Initial commitHEADmain

1 files changed, 997 insertions, 0 deletions

diff --git a/SDL-3.2.8/src/core/linux/SDL_evdev_kbd.c b/SDL-3.2.8/src/core/linux/SDL_evdev_kbd.c
new file mode 100644
index 0000000..b1a5664
--- /dev/null
+++ b/SDL-3.2.8/src/core/linux/SDL_evdev_kbd.c
@@ -0,0 +1,997 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#include "SDL_evdev_kbd.h"
+
+#ifdef SDL_INPUT_LINUXKD
+
+// This logic is adapted from drivers/tty/vt/keyboard.c in the Linux kernel source
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#include <linux/keyboard.h>
+#include <linux/vt.h>
+#include <linux/tiocl.h> // for TIOCL_GETSHIFTSTATE
+
+#include <signal.h>
+
+#include "../../events/SDL_events_c.h"
+#include "SDL_evdev_kbd_default_accents.h"
+#include "SDL_evdev_kbd_default_keymap.h"
+
+// These are not defined in older Linux kernel headers
+#ifndef K_UNICODE
+#define K_UNICODE 0x03
+#endif
+#ifndef K_OFF
+#define K_OFF 0x04
+#endif
+
+/*
+ * Handler Tables.
+ */
+
+#define K_HANDLERS                            \
+    k_self, k_fn, k_spec, k_pad,              \
+        k_dead, k_cons, k_cur, k_shift,       \
+        k_meta, k_ascii, k_lock, k_lowercase, \
+        k_slock, k_dead2, k_brl, k_ignore
+
+typedef void(k_handler_fn)(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag);
+static k_handler_fn K_HANDLERS;
+static k_handler_fn *k_handler[16] = { K_HANDLERS };
+
+typedef void(fn_handler_fn)(SDL_EVDEV_keyboard_state *kbd);
+static void fn_enter(SDL_EVDEV_keyboard_state *kbd);
+static void fn_caps_toggle(SDL_EVDEV_keyboard_state *kbd);
+static void fn_caps_on(SDL_EVDEV_keyboard_state *kbd);
+static void fn_num(SDL_EVDEV_keyboard_state *kbd);
+static void fn_compose(SDL_EVDEV_keyboard_state *kbd);
+
+static fn_handler_fn *fn_handler[] = {
+    NULL, fn_enter, NULL, NULL,
+    NULL, NULL, NULL, fn_caps_toggle,
+    fn_num, NULL, NULL, NULL,
+    NULL, fn_caps_on, fn_compose, NULL,
+    NULL, NULL, NULL, fn_num
+};
+
+/*
+ * Keyboard State
+ */
+
+struct SDL_EVDEV_keyboard_state
+{
+    int console_fd;
+    bool muted;
+    int old_kbd_mode;
+    unsigned short **key_maps;
+    unsigned char shift_down[NR_SHIFT]; // shift state counters..
