Replace ugly year/month calculations in resettodr to more clean

variants, idea taken from NetBSD clock.c.
At least year calculation was wrong, pointed by Bruce.
Use different strategy to store year for BIOS without RTC_CENTURY

5 files changed, 60 insertions, 70 deletions

diff --git a/sys/amd64/amd64/tsc.c b/sys/amd64/amd64/tsc.c
index 6dc5896..487e7bc 100644
--- a/sys/amd64/amd64/tsc.c
+++ b/sys/amd64/amd64/tsc.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.43 1995/12/24 08:10:52 davidg Exp $
+ *	$Id: clock.c,v 1.44 1996/01/04 21:11:33 wollman Exp $
  */
 
 /*
@@ -529,27 +529,25 @@ resettodr()
 
 	/* We have now the days	since 01-01-1970 in tm */
 	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
-	for (y=1970;; y++)
-		if ((tm	- DAYSPERYEAR -	LEAPYEAR(y)) > tm)
-			break;
-		else
-			tm -= DAYSPERYEAR + LEAPYEAR(y);
+	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
+	     tm >= m;
+	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
+	     tm -= m;
 
 	/* Now we have the years in y and the day-of-the-year in tm */
-	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 #ifdef USE_RTC_CENTURY
+	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 	writertc(RTC_CENTURY, int2bcd(y/100));		/* ... and Century    */
+#else
+	writertc(RTC_YEAR, int2bcd(y - 1900));          /* Write back Year    */
 #endif
 	if (LEAPYEAR(y)	&& (tm >= 31+29))
 		tm--;					/* Subtract Feb-29 */
-	for (m=1;; m++)
-		if (tm - daysinmonth[m-1] > tm)
-			break;
-		else
-			tm -= daysinmonth[m-1];
+	for (m = 0; tm >= daysinmonth[m]; m++)
+		tm -= daysinmonth[m];
 
-	writertc(RTC_MONTH, int2bcd(m));		/* Write back Month   */
-	writertc(RTC_DAY, int2bcd(tm+1));		/* Write back Day     */
+	writertc(RTC_MONTH, int2bcd(m + 1));            /* Write back Month   */
+	writertc(RTC_DAY, int2bcd(tm + 1));             /* Write back Month Day */
 
 	/* Reenable RTC updates and interrupts. */
 	writertc(RTC_STATUSB, RTCSB_24HR | RTCSB_PINTR);
diff --git a/sys/amd64/isa/clock.c b/sys/amd64/isa/clock.c
index 6dc5896..487e7bc 100644
--- a/sys/amd64/isa/clock.c
+++ b/sys/amd64/isa/clock.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.43 1995/12/24 08:10:52 davidg Exp $
+ *	$Id: clock.c,v 1.44 1996/01/04 21:11:33 wollman Exp $
  */
 
 /*
@@ -529,27 +529,25 @@ resettodr()
 
 	/* We have now the days	since 01-01-1970 in tm */
 	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
-	for (y=1970;; y++)
-		if ((tm	- DAYSPERYEAR -	LEAPYEAR(y)) > tm)
-			break;
-		else
-			tm -= DAYSPERYEAR + LEAPYEAR(y);
+	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
+	     tm >= m;
+	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
+	     tm -= m;
 
 	/* Now we have the years in y and the day-of-the-year in tm */
-	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 #ifdef USE_RTC_CENTURY
+	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 	writertc(RTC_CENTURY, int2bcd(y/100));		/* ... and Century    */
+#else
+	writertc(RTC_YEAR, int2bcd(y - 1900));          /* Write back Year    */
 #endif
 	if (LEAPYEAR(y)	&& (tm >= 31+29))
 		tm--;					/* Subtract Feb-29 */
-	for (m=1;; m++)
-		if (tm - daysinmonth[m-1] > tm)
-			break;
-		else
-			tm -= daysinmonth[m-1];
+	for (m = 0; tm >= daysinmonth[m]; m++)
+		tm -= daysinmonth[m];
 
-	writertc(RTC_MONTH, int2bcd(m));		/* Write back Month   */
-	writertc(RTC_DAY, int2bcd(tm+1));		/* Write back Day     */
+	writertc(RTC_MONTH, int2bcd(m + 1));            /* Write back Month   */
+	writertc(RTC_DAY, int2bcd(tm + 1));             /* Write back Month Day */
 
 	/* Reenable RTC updates and interrupts. */
 	writertc(RTC_STATUSB, RTCSB_24HR | RTCSB_PINTR);
diff --git a/sys/i386/i386/tsc.c b/sys/i386/i386/tsc.c
index 6dc5896..487e7bc 100644
--- a/sys/i386/i386/tsc.c
+++ b/sys/i386/i386/tsc.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.43 1995/12/24 08:10:52 davidg Exp $
+ *	$Id: clock.c,v 1.44 1996/01/04 21:11:33 wollman Exp $
  */
 
 /*
@@ -529,27 +529,25 @@ resettodr()
 
 	/* We have now the days	since 01-01-1970 in tm */
 	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
-	for (y=1970;; y++)
-		if ((tm	- DAYSPERYEAR -	LEAPYEAR(y)) > tm)
-			break;
-		else
-			tm -= DAYSPERYEAR + LEAPYEAR(y);
+	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
+	     tm >= m;
+	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
+	     tm -= m;
 
