utils: add get_datetime and fat32_datetime

include/utils.h

@@ -1,11 +1,15 @@
 #ifndef UTILS_H
 #define UTILS_H
 #include "../include/types.h"
+#include "../include/stdio.h"
+#include <stdint.h>
 
 uint8 inportb(uint16 _port);
 void outportb(uint16 _port, uint8 _data);
 uint8_t get_rtc(uint8_t reg);
 void get_fancy_datetime();
+void get_datetime(uint16_t *year, uint8_t *month, uint8_t *day, uint8_t *hour, uint8_t *minute, uint8_t *second);
+uint32_t fat32_datetime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second);
 
 #define inb inportb
 #define outb outportb

src/utils.c

@@ -33,3 +33,27 @@ void get_fancy_datetime()
         uint8_t second = get_rtc(0x00);
         printf("%X-%X-%X%X %X:%X:%X\n", day_of_month, month, century, year, hour, minute, second);
 }
+
+void get_datetime(uint16_t *year, uint8_t *month, uint8_t *day, uint8_t *hour, uint8_t *minute, uint8_t *second)
+{
+	uint8_t century = get_rtc(0x32);
+	uint8_t year_rtc = get_rtc(0x09);
+
+	*year = century * 100 + year_rtc;
+	*month = get_rtc(0x08);
+	*day = get_rtc(0x07);
+	*hour = get_rtc(0x04);
+	*minute = get_rtc(0x02);
+	*second = get_rtc(0x00);
+}
+
+uint32_t fat32_datetime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second)
+{
+	uint16_t fat_year = year - 1980;
+
+	uint16_t fat_date = (fat_year << 9) | ((month & 0x0F) << 5) | (day & 0x1F);
+	uint16_t fat_time = (hour & 0x1F) << 11 | ((minute & 0x3F) >> 1) << 5 | (second / 2) & 0x1F;
+	uint32_t fat_datetime = ((uint32_t)fat_date << 16) | fat_time;
+
+	return fat_datetime;
+}