+    bool dead_key_next;
+    int npadch; // -1 or number assembled on pad
+    struct kbdiacrs *accents;
+    unsigned int diacr;
+    bool rep; // flag telling character repeat
+    unsigned char lockstate;
+    unsigned char slockstate;
+    unsigned char ledflagstate;
+    char shift_state;
+    char text[128];
+    unsigned int text_len;
+    void (*vt_release_callback)(void *);
+    void *vt_release_callback_data;
+    void (*vt_acquire_callback)(void *);
+    void *vt_acquire_callback_data;
+};
+
+#ifdef DUMP_ACCENTS
+static void SDL_EVDEV_dump_accents(SDL_EVDEV_keyboard_state *kbd)
+{
+    unsigned int i;
+
+    printf("static struct kbdiacrs default_accents = {\n");
+    printf("    %d,\n", kbd->accents->kb_cnt);
+    printf("    {\n");
+    for (i = 0; i < kbd->accents->kb_cnt; ++i) {
+        struct kbdiacr *diacr = &kbd->accents->kbdiacr[i];
+        printf("        { 0x%.2x, 0x%.2x, 0x%.2x },\n",
+               diacr->diacr, diacr->base, diacr->result);
+    }
+    while (i < 256) {
+        printf("        { 0x00, 0x00, 0x00 },\n");
+        ++i;
+    }
+    printf("    }\n");
+    printf("};\n");
+}
+#endif // DUMP_ACCENTS
+
+#ifdef DUMP_KEYMAP
+static void SDL_EVDEV_dump_keymap(SDL_EVDEV_keyboard_state *kbd)
+{
+    int i, j;
+
+    for (i = 0; i < MAX_NR_KEYMAPS; ++i) {
+        if (kbd->key_maps[i]) {
+            printf("static unsigned short default_key_map_%d[NR_KEYS] = {", i);
+            for (j = 0; j < NR_KEYS; ++j) {
+                if ((j % 8) == 0) {
+                    printf("\n    ");
+                }
+                printf("0x%.4x, ", kbd->key_maps[i][j]);
+            }
+            printf("\n};\n");
+        }
+    }
+    printf("\n");
+    printf("static unsigned short *default_key_maps[MAX_NR_KEYMAPS] = {\n");
+    for (i = 0; i < MAX_NR_KEYMAPS; ++i) {
+        if (kbd->key_maps[i]) {
+            printf("    default_key_map_%d,\n", i);
+        } else {
+            printf("    NULL,\n");
+        }
+    }
+    printf("};\n");
+}
+#endif // DUMP_KEYMAP
+
+static SDL_EVDEV_keyboard_state *kbd_cleanup_state = NULL;
+static int kbd_cleanup_sigactions_installed = 0;
+static int kbd_cleanup_atexit_installed = 0;
+
+static struct sigaction old_sigaction[NSIG];
+
+static int fatal_signals[] = {
+    // Handlers for SIGTERM and SIGINT are installed in SDL_InitQuit.
+    SIGHUP, SIGQUIT, SIGILL, SIGABRT,
+    SIGFPE, SIGSEGV, SIGPIPE, SIGBUS,
+    SIGSYS
+};
+
+static void kbd_cleanup(void)
+{
+    SDL_EVDEV_keyboard_state *kbd = kbd_cleanup_state;
+    if (!kbd) {
+        return;
+    }
+    kbd_cleanup_state = NULL;
+
+    ioctl(kbd->console_fd, KDSKBMODE, kbd->old_kbd_mode);
+}
+
+static void SDL_EVDEV_kbd_reraise_signal(int sig)
+{
+    (void)raise(sig);
+}
+
+static siginfo_t *SDL_EVDEV_kdb_cleanup_siginfo = NULL;
+static void *SDL_EVDEV_kdb_cleanup_ucontext = NULL;
+
+static void kbd_cleanup_signal_action(int signum, siginfo_t *info, void *ucontext)
+{
+    struct sigaction *old_action_p = &(old_sigaction[signum]);
+    sigset_t sigset;
+
+    // Restore original signal handler before going any further.
+    sigaction(signum, old_action_p, NULL);
+
+    // Unmask current signal.
+    sigemptyset(&sigset);
+    sigaddset(&sigset, signum);
+    sigprocmask(SIG_UNBLOCK, &sigset, NULL);
+
+    // Save original signal info and context for archeologists.
+    SDL_EVDEV_kdb_cleanup_siginfo = info;
+    SDL_EVDEV_kdb_cleanup_ucontext = ucontext;
+
+    // Restore keyboard.
+    kbd_cleanup();
+
+    // Reraise signal.
