feat(userspace): terminal server + shell desktop; US keymap w/ shift; libkos allocator multi-page fix; panics print

crates/drivers/input/virtio/src/keymap.rs

@@ -0,0 +1,56 @@
+//! Linux key codes (what virtio-input reports) to keys, US layout.
+
+use port_input_device::Key;
+
+pub const LEFT_SHIFT: u16 = 42;
+pub const RIGHT_SHIFT: u16 = 54;
+
+/// Rows of the main block: the first key's code, then each key unshifted
+/// and shifted.
+const ROWS: [(u16, &[u8], &[u8]); 4] = [
+    (2, b"1234567890-=", b"!@#$%^&*()_+"),
+    (16, b"qwertyuiop[]", b"QWERTYUIOP{}"),
+    (30, b"asdfghjkl;'`", b"ASDFGHJKL:\"~"),
+    (44, b"zxcvbnm,./", b"ZXCVBNM<>?"),
+];
+
+pub fn key(code: u16, shift: bool) -> Option<Key> {
+    let named = match code {
+        1 => Some(Key::Escape),
+        14 => Some(Key::Backspace),
+        15 => Some(Key::Tab),
+        28 => Some(Key::Enter),
+        57 => Some(Key::Space),
+        103 => Some(Key::Up),
+        108 => Some(Key::Down),
+        105 => Some(Key::Left),
+        106 => Some(Key::Right),
+        43 => Some(Key::Char(if shift { b'|' } else { b'\\' })),
+        _ => None,
+    };
+    named.or_else(|| {
+        ROWS.iter().find_map(|(first, plain, shifted)| {
+            let i = usize::from(code.checked_sub(*first)?);
+            let row = if shift { shifted } else { plain };
+            row.get(i).map(|c| Key::Char(*c))
+        })
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn letters_digits_and_shift() {
+        assert_eq!(key(35, false), Some(Key::Char(b'h')));
+        assert_eq!(key(35, true), Some(Key::Char(b'H')));
+        assert_eq!(key(11, false), Some(Key::Char(b'0')));
+        assert_eq!(key(12, true), Some(Key::Char(b'_')));
+        assert_eq!(key(53, false), Some(Key::Char(b'/')));
+        assert_eq!(key(41, true), Some(Key::Char(b'~')));
+        assert_eq!(key(28, false), Some(Key::Enter));
+        assert_eq!(key(103, false), Some(Key::Up));
+        assert_eq!(key(29, false), None, "left ctrl is not a character");
+    }
+}