  The HERMES Technologic and Scientific Pathfinder project is a constellation
of six CubeSats aiming to observe transient high-energy events such as the
Gamma Ray Bursts (GRBs). HERMES will be the first space telescope to include a
siswich detector, able to perform spectroscopy in the 2 keV to 2 MeV energy
band. The particular siswich architecture, which combines a solid-state Silicon
Drift Detector and a scintillator crystal, requires specific calibration
procedures that have not been yet standardized in a pipeline. We present in
this paper the HERMES calibration pipeline, mescal, intended for raw HERMES
data energy calibration and formatting. The software is designed to deal with
the particularities of the siswich architecture and to minimize user
interaction, including also an automated calibration line identification
procedure, and an independent calibration of each detector pixel, in its two
different operating modes. The mescal pipeline can set the basis for similar
applications in future siswich telescopes.