+    SDL_EVDEV_kbd_reraise_signal(signum);
+}
+
+static void kbd_unregister_emerg_cleanup(void)
+{
+    int tabidx;
+
+    kbd_cleanup_state = NULL;
+
+    if (!kbd_cleanup_sigactions_installed) {
+        return;
+    }
+    kbd_cleanup_sigactions_installed = 0;
+
+    for (tabidx = 0; tabidx < sizeof(fatal_signals) / sizeof(fatal_signals[0]); ++tabidx) {
+        struct sigaction *old_action_p;
+        struct sigaction cur_action;
+        int signum = fatal_signals[tabidx];
+        old_action_p = &(old_sigaction[signum]);
+
+        // Examine current signal action
+        if (sigaction(signum, NULL, &cur_action)) {
+            continue;
+        }
+
+        // Check if action installed and not modified
+        if (!(cur_action.sa_flags & SA_SIGINFO) || cur_action.sa_sigaction != &kbd_cleanup_signal_action) {
+            continue;
+        }
+
+        // Restore original action
+        sigaction(signum, old_action_p, NULL);
+    }
+}
+
+static void kbd_cleanup_atexit(void)
+{
+    // Restore keyboard.
+    kbd_cleanup();
+
+    // Try to restore signal handlers in case shared library is being unloaded
+    kbd_unregister_emerg_cleanup();
+}
+
+static void kbd_register_emerg_cleanup(SDL_EVDEV_keyboard_state *kbd)
+{
+    int tabidx;
+
+    if (kbd_cleanup_state) {
+        return;
+    }
+    kbd_cleanup_state = kbd;
+
+    if (!kbd_cleanup_atexit_installed) {
+        /* Since glibc 2.2.3, atexit() (and on_exit(3)) can be used within a shared library to establish
+         * functions that are called when the shared library is unloaded.
+         * -- man atexit(3)
+         */
+        (void)atexit(kbd_cleanup_atexit);
+        kbd_cleanup_atexit_installed = 1;
+    }
+
+    if (kbd_cleanup_sigactions_installed) {
+        return;
+    }
+    kbd_cleanup_sigactions_installed = 1;
+
+    for (tabidx = 0; tabidx < sizeof(fatal_signals) / sizeof(fatal_signals[0]); ++tabidx) {
+        struct sigaction *old_action_p;
+        struct sigaction new_action;
+        int signum = fatal_signals[tabidx];
+        old_action_p = &(old_sigaction[signum]);
+        if (sigaction(signum, NULL, old_action_p)) {
+            continue;
+        }
+
+        /* Skip SIGHUP and SIGPIPE if handler is already installed
+         * - assume the handler will do the cleanup
+         */
+        if ((signum == SIGHUP || signum == SIGPIPE) && (old_action_p->sa_handler != SIG_DFL || (void (*)(int))old_action_p->sa_sigaction != SIG_DFL)) {
+            continue;
+        }
+
+        new_action = *old_action_p;
+        new_action.sa_flags |= SA_SIGINFO;
+        new_action.sa_sigaction = &kbd_cleanup_signal_action;
+        sigaction(signum, &new_action, NULL);
+    }
+}
+
+enum {
+    VT_SIGNAL_NONE,
+    VT_SIGNAL_RELEASE,
+    VT_SIGNAL_ACQUIRE,
+};
+static int vt_release_signal;
+static int vt_acquire_signal;
+static SDL_AtomicInt vt_signal_pending;
+
+typedef void (*signal_handler)(int signum);
+
+static void kbd_vt_release_signal_action(int signum)
+{
+    SDL_SetAtomicInt(&vt_signal_pending, VT_SIGNAL_RELEASE);
+}
+
+static void kbd_vt_acquire_signal_action(int signum)
+{
+    SDL_SetAtomicInt(&vt_signal_pending, VT_SIGNAL_ACQUIRE);
