ArmPlatformPkg: Set Juno debug serial port defaults

Juno has several serial ports, one of which may be used for a remote
debug interface (e.g. gdb, WinDbg).  The debug serial port needs to
be distinct from that used for UEFI trace to prevent corruption of
debugger protocol messaging.
The UEFI spec requires that serial devices be initialised to default
settings. (11.8 Serial I/O Protocol - "The default attributes for all
UART-style serial device interfaces are: 115,200 baud, ..."
and 17.3.3 EFI Debugport Variable - "These defaults must be used in the
absence of a DEBUGPORT variable...")

This change adds initialization of the serial device reported in the
ACPI DBG2 table.  The initialisation is done early in the boot to allow
the possibility of remote debug of UEFI itself.

NOTE: This is functionally dependent on the DBG2 table being updated in
OpenPlatformPkg, but is required as a precursor to that change.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

2 files changed, 48 insertions, 3 deletions

diff --git a/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJuno.c b/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJuno.c
index ffff562824..4a57ec5517 100644
--- a/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJuno.c
+++ b/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJuno.c
@@ -1,6 +1,6 @@
 /** @file

 *

-*  Copyright (c) 2013-2014, ARM Limited. All rights reserved.

+*  Copyright (c) 2013-2016, ARM Limited. All rights reserved.

 *

 *  This program and the accompanying materials

 *  are licensed and made available under the terms and conditions of the BSD License

@@ -12,6 +12,8 @@
 *

 **/

 

+#include <Drivers/PL011Uart.h>

+

 #include <Library/IoLib.h>

 #include <Library/ArmPlatformLib.h>

 #include <Library/DebugLib.h>

@@ -112,7 +114,37 @@ ArmPlatformInitialize (
   IN  UINTN                     MpId

   )

 {

-  return RETURN_SUCCESS;

+  RETURN_STATUS       Status;

+  UINT64              BaudRate;

+  UINT32              ReceiveFifoDepth;

+  EFI_PARITY_TYPE     Parity;

+  UINT8               DataBits;

+  EFI_STOP_BITS_TYPE  StopBits;

+

+  Status = RETURN_SUCCESS;

+

+  //

+  // Initialize the Serial Debug UART

+  //

+  if (FixedPcdGet64 (PcdSerialDbgRegisterBase)) {

+    ReceiveFifoDepth = 0; // Use the default value for FIFO depth

+    Parity = (EFI_PARITY_TYPE)FixedPcdGet8 (PcdUartDefaultParity);

+    DataBits = FixedPcdGet8 (PcdUartDefaultDataBits);

+    StopBits = (EFI_STOP_BITS_TYPE)FixedPcdGet8 (PcdUartDefaultStopBits);

+

+    BaudRate = (UINTN)FixedPcdGet64 (PcdSerialDbgUartBaudRate);

+    Status = PL011UartInitializePort (

+               (UINTN)FixedPcdGet64 (PcdSerialDbgRegisterBase),

+               FixedPcdGet32 (PcdSerialDbgUartClkInHz),

+               &BaudRate,

+               &ReceiveFifoDepth,

+               &Parity,

+               &DataBits,

+               &StopBits

+               );

+  }

+

+  return Status;

 }

 

 /**

diff --git a/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJunoLib.inf b/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJunoLib.inf
index 8c8b141c35..77d18f855a 100644
--- a/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJunoLib.inf
+++ b/ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/ArmJunoLib.inf
@@ -1,5 +1,5 @@
 #

-#  Copyright (c) 2013-2015, ARM Limited. All rights reserved.

+#  Copyright (c) 2013-2016, ARM Limited. All rights reserved.

 #

 #  This program and the accompanying materials

 #  are licensed and made available under the terms and conditions of the BSD License

@@ -57,6 +57,19 @@
   gArmJunoTokenSpaceGuid.PcdPciConfigurationSpaceBaseAddress

   gArmJunoTokenSpaceGuid.PcdPciConfigurationSpaceSize

 

+

+  #

+  # PL011 Serial Debug UART

+  #

+  gArmPlatformTokenSpaceGuid.PcdSerialDbgRegisterBase

+  gArmPlatformTokenSpaceGuid.PcdSerialDbgUartBaudRate

+  gArmPlatformTokenSpaceGuid.PcdSerialDbgUartClkInHz

+

+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultBaudRate

+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultDataBits

+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultParity

+  gEfiMdePkgTokenSpaceGuid.PcdUartDefaultStopBits

+

 [Pcd]

   gArmTokenSpaceGuid.PcdPciMmio32Base

   gArmTokenSpaceGuid.PcdPciMmio32Size