starting implicit function calls cleanup

1 files changed, 181 insertions, 23 deletions

diff --git a/kernel/timer.c b/kernel/timer.c
index 9ca748c..a339d70 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1,7 +1,8 @@
-/// PIT /// Timer stuff
+/// PIT /// Timer stuff // CMOS
 
 /*
  http://www.brokenthorn.com/Resources/OSDevPit.html
+ https://wiki.osdev.org/CMOS
 
  vcc/gnd - voltage/ground
 
@@ -26,20 +27,195 @@
     mode1: 
     mode2: rate generator (sys timer)
     ....
-
-
  */
 
 #define FOOLOS_MODULE_NAME "timer"
 
 #include "timer.h"
+#include "x86.h"
+#include "lib/logger/log.h"
 
-#include "lib/logger/log.h"	// logger facilities
-
+// TODO: use mutex? do we need volatile at all!??
+// abstract atomic variable set,get,increment
 static volatile uint64_t task_system_clock=0;
 
+//called by interrupt
+void timer_tick()
+{
+    task_system_clock++;
+}
+
+// get value
+uint64_t timer_get_ticks()
+{
+    return task_system_clock;
+}
+///
+
+uint64_t timer_get_ms()
+{
+    uint64_t t=timer_get_ticks();
+    uint64_t s=t/25;
+    uint64_t ms=0; // TODO ms
+    return s*1000;
+}
+
+// CMOS RTC
+
+ 
+// read real time clock register
+unsigned char get_rtc_reg(int reg) {
+      x86_outb(0x70, reg);	//cmos at addr 0x70
+      return x86_inb(0x71);	//cmos data at addr 0x71
+}
+
+// check if cmos rtc update in progress
+int get_rtc_update_flag() {
+      x86_outb(0x70, 0x0A);
+      return (x86_inb(0x71) & 0x80);
+}
+
+// get real time clock rom cmos (seconds since jan)
+uint64_t get_rtc_time()
+{
+
+    int CURRENT_YEAR = 2018;	    // Change this each year!
+ 
+    int century_register = 0x00;    // Set by ACPI table parsing code if possible
+    
+    unsigned char second;
+    unsigned char minute;
+    unsigned char hour;
+    unsigned char day;
+    unsigned char month;
+    unsigned int year;
+
+      unsigned char century;
+      unsigned char last_second;
+      unsigned char last_minute;
+      unsigned char last_hour;
+      unsigned char last_day;
+      unsigned char last_month;
+      unsigned char last_year;
+      unsigned char last_century;
+      unsigned char registerB;
+ 
+      // Note: This uses the "read registers until you get the same values twice in a row" technique
+      //       to avoid getting dodgy/inconsistent values due to RTC updates
+ 
+      while (get_rtc_update_flag());                // Make sure an update isn't in progress
+      second = get_rtc_reg(0x00);
+      minute = get_rtc_reg(0x02);
+      hour = get_rtc_reg(0x04);
+      day = get_rtc_reg(0x07);
+      month = get_rtc_reg(0x08);
+      year = get_rtc_reg(0x09);
+
+      if(century_register != 0) {
+            century = get_rtc_reg(century_register);
+      }
+ 
+      do {
+            last_second = second;
+            last_minute = minute;
+            last_hour = hour;
+            last_day = day;
+            last_month = month;
+            last_year = year;
+            last_century = century;
+ 
+            while (get_rtc_update_flag());           // Make sure an update isn't in progress
+            second = get_rtc_reg(0x00);
+            minute = get_rtc_reg(0x02);
+            hour = get_rtc_reg(0x04);
+            day = get_rtc_reg(0x07);
+            month = get_rtc_reg(0x08);
+            year = get_rtc_reg(0x09);
+            if(century_register != 0) {
+                  century = get_rtc_reg(century_register);
+            }
+      } while( (last_second != second) || (last_minute != minute) || (last_hour != hour) ||
+               (last_day != day) || (last_month != month) || (last_year != year) ||
+               (last_century != century) );
+ 
+      registerB = get_rtc_reg(0x0B);
+ 
+      // Convert BCD to binary values if necessary
+      if (!(registerB & 0x04)) {
+            second = (second & 0x0F) + ((second / 16) * 10);
+            minute = (minute & 0x0F) + ((minute / 16) * 10);
+            hour = ( (hour & 0x0F) + (((hour & 0x70) / 16) * 10) ) | (hour & 0x80);
+            day = (day & 0x0F) + ((day / 16) * 10);
+            month = (month & 0x0F) + ((month / 16) * 10);
+            year = (year & 0x0F) + ((year / 16) * 10);
+            if(century_register != 0) {
+                  century = (century & 0x0F) + ((century / 16) * 10);
+            }
+      }
+ 
+      // Convert 12 hour clock to 24 hour clock if necessary
+      if (!(registerB & 0x02) && (hour & 0x80)) {
+            hour = ((hour & 0x7F) + 12) % 24;
+      }
+ 
+      // Calculate the full (4-digit) year
+      if(century_register != 0) {
+            year += century * 100;
+      } else {
+            year += (CURRENT_YEAR / 100) * 100;
+            if(year < CURRENT_YEAR) year += 100;
+      }
+    
+     // return ((((uint64_t)year-1970)*356;//+month*30+day)*24+hour*60+minute)*60+second;
+     
+     // thank you doug16k @ #osdev
+     // https://github.com/doug65536/dgos/blob/eab7080e69360493381669e7ce0ff27587d3127a/kernel/lib/time.cc
+          int days[] = {
+        31,
+        (year-1900) % 4 ? 28 :
+        (year-1900) % 100 ? 29 :
+        (year-1900) % 400 ? 28 :
+        29,
+        31,
+        30,
+        31,
+        30,
+        31,
+        31,
+        30,
+        31,
+        30,
+        31
+    };
+
+    int yday = 0;
+    for (int m = 1; m < month; ++m)
+        yday += days[m-1];
+    yday += day - 1;
+
+      uint64_t epoch_seconds= ((uint64_t)(second)) +
+            minute * 60 +
+            hour * 3600 +
+            (yday) * 86400 +
+            (year-1900 - 70) * 365 * 86400 +
+            ((year-1900 - 69) / 4) * 86400 -
+            ((year-1900 - 1) / 100) * 86400 +
+            ((year-1900 + 299) / 400) * 86400;
+
+      log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"CMOS Hardware Clock: %u-%u-%u %u:%u:%u",day,month,year,hour,minute,second);
+      log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"CMOS Hardware Clock: %u seconds since Epoch",epoch_seconds);
+
+      return epoch_seconds;
+}
+
+// PIT
+// TODO: move to asm file
 void timer_init()
 {
+    uint64_t epoch_time=get_rtc_time();
+    epoch_time*=25;
+    task_system_clock=epoch_time;
+
     // config out timer on channel 0 : mode 2 (sys timer)
     // http://en.wikipedia.org/wiki/Intel_8253#Control_Word_Register
     // http://www.brokenthorn.com/Resources/OSDevPit.html
@@ -61,23 +237,5 @@ void timer_init()
     __asm__("popa");
 
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"Configured PIT Channel 0 : Mode 2 : 1/25 s.");
-
-}
-
-void timer_tick()
-{
-    task_system_clock++;
-}
-
-uint64_t timer_get_ticks()
-{
-    return task_system_clock;
 }
 
-uint32_t timer_get_ms()
-{
-    uint32_t t=timer_get_ticks();
-    uint32_t s=t/25;
-    uint32_t ms=t*1000/25-1000*s;
-    return s*1000;//+ms;
-}