+}
+
+static bool setup_vt_signal(int signum, signal_handler handler)
+{
+    struct sigaction *old_action_p;
+    struct sigaction new_action;
+    old_action_p = &(old_sigaction[signum]);
+    SDL_zero(new_action);
+    new_action.sa_handler = handler;
+    new_action.sa_flags = SA_RESTART;
+    if (sigaction(signum, &new_action, old_action_p) < 0) {
+        return false;
+    }
+    if (old_action_p->sa_handler != SIG_DFL) {
+        // This signal is already in use
+        sigaction(signum, old_action_p, NULL);
+        return false;
+    }
+    return true;
+}
+
+static int find_free_signal(signal_handler handler)
+{
+#ifdef SIGRTMIN
+    int i;
+
+    for (i = SIGRTMIN + 2; i <= SIGRTMAX; ++i) {
+        if (setup_vt_signal(i, handler)) {
+            return i;
+        }
+    }
+#endif
+    if (setup_vt_signal(SIGUSR1, handler)) {
+        return SIGUSR1;
+    }
+    if (setup_vt_signal(SIGUSR2, handler)) {
+        return SIGUSR2;
+    }
+    return 0;
+}
+
+static void kbd_vt_quit(int console_fd)
+{
+    struct vt_mode mode;
+
+    if (vt_release_signal) {
+        sigaction(vt_release_signal, &old_sigaction[vt_release_signal], NULL);
+        vt_release_signal = 0;
+    }
+    if (vt_acquire_signal) {
+        sigaction(vt_acquire_signal, &old_sigaction[vt_acquire_signal], NULL);
+        vt_acquire_signal = 0;
+    }
+
+    SDL_zero(mode);
+    mode.mode = VT_AUTO;
+    ioctl(console_fd, VT_SETMODE, &mode);
+}
+
+static bool kbd_vt_init(int console_fd)
+{
+    struct vt_mode mode;
+
+    vt_release_signal = find_free_signal(kbd_vt_release_signal_action);
+    vt_acquire_signal = find_free_signal(kbd_vt_acquire_signal_action);
+    if (!vt_release_signal || !vt_acquire_signal ) {
+        kbd_vt_quit(console_fd);
+        return false;
+    }
+
+    SDL_zero(mode);
+    mode.mode = VT_PROCESS;
+    mode.relsig = vt_release_signal;
+    mode.acqsig = vt_acquire_signal;
+    mode.frsig = SIGIO;
+    if (ioctl(console_fd, VT_SETMODE, &mode) < 0) {
+        kbd_vt_quit(console_fd);
+        return false;
+    }
+    return true;
+}
+
+static void kbd_vt_update(SDL_EVDEV_keyboard_state *state)
+{
+    int signal_pending = SDL_GetAtomicInt(&vt_signal_pending);
+    if (signal_pending != VT_SIGNAL_NONE) {
+        if (signal_pending == VT_SIGNAL_RELEASE) {
+            if (state->vt_release_callback) {
+                state->vt_release_callback(state->vt_release_callback_data);
+            }
+            ioctl(state->console_fd, VT_RELDISP, 1);
+        } else {
+            if (state->vt_acquire_callback) {
+                state->vt_acquire_callback(state->vt_acquire_callback_data);
+            }
+            ioctl(state->console_fd, VT_RELDISP, VT_ACKACQ);
+        }
+        SDL_CompareAndSwapAtomicInt(&vt_signal_pending, signal_pending, VT_SIGNAL_NONE);
+    }
+}
+
+SDL_EVDEV_keyboard_state *SDL_EVDEV_kbd_init(void)
+{
+    SDL_EVDEV_keyboard_state *kbd;
+    char flag_state;
+    char kbtype;
+    char shift_state[sizeof(long)] = { TIOCL_GETSHIFTSTATE, 0 };
+
+    kbd = (SDL_EVDEV_keyboard_state *)SDL_calloc(1, sizeof(*kbd));
+    if (!kbd) {
+        return NULL;
+    }
+
