Add: ISR now handling common exceptions

<

@@ -0,0 +1,50 @@
+#include "stdio.h"
+#include "serial.h"
+#include "gdt.h"
+#include "idt.h"
+#include "system.h"
+
+int kmain(int retvalue)
+{
+  
+  gdt_install();
+  idt_install();
+  isr_install();
+
+  // serial testing
+
+  init_serial();
+  
+  log("serial connection established", 3);
+  log("initialized GDT entries", 2);
+  log("kernel started", 2);
+  log("initialized IDT", 2);
+  log("initialized ISRs", 3);
+
+  clear();
+
+  // printf testing
+
+  // TODO: Framebuffer upgrade: color output
+
+  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);
+ 
+  // Div by zero exception
+  
+  printf("Lalala, what a beautiful day! %d", 4/0);
+
+  return retvalue;
+}