PORTMAP_L0_MASK
KASSERT(bit <= (PORTMAP_L0_MASK + 1));
KASSERT((unsigned)bit <= (PORTMAP_L0_MASK + 1));
chunk_bit = bit & PORTMAP_L0_MASK;
chunk_bit = bit & PORTMAP_L0_MASK;
KASSERT(v <= PORTMAP_L0_MASK);
chunk_bit = bit & PORTMAP_L0_MASK;