Add: PIT (sysclock)

kmain.c

@@ -23,34 +23,13 @@ int kmain(int retvalue)
 
   clear();
 
-  // printf testing
+  colorputs("Blank OS version 1 iteration 3 minor 20\n", 10);
 
   // TODO: Framebuffer upgrade: color output
   // TODO: Serial printf to dump registers on kernel panic
   // TODO: Fix scrolling bug (framebuffer driver)
 
-  int age = 34;
-  int problems = 124;
-  char* name = "xamidev"; 
-  
-  printf("Hello %s, you are %d years old and have %d problems. wow %%\n", name, age, problems);
-  
-  long suchwow = 2934342;
-  char character = 65;
-  printf("such number %u\nsuch character %c", suchwow, character);
-  
-  printf("wow negative %d\n", -3742);
-  printf("such hex %x %X\n", 0xcafe, 0xdeadbeef);
-  
-  printf("such pointer %p\n", (void*)0xcafe1234);
-
-  for (int i=0; i<10; i++)
-  {
-    colorputs("hello colorful world!!\n", i);
-  }
-  // Div by zero exception
-  
-  //printf("Lalala, what a beautiful day! %d", 4/0);
+  timer_install();
 
   return retvalue;
 }

makefile

@@ -1,4 +1,4 @@
-OBJECTS = loader.o kmain.o stdio.o io.o string.o serial.o gdt.o idt.o system.o isr.o irq.o 
+OBJECTS = loader.o kmain.o stdio.o io.o string.o serial.o gdt.o idt.o system.o isr.o irq.o timer.o 
 CC = gcc
 CFLAGS = -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs -Wall -Wextra -c
 LDFLAGS = -T link.ld -melf_i386

system.h

@@ -17,4 +17,7 @@ void isr_install();
 void irq_install();
 void irq_install_handler(int irq, void (*handler)(struct regs *r));
 void irq_uninstall_handler(int irq);
+void timer_install();
+void delay(int ticks);
 #endif
+

timer.c

@@ -0,0 +1,26 @@
+#include "system.h"
+#include "stdio.h"
+
+int timer_ticks = 0;
+
+void timer_handler()
+{
+	timer_ticks++;
+
+	if(timer_ticks % 18 == 0)
+	{
+		puts("One second has passed\n");
+	}
+}
+
+void timer_install()
+{
+	irq_install_handler(0, timer_handler);
+}
+
+void delay(int ticks)
+{
+	unsigned long eticks;
+	eticks = timer_ticks + ticks;
+	while ((unsigned long)timer_ticks < eticks);
+}