Variable values can be assigned when the adapter is started by using the -D option. Variables assigned by using this method have a static lifetime. Default variables that are locally scoped cannot be assigned a value by using this method.
The value that is assigned by the switch can be overridden by a standard variable assignment through either pattern matching or by a variable assignment statement. To define a variable so that the -D option overrides the value set in the ASL script, define the variable as a default variable in the ASL script.