feat: switch text to UTF-8; add Unicode key events, dead keys & Czech layout; fix numpad navigation; add NumLock support

kernel/src/Drivers/PS2/Keyboard.cpp

@@ -139,6 +139,7 @@ namespace Drivers::PS2::Keyboard {
         ack = Drivers::PS2::ReadData();
 
         g_Modifiers = {};
+        g_Modifiers.NumLock = true;   // keypad types digits, as on most PCs
         g_BufferHead = 0;
         g_BufferTail = 0;
         g_ExtendedScancode = false;
@@ -257,6 +258,9 @@ namespace Drivers::PS2::Keyboard {
                 ascii = g_ScancodeToAscii[keycode];
             }
         }
+        // Num Lock off: the keypad is navigation keys, which type nothing.
+        if (!g_Modifiers.NumLock && IsKeypadNavScancode(keycode))
+            ascii = 0;
 
         KeyEvent event = {
             .Scancode = scancode,
@@ -310,6 +314,12 @@ namespace Drivers::PS2::Keyboard {
         KeyEvent stamped = event;
         if (stamped.Scancode == ScCapsLock && stamped.Pressed)
             g_Modifiers.CapsLock = !g_Modifiers.CapsLock;
+        // Num Lock likewise. Like the PS/2 path, the lock key itself is not
+        // delivered to apps.
+        if (stamped.Scancode == ScNumLock) {
+            if (stamped.Pressed) g_Modifiers.NumLock = !g_Modifiers.NumLock;
+            return;
+        }
         stamped.CapsLock = g_Modifiers.CapsLock;
         PushAndNotify(stamped);
     }
@@ -318,4 +328,8 @@ namespace Drivers::PS2::Keyboard {
         return g_Modifiers.CapsLock;
     }
 
+    bool GetNumLock() {
+        return g_Modifiers.NumLock;
+    }
+
 };

kernel/src/Drivers/PS2/Keyboard.hpp

@@ -63,4 +63,14 @@ namespace Drivers::PS2::Keyboard {
     // compute ASCII, since the lock is toggled centrally here.
     bool GetCapsLock();
 
+    // Current Num Lock state, owned here like Caps Lock. On (the default), the
+    // keypad types digits; off, it acts as the navigation keys printed on it.
+    bool GetNumLock();
+
+    // Set-1 scancodes of the keypad keys that are a digit/'.' with Num Lock on
+    // and Home/arrows/PgUp/End/PgDn/Ins/Del with it off (not '-' and '+').
+    inline bool IsKeypadNavScancode(uint8_t keycode) {
+        return keycode >= 0x47 && keycode <= 0x53 && keycode != 0x4A && keycode != 0x4E;
+    }
+
 };