Global descriptor table added

src/kernel.cpp

@@ -0,0 +1,31 @@
+/* 
+ *  kernel.cpp 
+ *  Author: Fergal Moran
+ *  Copyright: 2020 Fergal Moran
+ *  
+ *  BSD License - do what you want
+ */
+
+#include "../include/gdt.h"
+#include "../include/types.h"
+
+void printf(char* str) {
+    static uint16_t* VideoMemory = (uint16_t*)0xb8000;
+
+    for (int i = 0; str[i] != '\0'; ++i)
+        VideoMemory[i] = (VideoMemory[i] & 0xFF00) | str[i];
+}
+
+typedef void (*constructor)();
+extern "C" constructor start_ctors;
+extern "C" constructor end_ctors;
+extern "C" void call_constructors() {
+    for (constructor* i = &start_ctors; i != &end_ctors; i++)
+        (*i)();
+}
+
+extern "C" void ferglos_Main(const void* multiboot_structure, uint32_t /*mb_mag*/) {
+    printf("Welcome to FerglOS v0.0.1!");
+    while (1)
+        ;
+}