1 files changed, 124 insertions, 0 deletions
diff --git a/ArmVirtPkg/Library/DebugLibFdtPL011Uart/Ram.c b/ArmVirtPkg/Library/DebugLibFdtPL011Uart/Ram.c
new file mode 100644
index 0000000000..bc5be015bd
--- /dev/null
+++ b/ArmVirtPkg/Library/DebugLibFdtPL011Uart/Ram.c
@@ -0,0 +1,124 @@
+/** @file
+  Define DebugLibFdtPL011UartWrite() for modules that can only run from RAM.
+
+  Copyright (C) Red Hat
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi/UefiBaseType.h>
+#include <Uefi/UefiMultiPhase.h>
+#include <Pi/PiBootMode.h>
+#include <Pi/PiHob.h>
+#include <Library/HobLib.h>
+#include <Library/PL011UartLib.h>
+#include <Library/PcdLib.h>
+#include <Guid/EarlyPL011BaseAddress.h>
+
+#include "Ram.h"
+#include "Write.h"
+
+UINTN          mDebugLibFdtPL011UartAddress;
+RETURN_STATUS  mDebugLibFdtPL011UartPermanentStatus = RETURN_SUCCESS;
+
+/**
+  Statefully initialize both the library instance and the debug PL011 UART.
+**/
+STATIC
+RETURN_STATUS
+Initialize (
+  VOID
+  )
+{
+  CONST VOID                      *Hob;
+  CONST EARLY_PL011_BASE_ADDRESS  *UartBase;
+  RETURN_STATUS                   Status;
+  UINTN                           DebugAddress;
+  UINT64                          BaudRate;
+  UINT32                          ReceiveFifoDepth;
+  EFI_PARITY_TYPE                 Parity;
+  UINT8                           DataBits;
+  EFI_STOP_BITS_TYPE              StopBits;
+
+  if (mDebugLibFdtPL011UartAddress != 0) {
+    return RETURN_SUCCESS;
+  }
+
+  if (RETURN_ERROR (mDebugLibFdtPL011UartPermanentStatus)) {
+    return mDebugLibFdtPL011UartPermanentStatus;
+  }
+
+  Hob = GetFirstGuidHob (&gEarlyPL011BaseAddressGuid);
+  if ((Hob == NULL) || (GET_GUID_HOB_DATA_SIZE (Hob) != sizeof *UartBase)) {
+    Status = RETURN_NOT_FOUND;
+    goto Failed;
+  }
+
+  UartBase = GET_GUID_HOB_DATA (Hob);
+
+  DebugAddress = (UINTN)UartBase->DebugAddress;
+  if (DebugAddress == 0) {
+    Status = RETURN_NOT_FOUND;
+    goto Failed;
+  }
+
+  BaudRate         = (UINTN)PcdGet64 (PcdUartDefaultBaudRate);
+  ReceiveFifoDepth = 0; // Use the default value for Fifo depth
+  Parity           = (EFI_PARITY_TYPE)PcdGet8 (PcdUartDefaultParity);
+  DataBits         = PcdGet8 (PcdUartDefaultDataBits);
+  StopBits         = (EFI_STOP_BITS_TYPE)PcdGet8 (PcdUartDefaultStopBits);
+
+  Status = PL011UartInitializePort (
+             DebugAddress,
+             FixedPcdGet32 (PL011UartClkInHz),
+             &BaudRate,
+             &ReceiveFifoDepth,
+             &Parity,
+             &DataBits,
+             &StopBits
+             );
+  if (RETURN_ERROR (Status)) {
+    goto Failed;
+  }
+
+  mDebugLibFdtPL011UartAddress = DebugAddress;
+  return RETURN_SUCCESS;
+
+Failed:
+  mDebugLibFdtPL011UartPermanentStatus = Status;
+  return Status;
+}
+
+/**
+  (Copied from SerialPortWrite() in "MdePkg/Include/Library/SerialPortLib.h" at
+  commit c4547aefb3d0, with the Buffer non-nullity assertion removed:)
+
+  Write data from buffer to serial device.
+
+  Writes NumberOfBytes data bytes from Buffer to the serial device.
+  The number of bytes actually written to the serial device is returned.
+  If the return value is less than NumberOfBytes, then the write operation failed.
+  If NumberOfBytes is zero, then return 0.
+
+  @param  Buffer           Pointer to the data buffer to be written.
+  @param  NumberOfBytes    Number of bytes to written to the serial device.
+
+  @retval 0                NumberOfBytes is 0.
+  @retval >0               The number of bytes written to the serial device.
+                           If this value is less than NumberOfBytes, then the write operation failed.
+**/
+UINTN
+DebugLibFdtPL011UartWrite (
+  IN UINT8  *Buffer,
+  IN UINTN  NumberOfBytes
+  )
+{
+  RETURN_STATUS  Status;
+
+  Status = Initialize ();
+  if (RETURN_ERROR (Status)) {
+    return 0;
+  }
+
+  return PL011UartWrite (mDebugLibFdtPL011UartAddress, Buffer, NumberOfBytes);
+}