Some time manipulation. Added the targets to the .gitignore file.

.gitignore

@@ -10,3 +10,8 @@ build/**
 
 # Some notes.
 LIBC
+
+# Output files
+libc.a
+libgint.a
+gintdemo.g1a

Makefile

@@ -14,7 +14,7 @@
 # Modules
 modules-gint	= core keyboard mmu mpu rtc screen timer \
 		  bopti display gray tales
-modules-libc	= setjmp string stdio stdlib
+modules-libc	= setjmp string stdio stdlib time
 
 # Targets
 target-g1a	= gintdemo.g1a

README.md

@@ -38,7 +38,7 @@ register access and implements a few standard functions.
 Building and installing
 -----------------------
 
-There a some dependencies:
+There are some dependencies:
 * The `sh3eb-elf` toolchain somewhere in the PATH
 * The fxSDK installed and available in the PATH
 

TODO

@@ -18,11 +18,10 @@
 +  partial transparency
 +  gint vs. ML with 248x124 at (-60, -28)
 +  call exit handlers
-+  compute frequencies
++  compute frequencies and CLOCKS_PER_SEC
 +  test all font encodings
 
 -  improve exception handler debugging information (if possible)
--  full rtc driver (time)
 -  callbacks and complete user API
 
 ~  packed bit fields

include/internals/time.h

@@ -0,0 +1,16 @@
+#ifndef	_INTERNALS_TIME_H
+#define	_INTERNALS_TIME_H	1
+
+/*
+	isLeap()
+	Determines whether the given year is a leap year.
+*/
+int isLeap(int year);
+
+/*
+	daysInMonth()
+	Returns number of days for the given month (between 0 and 11) and year.
+*/
+int daysInMonth(int month, int year);
+
+#endif	// _INTERNALS_TIME_H

include/rtc.h

@@ -15,9 +15,7 @@
 
 /*
 	struct RTCTime
-	Defines a point in time. This structure *is* the standard struct tm to
-	avoid useless data copy in the interface between this module and the
-	standard time module.
+	Defines a point in time.
 */
 struct RTCTime
 {
@@ -26,21 +24,21 @@ struct RTCTime
 	int hours;		// Hours in range 0-23
 	int month_day;		// Day of month in range 1-31
 	int month;		// Month in range 0-11
-	int year;		// Number of years since 1900
+	int year;		// Years (full value)
 	int week_day;		// Day of week in range 0(Sunday)-6(Saturday).
-	int year_day;		// Day of the year in range 0-365.
-	int daylight_saving;	// As far as I known the RTC does not use DST.
 };
 
 /*
 	rtc_getTime()
-	Reads the current time from the RTC.
+	Reads the current time from the RTC. There is no guarantee that the
+	week day is correct (use the time API for that).
 */
 struct RTCTime rtc_getTime(void);
 
 /*
 	rtc_setTime()
-	Sets the time in the RTC registers.
+	Sets the time in the RTC registers. The week day is set to 0 if greater
+	than 6. Other fields are not checked.
 */
 void rtc_setTime(struct RTCTime time);
 

include/time.h

@@ -29,7 +29,7 @@ struct tm
 	int tm_year;		// Number of years since 1900
 	int tm_wday;		// Day of week in range 0(Sunday)-6(Saturday).
 	int tm_yday;		// Day of the year in range 0-365.
-	int tm_isdst;		// Always -1 (not available).
+	int tm_isdst;		// This will always be 0.
 };
 
 /*
@@ -57,6 +57,17 @@ typedef signed int time_t;
 */
 clock_t clock(void);
 
+/*
+	time()
+	Returns the current time as calendar time. If you need a broken-down
+	time, either use the RTC API or gmtime(). However, this function is
+	already based on mktime() (for hardware reasons) so it would be much
+	faster to use the RTC API if possible.
+	If timeptr is not NULL, it is set to the current time, that is, the
+	value that is returned.
+*/
+time_t time(time_t *timeptr);
+
 /*
 	difftime()
 	Returns the number of seconds between the given points.
@@ -71,15 +82,45 @@ double difftime(time_t end, time_t beginning);
 //	Time representation.
 //---
 
