edk2/MdeModulePkg/Universal/DebugSupportDxe/DebugSupport.c

/** @file
  Top level C file for debug support driver.  Contains initialization function.

Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "PlDebugSupport.h"

EFI_DEBUG_SUPPORT_PROTOCOL  mDebugSupportProtocolInterface = {
  EFI_ISA,
  GetMaximumProcessorIndex,
  RegisterPeriodicCallback,
  RegisterExceptionCallback,
  InvalidateInstructionCache
};

/**
  Debug Support Driver entry point.

  Checks to see if there's not already a Debug Support protocol installed for
  the selected processor before installing it.

  @param[in] ImageHandle       The firmware allocated handle for the EFI image.
  @param[in] SystemTable       A pointer to the EFI System Table.

  @retval EFI_SUCCESS          The entry point is executed successfully.
  @retval EFI_ALREADY_STARTED  Debug Support protocol is installed already.
  @retval other                Some error occurs when executing this entry point.

**/
EFI_STATUS
EFIAPI
InitializeDebugSupportDriver (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_LOADED_IMAGE_PROTOCOL   *LoadedImageProtocolPtr;
  EFI_STATUS                  Status;
  EFI_HANDLE                  Handle;
  EFI_HANDLE                  *HandlePtr;
  UINTN                       NumHandles;
  EFI_DEBUG_SUPPORT_PROTOCOL  *DebugSupportProtocolPtr;

  //
  // First check to see that the debug support protocol for this processor
  // type is not already installed
  //
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiDebugSupportProtocolGuid,
                  NULL,
                  &NumHandles,
                  &HandlePtr
                  );

  if (Status != EFI_NOT_FOUND) {
    do {
      NumHandles--;
      Status = gBS->OpenProtocol (
                      HandlePtr[NumHandles],
                      &gEfiDebugSupportProtocolGuid,
                      (VOID **)&DebugSupportProtocolPtr,
                      ImageHandle,
                      NULL,
                      EFI_OPEN_PROTOCOL_GET_PROTOCOL
                      );
      if ((Status == EFI_SUCCESS) && (DebugSupportProtocolPtr->Isa == EFI_ISA)) {
        //
        // a Debug Support protocol has been installed for this processor
        //
        FreePool (HandlePtr);
        Status = EFI_ALREADY_STARTED;
        goto ErrExit;
      }
    } while (NumHandles > 0);

    FreePool (HandlePtr);
  }

  //
  // Get our image information and install platform specific unload handler
  //
  Status = gBS->OpenProtocol (
                  ImageHandle,
                  &gEfiLoadedImageProtocolGuid,
                  (VOID **)&LoadedImageProtocolPtr,
                  ImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  ASSERT (!EFI_ERROR (Status));
  if (Status != EFI_SUCCESS) {
    goto ErrExit;
  }

  LoadedImageProtocolPtr->Unload = PlUnloadDebugSupportDriver;

  //
  // Call hook for processor specific initialization
  //
  Status = PlInitializeDebugSupportDriver ();
  ASSERT (!EFI_ERROR (Status));
  if (Status != EFI_SUCCESS) {
    goto ErrExit;
  }

  //
  // Install Debug Support protocol to new handle
  //
  Handle = NULL;
  Status = gBS->InstallProtocolInterface (
                  &Handle,
                  &gEfiDebugSupportProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &mDebugSupportProtocolInterface
                  );
  ASSERT (!EFI_ERROR (Status));
  if (Status != EFI_SUCCESS) {
    goto ErrExit;
  }

ErrExit:
  return Status;
}