Kernel: Implement the setkeymap() syscall.

Author: https://github.com/asliturk
Commit: https://github.com/SerenityOS/serenity/commit/794ca16cca4
Pull-request: https://github.com/SerenityOS/serenity/pull/820

Kernel/Devices/KeyboardDevice.cpp

@@ -17,7 +17,11 @@
 #define I8042_MOUSE_BUFFER 0x20
 #define I8042_KEYBOARD_BUFFER 0x00
 
-static char map[0x80] = {
+char *map;
+char *shift_map;
+char *alt_map;
+
+static char en_map[0x80] = {
     0, '\033', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', 0x08, '\t',
     'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n', 0,
     'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`', 0, '\\',
@@ -31,7 +35,7 @@ static char map[0x80] = {
     0, 0, 0, 0, 0, 0, '\\', 0, 0, 0,
 };
 
-static char shift_map[0x80] = {
+static char en_shift_map[0x80] = {
     0, '\033', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', 0x08, '\t',
     'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n', 0,
     'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~', 0, '|',
@@ -242,7 +246,7 @@ 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] : map[raw];
+    char character = (m_modifiers & Mod_Shift) ? shift_map[raw]: (m_modifiers & Mod_Alt) ? alt_map[raw] : map[raw];
 
     if (key == Key_NumLock && pressed)
         m_num_lock_on = !m_num_lock_on;
@@ -261,6 +265,14 @@ void KeyboardDevice::key_state_changed(u8 raw, bool pressed)
             }
         }
     }
+    else
+    {
+        if(m_has_e0_prefix) {
+            if(key == Key_Slash) {
+                character = '/'; // On Turkish-QWERTY Keyboard Key_Slash mapped to '.' char, if e0 prefix is true remap to '/' char
+            }
+        }
+    }
 
     if (key == Key_CapsLock && pressed)
         m_caps_lock_on = !m_caps_lock_on;
@@ -356,6 +368,8 @@ KeyboardDevice::KeyboardDevice()
 {
     s_the = this;
 
+    KeyboardDevice::set_maps(en_map, en_shift_map, en_map);
+
     // Empty the buffer of any pending data.
     // I don't care what you've been pressing until now!
     while (IO::in8(I8042_STATUS) & I8042_BUFFER_FULL)
@@ -397,3 +411,20 @@ ssize_t KeyboardDevice::write(FileDescription&, const u8*, ssize_t)
 KeyboardClient::~KeyboardClient()
 {
 }
+
+void KeyboardDevice::set_maps(char* n_map, char* n_shift_map, char* n_alt_map)
+{
+    kfree(map);
+    kfree(shift_map);
+    kfree(alt_map);
+
+    map = (char*) kmalloc(0x80);
+    shift_map = (char*) kmalloc(0x80);
+    alt_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];
+    }
+}

Kernel/Devices/KeyboardDevice.h

@@ -21,6 +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);
 
     // ^CharacterDevice
     virtual ssize_t read(FileDescription&, u8* buffer, ssize_t) override;

Kernel/Process.cpp

@@ -7,6 +7,7 @@
 #include <Kernel/Arch/i386/PIT.h>
 #include <Kernel/Console.h>
 #include <Kernel/Devices/NullDevice.h>
+#include <Kernel/Devices/KeyboardDevice.h>
 #include <Kernel/Devices/RandomDevice.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/DevPtsFS.h>
@@ -3276,6 +3277,22 @@ int Process::sys$getrandom(void* buffer, size_t buffer_size, unsigned int flags
     return 0;
 }
 
+int Process::sys$setkeymap(char* map, char* shift_map, char* alt_map)
+{
+    if (!is_superuser())
+        return -EPERM;
+
+    if (!validate_read(map, 0x80))
+        return -EFAULT;
+    if (!validate_read(shift_map, 0x80))
+        return -EFAULT;
+    if (!validate_read(alt_map, 0x80))
+        return -EFAULT;
+
+    KeyboardDevice::the().set_maps(map, shift_map, alt_map);
+    return 0;
+}
+
 int Process::sys$clock_gettime(clockid_t clock_id, timespec* ts)
 {
     if (!validate_write_typed(ts))

Kernel/Process.h

@@ -221,6 +221,7 @@ 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);
 
     static void initialize();
 

Kernel/Syscall.h

@@ -135,6 +135,7 @@ typedef u32 socklen_t;
     __ENUMERATE_SYSCALL(get_process_name)       \
     __ENUMERATE_SYSCALL(fchdir)                 \
     __ENUMERATE_SYSCALL(getrandom)              \
+    __ENUMERATE_SYSCALL(setkeymap)              \
     __ENUMERATE_SYSCALL(clock_gettime)          \
     __ENUMERATE_SYSCALL(clock_nanosleep)        \
     __ENUMERATE_SYSCALL(openat)                 \