TIMER_ALARM_HIGH
gf_iowrite32(0, base + TIMER_ALARM_HIGH);
gf_iowrite32(upper_32_bits(now), base + TIMER_ALARM_HIGH);
rtc_alarm_high = gf_ioread32(base + TIMER_ALARM_HIGH);
gf_iowrite32((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH);