reserve_exception_space
extern void reserve_exception_space(phys_addr_t addr, unsigned long size);
reserve_exception_space(0x400, VECTORSPACING * 64);
reserve_exception_space(0x400, VECTORSPACING * 64);
reserve_exception_space(0x1000, VECTORSPACING * 64);
reserve_exception_space(0, 0x1000);
reserve_exception_space(0, 0x400);