Implemented Higher Half Kernel!

- Minor makefile chnages
- stage3.c "prekernel", sets up memory stuff and jumps to kernel
- kernel is now at 0xC0000000 - 3GB+ "higher half"
- Added some global variables in memory/addresses.h

include/disk/filesys.h

@@ -48,14 +48,15 @@ void updateFiletable() {
     // TODO: Update the filetable by writing data from memory to disk!
 }
 
-void readFile(char* filename, void* buffer) { // Hopefully the buffer is large enought :/
+uint8_t readFile(char* filename, void* buffer) { // Hopefully the buffer is large enought :/
     fileEntry_t* file = findFile(filename);
-    if (file == NULL) { return; } // File doesn't exist!
+    if (file == NULL) { return 1; } // File doesn't exist!
 
     diskRead(file->startAddress, file->length, buffer);
+    return 0; // Success
 }
 
-void writeFile(char* filename, void* buffer) { // TODO: Add length so we don't write too much/too little
+uint8_t writeFile(char* filename, void* buffer) { // TODO: Add length so we don't write too much/too little
     fileEntry_t* file = findFile(filetable);
     if (file == NULL) { // File exists -> override
         // File doesn't exist -> create new file
@@ -74,6 +75,7 @@ void writeFile(char* filename, void* buffer) { // TODO: Add length so we don't w
     }
 
     diskWrite(file->startAddress, file->length, buffer); // Write the file
+    return 0; // Success
 }
 
 void printFiletable(char* ft) {

include/memory/addresses.h

@@ -1,10 +1,18 @@
 #ifndef ADDRESSES_H
 #define ADDRESSES_H
 
-#define MEMMAP_AREA 0x30000
-#define KERNEL_LOC 0x50000
-#define FILETABLE_LOC 0x7000
-#define SMAP_ENTRY_COUNT 0x8500
-#define SMAP_ENTRIES 0x8504
+// Locations
+#define KERNEL_LOC              0x100000
+#define FILETABLE_LOC           0x7000
+
+// Physical memory manager
+#define MEMMAP_AREA             0x30000
+#define SMAP_ENTRY_COUNT        0x8500
+#define SMAP_ENTRIES            0x8504
+#define PHYS_MEM_MAX_BLOCKS     0x1804
+#define PHYS_MEM_USED_BLOCKS    0x1808
+
+// Virtual memory manager
+#define CURRENT_PAGE_DIR_ADDR   0x1800
 
 #endif