newlib: persist rtc clk corrections
#include <sys/time.h>
#include <sys/lock.h>
+#include "esp_attr.h"
#include "esp_system.h"
#include "soc/rtc.h"
@@ -60,7 +61,7 @@ static uint64_t s_boot_time; // when RTC is used to persist time, two RTC_STORE
static _lock_t s_boot_time_lock;
static _lock_t s_esp_rtc_time_lock;
-static uint64_t s_esp_rtc_time_us, s_rtc_last_ticks;
+static RTC_DATA_ATTR uint64_t s_esp_rtc_time_us = 0, s_rtc_last_ticks = 0;
#if defined( CONFIG_ESP_TIME_FUNCS_USE_ESP_TIMER ) || defined( CONFIG_ESP_TIME_FUNCS_USE_RTC_TIMER )
uint64_t esp_time_impl_get_time_since_boot(void)
