system76-edk2/MdePkg/Library/UefiDriverEntryPoint/DriverEntryPoint.c

/** @file
  Entry point to a EFI/DXE driver.

Copyright (c) 2006 - 2007, Intel Corporation<BR>
All rights reserved. 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 <Uefi.h>

#include <Protocol/LoadedImage.h>

#include <Library/UefiDriverEntryPoint.h>
#include <Library/DebugLib.h>
#include <Library/UefiBootServicesTableLib.h>


/**
  Unload function that is registered in the LoadImage protocol.  It un-installs
  protocols produced and deallocates pool used by the driver.  Called by the core
  when unloading the driver.

  @param  ImageHandle ImageHandle of the loaded driver.

  @return Status returned by all unload().

**/
EFI_STATUS
EFIAPI
_DriverUnloadHandler (
  EFI_HANDLE ImageHandle
  )
{
  EFI_STATUS  Status;

  //
  // If an UnloadImage() handler is specified, then call it
  //
  Status = ProcessModuleUnloadList (ImageHandle);

  //
  // If the driver specific unload handler does not return an error, then call all of the
  // library destructors.  If the unload handler returned an error, then the driver can not be
  // unloaded, and the library destructors should not be called
  //
  if (!EFI_ERROR (Status)) {
    ProcessLibraryDestructorList (ImageHandle, gST);
  }

  //
  // Return the status from the driver specific unload handler
  //
  return Status;
}


/**
  The entry point of PE/COFF Image for a DXE Driver, DXE Runtime Driver, DXE SMM Driver, or UEFI Driver. 

  This function is the entry point for a DXE Driver, DXE Runtime Driver, DXE SMM Driver,
  or UEFI Driver.  This function must call ProcessLibraryConstructorList() and
  ProcessModuleEntryPointList(). If the return status from ProcessModuleEntryPointList()
  is an error status, then ProcessLibraryDestructorList() must be called. The return value
  from ProcessModuleEntryPointList() is returned. If _gDriverUnloadImageCount is greater
  than zero, then an unload handler must be registered for this image and the unload handler
  must invoke ProcessModuleUnloadList().
  If _gUefiDriverRevision is not zero and SystemTable->Hdr.Revision is less than _gUefiDriverRevison,
  then return EFI_INCOMPATIBLE_VERSION.


  @param  ImageHandle  ImageHandle of the loaded driver.
  @param  SystemTable  Pointer to the EFI System Table.

  @retval  EFI_SUCCESS               The DXE Driver, DXE Runtime Driver, DXE SMM Driver,
                                     or UEFI Driver exited normally.
  @retval  EFI_INCOMPATIBLE_VERSION  _gUefiDriverRevision is greater than SystemTable->Hdr.Revision.
  @retval  Other                     Return value from ProcessModuleEntryPointList().

**/
EFI_STATUS
EFIAPI
_ModuleEntryPoint (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS                 Status;
  EFI_LOADED_IMAGE_PROTOCOL  *LoadedImage;

  if (_gUefiDriverRevision != 0) {
    //
    // Make sure that the EFI/UEFI spec revision of the platform is >= EFI/UEFI spec revision of the driver
    //
    if (SystemTable->Hdr.Revision < _gUefiDriverRevision) {
      return EFI_INCOMPATIBLE_VERSION;
    }
  }

  //
  // Call constructor for all libraries
  //
  ProcessLibraryConstructorList (ImageHandle, SystemTable);

  //
  //  Install unload handler...
  //
  if (_gDriverUnloadImageCount != 0) {
    Status = gBS->HandleProtocol (
                    ImageHandle,
                    &gEfiLoadedImageProtocolGuid,
                    (VOID **)&LoadedImage
                    );
    ASSERT_EFI_ERROR (Status);
    LoadedImage->Unload = _DriverUnloadHandler;
  }

  //
  // Call the driver entry point
  //
  Status = ProcessModuleEntryPointList (ImageHandle, SystemTable);

  //
  // If all of the drivers returned errors, then invoke all of the library destructors
  //
  if (EFI_ERROR (Status)) {
    ProcessLibraryDestructorList (ImageHandle, SystemTable);
  }

  //
  // Return the cummalative return status code from all of the driver entry points
  //
  return Status;
}


/**
  Required by the EBC compiler and identical in functionality to _ModuleEntryPoint(). 

  This function is required to call _ModuleEntryPoint() passing in ImageHandle, and SystemTable.

  @param  ImageHandle ImageHandle of the loaded driver.
  @param  SystemTable Pointer to the EFI System Table.

  @retval  EFI_SUCCESS               The DXE Driver, DXE Runtime Driver, DXE SMM Driver,
                                     or UEFI Driver exited normally.
  @retval  EFI_INCOMPATIBLE_VERSION  _gUefiDriverRevision is greater than SystemTable->Hdr.Revision.
  @retval  Other                     Return value from ProcessModuleEntryPointList().
**/
EFI_STATUS
EFIAPI
EfiMain (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  return _ModuleEntryPoint (ImageHandle, SystemTable);
}