BOOLEAN
InbvEnableDisplayString(
      BOOLEAN bEnable
  );

Routine Description:

    This routine allows the kernel to control when HalDisplayString
    calls make it through to the boot driver, and when they don't.

Arguments:

    bEnable - If TRUE, we will allow HalDisplayString calls to display,
              otherwise we will not.

Returns:

    TRUE  - If display string were currently being dumped.
    FALSE - otherwise.