Pion and eta production in elementary and heavy-ion collisions at SIS energies

A main emphasis of the HADES program is on the dielectron signal from the early phase of heavy-ion collisions. We discuss the data with respect to the emission of charged hadrons, specifically the production of π+ and π− mesons, which are related to neutral pions representing a dominant contribution to the dielectron yield. In addition, inclusive pion production obtained with the photon-conversion method is disscused. Preliminary results from Au+Au at 1.23 AGeV are presented