如何在我的操作系统内核中启用IRQ8？

I want to know that, how to enable IRQ8 (RTC) in my own Kernel written in C++. I already have the module for installing interrupt handlers. But after installing IRQ8 interrupt handlers it doesn't generate any interrupt. So how can i enable IRQ8 ? and after enabling it what interrupt it will generate ? I know that RTC generates INT 70h interrupt, but i am installing RTC interrupt handler on int 29h in IDT. So that it's not working.I want to know that, how to enable IRQ8 (RTC) i