Kernel: Implement AltGr key support

Author: https://github.com/xTibor
Commit: https://github.com/SerenityOS/serenity/commit/624116a8b1c
Pull-request: https://github.com/SerenityOS/serenity/pull/972

Kernel/Devices/KeyboardDevice.cpp

@@ -20,6 +20,7 @@
 char *map;
 char *shift_map;
 char *alt_map;
+char *altgr_map;
 
 static char en_map[0x80] = {
     0, '\033', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', 0x08, '\t',
@@ -246,7 +247,7 @@ static KeyCode numpad_key_map[13] = { Key_7, Key_8, Key_9, Key_Invalid, Key_4, K
 void KeyboardDevice::key_state_changed(u8 raw, bool pressed)
 {
     KeyCode key = (m_modifiers & Mod_Shift) ? shifted_key_map[raw] : unshifted_key_map[raw];
-    char character = (m_modifiers & Mod_Shift) ? shift_map[raw]: (m_modifiers & Mod_Alt) ? alt_map[raw] : map[raw];
+    char character = (m_modifiers & Mod_Shift) ? shift_map[raw] : (m_modifiers & Mod_Alt) ? alt_map[raw] : (m_modifiers & Mod_AltGr) ? altgr_map[raw] : map[raw];
 
     if (key == Key_NumLock && pressed)
         m_num_lock_on = !m_num_lock_on;
@@ -318,7 +319,10 @@ void KeyboardDevice::handle_irq()
 #endif
         switch (ch) {
         case 0x38:
-            update_modifier(Mod_Alt, pressed);
+            if (m_has_e0_prefix)
+                update_modifier(Mod_AltGr, pressed);
+            else
+                update_modifier(Mod_Alt, pressed);
             break;
         case 0x1d:
             update_modifier(Mod_Ctrl, pressed);
@@ -368,7 +372,7 @@ KeyboardDevice::KeyboardDevice()
 {
     s_the = this;
 
-    KeyboardDevice::set_maps(en_map, en_shift_map, en_map);
+    KeyboardDevice::set_maps(en_map, en_shift_map, en_map, en_map);
 
     // Empty the buffer of any pending data.
     // I don't care what you've been pressing until now!
@@ -412,19 +416,22 @@ KeyboardClient::~KeyboardClient()
 {
 }
 
-void KeyboardDevice::set_maps(char* n_map, char* n_shift_map, char* n_alt_map)
+void KeyboardDevice::set_maps(const char* n_map, const char* n_shift_map, const char* n_alt_map, const char* n_altgr_map)
 {
     kfree(map);
     kfree(shift_map);
     kfree(alt_map);
+    kfree(altgr_map);
 
     map = (char*) kmalloc(0x80);
     shift_map = (char*) kmalloc(0x80);
     alt_map = (char*) kmalloc(0x80);
+    altgr_map = (char*) kmalloc(0x80);
 
     for(int i=0; i < 0x80; i++) {
         map[i] = n_map[i];
         shift_map[i] = n_shift_map[i];
         alt_map[i] = n_alt_map[i];
+        altgr_map[i] = n_altgr_map[i];
     }
-}
+}

Kernel/Devices/KeyboardDevice.h

@@ -21,7 +21,7 @@ public:
     KeyboardDevice();
 
     void set_client(KeyboardClient* client) { m_client = client; }
-    void set_maps(char* n_map, char* n_shift_map, char* n_alt_map);
+    void set_maps(const char* n_map, const char* n_shift_map, const char* n_alt_map, const char* n_altgr_map);
 
     // ^CharacterDevice
     virtual ssize_t read(FileDescription&, u8* buffer, ssize_t) override;

Kernel/KeyCode.h

@@ -119,7 +119,8 @@ enum KeyModifier {
     Mod_Ctrl = 0x02,
     Mod_Shift = 0x04,
     Mod_Logo = 0x08,
-    Mod_Mask = 0x0f,
+    Mod_AltGr = 0x10,
+    Mod_Mask = 0x1f,
 
     Is_Press = 0x80,
 };
@@ -132,6 +133,7 @@ struct KeyEvent {
     bool ctrl() const { return flags & Mod_Ctrl; }
     bool shift() const { return flags & Mod_Shift; }
     bool logo() const { return flags & Mod_Logo; }
+    bool altgr() const { return flags & Mod_AltGr; }
     unsigned modifiers() const { return flags & Mod_Mask; }
     bool is_press() const { return flags & Is_Press; }
 };

Kernel/Process.cpp

@@ -3584,19 +3584,24 @@ int Process::sys$getrandom(void* buffer, size_t buffer_size, unsigned int flags
     return 0;
 }
 
-int Process::sys$setkeymap(char* map, char* shift_map, char* alt_map)
+int Process::sys$setkeymap(const Syscall::SC_setkeymap_params* params)
 {
     if (!is_superuser())
         return -EPERM;
 
-    if (!validate_read(map, 0x80))
-        return -EFAULT;
-    if (!validate_read(shift_map, 0x80))
-        return -EFAULT;
-    if (!validate_read(alt_map, 0x80))
+    if (!validate_read_typed(params))
         return -EFAULT;
 
-    KeyboardDevice::the().set_maps(map, shift_map, alt_map);
+    if (!validate_read(params->map, 0x80))
+        return -EFAULT;
+    if (!validate_read(params->shift_map, 0x80))
+        return -EFAULT;
+    if (!validate_read(params->alt_map, 0x80))
+        return -EFAULT;
+    if (!validate_read(params->altgr_map, 0x80))
+        return -EFAULT;
+
+    KeyboardDevice::the().set_maps(params->map, params->shift_map, params->alt_map, params->altgr_map);
     return 0;
 }
 

Kernel/Process.h

@@ -227,7 +227,7 @@ public:
     int sys$set_process_icon(int icon_id);
     int sys$realpath(const char* pathname, char*, size_t);
     ssize_t sys$getrandom(void*, size_t, unsigned int);
-    int sys$setkeymap(char* map, char* shift_map, char* alt_map);
+    int sys$setkeymap(const Syscall::SC_setkeymap_params*);
     int sys$module_load(const char* path, size_t path_length);
     int sys$module_unload(const char* name, size_t name_length);
     int sys$profiling_enable(pid_t);

Kernel/Syscall.h

@@ -270,6 +270,13 @@ struct SC_futex_params {
     const timespec* timeout;
 };
 
+struct SC_setkeymap_params {
+    const char* map;
+    const char* shift_map;
+    const char* alt_map;
+    const char* altgr_map;
+};
+
 struct SC_create_thread_params {
     unsigned int m_detach_state = 0; // JOINABLE or DETACHED
     int m_schedule_priority = 30;    // THREAD_PRIORITY_NORMAL