Add timer and keyboard interrupt handling (#8)

Cargo.toml

@@ -11,6 +11,8 @@ volatile = "0.2.6"
 spin = "0.5.2"
 x86_64 = "0.14.2"
 uart_16550 = "0.2.0"
+pic8259 = "0.10.1"
+pc-keyboard = "0.5.0"
 
 [dependencies.lazy_static]
 version = "1.0"

src/interrupts.rs

@@ -1,7 +1,17 @@
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 use crate::println;
+use crate::print;
 use crate::gdt;
 use lazy_static::lazy_static;
+use pic8259::ChainedPics;
+use spin;
+
+#[derive(Debug, Clone, Copy)]
+#[repr(u8)]
+pub enum InterruptIndex {
+    Timer = PIC_1_OFFSET,
+    Keyboard,
+}
 
 lazy_static! {
     static ref IDT: InterruptDescriptorTable = {
@@ -11,6 +21,8 @@ lazy_static! {
             idt.double_fault.set_handler_fn(double_fault_handler)
                 .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
         }
+        idt[InterruptIndex::Timer.as_usize()].set_handler_fn(timer_interrupt_handler);
+        idt[InterruptIndex::Keyboard.as_usize()].set_handler_fn(keyboard_interrupt_handler);
         idt
     };
 }
@@ -27,6 +39,59 @@ extern "x86-interrupt" fn double_fault_handler(stack_frame: InterruptStackFrame,
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
 
+extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: InterruptStackFrame) {
+    unsafe {
+        PICS.lock().notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
+    }
+}
+
+extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStackFrame) {
+    use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
+    use spin::Mutex;
+    use x86_64::instructions::port::Port;
+
+    lazy_static! {
+        static ref KEYBOARD: Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>> =
+            Mutex::new(Keyboard::new(layouts::Us104Key, ScancodeSet1,
+                HandleControl::Ignore)
+            );
+    }
+
+    let mut keyboard = KEYBOARD.lock();
+    let mut port = Port::new(0x60);
+
+    let scancode: u8 = unsafe { port.read() };
+    if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
+        if let Some(key) = keyboard.process_keyevent(key_event) {
+            match key {
+                DecodedKey::Unicode(character) => print!("{}", character),
+                DecodedKey::RawKey(key) => print!("{:?}", key),
+            }
+        }
+    }
+
+    unsafe {
+        PICS.lock()
+            .notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
+    }
+}
+
+pub const PIC_1_OFFSET: u8 = 32;
+pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;
+
+impl InterruptIndex {
+    fn as_u8(self) -> u8 {
+        self as u8
+    }
+
+    fn as_usize(self) -> usize {
+        usize::from(self.as_u8())
+    }
+}
+
+pub static PICS: spin::Mutex<ChainedPics> =
+    spin::Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });
+
 #[test_case]
 fn test_breakpoint_exceptions() {
     x86_64::instructions::interrupts::int3();

src/lib.rs

@@ -15,6 +15,8 @@ pub mod gdt;
 pub fn init() {
     gdt::init();
     interrupts::init_idt();
+    unsafe { interrupts::PICS.lock().initialize() };
+    x86_64::instructions::interrupts::enable();
 }
 
 pub trait Testable {
@@ -44,7 +46,13 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
     exit_qemu(QemuExitCode::Failed);
-    loop {}
+    hlt_loop();
+}
+
+pub fn hlt_loop() -> ! {
+    loop {
+        x86_64::instructions::hlt();
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -69,7 +77,7 @@ pub fn exit_qemu(exit_code: QemuExitCode) {
 pub extern "C" fn _start() -> ! {
     init();
     test_main();
-    loop {}
+    hlt_loop();
 }
 
 #[cfg(test)]

src/main.rs

@@ -24,15 +24,15 @@ pub extern "C" fn _start() -> ! {
     #[cfg(test)]
     test_main();
 
-    loop {}
+    os::hlt_loop();
 }
 
 // This function is called on panic in non-test mode.
 #[cfg(not(test))] // new attribute
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
-    loop {}
+    os::hlt_loop();
 }
 
 #[cfg(test)]

src/serial.rs

@@ -13,7 +13,13 @@ lazy_static! {
 #[doc(hidden)]
 pub fn _print(args: ::core::fmt::Arguments) {
     use core::fmt::Write;
-    SERIAL1.lock().write_fmt(args).expect("Printing to serial failed");
+    use x86_64::instructions::interrupts;
+    interrupts::without_interrupts(|| {
+        SERIAL1
+            .lock()
+            .write_fmt(args)
+            .expect("Printing to serial failed");
+    });
 }
 
 /// Prints to the host through the serial interface.

src/vga_buffer.rs

@@ -141,10 +141,14 @@ macro_rules! println {
     ($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
 }
 
+// Prints the given formatted string to the VGA text buffer through the global `WRITER` instance.
 #[doc(hidden)]
 pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
-    WRITER.lock().write_fmt(args).unwrap();
+    use x86_64::instructions::interrupts;
+    interrupts::without_interrupts(|| {
+        WRITER.lock().write_fmt(args).unwrap();
+    });
 }
 
 #[test_case]