-extern void scheduler_return; // Return address in SchedulerBase
-extern void IRQCommon; // Common IRQ handler code
-extern void IRQCommon_handled; // IRQCommon call return location
-extern void GetEIP_Sched_ret; // GetEIP call return location
+extern char scheduler_return[]; // Return address in SchedulerBase
+extern char IRQCommon[]; // Common IRQ handler code
+extern char IRQCommon_handled[]; // IRQCommon call return location
+extern char GetEIP_Sched_ret[]; // GetEIP call return location