This paper proposes a hardware operating system which provides a number of basic resource management services aimed at facilitating the use of dynamically reconfigurable devices in the design and implementation of effective reconfigurable systems. In particular, a number of tedious and error prone low level resource management tasks are automatically supported by the proposed operating system, thus becoming transparent to the designer of the reconfigurable system. The several components of the operating system, as well as their implementation in a hardwate reconfiguration controller, are described in some detail.