#!/bin/sh

LOG_FILE="/home/root/rtc_init.log"
DATE_STR=$(/bin/date '+%Y-%m-%d %H:%M:%S')

echo "[$DATE_STR] RTC check started" > $LOG_FILE

# Try reading RTC
/sbin/hwclock -r >/dev/null 2>&1

if [ $? -eq 0 ]; then
    DATE_STR=$(/bin/date '+%Y-%m-%d %H:%M:%S')
    echo "[$DATE_STR] hwclock -r SUCCESS" >> $LOG_FILE
else
    DATE_STR=$(/bin/date '+%Y-%m-%d %H:%M:%S')
    echo "[$DATE_STR] hwclock -r FAILED -> writing system time to RTC" >> $LOG_FILE

    # small delay to ensure system time is valid (important in embedded boot)
    sleep 5

    /sbin/hwclock -w >/dev/null 2>&1

    if [ $? -eq 0 ]; then
        DATE_STR=$(/bin/date '+%Y-%m-%d %H:%M:%S')
        echo "[$DATE_STR] hwclock -w SUCCESS" >> $LOG_FILE
    else
        DATE_STR=$(/bin/date '+%Y-%m-%d %H:%M:%S')
        echo "[$DATE_STR] hwclock -w FAILED" >> $LOG_FILE
    fi
fi

echo "[$(date '+%Y-%m-%d %H:%M:%S')] RTC check finished" >> $LOG_FILE