  We construct a minimal circuit, based on the top-transmon design, to rotate a
qubit formed out of four Majorana zero-modes at the edge of a two-dimensional
topological insulator. Unlike braiding operations, generic rotations have no
topological protection, but they do allow for a full characterization of the
coherence times of the Majorana qubit. The rotation is controlled by variation
of the flux through a pair of split Josephson junctions in a Cooper pair box,
without any need to adjust gate voltages. The Rabi oscillations of the Majorana
qubit can be monitored via oscillations in the resonance frequency of the
microwave cavity that encloses the Cooper pair box.
