rust-osdev/Lobby

@cdrzewiecki_gitlab I had to do this too, here's what worked for me.
I first got an initial IDT up and running using lazy_static:

lazy_static! {
    pub static ref IDT: RwLock<InterruptDescriptorTable> = RwLock::new({
        let mut idt = InterruptDescriptorTable::new();
        idt.breakpoint.set_handler_fn(breakpoint_handler);
        unsafe {
            idt.double_fault.set_handler_fn(double_fault_handler)
                .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
        }
        idt.non_maskable_interrupt.set_handler_fn(non_maskable_interrupt_handler);
// ..... lines omitted for brevity
        idt[InterruptIndex::Keyboard.as_usize()].set_handler_fn(keyboard_interrupt_handler);
// ..... lines omitted for brevity
        idt
    });
}

then I declared the following function to load the IDT:

pub fn init_idt() {
    unsafe { IDT.read().load_unsafe(); }
}

so when the kernel starts, the first time the BSP will run init_idt().
Then later, when I need to make changes to the IDT I do this: (example taken from my VMware SVGA module)

// Set the interrupt handler and enable the IRQ
let mut idt = crate::interrupts::IDT.write();
idt[irq.into()].set_handler_fn(svga_interrupt_handler);
unsafe {
    idt.load_unsafe();
    (*crate::interrupts::PICS.lock()).set_mask(irq, true);
}

It may not be the best, cleanest solution but it works for me since I only have to mutate the handlers here. If I have to do that in the future I might consider a different approach but for now the reduced complexity and scope doesn't justify an overhaul. I want to have this be KISS.

Hope it helps! :)