Scripts and main daemon

This includes the scripts for the YAML parsing and the
main execution point.

Change-Id: If42154c621353b23370b63d4e58f6c75bca8b356
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/scripts/README b/scripts/README
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+# Sensor Config
+This program is only meant to control fans given thermal sensor readings.
+
+All sensors in phosphor-dbus-interfaces for OpenBMC use Sensor.Value as their
+accessor.  This provides read-only access to information.  The goal of the
+configuration is to specify how it can be read and if it's a fan, how the PID
+output can be written.  Initially there'll only be sysfs and passive dbus
+access.  If a writepath for a sensor is a dbus path, then the system will need
+to verify which Control.Fan* interfaces is registered and send values to the
+Target property of that interface.
+
+The min/max specified are to range a writePercent to the sensor.  The current
+FanController object outputs the new fan speed goal as a PWM percentage.  Other
+fan PID control objects may not, and they can leave the fields as 0 & 0.
+
+The only requirement for a sensor is that it isn't writeonly.  Only fans are
+expected to have a writepath set, and in this current version non-fan sensors
+are assumed readonly. 
+
+The sensor names are unique across all zones.
+
+# PID Config
+
+The PID configuation is a list of PIDs per zone.
+