- EC Lib

This wraps Blizzard driverlib and implements the EC chip interface defined
by Google. See below diagram for architecture.


  +--------------------+
  |   Host BIOS/OS     |
  +--------------------+

 ---- host interface ----

  +--------------------+
  | Google EC features |
  +--------------------+

 ---- chip interface ----  The interface is defined in
                           src/platform/ec/chip_interface/*.
  +--------------------+   But the real implementation is in EC Lib.
  |       EC Lib       |
  +--------------------+
  | Blizzard low level |
  |   driver, the      |
  |   driverlib.       |
  +--------------------+


Build Options
=============

NOTE: see include/config.h for the current list.  The information
below will be moved there over time.

- CONFIG_WATCHDOG_HELP

	Try to detect a watchdog that is about to fire, and print a trace.
	This is needed on STM32, where the independent watchdog has no early
	warning feature and the windowed watchdog has a very short period.

- CONFIG_AC_POWER_STATUS

	Monitor the state of the AC power input and drive out a GPIO to
	the AP indicating this state. The GPIO will be driven low when
	AC power is not connected, and high when it is connected. This
	uses GPIO_AC_STATUS for this purpose.