rem: int i386_double_fault(int errorcode)
add: int i386_double_fault(struct iframe *frame)
context: int i386_double_fault(int errorcode){	kprintf("double fault! errorcode = 0x%x\n", errorcode);	dprintf("double fault! errorcode = 0x%x\n", errorcode);	for(;;);	return B_HANDLED_INTERRUPT;}