+    // This might fail if we're not connected to a tty (e.g. on the Steam Link)
+    kbd->console_fd = open("/dev/tty", O_RDONLY | O_CLOEXEC);
+    if (!((ioctl(kbd->console_fd, KDGKBTYPE, &kbtype) == 0) && ((kbtype == KB_101) || (kbtype == KB_84)))) {
+        close(kbd->console_fd);
+        kbd->console_fd = -1;
+    }
+
+    kbd->npadch = -1;
+
+    if (ioctl(kbd->console_fd, TIOCLINUX, shift_state) == 0) {
+        kbd->shift_state = *shift_state;
+    }
+
+    if (ioctl(kbd->console_fd, KDGKBLED, &flag_state) == 0) {
+        kbd->ledflagstate = flag_state;
+    }
+
+    kbd->accents = &default_accents;
+    kbd->key_maps = default_key_maps;
+
+    if (ioctl(kbd->console_fd, KDGKBMODE, &kbd->old_kbd_mode) == 0) {
+        // Set the keyboard in UNICODE mode and load the keymaps
+        ioctl(kbd->console_fd, KDSKBMODE, K_UNICODE);
+    }
+
+    kbd_vt_init(kbd->console_fd);
+
+    return kbd;
+}
+
+void SDL_EVDEV_kbd_set_muted(SDL_EVDEV_keyboard_state *state, bool muted)
+{
+    if (!state) {
+        return;
+    }
+
+    if (muted == state->muted) {
+        return;
+    }
+
+    if (muted) {
+        if (SDL_GetHintBoolean(SDL_HINT_MUTE_CONSOLE_KEYBOARD, true)) {
+            /* Mute the keyboard so keystrokes only generate evdev events
+             * and do not leak through to the console
+             */
+            ioctl(state->console_fd, KDSKBMODE, K_OFF);
+
+            /* Make sure to restore keyboard if application fails to call
+             * SDL_Quit before exit or fatal signal is raised.
+             */
+            if (!SDL_GetHintBoolean(SDL_HINT_NO_SIGNAL_HANDLERS, false)) {
+                kbd_register_emerg_cleanup(state);
+            }
+        }
+    } else {
+        kbd_unregister_emerg_cleanup();
+
+        // Restore the original keyboard mode
+        ioctl(state->console_fd, KDSKBMODE, state->old_kbd_mode);
+    }
+    state->muted = muted;
+}
+
+void SDL_EVDEV_kbd_set_vt_switch_callbacks(SDL_EVDEV_keyboard_state *state, void (*release_callback)(void*), void *release_callback_data, void (*acquire_callback)(void*), void *acquire_callback_data)
+{
+    if (state == NULL) {
+        return;
+    }
+
+    state->vt_release_callback = release_callback;
+    state->vt_release_callback_data = release_callback_data;
+    state->vt_acquire_callback = acquire_callback;
+    state->vt_acquire_callback_data = acquire_callback_data;
+}
+
+void SDL_EVDEV_kbd_update(SDL_EVDEV_keyboard_state *state)
+{
+    if (!state) {
+        return;
+    }
+
+    kbd_vt_update(state);
+}
+
+void SDL_EVDEV_kbd_quit(SDL_EVDEV_keyboard_state *state)
+{
+    if (state == NULL) {
+        return;
+    }
+
+    SDL_EVDEV_kbd_set_muted(state, false);
+
+    kbd_vt_quit(state->console_fd);
+
+    if (state->console_fd >= 0) {
+        close(state->console_fd);
+        state->console_fd = -1;
+    }
+
+    if (state->key_maps && state->key_maps != default_key_maps) {
+        int i;
+        for (i = 0; i < MAX_NR_KEYMAPS; ++i) {
+            if (state->key_maps[i]) {
+                SDL_free(state->key_maps[i]);
+            }
+        }
+        SDL_free(state->key_maps);
+    }
+
+    SDL_free(state);
+}
+
+/*
+ * Helper Functions.
