Boot Service的定义在./MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c

 

首先，程序的入口是_ModuleEntryPoint，其中会调用  ProcessLibraryConstructorList，而该函数会调用UefiBootServicesTableLibConstructor等给gST等指针进行赋值

 

ProcessLibraryConstructorList是自动生成的。在autogen.c中定义

 

 

在MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.c

EFI_SYSTEM_TABLE   *gST         = NULL;

 

EFI_STATUS

EFIAPI

UefiBootServicesTableLibConstructor (

  IN EFI_HANDLE        ImageHandle,

  IN EFI_SYSTEM_TABLE  *SystemTable

  )

{

  //

  // Cache the Image Handle

  //

  gImageHandle = ImageHandle;

  ASSERT (gImageHandle != NULL);

 

  //

  // Cache pointer to the EFI System Table

  //

  gST = SystemTable;//这里进行的设定过程

  ASSERT (gST != NULL);

 

  //

  // Cache pointer to the EFI Boot Services Table

  //

  gBS = SystemTable->BootServices;

  ASSERT (gBS != NULL);

 

  return EFI_SUCCESS;

}

 

EFI_STATUS

EFIAPI

_ModuleEntryPoint (

  IN EFI_HANDLE        ImageHandle,

  IN EFI_SYSTEM_TABLE  *SystemTable

  )

{

  EFI_STATUS                 Status;

 

  if (_gUefiDriverRevision != 0) {

    //

    // Make sure that the EFI/UEFI spec revision of the platform is >= EFI/UEFI spec revision of the application.

    //

    if (SystemTable->Hdr.Revision < _gUefiDriverRevision) {

      return EFI_INCOMPATIBLE_VERSION;

    }

  }

 

  //

  // Call constructor for all libraries.

  //

  ProcessLibraryConstructorList(ImageHandle, SystemTable);

 

  //

  // Call the module's entry point

  //

  Status = ProcessModuleEntryPointList (ImageHandle, SystemTable);

 

  //

  // Process destructor for all libraries.

  //

  ProcessLibraryDestructorList (ImageHandle, SystemTable);

 

  //

  // Return the return status code from the driver entry point

  //

  return Status;

}

 

 

ProcessLibraryConstructorList是自动生成的。在autogen.c中定义

 

VOID

EFIAPI

ProcessLibraryConstructorList (

  IN EFI_HANDLE        ImageHandle,

  IN EFI_SYSTEM_TABLE  *SystemTable

  )

{

  EFI_STATUS  Status;

 

  Status = UefiBootServicesTableLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

  Status = UefiRuntimeServicesTableLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

  Status = PrintLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

  Status = UefiLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

  Status = HobLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

  Status = DxeDebugPrintErrorLevelLibConstructor (ImageHandle, SystemTable);

  ASSERT_EFI_ERROR (Status);

 

}