[PATCH 4/4] ArmPlatformPkg: add PL011 UART runtime debug driver

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Implement the new runtime debug output protocol on top of a PL011 UART.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.c   | 144 ++++++++++++++++++++
 ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.inf |  62 +++++++++
 2 files changed, 206 insertions(+)

diff --git a/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.c b/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.c
new file mode 100644
index 000000000000..155b2c50d463
--- /dev/null
+++ b/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.c
@@ -0,0 +1,144 @@
+/** @file
+  Runtime driver to produce debug output on a PL011 UART
+
+  Copyright (c) 2018, Linaro, Ltd. All rights reserved.<BR>
+
+  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
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <PiDxe.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/PL011UartLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeLib.h>
+#include <Protocol/RuntimeDebugOutput.h>
+
+STATIC UINTN        mUartBase;
+STATIC EFI_EVENT    mVirtualAddressChangeEvent;
+
+/**
+  Write data from buffer to debug output device
+
+  Writes NumberOfBytes data bytes from Buffer to the debug output device.
+  The number of bytes actually written to the 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 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.
+
+**/
+STATIC
+UINTN
+PL011RuntimeDebugOutputWrite (
+  IN  EDK2_RUNTIME_DEBUG_OUTPUT_PROTOCOL  *This,
+  IN  UINT8                               *Buffer,
+  IN  UINTN                               NumberOfBytes
+  )
+{
+  return PL011UartWrite (mUartBase, Buffer, NumberOfBytes);
+}
+
+STATIC EDK2_RUNTIME_DEBUG_OUTPUT_PROTOCOL mRuntimeDebugOutput = {
+  PL011RuntimeDebugOutputWrite
+};
+
+/**
+  Fixup internal data so that EFI can be called in virtual mode.
+
+  @param[in]    Event   The Event that is being processed
+  @param[in]    Context Event Context
+**/
+STATIC
+VOID
+EFIAPI
+VirtualNotifyEvent (
+  IN EFI_EVENT        Event,
+  IN VOID             *Context
+  )
+{
+  EfiConvertPointer (0x0, (VOID **)&mUartBase);
+}
+
+EFI_STATUS
+EFIAPI
+PL011RuntimeDebugOutputDxeEntry (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS          Status;
+  EFI_HANDLE          Handle;
+  UINT64              BaudRate;
+  UINT32              ReceiveFifoDepth;
+  EFI_PARITY_TYPE     Parity;
+  UINT8               DataBits;
+  EFI_STOP_BITS_TYPE  StopBits;
+
+  mUartBase        = (UINTN)FixedPcdGet64 (PcdSerialRegisterBase);
+  BaudRate         = FixedPcdGet64 (PcdUartDefaultBaudRate);
+  ReceiveFifoDepth = 0;         // Use default FIFO depth
+  Parity           = (EFI_PARITY_TYPE)FixedPcdGet8 (PcdUartDefaultParity);
+  DataBits         = FixedPcdGet8 (PcdUartDefaultDataBits);
+  StopBits         = (EFI_STOP_BITS_TYPE) FixedPcdGet8 (PcdUartDefaultStopBits);
+
+  Status = PL011UartInitializePort (mUartBase, FixedPcdGet32 (PL011UartClkInHz),
+             &BaudRate, &ReceiveFifoDepth, &Parity, &DataBits, &StopBits);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Register for the virtual address change event
+  //
+  Status = gBS->CreateEventEx (EVT_NOTIFY_SIGNAL, TPL_NOTIFY,
+                  VirtualNotifyEvent, NULL, &gEfiEventVirtualAddressChangeGuid,
+                  &mVirtualAddressChangeEvent);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Declare the UART MMIO region as EFI_MEMORY_RUNTIME
+  //
+  Status = gDS->AddMemorySpace (EfiGcdMemoryTypeMemoryMappedIo, mUartBase,
+                  SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
+  if (EFI_ERROR (Status)) {
+    goto CloseEvent;
+  }
+
+  Status = gDS->SetMemorySpaceAttributes (mUartBase, SIZE_4KB,
+                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
+  if (EFI_ERROR (Status)) {
+    goto CloseEvent;
+  }
+
+  Handle = NULL;
+  Status = gBS->InstallMultipleProtocolInterfaces (&Handle,
+                  &gEdkiiRuntimeDebugOutputProtocolGuid, &mRuntimeDebugOutput,
+                  NULL);
+  if (EFI_ERROR (Status)) {
+    goto CloseEvent;
+  }
+
+  return EFI_SUCCESS;
+
+CloseEvent:
+  gBS->CloseEvent (mVirtualAddressChangeEvent);
+
+  return Status;
+}
diff --git a/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.inf b/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.inf
new file mode 100644
index 000000000000..28a8e514552e
--- /dev/null
+++ b/ArmPlatformPkg/Drivers/PL011RuntimeDebugOutputDxe/PL011RuntimeDebugOutputDxe.inf
@@ -0,0 +1,62 @@
+#/** @file
+#  Runtime driver to produce debug output on a PL011 UART
+#
+#  Copyright (c) 2018, Linaro, Ltd. All rights reserved.<BR>
+#
+#  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
+#  http://opensource.org/licenses/bsd-license.php
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x0001001A
+  BASE_NAME                      = PL011RuntimeDebugOutputDxe
+  FILE_GUID                      = 494297ca-9205-463a-aae5-215ffd067cbb
+  MODULE_TYPE                    = DXE_RUNTIME_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = PL011RuntimeDebugOutputDxeEntry
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = AARCH64 ARM
+#
+
+[Sources.common]
+  PL011RuntimeDebugOutputDxe.c
+
+[Packages]
+  ArmPlatformPkg/ArmPlatformPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  DxeServicesTableLib
+  PcdLib
+  PL011UartLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  UefiRuntimeLib
+
+[Guids]
+  gEfiEventVirtualAddressChangeGuid             ## CONSUMES # Event
+
+[Protocols]
+  gEdkiiRuntimeDebugOutputProtocolGuid          ## PROTOCOL ALWAYS_PRODUCED
+
+[FixedPcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterBase
+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultBaudRate
+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultDataBits
+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultParity
+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultStopBits
+  gArmPlatformTokenSpaceGuid.PL011UartClkInHz
+
+[Depex]
+  TRUE
-- 
2.11.0