 	/* Now we have the years in y and the day-of-the-year in tm */
-	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 #ifdef USE_RTC_CENTURY
+	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 	writertc(RTC_CENTURY, int2bcd(y/100));		/* ... and Century    */
+#else
+	writertc(RTC_YEAR, int2bcd(y - 1900));          /* Write back Year    */
 #endif
 	if (LEAPYEAR(y)	&& (tm >= 31+29))
 		tm--;					/* Subtract Feb-29 */
-	for (m=1;; m++)
-		if (tm - daysinmonth[m-1] > tm)
-			break;
-		else
-			tm -= daysinmonth[m-1];
+	for (m = 0; tm >= daysinmonth[m]; m++)
+		tm -= daysinmonth[m];
 
-	writertc(RTC_MONTH, int2bcd(m));		/* Write back Month   */
-	writertc(RTC_DAY, int2bcd(tm+1));		/* Write back Day     */
+	writertc(RTC_MONTH, int2bcd(m + 1));            /* Write back Month   */
+	writertc(RTC_DAY, int2bcd(tm + 1));             /* Write back Month Day */
 
 	/* Reenable RTC updates and interrupts. */
 	writertc(RTC_STATUSB, RTCSB_24HR | RTCSB_PINTR);
diff --git a/sys/i386/isa/clock.c b/sys/i386/isa/clock.c
index 6dc5896..487e7bc 100644
--- a/sys/i386/isa/clock.c
+++ b/sys/i386/isa/clock.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.43 1995/12/24 08:10:52 davidg Exp $
+ *	$Id: clock.c,v 1.44 1996/01/04 21:11:33 wollman Exp $
  */
 
 /*
@@ -529,27 +529,25 @@ resettodr()
 
 	/* We have now the days	since 01-01-1970 in tm */
 	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
-	for (y=1970;; y++)
-		if ((tm	- DAYSPERYEAR -	LEAPYEAR(y)) > tm)
-			break;
-		else
-			tm -= DAYSPERYEAR + LEAPYEAR(y);
+	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
+	     tm >= m;
+	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
+	     tm -= m;
 
 	/* Now we have the years in y and the day-of-the-year in tm */
-	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 #ifdef USE_RTC_CENTURY
+	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 	writertc(RTC_CENTURY, int2bcd(y/100));		/* ... and Century    */
+#else
+	writertc(RTC_YEAR, int2bcd(y - 1900));          /* Write back Year    */
 #endif
 	if (LEAPYEAR(y)	&& (tm >= 31+29))
 		tm--;					/* Subtract Feb-29 */
-	for (m=1;; m++)
-		if (tm - daysinmonth[m-1] > tm)
-			break;
-		else
-			tm -= daysinmonth[m-1];
+	for (m = 0; tm >= daysinmonth[m]; m++)
+		tm -= daysinmonth[m];
 
-	writertc(RTC_MONTH, int2bcd(m));		/* Write back Month   */
-	writertc(RTC_DAY, int2bcd(tm+1));		/* Write back Day     */
+	writertc(RTC_MONTH, int2bcd(m + 1));            /* Write back Month   */
+	writertc(RTC_DAY, int2bcd(tm + 1));             /* Write back Month Day */
 
 	/* Reenable RTC updates and interrupts. */
 	writertc(RTC_STATUSB, RTCSB_24HR | RTCSB_PINTR);
diff --git a/sys/isa/atrtc.c b/sys/isa/atrtc.c
index 6dc5896..487e7bc 100644
--- a/sys/isa/atrtc.c
+++ b/sys/isa/atrtc.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.43 1995/12/24 08:10:52 davidg Exp $
+ *	$Id: clock.c,v 1.44 1996/01/04 21:11:33 wollman Exp $
  */
 
 /*
@@ -529,27 +529,25 @@ resettodr()
 
 	/* We have now the days	since 01-01-1970 in tm */
 	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
-	for (y=1970;; y++)
-		if ((tm	- DAYSPERYEAR -	LEAPYEAR(y)) > tm)
-			break;
-		else
-			tm -= DAYSPERYEAR + LEAPYEAR(y);
+	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
+	     tm >= m;
+	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
+	     tm -= m;
 
 	/* Now we have the years in y and the day-of-the-year in tm */
-	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 #ifdef USE_RTC_CENTURY
+	writertc(RTC_YEAR, int2bcd(y%100));		/* Write back Year    */
 	writertc(RTC_CENTURY, int2bcd(y/100));		/* ... and Century    */
+#else
+	writertc(RTC_YEAR, int2bcd(y - 1900));          /* Write back Year    */
 #endif
 	if (LEAPYEAR(y)	&& (tm >= 31+29))
 		tm--;					/* Subtract Feb-29 */
-	for (m=1;; m++)
-		if (tm - daysinmonth[m-1] > tm)
-			break;
-		else
-			tm -= daysinmonth[m-1];
+	for (m = 0; tm >= daysinmonth[m]; m++)
+		tm -= daysinmonth[m];
 
-	writertc(RTC_MONTH, int2bcd(m));		/* Write back Month   */
-	writertc(RTC_DAY, int2bcd(tm+1));		/* Write back Day     */
+	writertc(RTC_MONTH, int2bcd(m + 1));            /* Write back Month   */
+	writertc(RTC_DAY, int2bcd(tm + 1));             /* Write back Month Day */
 
 	/* Reenable RTC updates and interrupts. */
 	writertc(RTC_STATUSB, RTCSB_24HR | RTCSB_PINTR);