1 files changed, 56 insertions, 0 deletions
diff --git a/ArmVirtPkg/Library/Fdt16550SerialPortHookLib/Fdt16550SerialPortHookLib.c b/ArmVirtPkg/Library/Fdt16550SerialPortHookLib/Fdt16550SerialPortHookLib.c
new file mode 100644
index 0000000000..803725c3ce
--- /dev/null
+++ b/ArmVirtPkg/Library/Fdt16550SerialPortHookLib/Fdt16550SerialPortHookLib.c
@@ -0,0 +1,56 @@
+/** @file
+  Platform Hook Library instance for 16550 Uart.
+
+  Copyright (c) 2020, ARM Ltd. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+
+#include <Pi/PiBootMode.h>
+#include <Pi/PiHob.h>
+
+#include <Guid/Early16550UartBaseAddress.h>
+#include <Guid/Fdt.h>
+#include <Guid/FdtHob.h>
+
+#include <Library/BaseLib.h>
+#include <Library/HobLib.h>
+#include <Library/PcdLib.h>
+#include <Library/PlatformHookLib.h>
+
+/** Platform hook to retrieve the 16550 UART base address from the GUID Hob
+    that caches the UART base address from early boot stage and store it in
+    PcdSerialRegisterBase.
+
+  @retval RETURN_SUCCESS    Success.
+  @retval RETURN_NOT_FOUND  Serial Port information not found.
+
+**/
+RETURN_STATUS
+EFIAPI
+PlatformHookSerialPortInitialize (
+  VOID
+  )
+{
+  VOID            *Hob;
+  UINT64          *UartBase;
+
+  if (PcdGet64 (PcdSerialRegisterBase) != 0) {
+    return RETURN_SUCCESS;
+  }
+
+  Hob = GetFirstGuidHob (&gEarly16550UartBaseAddressGuid);
+  if ((Hob == NULL) || (GET_GUID_HOB_DATA_SIZE (Hob) != sizeof (*UartBase))) {
+    return RETURN_NOT_FOUND;
+  }
+
+  UartBase = GET_GUID_HOB_DATA (Hob);
+  if ((UINTN)*UartBase == 0) {
+    return RETURN_NOT_FOUND;
+  }
+
+  return (RETURN_STATUS)PcdSet64S (PcdSerialRegisterBase, (UINTN)*UartBase);
+}