readw
#define readw(va) (*(volatile uint16_t *) (va))
#undef readw
readw(const volatile void *addr)
#define readw(addr) readw(addr)
#define readw(a) ofwfb_readw((u_int16_t *)(a))
#define readw(a) (*(uint16_t*)(a))
#define readw(va) (*(volatile uint16_t *) (va))