The problem of modeling the distribution of dark matter in galaxies in terms of equilibrium configurations of collisionless self-gravitating quantum particles is considered. We first summarize the pioneering model of a Newtonian self-gravitating Fermi gas in thermodynamic equilibrium developed by Ruffini and Stella (1983), which is shown to be a generalization of the King model for fermions. We further review the extension of the former model developed by Gao, Merafina and Ruffini (1990), done for any degree of fermion degeneracy at the center (θ 0), within general relativity. Finally, we present here for the first time the solutions of the density profiles and rotation curves corresponding to the model of Gao et al. Those solutions have a definite mass M h and a circular velocity v h at the halo radius r h of the configurations, which are typical of spiral galaxies. This treatment allows us to determine a novel core-halo morphology for the dark-matter profiles, as well as a novel bound on the particle mass associated with those profiles.