+/*
+	asctime()
+	Converts broken-down time to string representation on the form
+	"Wed Jun 30 21:49:08 1993\n". The returned string is statically
+	allocated and may be overwritten by any subsequent call to a time
+	function.
+*/
+char *asctime(const struct tm *time);
+
+/*
+	ctime()
+	Converts calendar time to string representation on the form
+	"Wed Jun 30 21:49:08 1993\n". The returned string is statically
+	allocated and may be overwritten by any subsequent call to a time
+	function.
+*/
+char *ctime(const time_t *timer);
+
+
+
 //---
-//
+//	Time conversion.
 //---
 
 /*
 	mktime()
-	Computes fields tm_wday and tm_yday using the other fields. Member
-	structures outside their range are normalized and tm_isdst is set.
+	Converts broken-down time to calendar time. Computes structure fields
+	tm_wday and tm_yday using the other fields. Member structures outside
+	their range are normalized (e.g. 40 October becomes 9 November) and
+	tm_isdst is set.
 */
 time_t mktime(struct tm *time);
 
+/*
+	gmtime()
+	Converts calendar time to broken-down time. The returned pointer is
+	statically allocated and may be overwritten by any subsequent call to
+	a time function.
+*/
+struct tm *gmtime(const time_t *t);
+
 #endif	// _TIME_H

src/rtc/rtc_getTime.c

@@ -16,23 +16,11 @@ static int integer16(int bcd)
 		+ 1000 * (bcd >> 12);
 }
 
-static int year_day(int year, int year_bcd, int month, int month_day)
-{
-	int days_in_month[12] = {
-		31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
-	int leap;
-	int hundreds = integer8(year_bcd >> 8);
-	int day, i;
-
-	leap = !(year & 3);			// Take multiples of 4
-	if(!((year_bcd >> 8) & 0xf)) leap = 0;	// Remove multiples of 100
-	if(!(hundreds & 3)) leap = 1;		// Take multiples of 400
-
-	day = leap && (month > 2);
-	for(i = 0; i < month - 1; i++) day += days_in_month[i];
-	return day + month_day - 1;
-}
-
+/*
+	rtc_getTime()
+	Reads the current time from the RTC. There is no guarantee that the
+	week day is correct (use the time API for that).
+*/
 struct RTCTime rtc_getTime(void)
 {
 	volatile struct mod_rtc *rtc = isSH3() ? RTC_SH7705 : RTC_SH7305;
@@ -43,11 +31,8 @@ struct RTCTime rtc_getTime(void)
 	time.hours	= integer8(rtc->RHRCNT.BYTE);
 	time.month_day	= integer8(rtc->RDAYCNT.BYTE);
 	time.month	= integer8(rtc->RMONCNT.BYTE);
-	time.year	= integer16(rtc->RYRCNT.WORD) - 1900;
+	time.year	= integer16(rtc->RYRCNT.WORD);
 	time.week_day	= rtc->RWKCNT;
-	time.year_day	= year_day(time.year + 1900, rtc->RYRCNT.WORD,
-		time.month, time.month_day);
 
-	time.daylight_saving = 0;
 	return time;
 }

src/rtc/rtc_setTime.c

@@ -17,6 +17,11 @@ static int bcd16(int integer)
 	return (bcd8(integer / 100) << 8) | bcd8(integer % 100);
 }
 
