Add x86 realtime clock support.

sortix/Makefile

@@ -54,6 +54,7 @@ ifdef X86FAMILY
              $(CPU)/thread.o \
              $(CPU)/scheduler.o \
              $(CPU)/process.o \
+             x86-family/cmos.o \
              x86-family/time.o \
              x86-family/msr.o \
              x86-family/float.o \

sortix/kernel.cpp

@@ -62,6 +62,7 @@
 #include <malloc.h>
 
 #include "kernelinfo.h"
+#include "x86-family/cmos.h"
 #include "x86-family/gdt.h"
 #include "x86-family/float.h"
 #include "multiboot.h"
@@ -380,6 +381,13 @@ static void BootThread(void* /*user*/)
 	// We no longer need the initrd, so free its resources.
 	InitRD::Delete();
 
+	//
+	// Stage 5. Loading and Initializing Core Drivers.
+	//
+
+	// Initialize the real-time clock.
+	CMOS::Init();
+
 	// Get a descriptor for the /dev directory so we can populate it.
 	if ( droot->mkdir(&ctx, "dev", 0775) != 0 && errno != EEXIST )
 		Panic("Unable to create RAM filesystem /dev directory.");
@@ -387,10 +395,6 @@ static void BootThread(void* /*user*/)
 	if ( !slashdev )
 		Panic("Unable to create descriptor for RAM filesystem /dev directory.");
 
-	//
-	// Stage 5. Loading and Initializing Core Drivers.
-	//
-
 	// Initialize the keyboard.
 	Keyboard* keyboard = new PS2Keyboard(0x60, Interrupt::IRQ1);
 	if ( !keyboard )

sortix/x86-family/cmos.cpp

@@ -0,0 +1,109 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of Sortix.
+
+    Sortix is free software: you can redistribute it and/or modify it under the
+    terms of the GNU General Public License as published by the Free Software
+    Foundation, either version 3 of the License, or (at your option) any later
+    version.
+
+    Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+    details.
+
+    You should have received a copy of the GNU General Public License along with
+    Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+    x86-family/cmos.cpp
+    Provides access to CMOS and the real-time clock.
+
+*******************************************************************************/
+
+#include <sys/types.h>
+
+#include <stdint.h>
+#include <time.h>
+#include <timespec.h>
+
+#include <sortix/clock.h>
+
+#include <sortix/kernel/platform.h>
+#include <sortix/kernel/clock.h>
+#include <sortix/kernel/cpu.h>
+#include <sortix/kernel/time.h>
+
+namespace Sortix {
+namespace CMOS {
+
+const uint16_t CMOS_ADDRESS_REG = 0x70;
+const uint16_t CMOS_DATA_REG = 0x71;
+
+uint8_t ReadRTC(uint8_t reg)
+{
+	CPU::OutPortB(CMOS_ADDRESS_REG, reg);
+	return CPU::InPortB(CMOS_DATA_REG);
+}
+
+bool IsRTCUpdateInProgress()
+{
+	return ReadRTC(0x0A) & 0x80;
+}
+
+uint8_t DecodeBCD(uint8_t bcd)
+{
+	return bcd / 16 * 10 + bcd % 16;
+}
+
+void Init()
+{
+	while ( !IsRTCUpdateInProgress() );
+	while ( IsRTCUpdateInProgress() );
+	uint8_t second = ReadRTC(0x00);
+	uint8_t minute = ReadRTC(0x02);
+	uint8_t hour = ReadRTC(0x04);
+	uint8_t day = ReadRTC(0x07);
+	uint8_t month = ReadRTC(0x08);
+	uint8_t year = ReadRTC(0x09);
+	uint8_t century = ReadRTC(0x32);
+	uint8_t reg_b = ReadRTC(0x0B);
+
+	bool hour12 = !(reg_b & 0x02);
+	bool is_pm = hour12 && hour & 0x80;
+	if ( hour12 )
+		hour &= 0x7F;
+
+	if ( !(reg_b & 0x04) )
+	{
+		second = DecodeBCD(second);
+		minute = DecodeBCD(minute);
+		hour = DecodeBCD(hour);
+		day = DecodeBCD(day);
+		month = DecodeBCD(month);
+		year = DecodeBCD(year);
+		century = DecodeBCD(century);
+	}
+
+	if ( hour12 && is_pm )
+		hour = (hour + 12) % 24;
+
+	time_t full_year = century * 100 + year;
+
+	struct tm tm;
+	memset(&tm, 0, sizeof(tm));
+	tm.tm_sec = second;
+	tm.tm_min = minute;
+	tm.tm_hour = hour;
+	tm.tm_mday = day ;
+	tm.tm_mon = month - 1;
+	tm.tm_year = full_year - 1900;
+	time_t now = timegm(&tm);
+
+	struct timespec current_time = timespec_make(now, 0);
+	Time::GetClock(CLOCK_REALTIME)->Set(&current_time, NULL);
+}
+
+} // namespace CMOS
+} // namespace Sortix

sortix/x86-family/cmos.h

@@ -0,0 +1,59 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of Sortix.
+
+    Sortix is free software: you can redistribute it and/or modify it under the
+    terms of the GNU General Public License as published by the Free Software
+    Foundation, either version 3 of the License, or (at your option) any later
+    version.
+
+    Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+    details.
+
+    You should have received a copy of the GNU General Public License along with
+    Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+    x86-family/cmos.h
+    Provides access to CMOS and the real-time clock.
+
+*******************************************************************************/
+
+#ifndef SORTIX_X86_FAMILY_CMOS_H
+#define SORTIX_X86_FAMILY_CMOS_H
+
+#include <sortix/timespec.h>
+
+namespace Sortix {
+namespace CMOS {
+
+uint8_t Read(uint8_t reg);
+uint8_t Write(uint8_t reg, uint8_t val);
+
+struct cmos_tm
+{
+	uint8_t seconds;
+	uint8_t minutes;
+	uint8_t hours;
+	uint8_t weekday; /* Supposedly not reliably set in CMOS. */
+	uint8_t day_of_month;
+	uint8_t month;
+	uint8_t year;
+	uint8_t century;
+};
+
+struct timespec DecodeTime(struct cmos_tm time);
+struct cmos_tm EncodeTIme(struct timespec time);
+
+struct cmos_tm GetTime();
+void SetTime(struct cmos_tm time);
+
+void Init();
+
+} // namespace CMOS
+} // namespace Sortix
+
+#endif