+ */
+static void put_queue(SDL_EVDEV_keyboard_state *kbd, uint c)
+{
+    // c is already part of a UTF-8 sequence and safe to add as a character
+    if (kbd->text_len < (sizeof(kbd->text) - 1)) {
+        kbd->text[kbd->text_len++] = (char)c;
+    }
+}
+
+static void put_utf8(SDL_EVDEV_keyboard_state *kbd, uint c)
+{
+    if (c < 0x80) {
+        put_queue(kbd, c); /*  0******* */
+    } else if (c < 0x800) {
+        /* 110***** 10****** */
+        put_queue(kbd, 0xc0 | (c >> 6));
+        put_queue(kbd, 0x80 | (c & 0x3f));
+    } else if (c < 0x10000) {
+        if (c >= 0xD800 && c < 0xE000) {
+            return;
+        }
+        if (c == 0xFFFF) {
+            return;
+        }
+        /* 1110**** 10****** 10****** */
+        put_queue(kbd, 0xe0 | (c >> 12));
+        put_queue(kbd, 0x80 | ((c >> 6) & 0x3f));
+        put_queue(kbd, 0x80 | (c & 0x3f));
+    } else if (c < 0x110000) {
+        /* 11110*** 10****** 10****** 10****** */
+        put_queue(kbd, 0xf0 | (c >> 18));
+        put_queue(kbd, 0x80 | ((c >> 12) & 0x3f));
+        put_queue(kbd, 0x80 | ((c >> 6) & 0x3f));
+        put_queue(kbd, 0x80 | (c & 0x3f));
+    }
+}
+
+/*
+ * We have a combining character DIACR here, followed by the character CH.
+ * If the combination occurs in the table, return the corresponding value.
+ * Otherwise, if CH is a space or equals DIACR, return DIACR.
+ * Otherwise, conclude that DIACR was not combining after all,
+ * queue it and return CH.
+ */
+static unsigned int handle_diacr(SDL_EVDEV_keyboard_state *kbd, unsigned int ch)
+{
+    unsigned int d = kbd->diacr;
+    unsigned int i;
+
+    kbd->diacr = 0;
+
+    if (kbd->console_fd >= 0)
+        if (ioctl(kbd->console_fd, KDGKBDIACR, kbd->accents) < 0) {
+            // No worries, we'll use the default accent table
+        }
+
+    for (i = 0; i < kbd->accents->kb_cnt; i++) {
+        if (kbd->accents->kbdiacr[i].diacr == d &&
+            kbd->accents->kbdiacr[i].base == ch) {
+            return kbd->accents->kbdiacr[i].result;
+        }
+    }
+
+    if (ch == ' ' || ch == d) {
+        return d;
+    }
+
+    put_utf8(kbd, d);
+
+    return ch;
+}
+
+static bool vc_kbd_led(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    return (kbd->ledflagstate & flag) != 0;
+}
+
+static void set_vc_kbd_led(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    kbd->ledflagstate |= flag;
+    ioctl(kbd->console_fd, KDSETLED, (unsigned long)(kbd->ledflagstate));
+}
+
+static void clr_vc_kbd_led(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    kbd->ledflagstate &= ~flag;
+    ioctl(kbd->console_fd, KDSETLED, (unsigned long)(kbd->ledflagstate));
+}
+
+static void chg_vc_kbd_lock(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    kbd->lockstate ^= 1 << flag;
+}
+
+static void chg_vc_kbd_slock(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    kbd->slockstate ^= 1 << flag;
+}
+
+static void chg_vc_kbd_led(SDL_EVDEV_keyboard_state *kbd, int flag)
+{
+    kbd->ledflagstate ^= flag;
+    ioctl(kbd->console_fd, KDSETLED, (unsigned long)(kbd->ledflagstate));
+}
+
+/*
+ * Special function handlers
+ */
+
+static void fn_enter(SDL_EVDEV_keyboard_state *kbd)
+{
+    if (kbd->diacr) {
+        put_utf8(kbd, kbd->diacr);
+        kbd->diacr = 0;
+    }
+}
+
+static void fn_caps_toggle(SDL_EVDEV_keyboard_state *kbd)
+{
+    if (kbd->rep) {
+        return;
+    }
+
+    chg_vc_kbd_led(kbd, K_CAPSLOCK);
+}
+
+static void fn_caps_on(SDL_EVDEV_keyboard_state *kbd)
+{
+    if (kbd->rep) {
+        return;
+    }
+
+    set_vc_kbd_led(kbd, K_CAPSLOCK);
+}
+
+static void fn_num(SDL_EVDEV_keyboard_state *kbd)
+{
+    if (!kbd->rep) {
