Added functions to enable MMU with paging

src/kernel/MMU.cpp

@@ -0,0 +1,35 @@
+#include "MMU.h"
+
+
+
+void MMU::enable(){
+
+    //set each entry to not present
+    int i;
+    for(i = 0; i < 1024; i++)
+    {
+        // This sets the following flags to the pages:
+        //   Supervisor: Only kernel-mode can access them
+        //   Write Enabled: It can be both read from and written to
+        //   Not Present: The page table is not present
+        this->page_directory[i] = 0x00000002;
+    }
+
+    // holds the physical address where we want to start mapping these pages to.
+    // in this case, we want to map these pages to the very beginning of memory.
+
+    //we will fill all 1024 entries in the table, mapping 4 megabytes
+    for(unsigned int i = 0; i < 1024; i++)
+    {
+    // As the address is page aligned, it will always leave 12 bits zeroed.
+    // Those bits are used by the attributes ;)
+    first_page_table[i] = (i * 0x1000) | 3; // attributes: supervisor level, read/write, present.
+    }
+
+    // attributes: supervisor level, read/write, present
+    this->page_directory[0] = ((unsigned int)first_page_table) | 3;
+
+
+    loadPageDirectory(this->page_directory);
+    enablePaging();
+}