HelenOS sources

PTA_BASE_SHIFT     95 kernel/arch/ia64/src/mm/page.c 	pta.map.base = 0 >> PTA_BASE_SHIFT;
PTA_BASE_SHIFT     98 kernel/arch/ia64/src/mm/page.c 	pta.map.base = vhpt_base >> PTA_BASE_SHIFT;
HelenOS homepage, sources at GitHub