+/*
+	rtc_setTime()
+	Sets the time in the RTC registers. The week day is set to 0 if greater
+	than 6. Other fields are not checked.
+*/
 void rtc_setTime(struct RTCTime time)
 {
 	volatile struct mod_rtc *rtc = isSH3() ? RTC_SH7705 : RTC_SH7305;
@@ -26,6 +31,6 @@ void rtc_setTime(struct RTCTime time)
 	rtc->RHRCNT.BYTE	= bcd8(time.hours);
 	rtc->RDAYCNT.BYTE	= bcd8(time.month_day);
 	rtc->RMONCNT.BYTE	= bcd8(time.month);
-	rtc->RYRCNT.WORD	= bcd16(time.year + 1900);
+	rtc->RYRCNT.WORD	= bcd16(time.year);
 	rtc->RWKCNT		= time.week_day < 7 ? time.week_day : 0;
 }

src/time/asctime.c

@@ -0,0 +1,57 @@
+#include <time.h>
+
+static char str[26];
+
+/*
+	asctime()
+	Converts broken-down time to string representation on the form
+	"Wed Jun 30 21:49:08 1993\n". The returned string is statically
+	allocated and may be overwritten by any subsequent call to a time
+	function.
+*/
+char *asctime(const struct tm *time)
+{
+	const char *days[] = {
+		"Sun",	"Mon",	"Tue",	"Wed",	"Thu",	"Fri",	"Sat"
+	}, *months[] = {
+		"Jan",	"Feb",	"Mar",	"Apr",	"May",	"Jun",	"Jul",	"Aug",
+		"Sep",	"Oct",	"Nov",	"Dec"
+	};
+	int year = time->tm_year + 1900;
+
+	str[0]	= days[time->tm_wday][0];
+	str[1]	= days[time->tm_wday][1];
+	str[2]	= days[time->tm_wday][2];
+	str[3]	= ' ';
+
+	str[4]	= months[time->tm_mon][0];
+	str[5]	= months[time->tm_mon][1];
+	str[6]	= months[time->tm_mon][2];
+	str[7]	= ' ';
+
+	str[8]	= '0' + (time->tm_mday / 10);
+	str[9]	= '0' + (time->tm_mday % 10);
+	str[10]	= ' ';
+
+	str[11]	= '0' + (time->tm_hour / 10);
+	str[12]	= '0' + (time->tm_hour % 10);
+	str[13] = ':';
+	str[14]	= '0' + (time->tm_min / 10);
+	str[15]	= '0' + (time->tm_min % 10);
+	str[16] = ':';
+	str[17]	= '0' + (time->tm_sec / 10);
+	str[18]	= '0' + (time->tm_sec % 10);
+	str[19] = ' ';
+
+	str[20] = '0' + (year / 1000);
+	year %= 1000;
+	str[21] = '0' + (year / 100);
+	year %= 100;
+	str[22] = '0' + (year / 10);
+	str[23] = '0' + (year % 10);
+
+	str[24] = '\n';
+	str[25] = 0;
+
+	return str;
+}

src/time/ctime.c

@@ -0,0 +1,13 @@
+#include <time.h>
+
+/*
+	ctime()
+	Converts calendar time to string representation on the form
+	"Wed Jun 30 21:49:08 1993\n". The returned string is statically
+	allocated and may be overwritten by any subsequent call to a time
+	function.
+*/
+char *ctime(const time_t *timer)
+{
+	return asctime(gmtime(timer));
+}

src/time/gmtime.c

@@ -0,0 +1,45 @@
+#include <time.h>
+#include <internals/time.h>
+#include <stdlib.h>
+
+static struct tm tm;
+
+/*
+	gmtime()
+	Converts calendar time to broken-down time. The returned pointer is
+	statically allocated and may be overwritten by any subsequent call to
+	a time function.
+*/
+struct tm *gmtime(const time_t *timeptr)
+{
+	time_t t = *timeptr;
+	div_t d;
+	int sec;
+
+	tm.tm_year	= 1970;
+	tm.tm_mon	= 0;
+
+	sec = daysInMonth(tm.tm_mon, tm.tm_year) * 24 * 3600;
+	while(t >= sec)
+	{
+		t -= sec;
+		if(++tm.tm_mon == 12)
+		{
+			tm.tm_year++;
+			tm.tm_mon = 0;
+		}
+		sec = daysInMonth(tm.tm_mon, tm.tm_year) * 24 * 3600;
+	}
+	tm.tm_year	-= 1900;
+
+	d = div(sec, 24 * 3600);
+	tm.tm_mday	= d.quot;
+	d = div(d.rem, 3600);
+	tm.tm_hour	= d.quot;
+	d = div(d.rem, 60);
+	tm.tm_min	= d.quot;
+	tm.tm_sec	= d.rem;
+
+	mktime(&tm);
+	return &tm;
+}