+        chg_vc_kbd_led(kbd, K_NUMLOCK);
+    }
+}
+
+static void fn_compose(SDL_EVDEV_keyboard_state *kbd)
+{
+    kbd->dead_key_next = true;
+}
+
+/*
+ * Special key handlers
+ */
+
+static void k_ignore(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_spec(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    if (up_flag) {
+        return;
+    }
+    if (value >= SDL_arraysize(fn_handler)) {
+        return;
+    }
+    if (fn_handler[value]) {
+        fn_handler[value](kbd);
+    }
+}
+
+static void k_lowercase(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_self(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    if (up_flag) {
+        return; // no action, if this is a key release
+    }
+
+    if (kbd->diacr) {
+        value = handle_diacr(kbd, value);
+    }
+
+    if (kbd->dead_key_next) {
+        kbd->dead_key_next = false;
+        kbd->diacr = value;
+        return;
+    }
+    put_utf8(kbd, value);
+}
+
+static void k_deadunicode(SDL_EVDEV_keyboard_state *kbd, unsigned int value, char up_flag)
+{
+    if (up_flag) {
+        return;
+    }
+
+    kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
+}
+
+static void k_dead(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    const unsigned char ret_diacr[NR_DEAD] = { '`', '\'', '^', '~', '"', ',' };
+
+    k_deadunicode(kbd, ret_diacr[value], up_flag);
+}
+
+static void k_dead2(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    k_deadunicode(kbd, value, up_flag);
+}
+
+static void k_cons(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_fn(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_cur(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_pad(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    static const char pad_chars[] = "0123456789+-*/\015,.?()#";
+
+    if (up_flag) {
+        return; // no action, if this is a key release
+    }
+
+    if (!vc_kbd_led(kbd, K_NUMLOCK)) {
+        // unprintable action
+        return;
+    }
+
+    put_queue(kbd, pad_chars[value]);
+}
+
+static void k_shift(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    int old_state = kbd->shift_state;
+
+    if (kbd->rep) {
+        return;
+    }
+    /*
+     * Mimic typewriter:
+     * a CapsShift key acts like Shift but undoes CapsLock
+     */
+    if (value == KVAL(K_CAPSSHIFT)) {
+        value = KVAL(K_SHIFT);
+        if (!up_flag) {
+            clr_vc_kbd_led(kbd, K_CAPSLOCK);
+        }
+    }
+
+    if (up_flag) {
+        /*
+         * handle the case that two shift or control
+         * keys are depressed simultaneously
+         */
+        if (kbd->shift_down[value]) {
+            kbd->shift_down[value]--;
+        }
+    } else {
+        kbd->shift_down[value]++;
+    }
+
+    if (kbd->shift_down[value]) {
+        kbd->shift_state |= (1 << value);
+    } else {
+        kbd->shift_state &= ~(1 << value);
+    }
+
+    // kludge
+    if (up_flag && kbd->shift_state != old_state && kbd->npadch != -1) {
+        put_utf8(kbd, kbd->npadch);
+        kbd->npadch = -1;
+    }
+}
+
+static void k_meta(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+static void k_ascii(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    int base;
+
+    if (up_flag) {
+        return;
+    }
+
+    if (value < 10) {
+        // decimal input of code, while Alt depressed
+        base = 10;
+    } else {
+        // hexadecimal input of code, while AltGr depressed
+        value -= 10;
+        base = 16;
+    }
+
+    if (kbd->npadch == -1) {
+        kbd->npadch = value;
+    } else {
+        kbd->npadch = kbd->npadch * base + value;
+    }
+}
+
+static void k_lock(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    if (up_flag || kbd->rep) {
