-                                 EFI_SERIAL_CARRIER_DETECT      | \
-                                 EFI_SERIAL_REQUEST_TO_SEND     | \
-                                 EFI_SERIAL_DATA_TERMINAL_READY | \
+#define SERIAL_CONTROL_MASK     (EFI_SERIAL_CLEAR_TO_SEND                | \
+                                 EFI_SERIAL_DATA_SET_READY               | \
+                                 EFI_SERIAL_RING_INDICATE                | \
+                                 EFI_SERIAL_CARRIER_DETECT               | \
+                                 EFI_SERIAL_REQUEST_TO_SEND              | \
+                                 EFI_SERIAL_DATA_TERMINAL_READY          | \
+                                 EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE     | \
+                                 EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE     | \
+                                 EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE | \
                                  EFI_SERIAL_INPUT_BUFFER_EMPTY)
 
 #define ConvertBaud2Nt(x)       (DWORD) x
diff --git a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.inf b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.inf
index 0dd672b313..e951d80736 100644
--- a/UnixPkg/UnixSerialIoDxe/UnixSerialIo.inf
+++ b/UnixPkg/UnixSerialIoDxe/UnixSerialIo.inf
@@ -57,8 +57,8 @@
 
 
 [Guids]
-  gEfiUnixSerialPortGuid                       # ALWAYS_CONSUMED
-
+  gEfiUnixSerialPortGuid                        # ALWAYS_CONSUMED
+  gEfiUartDevicePathGuid                        # BY_START
 
 [Protocols]
   gEfiSerialIoProtocolGuid                      # PROTOCOL BY_START