src/time/mktime.c

@@ -1,42 +1,17 @@
 #include <time.h>
-
-/*
-	isLeap()
-	Determines whether the given year is a leap year.
-*/
-int isLeap(int year)
-{
-	int leap = !(year & 3);		// Take multiples of 4
-	if(!(year % 100)) leap = 0;	// Remove multiples of 100
-	if(!(year % 400)) leap = 1;	// Take multiples of 400
-
-	return leap;
-}
-
-/*
-	daysInMonth()
-	Returns number of days for the given month (between 0 and 11) and year.
-*/
-int daysInMonth(int month, int year)
-{
-	int days[12] = {
-		31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-	};
-
-	if(month != 1) return days[month];
-	return days[month] + isLeap(year);
-}
+#include <internals/time.h>
 
 /*
 	mktime()
-	Computes fields tm_wday and tm_yday using the other fields. Member
-	structures outside their range are normalized and tm_isdst is set.
+	Converts broken-down time to calendar time. Computes structure fields
+	tm_wday and tm_yday using the other fields. Member structures outside
+	their range are normalized (e.g. 40 October becomes 9 November) and
+	tm_isdst is set.
 */
 time_t mktime(struct tm *time)
 {
-	int first, leaps, yr;
+	int leaps, yr;
 	int days, i;
-	time_t elapsed;
 
 	// Normalizing time.
 	time->tm_min	+= (time->tm_sec / 60);
@@ -88,6 +63,6 @@ time_t mktime(struct tm *time)
 	// days may become negative, so add the calendar period.
 	if(days < 0) days += 146097;
 
-	return (24 * 3600) * days + 3600 * time->tm_hour + 60 * time->tm_min +
-		time->tm_sec;
+	return (time_t)((24 * 3600) * days + 3600 * time->tm_hour +
+		60 * time->tm_min + time->tm_sec);
 }

src/time/time.c

@@ -0,0 +1,29 @@
+#include <time.h>
+#include <rtc.h>
+
+/*
+	time()
+	Returns the current time as calendar time. If you need a broken-down
+	time, either use the RTC API or gmtime(). However, this function is
+	already based on mktime() (for hardware reasons) so it would be much
+	faster to use the RTC API if possible.
+	If timeptr is not NULL, it is set to the current time, that is, the
+	value that is returned.
+*/
+time_t time(time_t *timeptr)
+{
+	struct RTCTime rtc = rtc_getTime();
+	struct tm tm;
+	time_t calendar;
+
+	tm.tm_sec	= rtc.seconds;
+	tm.tm_min	= rtc.minutes;
+	tm.tm_hour	= rtc.hours;
+	tm.tm_mday	= rtc.month_day;
+	tm.tm_mon	= rtc.month;
+	tm.tm_year	= rtc.year - 1900;
+
+	calendar = mktime(&tm);
+	if(timeptr) *timeptr = calendar;
+	return calendar;
+}

src/time/time_misc.c

@@ -1,4 +1,5 @@
 #include <time.h>
+#undef difftime
 
 /*
 	clock()

src/time/time_util.c

@@ -0,0 +1,28 @@
+#include <internals/time.h>
+
+/*
+	isLeap()
+	Determines whether the given year is a leap year.
+*/
+int isLeap(int year)
+{
+	int leap = !(year & 3);		// Take multiples of 4
+	if(!(year % 100)) leap = 0;	// Remove multiples of 100
+	if(!(year % 400)) leap = 1;	// Take multiples of 400
+
+	return leap;
+}
+
+/*
+	daysInMonth()
+	Returns number of days for the given month (between 0 and 11) and year.
+*/
+int daysInMonth(int month, int year)
+{
+	int days[12] = {
+		31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+	};
+
+	if(month != 1) return days[month];
+	return days[month] + isLeap(year);
+}