PTE40_CM_WT
#define PG_CWT PTE40_CM_WT /* writethrough caching */
proto_ro_pte = PTE_VALID|PTE_WIRED|PTE_WP|PTE40_CM_WT;
proto_rw_cwt_pte = PTE_VALID|PTE_WIRED |PTE40_CM_WT;
pte |= (pte & PTE_WP) ? PTE40_CM_WT
ro_c_bits = PTE40_CM_WT; /* this is what the Hibler pmap did */