1 files changed, 135 insertions, 0 deletions
diff --git a/libgloss/m68k/atari/atari-gettod.c b/libgloss/m68k/atari/atari-gettod.c
new file mode 100644
index 0000000..5477916
--- /dev/null
+++ b/libgloss/m68k/atari/atari-gettod.c
@@ -0,0 +1,135 @@
+/*
+	Copyright (C) 2025 Mikael Hildenborg
+	SPDX-License-Identifier: BSD-2-Clause
+*/
+
+#include <sys/time.h>
+#include <time.h>
+#include "atari-gem_errno.h"
+#include "atari-traps.h"
+
+/*
+	Atari can only handle dates from 1980 to 2107.
+	time_t on m68k is 32bit signed, so that gives us an upper limit of 2038.
+	The code below uses that limitation to simplify the code.
+*/
+
+#define SEC_1900_TO_1980 2524521600
+#define SEC_1900_TO_MAX 0x7fffffff
+#define SECONDS_IN_A_DAY (24 * 60 * 60)
+#define SEC_JAN_AND_FEB ((31 + 29) * SECONDS_IN_A_DAY)	// In a leap year
+#define SECONDS_IN_A_YEAR (365 * SECONDS_IN_A_DAY)
+
+static const short month_to_day[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365};
+
+int gettimeofday(struct timeval* tv, void* __tz)
+{
+	struct timezone* tz = __tz;
+	if (tz != 0)
+	{
+		// Support for timezone have been removed from linux glibc, so we just fill in a zero timezone.
+		tz->tz_minuteswest = 0;
+		tz->tz_dsttime = 0;
+	}
+	if (tv != 0)
+	{
+		unsigned short date = trap1_2a();
+		unsigned short time = trap1_2c();
+
+		int year = ((date >> 9) & 0x7f);	// from 1980
+		int month = ((date >> 5) & 0xf) - 1;
+		int day = date & 0x1f;
+		int hour = ((time >> 11) & 0x1f);
+		int min = ((time >> 5) & 0x3f);
+		int sec = (time & 0x1f) * 2;
+
+		// Days passed in current year
+		time_t days = day + month_to_day[month];
+		// Add days for every passed year
+		days += year * 365;
+
+		// Add days for every passed leap year
+		int months = year * 12 + month;	// total months
+		months -= 2;	// remove januari and februari
+		if (months > 0)
+		{
+			// We must have passed at least one leap day.
+			int leap_days = (months / (12*4)) + 1;
+			days += leap_days;
+		}
+
+		// Add it all together
+		tv->tv_sec = (((((days * 24) + hour) * 60) + min) * 60) + sec + SEC_1900_TO_1980;
+		tv->tv_usec = 0;
+	}
+	return 0;
+}
+
+int settimeofday(const struct timeval* tv, const struct timezone* tz)
+{
+	// Support for timezone have been removed from linux glibc, so we just ignore it.
+	if (tv != 0)
+	{
+		if (tv->tv_sec < SEC_1900_TO_1980 || tv->tv_sec >= SEC_1900_TO_MAX)
+		{
+			// Outside the ranges we can handle.
+			gem_error_to_errno(GEM_EBADRQ);
+			return -1;
+		}
+
+		time_t seconds = tv->tv_sec - SEC_1900_TO_1980;
+		int year = 0;
+		time_t ysec = SECONDS_IN_A_YEAR;
+		do
+		{
+			ysec = SECONDS_IN_A_YEAR;
+			if ((year % 4) == 0)
+			{
+				ysec += SECONDS_IN_A_DAY;
+			}
+			++year;
+			seconds -= ysec;
+		} while (seconds >= 0);
+		--year;
+		seconds += ysec;
+
+		int minutes = seconds / 60;
+		int hours = minutes / 60;
+		int days = hours / 24;
+		int month = 0;
+		int leap = year % 4;
+		short ld = month_to_day[0];
+		for (int m = 0; m < 12; ++m)
+		{
+			short d = month_to_day[m + 1];
+			if (leap == 0 && m > 0) {d += 1;}
+			if (d > days)
+			{
+				month = m;
+				days -= ld;
+				break;
+			}
+			ld = d;
+		}
+
+		unsigned short date = (unsigned short)(year << 9);
+		date |= (unsigned short)((month + 1) << 5);
+		date |= (unsigned short)days;
+		unsigned short time = (unsigned short)((hours % 24) << 11);
+		time |= (unsigned short)((minutes % 60) << 5);
+		time |= (unsigned short)((seconds % 60) >> 1);
+
+		int err;
+		if ((err = trap1_2b(date)) < 0)
+		{
+			gem_error_to_errno(err);
+			return -1;
+		}
+		if ((err = trap1_2d(time)) < 0)
+		{
+			gem_error_to_errno(err);
+			return -1;
+		}
+	}
+	return 0;
+}