Kernel: Move RTC to Timer directory

PIT ms counter seems to be off by multiple seconds/minute. I will
be probably changing to HPET for system time

kernel/kernel/Timer/RTC.cpp

@@ -0,0 +1,90 @@
+#include <kernel/IO.h>
+#include <kernel/Timer/RTC.h>
+
+#include <string.h>
+
+#define CURRENT_YEAR 2022
+
+#define CMOS_ADDRESS			0x70
+#define CMOS_DATA				0x71
+
+#define CMOS_REGISTER_SECOND	0x00
+#define CMOS_REGISTER_MINUTE	0x02
+#define CMOS_REGISTER_HOUR		0x04
+#define CMOS_REGISTER_WEEK_DAY	0x06
+#define CMOS_REGISTER_DAY		0x07
+#define CMOS_REGISTER_MONTH		0x08
+#define CMOS_REGISTER_YEAR		0x09
+#define CMOS_REGISTER_STATUS_1	0x0A
+#define CMOS_REGISTER_STATUS_2	0x0B
+
+namespace Kernel
+{
+
+	bool RTC::is_update_in_progress()
+	{
+		IO::outb(CMOS_ADDRESS, CMOS_REGISTER_STATUS_1);
+		return IO::inb(CMOS_DATA) & 0x80;
+	}
+
+	uint8_t RTC::read_register8(uint8_t reg)
+	{
+		IO::outb(CMOS_ADDRESS, reg);
+		return IO::inb(CMOS_DATA);
+	}
+
+	void RTC::get_time(BAN::Time& out)
+	{
+		out.second		= read_register8(CMOS_REGISTER_SECOND);
+		out.minute		= read_register8(CMOS_REGISTER_MINUTE);
+		out.hour		= read_register8(CMOS_REGISTER_HOUR);
+		out.week_day	= read_register8(CMOS_REGISTER_WEEK_DAY);
+		out.day			= read_register8(CMOS_REGISTER_DAY);
+		out.month		= read_register8(CMOS_REGISTER_MONTH);
+		out.year		= read_register8(CMOS_REGISTER_YEAR);
+	}
+
+	BAN::Time RTC::get_current_time()
+	{
+		BAN::Time last_time	= {};
+		BAN::Time time		= {};
+
+		while (is_update_in_progress())
+			continue;
+
+		get_time(time);
+		last_time.second = time.second + 1;
+
+		while (memcmp(&last_time, &time, sizeof(BAN::Time)))
+		{
+			last_time = time;
+			get_time(time);
+		}
+		
+		uint8_t regB = read_register8(0x0B);
+
+		// Convert BCD to binary values if necessary
+		if (!(regB & 0x04))
+		{
+			time.second		=  (time.second		& 0x0F) + ((time.second		/ 16) * 10);
+			time.minute		=  (time.minute		& 0x0F) + ((time.minute		/ 16) * 10);
+			time.hour		= ((time.hour		& 0x0F) + (((time.hour & 0x70) / 16) * 10) ) | (time.hour & 0x80);
+			time.week_day	=  (time.week_day	& 0x0F) + ((time.week_day	/ 16) * 10);
+			time.day		=  (time.day		& 0x0F) + ((time.day		/ 16) * 10);
+			time.month		=  (time.month		& 0x0F) + ((time.month		/ 16) * 10);
+			time.year		=  (time.year		& 0x0F) + ((time.year		/ 16) * 10);
+		}
+
+		// Convert 12 hour clock to 24 hour clock if necessary
+		if (!(regB & 0x02) && (time.hour & 0x80))
+			time.hour = ((time.hour & 0x7F) + 12) % 24;
+
+		// Calculate the full 4 digit year
+		time.year += (CURRENT_YEAR / 100) * 100;
+		if (time.year < CURRENT_YEAR)
+			time.year += 100;
+
+		return time;
+	}
+
+}

kernel/kernel/Timer/Timer.cpp

@@ -9,9 +9,10 @@ namespace Kernel
 	void TimerHandler::initialize()
 	{
 		ASSERT(s_instance == nullptr);
-		s_instance = new TimerHandler;
-		ASSERT(s_instance);
-		s_instance->initialize_timers();
+		auto* temp = new TimerHandler;
+		ASSERT(temp);
+		temp->initialize_timers();
+		s_instance = temp;
 	}
 
 	TimerHandler& TimerHandler::get()
@@ -27,6 +28,9 @@ namespace Kernel
 
 	void TimerHandler::initialize_timers()
 	{
+		m_rtc = MUST(BAN::UniqPtr<RTC>::create());
+		m_boot_time = BAN::to_unix_time(m_rtc->get_current_time());
+
 		if (auto res = PIT::create(); res.is_error())
 			dwarnln("PIT: {}", res.error());
 		else
@@ -48,4 +52,9 @@ namespace Kernel
 		return m_timers.front()->sleep(ms);
 	}
 
+	uint64_t TimerHandler::get_unix_timestamp()
+	{
+		return m_boot_time + ms_since_boot() / 1000;
+	}
+
 }