Improved build system

Added new entries to .gitignore
Moved away from source directory as central spot for all source code

kernel/memory/gdt/gdt.s

@@ -0,0 +1,19 @@
+.global LoadGlobalDescriptorTable
+
+	LoadGlobalDescriptorTable:
+		lgdt gdtDescriptor
+
+		movw $16, %ax 
+		movw %ax, %ds
+		movw %ax, %es
+		movw %ax, %fs
+		movw %ax, %gs
+		movw %ax, %ss
+		
+		jmp $8,$flush 
+
+		flush: 
+		ret
+		
+	
+

kernel/memory/gdt/gdtc.cpp

@@ -0,0 +1,46 @@
+#include "gdtc.h"
+#include "../../terminal/kterm.h"
+
+
+SegmentDescriptor GlobalDescriptorTable[6];
+GlobalDescriptorTableDescriptor gdtDescriptor;
+
+
+void add_descriptor(int which , unsigned long base, unsigned long limit, unsigned char access, unsigned char granularity ){
+   GlobalDescriptorTable[which].base_low = (base & 0xFFFF );
+   GlobalDescriptorTable[which].base_middle = (base >> 6) & 0xFF;
+   GlobalDescriptorTable[which].base_high = (base >> 24) & 0xFF;
+   
+   GlobalDescriptorTable[which].limit_low = (limit & 0xFFFF);
+   GlobalDescriptorTable[which].granularity = ((limit >> 16) & 0x0F);
+
+   GlobalDescriptorTable[which].granularity |= (granularity & 0xF0);
+   GlobalDescriptorTable[which].access = access;
+
+}
+
+
+
+
+void initGDT(){
+
+      // NULL segment
+      add_descriptor(NULL_SEGMENT, 0,0,0,0);
+
+      // Kernel Code Segment
+      add_descriptor(KERNEL_CODE_SEGMENT, 0, 0xFFFFFFFF, 0x9A, 0xCF);
+
+      // Kernel Data Segment
+      add_descriptor(KERNEL_DATA_SEGMENT, 0, 0xFFFFFFFF, 0x92, 0xCF);      
+
+      // User Code Segment
+      add_descriptor(USER_CODE_SEGMENT, 0, 0xFFFFFFFF, 0xFA, 0xCF);
+      
+      // User Data Segement
+      add_descriptor(USER_DATA_SEGMENT, 0, 0xFFFFFFFF, 0xF2, 0xCF);
+
+      // init Gdt Descriptor
+      gdtDescriptor.limit = ((sizeof(SegmentDescriptor ) * 6 ) - 1);
+      gdtDescriptor.base = (unsigned int) (&GlobalDescriptorTable);
+
+}

kernel/memory/gdt/gdtc.h

@@ -0,0 +1,35 @@
+#pragma once
+#include <stdint.h>
+
+
+#define NULL_SEGMENT          0
+#define KERNEL_CODE_SEGMENT   1
+#define KERNEL_DATA_SEGMENT   2
+#define USER_CODE_SEGMENT     3
+#define USER_DATA_SEGMENT     4
+#define TASK_STATE_SEGMENT    5
+
+
+
+struct SegmentDescriptor {
+   unsigned short limit_low;
+   unsigned short base_low;
+   unsigned char base_middle;
+   unsigned char access;
+   unsigned char granularity;
+   unsigned char base_high;
+}__attribute__((packed));
+
+extern SegmentDescriptor GlobalDescriptorTable[6];
+
+struct GlobalDescriptorTableDescriptor{
+   unsigned short limit;
+   unsigned int base;
+}__attribute__((packed)) ;
+
+
+
+void add_descriptor(int which , unsigned long base, unsigned long limit, unsigned char access, unsigned char granularity );
+
+
+void initGDT();