Title: Great sky river
Description: From back cover Warner paperback August 2004:

Nearly 100,000 years after first contact with the machines that dominate the universe, only a few hundred humans survive.  Trapped on Snowglade, a barren world near the center of the galaxy, Killeen and his child Toby of the Bishop Tribe are primitive scavengers, homeless and hunted by the ruling "mechs."  Then suddenly, a strange cosmic entity -- neither organic, nor cybernetic nor living matter -- reaches out from a black hole to speak with Killeen.  But can the fallen descendant of starfarers understand this alien being in time -- and seize his only chance to save his family and mankind from final annihilation?
Subjects: Artificial intelligence, Fiction, Black holes (Astronomy), Fiction, science fiction, general, Science fiction