+#include <time.h>
+#include <stdio.h>
+#include <stdint.h>
+#include "rtc.h"
+
+static unsigned char rtc_mystery_reg[3];
+unsigned char ricoh_memory[0x0F];
+unsigned char ricoh_alarm[0x0F];
+
+void put_rtc_byte(uint32_t address_, uint8_t value, uint8_t rtc_type) {
+ uint32_t address = address_ & 0x3F;
+ address >>= 2;
+ if (rtc_type == RTC_TYPE_MSM) {
+ switch(address) {
+ case 0x0D:
+ rtc_mystery_reg[address - 0x0D] = value & (0x01 | 0x08);
+ break;
+ case 0x0E:
+ case 0x0F:
+ rtc_mystery_reg[address - 0x0D] = value;
+ break;
+ default:
+ return;
+ }
+ }
+ else {
+ int rtc_bank = (rtc_mystery_reg[0] & 0x03);
+ if ((rtc_bank & 0x02) && address < 0x0D) {
+ if (rtc_bank & 0x01) {
+ // Low nibble of value -> high nibble in RTC memory
+ ricoh_memory[address] &= 0x0F;
+ ricoh_memory[address] |= ((value & 0x0F) << 4);
+ }
+ else {
+ // Low nibble of value -> low nibble in RTC memory
+ ricoh_memory[address] &= 0xF0;
+ ricoh_memory[address] |= (value & 0x0F);
+ }
+ return;
+ }
+ else if ((rtc_bank & 0x01) && address < 0x0D) {
+ // RTC alarm stuff, no idea what this is supposed to be for.
+ switch(address) {
+ case 0x00:
+ case 0x01:
+ case 0x09:
+ case 0x0C:
+ ricoh_alarm[address] = 0;
+ break;
+ case 0x03:
+ case 0x06:
+ ricoh_alarm[address] = (value & (0x08 & 0xFF));
+ break;
+ case 0x05:
+ case 0x08:
+ case 0x0B:
+ ricoh_alarm[address] = (value & (0x0C & 0xFF));
+ break;
+ case 0x0A:
+ ricoh_alarm[address] = (value & (0x0E & 0xFF));
+ break;
+ default:
+ ricoh_alarm[address] = value;
+ break;
+ }
+ return;
+ }
+ else if (address >= 0x0D) {
+ rtc_mystery_reg[address - 0x0D] = value;
+ return;
+ }
+ }
+}
+
+uint8_t get_rtc_byte(uint32_t address_, uint8_t rtc_type) {
+ uint32_t address = address_ & 0x3F;
+ address >>= 2;
+ time_t t;
+ time(&t);
+ struct tm *rtc_time = localtime(&t);
+
+ if (rtc_type == RTC_TYPE_RICOH) {
+ int rtc_bank = (rtc_mystery_reg[0] & 0x03);
+ if ((rtc_bank & 0x02) && address < 0x0D) {
+ // Get low/high nibble from memory (bank 2/3)
+ return ((ricoh_memory[address] >> (rtc_bank & 0x01) ? 4 : 0) & 0x0F);
+ }
+ else if ((rtc_bank & 0x01) && address < 0x0D) {
+ // Get byte from alarm
+ return ricoh_alarm[address];
+ }
+ }
+
+ switch (address) {
+ case 0x00: // Seconds low?
+ return rtc_time->tm_sec % 10;
+ case 0x01: // Seconds high?
+ return rtc_time->tm_sec / 10;
+ case 0x02: // Minutes low?
+ return rtc_time->tm_min % 10;
+ case 0x03: // Minutes high?
+ return rtc_time->tm_min / 10;
+ case 0x04: // Hours low?
+ return rtc_time->tm_hour % 10;
+ case 0x05: // Hours high?
+ if (rtc_type == RTC_TYPE_MSM) {
+ if (rtc_mystery_reg[2] & 4) {
+ return ((rtc_time->tm_hour / 10) | (rtc_time->tm_hour >= 12) ? 0x04 : 0x00);
+ }
+ else
+ return rtc_time->tm_hour / 10;
+ }
+ else {
+ if (ricoh_alarm[10] & 0x01) {
+ return rtc_time->tm_hour / 10;
+ }
+ else {
+ return ((rtc_time->tm_hour / 10) | (rtc_time->tm_hour >= 12) ? 0x02 : 0x00);
+ }
+ break;
+ }
+ case 0x06: // Day low?
+ if (rtc_type == RTC_TYPE_MSM)
+ return rtc_time->tm_mday % 10;
+ else
+ return rtc_time->tm_wday;
+ case 0x07: // Day high?
+ if (rtc_type == RTC_TYPE_MSM)
+ return rtc_time->tm_mday / 10;
+ else
+ return rtc_time->tm_mday % 10;
+ case 0x08: // Month low?
+ if (rtc_type == RTC_TYPE_MSM)
+ return (rtc_time->tm_mon + 1) % 10;
+ else
+ return rtc_time->tm_mday / 10;
+ case 0x09: // Month high?
+ if (rtc_type == RTC_TYPE_MSM)
+ return (rtc_time->tm_mon + 1) / 10;
+ else
+ return (rtc_time->tm_mon + 1) % 10;
+ case 0x0A: // Year low?
+ if (rtc_type == RTC_TYPE_MSM)
+ return rtc_time->tm_year % 10;
+ else
+ return (rtc_time->tm_mon + 1) / 10;
+ case 0x0B: // Year high?
+ if (rtc_type == RTC_TYPE_MSM)
+ return rtc_time->tm_year / 10;
+ else
+ return rtc_time->tm_year % 10;
+ case 0x0C: // Day of week?
+ if (rtc_type == RTC_TYPE_MSM)
+ return rtc_time->tm_wday;
+ else
+ return rtc_time->tm_year / 10;
+ case 0x0D: // Mystery register D-F?
+ case 0x0E:
+ case 0x0F:
+ if (rtc_type == RTC_TYPE_MSM) {
+ return rtc_mystery_reg[address - 0x0D];
+ }
+ else {
+ if (address == 0x0D) return rtc_mystery_reg[address - 0x0D];
+ return 0;
+ }
+ default:
+ break;
+ }
+
+ return 0x00;
+}