Accessing the EC space
======================

The ACPI implementation uses the standard I/O ports 0x62 and 0x66 to access the
EC functionality. Accesses to these ports must be directed to the LPC bus to
which the EC is connected.


Interfacing with the ASL files
==============================

The mainboard code must define several variables for the ASL files.

* EC_SCI
  Defines the General Purpose Event (GPE) corresponding to the EC's SCI line.
* EC_ACPI_LID_SWITCH_OBJECT
  Defines the APCI object which reads the state of the lid, with 0 = open, and
  1 = closed. This is usually the bit which reads the GPIO input corresponding
  to the lid switch.
* PNOT()
  The mainboard must define a PNOT method to handle power state notifications
  and Notify CPU device objects to re-evaluate their _PPC and _CST tables.