// === IMPORTS ===
extern tGDT gGDT[];
-extern void APStartup(void); // 16-bit AP startup code
+extern void APStartup(void); // 16-bit AP startup code
extern Uint GetRIP(void); // start.asm
extern Uint64 gInitialPML4[512]; // start.asm
-extern void gInitialKernelStack;
+extern char gInitialKernelStack[];
extern tSpinlock glThreadListLock;
extern int giNumCPUs;
extern int giNextTID;