src/kernel/arch/i386/tty/kterm.c

@@ -62,15 +62,17 @@ void kterm_scrollup(){
 }
 
 void kterm_put (char c) {
- 
     if(++kterm_column == VGA_WIDTH || c == '\n' ) {
         kterm_column = 0;
-        if(kterm_row == VGA_HEIGHT-1) {       
+        if(kterm_row == VGA_HEIGHT-1 ) {       
             kterm_scrollup();
         } else {
             kterm_row ++;
         }
-            
+    }
+    if ( c == '\r'){
+        kterm_column = 0;
+        return;
     }
     
     if(c == '\n') return;
@@ -89,3 +91,100 @@ void kterm_writestring(const char* data ){
     AS_KERNEL();
     kterm_write(data, strlen(data));
 }
+
+
+static void itoa (char *buf, int base, int d) {
+    char *p = buf;
+    char *p1, *p2;
+    unsigned long ud = d;
+    int divisor = 10;
+    if ( base == 'd' && d < 0){
+        *p++ = '-';
+        buf++;
+        ud = -d;
+    } else if (base == 'x'){
+        divisor = 16;
+    }
+
+    do { 
+        int remainder = ud % divisor;
+
+         *p++ = (remainder < 10 ) ? remainder + '0' : remainder + 'a' -10;
+    } while(ud /= divisor);
+
+    /*terminate buf*/
+    *p =0;
+    p1 = buf;
+    p2 = p -1;
+
+    while (p1 < p2)
+    {
+        char tmp = *p1;
+        *p1 = *p2;
+        *p2 = tmp;
+        p1++;
+        p2--;
+
+    }
+
+}
+
+void printf ( const char *format, ...) {
+    
+    char **arg = (char **)&format;
+    int c;
+    char buf[20];
+
+    arg++;
+    
+    while ((c = *format++) != 0){
+        if( c != '%')
+            kterm_put(c);
+        else{
+            char *p, *p2;
+            int pad0 = 0, pad = 0;
+
+            c = *format++;
+            if(c =='0'){
+                pad0 = 1;
+                c = *format++;
+            }
+
+            if ( c >= '0' && c <= '9'){
+                pad = c - '0';
+                c = *format++;
+            }
+
+            switch (c)
+            {
+            case 'd':
+
+            case 'u':
+            case 'x':
+                itoa(buf, c, *((int *) arg++));
+
+                p = buf;
+                goto string;
+                break;
+            
+            case 's':
+                p = *arg++;
+                if(!p)
+                    p = "(null)";
+                
+                string: 
+                    for (p2 = p; *p2; p2++);
+                    for (; p2 < p + pad; p2++)
+                        kterm_put(pad0 ? '0': ' ');
+                    while (*p)
+                        kterm_put(*p++);
+                    break;
+
+
+            default:
+                kterm_put(*((int *)arg++));
+                break;
+            }
+        }
+    }
+}

src/kernel/arch/i386/tty/kterm.h

@@ -15,10 +15,16 @@ void kterm_putat(char, uint8_t, size_t, size_t);
 void kterm_put(char);
 void kterm_write(const char*, size_t);
 void kterm_writestring(const char*);
-
 void kterm_scrollup();
 
+
+void printf ( const char *format, ...);
+
+static void itoa (char *buf, int base, int d);
+
 #define KernelTag "[Kernel]: "
 #define AS_KERNEL() (  kterm_setcolor(VGA_COLOR_LIGHT_BLUE),\
                        kterm_write(KernelTag, 10 ), \
-                       kterm_resetcolor())
+                       kterm_resetcolor())
+
+

src/kernel/time.h

@@ -0,0 +1,151 @@
+#define CURRENT_YEAR        2021                            // 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;
+ 
+
+ 
+enum {
+      cmos_address = 0x70,
+      cmos_data    = 0x71
+};
+ 
+int get_update_in_progress_flag() {
+      outb(cmos_address, 0x0A);
+      return (inb(cmos_data) & 0x80);
+}
+ 
+unsigned char get_RTC_register(int reg) {
+      outb(cmos_address, reg);
+      return inb(cmos_data);
+}
+ 
+void read_rtc() {
+      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_update_in_progress_flag());                // Make sure an update isn't in progress
+      second = get_RTC_register(0x00);
+      minute = get_RTC_register(0x02);
+      hour = get_RTC_register(0x04);
+      day = get_RTC_register(0x07);
+      month = get_RTC_register(0x08);
+      year = get_RTC_register(0x09);
+      if(century_register != 0) {
+            century = get_RTC_register(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_update_in_progress_flag());           // Make sure an update isn't in progress
+            second = get_RTC_register(0x00);
+            minute = get_RTC_register(0x02);
+            hour = get_RTC_register(0x04);
+            day = get_RTC_register(0x07);
+            month = get_RTC_register(0x08);
+            year = get_RTC_register(0x09);
+            if(century_register != 0) {
+                  century = get_RTC_register(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_register(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;
+      }
+}
+
+
+/*
+void ReadFromCMOS(unsigned char array[])
+{
+    unsigned char tvalue, index;
+
+    for (index = 0; index < 128; index++)
+    {
+        asm(
+            "cli\n\t"           // Disable interrupts
+            "mov al, index\n\t" // Move index address
+            // since the 0x80 bit of al is not set, NMI is active 
+            "out 0x70,al\n\t" // Copy address to CMOS register
+            // some kind of real delay here is probably best 
+            "in al,0x71\n\t" // Fetch 1 byte to al
+            "sti\n\t"        // Enable interrupts
+            "mov tvalue,al\n\t");
+
+        array[index] = tvalue;
+    }
+}
+*/
+
+/*
+void WriteTOCMOS(unsigned char array[])
+{
+   unsigned char index;
+ 
+   for(index = 0; index < 128; index++)
+   {
+      unsigned char tvalue = array[index];
+      
+       asm("cli\n\t"       // Clear interrupts
+         "mov al,index\n\t"    // move index address
+         "out 0x70,al\n\t"     // copy address to CMOS register
+         /* some kind of real delay here is probably best 
+         "mov al,tvalue\n\t"   // move value to al
+         "out 0x71,al\n\t"   // write 1 byte to CMOS
+         "sti\n\\t"   );        // Enable interrupts
+      
+   }
+}
+*/