Re: [PATCH] ArmPkg: add ArmCrashDumpDxe driver

[Leif Lindholm <leif.lindholm@linaro.org>]

On Tue, Sep 05, 2017 at 07:22:49PM +0100, Ard Biesheuvel wrote:
> Even though RELEASE builds produce some diagnostics when a crash
> occurs, they can be rather unhelpful:
> 
>   Synchronous Exception at 0x0000000000000000
> 
> and sometimes, it would be useful to get a full register dump from
> a production machine without having to modify the firmware.
> 
> This can be achieved very easily by incorporating a DEBUG build of
> ARM's DefaultExceptionHandlerLib into a DXE driver, and registering
> its DefaultExceptionHandler entry point as the synchronous exception
> handler, overriding the default one. If we then build this driver
> using the UefiDebugLibConOut DebugLib implementation, we end up
> with a module than can simply be loaded via the Shell on any system.
> 
> Shell> load fs0:ArmCrashDumpDxe.efi
> 
> As a bonus, the crash dump will also appear on the graphical display,
> not only on the serial port.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Really useful thing.
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

> ---
>  ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.c   | 38 +++++++++++++
>  ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.dsc | 56 ++++++++++++++++++++
>  ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.inf | 40 ++++++++++++++
>  3 files changed, 134 insertions(+)
> 
> diff --git a/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.c b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.c
> new file mode 100644
> index 000000000000..221798a26b22
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.c
> @@ -0,0 +1,38 @@
> +/** @file
> +
> +  Copyright (c) 2017, 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/DebugLib.h>
> +#include <Library/DefaultExceptionHandlerLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Protocol/Cpu.h>
> +
> +STATIC EFI_CPU_ARCH_PROTOCOL      *mCpu;
> +
> +EFI_STATUS
> +EFIAPI
> +ArmCrashDumpDxeInitialize (
> +  IN EFI_HANDLE         ImageHandle,
> +  IN EFI_SYSTEM_TABLE   *SystemTable
> +  )
> +{
> +  EFI_STATUS      Status;
> +
> +  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&mCpu);
> +  ASSERT_EFI_ERROR(Status);
> +
> +  return mCpu->RegisterInterruptHandler (mCpu,
> +                                         EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS,
> +                                         &DefaultExceptionHandler);
> +}
> diff --git a/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.dsc b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.dsc
> new file mode 100644
> index 000000000000..5bb27da14bd4
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.dsc
> @@ -0,0 +1,56 @@
> +#/** @file
> +#
> +#  Copyright (c) 2017, 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 Section - statements that will be processed to create a Makefile.
> +#
> +################################################################################
> +[Defines]
> +  PLATFORM_NAME                  = ArmCrashDumpDxe
> +  PLATFORM_GUID                  = 8dc3c2f8-988e-4e32-8fb7-0df43f6d0d8a
> +  PLATFORM_VERSION               = 0.1
> +  DSC_SPECIFICATION              = 0x00010019
> +  OUTPUT_DIRECTORY               = Build/ArmCrashDumpDxe
> +  SUPPORTED_ARCHITECTURES        = AARCH64
> +  BUILD_TARGETS                  = DEBUG
> +  SKUID_IDENTIFIER               = DEFAULT
> +
> +[PcdsFixedAtBuild]
> +  gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x8000004F
> +  gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask|0x27
> +
> +[LibraryClasses]
> +  ArmDisassemblerLib|ArmPkg/Library/ArmDisassemblerLib/ArmDisassemblerLib.inf
> +  BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
> +  BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
> +  DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
> +  DebugPrintErrorLevelLib|MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf
> +  DefaultExceptionHandlerLib|ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf
> +  DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
> +  MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
> +  PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
> +  PeCoffGetEntryPointLib|MdePkg/Library/BasePeCoffGetEntryPointLib/BasePeCoffGetEntryPointLib.inf
> +  PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
> +  SerialPortLib|MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.inf
> +  UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
> +  UefiDriverEntryPoint|MdePkg/Library/UefiDriverEntryPoint/UefiDriverEntryPoint.inf
> +  UefiLib|MdePkg/Library/UefiLib/UefiLib.inf
> +  UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
> +
> +  NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
> +  NULL|MdePkg/Library/BaseStackCheckLib/BaseStackCheckLib.inf
> +
> +[Components.common]
> +  ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.inf
> diff --git a/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.inf b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.inf
> new file mode 100644
> index 000000000000..828b23924920
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmCrashDumpDxe/ArmCrashDumpDxe.inf
> @@ -0,0 +1,40 @@
> +#/** @file
> +#
> +#  Copyright (c) 2017, 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                    = 0x00010018
> +  BASE_NAME                      = ArmCrashDumpDxe
> +  FILE_GUID                      = 0bda00b0-05d6-4bb8-bfc7-058ad13615cf
> +  MODULE_TYPE                    = DXE_DRIVER
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = ArmCrashDumpDxeInitialize
> +
> +[Sources]
> +  ArmCrashDumpDxe.c
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  DebugLib
> +  DefaultExceptionHandlerLib
> +  UefiBootServicesTableLib
> +  UefiDriverEntryPoint
> +
> +[Protocols]
> +  gEfiCpuArchProtocolGuid
> +
> +[Depex]
> +  gEfiCpuArchProtocolGuid
> -- 
> 2.11.0
>