rustos 0.4.3

Writing an OS in Rust
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//! CPU exception and hardware interrupt handling
extern crate pic8259_simple;
use self::pic8259_simple::ChainedPics;
use crate::println;
use lazy_static::lazy_static;
use spin::Mutex;
use x86_64::{
    instructions::port::Port,
    structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode},
};

pub(crate) fn init() {
    IDT.load();
    // Initialize the interrupt controller.
    unsafe { PICS.lock().initialize() };
    // Enable the hardware interrupts.
    x86_64::instructions::interrupts::enable();
}

lazy_static! {
    pub static ref IDT: InterruptDescriptorTable = {
        let mut idt = InterruptDescriptorTable::new();
        idt.breakpoint.set_handler_fn(breakpoint_handler);
        idt.double_fault.set_handler_fn(double_fault_handler);
        idt.page_fault.set_handler_fn(page_fault_handler);
        idt[InterruptIndex::Timer.as_usize()].set_handler_fn(timer_interrupt_handler);
        idt[InterruptIndex::Keyboard.as_usize()].set_handler_fn(keyboard_interrupt_handler);
        idt
    };
}

extern "x86-interrupt" fn breakpoint_handler(stack_frame: &mut InterruptStackFrame) {
    println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
}

extern "x86-interrupt" fn double_fault_handler(
    stack_frame: &mut InterruptStackFrame,
    _error_code: u64,
) -> ! {
    panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
}

extern "x86-interrupt" fn page_fault_handler(
    stack_frame: &mut InterruptStackFrame,
    error_code: PageFaultErrorCode,
) {
    use x86_64::registers::control::Cr2;
    println!("EXCEPTION: PAGE FAULT");
    println!("Accessed Address: {:?}", Cr2::read());
    println!("Error Code: {:?}", error_code);
    println!("{:#?}", stack_frame);
    crate::hlt_loop();
}

extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
    unsafe {
        PICS.lock()
            .notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
    }
}

extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
    let mut port = Port::new(0x60);
    let scancode: u8 = unsafe { port.read() };
    crate::task::keyboard::add_scancode(scancode);
    unsafe {
        PICS.lock()
            .notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
enum InterruptIndex {
    Timer = PIC_1_OFFSET,
    Keyboard,
}

impl InterruptIndex {
    fn as_u8(self) -> u8 {
        self as u8
    }
    fn as_usize(self) -> usize {
        usize::from(self.as_u8())
    }
}

const PIC_1_OFFSET: u8 = 32;
const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;

static PICS: Mutex<ChainedPics> =
    Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });

#[cfg(test)]
mod tests {
    use crate::{serial_print, serial_println};
    #[test_case]
    fn breakpoint_exception() {
        serial_print!("interrupts::breakpoint_exception... ");
        x86_64::instructions::interrupts::int3();
        serial_println!("[ok]");
    }
}