+        return;
+    }
+
+    chg_vc_kbd_lock(kbd, value);
+}
+
+static void k_slock(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+    k_shift(kbd, value, up_flag);
+    if (up_flag || kbd->rep) {
+        return;
+    }
+
+    chg_vc_kbd_slock(kbd, value);
+    // try to make Alt, oops, AltGr and such work
+    if (!kbd->key_maps[kbd->lockstate ^ kbd->slockstate]) {
+        kbd->slockstate = 0;
+        chg_vc_kbd_slock(kbd, value);
+    }
+}
+
+static void k_brl(SDL_EVDEV_keyboard_state *kbd, unsigned char value, char up_flag)
+{
+}
+
+void SDL_EVDEV_kbd_keycode(SDL_EVDEV_keyboard_state *state, unsigned int keycode, int down)
+{
+    unsigned char shift_final;
+    unsigned char type;
+    unsigned short *key_map;
+    unsigned short keysym;
+
+    if (!state) {
+        return;
+    }
+
+    state->rep = (down == 2);
+
+    shift_final = (state->shift_state | state->slockstate) ^ state->lockstate;
+    key_map = state->key_maps[shift_final];
+    if (!key_map) {
+        // Unsupported shift state (e.g. ctrl = 4, alt = 8), just reset to the default state
+        state->shift_state = 0;
+        state->slockstate = 0;
+        state->lockstate = 0;
+        return;
+    }
+
+    if (keycode < NR_KEYS) {
+        if (state->console_fd < 0) {
+            keysym = key_map[keycode];
+        } else {
+            struct kbentry kbe;
+            kbe.kb_table = shift_final;
+            kbe.kb_index = keycode;
+            if (ioctl(state->console_fd, KDGKBENT, &kbe) == 0)
+                keysym = (kbe.kb_value ^ 0xf000);
+            else
+                return;
+        }
+    } else {
+        return;
+    }
+
+    type = KTYP(keysym);
+
+    if (type < 0xf0) {
+        if (down) {
+            put_utf8(state, keysym);
+        }
+    } else {
+        type -= 0xf0;
+
+        // if type is KT_LETTER then it can be affected by Caps Lock
+        if (type == KT_LETTER) {
+            type = KT_LATIN;
+
+            if (vc_kbd_led(state, K_CAPSLOCK)) {
+                shift_final = shift_final ^ (1 << KG_SHIFT);
+                key_map = state->key_maps[shift_final];
+                if (key_map) {
+                    if (state->console_fd < 0) {
+                        keysym = key_map[keycode];
+                    } else {
+                        struct kbentry kbe;
+                        kbe.kb_table = shift_final;
+                        kbe.kb_index = keycode;
+                        if (ioctl(state->console_fd, KDGKBENT, &kbe) == 0)
+                            keysym = (kbe.kb_value ^ 0xf000);
+                    }
+                }
+            }
+        }
+
+        (*k_handler[type])(state, keysym & 0xff, !down);
+
+        if (type != KT_SLOCK) {
+            state->slockstate = 0;
+        }
+    }
+
+    if (state->text_len > 0) {
+        state->text[state->text_len] = '\0';
+        SDL_SendKeyboardText(state->text);
+        state->text_len = 0;
+    }
+}
+
+#elif !defined(SDL_INPUT_FBSDKBIO) // !SDL_INPUT_LINUXKD
+
+SDL_EVDEV_keyboard_state *SDL_EVDEV_kbd_init(void)
+{
+    return NULL;
+}
+
+void SDL_EVDEV_kbd_set_muted(SDL_EVDEV_keyboard_state *state, bool muted)
+{
+}
+
+void SDL_EVDEV_kbd_set_vt_switch_callbacks(SDL_EVDEV_keyboard_state *state, void (*release_callback)(void*), void *release_callback_data, void (*acquire_callback)(void*), void *acquire_callback_data)
+{
+}
+
+void SDL_EVDEV_kbd_update(SDL_EVDEV_keyboard_state *state)
+{
+}
+
+void SDL_EVDEV_kbd_keycode(SDL_EVDEV_keyboard_state *state, unsigned int keycode, int down)
+{
+}
+
+void SDL_EVDEV_kbd_quit(SDL_EVDEV_keyboard_state *state)
+{
+}
+
+#endif // SDL_INPUT_LINUXKD