Tad Williams: Stone Of Farewell [1991] paperback

In Osten Ard, the evil of the Storm King covers the land and the country is riven by war. Nature, unbalanced by the tide of evil, slips into a permanent winter. Simon, once a kitchen boy, now a hero hiding in the troll stronghold of Yiquanuc, has prophetic dreams. Only he and his companions can save the land, but to do this he must embark on the second part of his quest …to the Stone of Farewell.