Tools/validate_yaml: add schema validation for module yaml config files

test/module_schema.yaml

@@ -0,0 +1,73 @@
+# Cerberus Validation Schema for module configuration files.
+# See http://docs.python-cerberus.org/en/stable/validation-rules.html
+
+
+module_name:
+    # human-readable module name (used for descriptions, can contain spaces)
+    type: string
+    required: true
+
+serial_config:
+    # UART configuration (optional)
+    # A module can register autostart command(s) that are associated with a
+    # configuration parameter, so that a user can select on which serial port to
+    # run the command.
+    # One or several commands can be defined.
+    type: list
+    minlength: 1
+    schema:
+        type: dict
+        schema:
+            command:
+                # script command that is executed on autostart.
+                # These variables can be used:
+                #  ${SERIAL_DEV}       Serial device (e.g. /dev/ttyS1)
+                #  ${BAUD_PARAM}       param name for the baudrate
+                #  ${i}                instance in [0, N-1] (for multi-instance commands)
+                # It's possible to use multiple lines.
+                type: string
+                required: true
+
+            port_config_param:
+                # Parameter definition to configure on which port to run the
+                # command
+                type: dict
+                required: true
+                schema:
+                    name:
+                        # Parameter name (e.g. TEL_FRSKY_CONFIG, MAV_${i}_CONFIG)
+                        type: string
+                        regex: '[0-9A-Z_]+(\$\{i\}[0-9A-Z_]*)?'
+                        required: true
+                    group:
+                        # Associated parameter group (e.g. GPS)
+                        type: string
+                        required: true
+                    default:
+                        # Default value(s). This can be a string to specify the
+                        # serial tag (e.g. GPS1, TEL1, ...) or a list of strings
+                        # for multiple instances.
+                        # If omitted, the command is disabled by default.
+                        anyof:
+                            - type: string
+                            - type: list
+                              minlength: 1
+                              schema:
+                                  type: string
+            label:
+                # Optional command label (e.g. used in the autostart script).
+                # If omitted, module_name is used.
+                type: string
+            num_instances:
+                # Allow to configure and run multiple instances of a command.
+                # For multiple instances, '${i}' can be used to refer to
+                # an instance, for example in the parameter name or script
+                # command.
+                # Default: 1
+                type: integer
+                min: 1
+
+parameters:
+    type: list
+    # TODO
+