/** @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); | |
} |