1. A data processing system supporting a secure domain and a non-secure domain, the system comprising: a processor device having operating modes in the secure domain and non-secure domain, the processor device to execute a secure application in the secure domain, and a hardware component with a property, said property having a secure state, wherein said property in the secure state can only be reconfigured responsive to instructions received from the secure domain, wherein said secure application is operative to implement a configuration service to configure the property of the hardware component in the secure state, responsive to a request received from the non-secure domain according to an application programming interface associated with the secure application, and wherein the hardware component comprises plural sub-components, the plural sub-components include a first subcomponent and a second sub-component, wherein the first sub-component has said property that can only be reconfigured responsive to instructions received from the secure domain and the second sub-component does not have a property that can only be reconfigured responsive to instructions received from the secure domain; wherein the hardware component has a set of configuration options and the application programming interface exposes only a sub-set of the configuration options of the hardware component to applications in the non-secure domain.