extern struct task_struct *get_task(int pid, int require);
extern void machine_halt(void);
extern int is_syscall(unsigned long addr);
-extern void arch_switch(void);
+
+extern void arch_switch_to_tt(struct task_struct *from, struct task_struct *to);
+
+extern void arch_switch_to_skas(struct task_struct *from, struct task_struct *to);
+
extern void free_irq(unsigned int, void *);
extern int cpu(void);