struct IO_DRIVER_CREATE_CONTEXT

typedef struct _IO_DRIVER_CREATE_CONTEXT
{
     SHORT Size;
     _ECP_LIST * ExtraCreateParameter;
     PVOID DeviceObjectHint;
     PTXN_PARAMETER_BLOCK TxnParameters;
} IO_DRIVER_CREATE_CONTEXT, *PIO_DRIVER_CREATE_CONTEXT;

Windows Vista Kernel Structures