refactor mega-commit.

- reorganised the entire project so that the entire kernel is a single codebase rather than a kernel and a libk.

kernel/src/arch/x86_64/drivers/keyboard.rs

@@ -0,0 +1,202 @@
+use core::{
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use crate::println;
+use crossbeam::queue::ArrayQueue;
+use futures_util::{Stream, StreamExt, task::AtomicWaker};
+use pc_keyboard::{DecodedKey, HandleControl, KeyCode, Keyboard, ScancodeSet1, layouts::Uk105Key};
+use spin::{Lazy, Mutex, Once};
+
+static KBD_QUEUE: Once<ArrayQueue<u8>> = Once::new();
+static WAKER: AtomicWaker = AtomicWaker::new();
+
+pub static KEYBOARD: Lazy<Mutex<Keyboard<Uk105Key, ScancodeSet1>>> = Lazy::new(|| {
+    Mutex::new(Keyboard::new(
+        ScancodeSet1::new(),
+        // TODO: Expose an API to change the default KB layout.
+        Uk105Key,
+        HandleControl::Ignore,
+    ))
+});
+pub static SCANCODE_STREAM: Lazy<Mutex<ScancodeStream>> =
+    Lazy::new(|| Mutex::new(ScancodeStream::new()));
+
+pub fn add_scancode(scancode: u8) {
+    if let Some(queue) = KBD_QUEUE.get() {
+        if queue.push(scancode).is_err() {
+            println!("WARNING: scancode queue full; dropping keyboard input");
+        } else {
+            WAKER.wake();
+        }
+    } else {
+        println!("WARNING: scancode queue not initialized");
+    }
+}
+
+pub struct ScancodeStream {
+    _private: (),
+}
+
+impl ScancodeStream {
+    pub fn new() -> Self {
+        KBD_QUEUE.call_once(|| ArrayQueue::new(5));
+        Self { _private: () }
+    }
+
+    pub fn try_next(&mut self) -> Option<u8> {
+        KBD_QUEUE.get().and_then(|queue| queue.pop())
+    }
+}
+
+impl Default for ScancodeStream {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Stream for ScancodeStream {
+    type Item = u8;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let queue = KBD_QUEUE.get().unwrap();
+
+        if let Some(scancode) = queue.pop() {
+            return Poll::Ready(Some(scancode));
+        }
+
+        WAKER.register(cx.waker());
+        WAKER.register(cx.waker());
+
+        queue.pop().map_or(Poll::Pending, |scancode| {
+            WAKER.take();
+            Poll::Ready(Some(scancode))
+        })
+    }
+}
+
+pub async fn get_keystroke_async() -> KeyStroke {
+    loop {
+        if let Some(scancode) = SCANCODE_STREAM.lock().next().await {
+            if let Ok(keystroke) = KeyStroke::try_from(scancode) {
+                return keystroke;
+            }
+        }
+    }
+}
+
+pub fn get_keystroke_optional() -> Option<KeyStroke> {
+    if let Some(scancode) = SCANCODE_STREAM.lock().try_next() {
+        if let Ok(keystroke) = KeyStroke::try_from(scancode) {
+            return Some(keystroke);
+        }
+    }
+    None
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum KeyStroke {
+    Char(char),
+    Ctrl,
+    RCtrl,
+    Alt,
+    RAlt,
+    Shift,
+    RShift,
+    Meta,
+    RMeta,
+    Backspace,
+    Left,
+    Right,
+    Up,
+    Down,
+    None,
+    Enter,
+    Escape,
+    Del,
+}
+
+impl KeyStroke {
+    pub const fn from_keycode(key: KeyCode) -> Self {
+        match key {
+            KeyCode::LControl => Self::Ctrl,
+            KeyCode::RControl => Self::RCtrl,
+            KeyCode::LAlt => Self::Alt,
+            KeyCode::RAlt2 => Self::RAlt,
+            KeyCode::LShift => Self::Shift,
+            KeyCode::RShift => Self::RShift,
+            KeyCode::LWin => Self::Meta,
+            KeyCode::RWin => Self::RMeta,
+            KeyCode::Backspace => Self::Backspace,
+            KeyCode::ArrowLeft => Self::Left,
+            KeyCode::ArrowRight => Self::Right,
+            KeyCode::ArrowUp => Self::Up,
+            KeyCode::ArrowDown => Self::Down,
+            KeyCode::Return => Self::Enter,
+            KeyCode::Escape => Self::Escape,
+            KeyCode::Delete => Self::Del,
+            _ => Self::None,
+        }
+    }
+}
+
+impl TryFrom<u8> for KeyStroke {
+    type Error = ();
+
+    fn try_from(code: u8) -> Result<Self, Self::Error> {
+        let mut keyboard = KEYBOARD.lock();
+
+        let key = match keyboard.add_byte(code) {
+            Ok(Some(event)) => match keyboard.process_keyevent(event) {
+                Some(key) => key,
+                _ => return Err(()),
+            },
+            _ => return Err(()),
+        };
+
+        match key {
+            DecodedKey::Unicode(ch) => Ok(Self::Char(ch)),
+            DecodedKey::RawKey(key) => match Self::from_keycode(key) {
+                Self::None => Err(()),
+                key => Ok(key),
+            },
+        }
+    }
+}
+
+impl TryInto<char> for KeyStroke {
+    type Error = ();
+
+    fn try_into(self) -> Result<char, Self::Error> {
+        match self {
+            Self::Char(c) => Ok(c),
+            _ => Err(()),
+        }
+    }
+}
+
+impl core::fmt::Display for KeyStroke {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::Char(c) => write!(f, "{}", c),
+            Self::Ctrl => write!(f, "CTRL"),
+            Self::RCtrl => write!(f, "RCtrl"),
+            Self::Alt => write!(f, "ALT"),
+            Self::RAlt => write!(f, "RAlt"),
+            Self::Shift => write!(f, "SHIFT"),
+            Self::RShift => write!(f, "RShift"),
+            Self::Meta => write!(f, "META"),
+            Self::RMeta => write!(f, "RMeta"),
+            Self::Backspace => write!(f, "BACKSPACE"),
+            Self::Left => write!(f, "LEFT"),
+            Self::Right => write!(f, "RIGHT"),
+            Self::Up => write!(f, "UP"),
+            Self::Down => write!(f, "DOWN"),
+            Self::Enter => write!(f, "ENTER"),
+            Self::Escape => write!(f, "ESCAPE"),
+            Self::None => write!(f, "NONE"),
+            Self::Del => write!(f, "DEL"),
+        }
+    }
+}