diff --git a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
index 8216195c62..82d0dd5855 100644
--- a/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.c
@@ -52,7 +52,8 @@ typedef struct {
 } UART_INFO;
 
 UART_INFO  mUartInfo[MAX_SIZE];
-UINT8      mUartCount = 0;
+UINT8      mUartCount                     = 0;
+BOOLEAN    mBaseSerialPortLibHobAtRuntime = FALSE;
 
 /**
   Reads an 8-bit register. If UseMmio is TRUE, then the value is read from
@@ -285,6 +286,11 @@ SerialPortWrite (
     UseMmio     = mUartInfo[Count].UseMmio;
     Stride      = mUartInfo[Count].RegisterStride;
 
+    if (UseMmio && mBaseSerialPortLibHobAtRuntime) {
+      Count++;
+      continue;
+    }
+
     if (BaseAddress == 0) {
       Count++;
       continue;
@@ -294,6 +300,13 @@ SerialPortWrite (
     BytesLeft  = NumberOfBytes;
 
     while (BytesLeft != 0) {
+      //
+      // Wait for the serial port to be ready, to make sure both the transmit FIFO
+      // and shift register empty.
+      //
+      while ((SerialPortReadRegister (BaseAddress, R_UART_LSR, UseMmio, Stride) & B_UART_LSR_TXRDY) == 0) {
+      }
+
       //
       // Fill the entire Tx FIFO
       //
diff --git a/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c
new file mode 100644
index 0000000000..6106e9a933
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.c
@@ -0,0 +1,56 @@
+/** @file
+  UART Serial Port library functions.
+
+  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+#include <Uefi.h>
+
+extern BOOLEAN  mBaseSerialPortLibHobAtRuntime;
+
+/**
+  Set mSerialIoUartLibAtRuntime flag as TRUE after ExitBootServices.
+
+  @param[in]  Event   The Event that is being processed.
+  @param[in]  Context The Event Context.
+
+**/
+STATIC
+VOID
+EFIAPI
+BaseSerialPortLibHobExitBootServicesEvent (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  mBaseSerialPortLibHobAtRuntime = TRUE;
+}
+
+/**
+  The constructor function registers a callback for the ExitBootServices event.
+
+  @param[in]  ImageHandle   The firmware allocated handle for the EFI image.
+  @param[in]  SystemTable   A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS   The operation completed successfully.
+  @retval other         Either the serial port failed to initialize or the
+                        ExitBootServices event callback registration failed.
+**/
+EFI_STATUS
+EFIAPI
+DxeBaseSerialPortLibHobConstructor (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_EVENT  SerialPortLibHobExitBootServicesEvent;
+
+  return SystemTable->BootServices->CreateEvent (
+                                      EVT_SIGNAL_EXIT_BOOT_SERVICES,
+                                      TPL_NOTIFY,
+                                      BaseSerialPortLibHobExitBootServicesEvent,
+                                      NULL,
+                                      &SerialPortLibHobExitBootServicesEvent
+                                      );
+}
diff --git a/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
new file mode 100644
index 0000000000..7bb3a6ae96
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
@@ -0,0 +1,41 @@
+## @file
+#  SerialPortLib instance for UART information retrieved from bootloader.
+#
+#  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = DxeBaseSerialPortLibHob
+  FILE_GUID                      = c8def0c5-48e7-45b8-8299-485ea2e63b2c
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = SerialPortLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_APPLICATION UEFI_DRIVER
+  CONSTRUCTOR                    = DxeBaseSerialPortLibHobConstructor
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+  PcdLib
+  IoLib
+  HobLib
+  TimerLib
+
+[Sources]
+  DxeBaseSerialPortLibHob.c
+  BaseSerialPortLibHob.c
+
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialLineControl
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialFifoControl
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialExtendedTxFifoSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl
+
+[Guids]
+  gUniversalPayloadSerialPortInfoGuid
diff --git a/UefiPayloadPkg/UefiPayloadPkg.dsc b/UefiPayloadPkg/UefiPayloadPkg.dsc
index 9847f189ff..998d222909 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.dsc
+++ b/UefiPayloadPkg/UefiPayloadPkg.dsc
@@ -256,7 +256,11 @@
   SerialPortLib|UefiPayloadPkg/Library/CbSerialPortLib/CbSerialPortLib.inf
   PlatformHookLib|MdeModulePkg/Library/BasePlatformHookLibNull/BasePlatformHookLibNull.inf
 !else
-  SerialPortLib|MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+  !if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
+    SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
+  !else
+    SerialPortLib|MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+  !endif
   PlatformHookLib|UefiPayloadPkg/Library/PlatformHookLib/PlatformHookLib.inf
 !endif
   PlatformBootManagerLib|UefiPayloadPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
@@ -313,6 +317,9 @@
   PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
   DxeHobListLib|UefiPayloadPkg/Library/DxeHobListLibNull/DxeHobListLibNull.inf
   DebugLib|MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
+!if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
+  SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
+!endif
 
 [LibraryClasses.common.DXE_CORE]
   DxeHobListLib|UefiPayloadPkg/Library/DxeHobListLibNull/DxeHobListLibNull.inf
@@ -617,7 +624,7 @@
     <LibraryClasses>
       !if $(MULTIPLE_DEBUG_PORT_SUPPORT) == TRUE
         DebugLib|MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
-        SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/BaseSerialPortLibHob.inf
+        SerialPortLib|UefiPayloadPkg/Library/BaseSerialPortLibHob/DxeBaseSerialPortLibHob.inf
       !endif
       NULL|MdeModulePkg/Library/LzmaCustomDecompressLib/LzmaCustomDecompressLib.inf
   }