diff --git a/apps/plugins/doom/am_map.c b/apps/plugins/doom/am_map.c
index ff74e9938f..88e27b4dc2 100644
--- a/apps/plugins/doom/am_map.c
+++ b/apps/plugins/doom/am_map.c
@@ -632,7 +632,6 @@ boolean AM_Responder
 ( event_t*  ev )
 {
    int rc;
-   static int cheatstate=0;
    static int bigstate=0;
    static char buffer[20];
    int ch;                                                       // phares
@@ -732,7 +731,6 @@ boolean AM_Responder
       }
       else                                                        // phares
       {
-         cheatstate=0;
          rc = false;
       }
    }
diff --git a/apps/plugins/doom/d_main.c b/apps/plugins/doom/d_main.c
index 498d93cb62..be45e6a37e 100644
--- a/apps/plugins/doom/d_main.c
+++ b/apps/plugins/doom/d_main.c
@@ -179,7 +179,6 @@ void D_Display (void)
 {
    static boolean isborderstate        IDATA_ATTR= false;
    static boolean borderwillneedredraw IDATA_ATTR= false;
-   static  boolean  inhelpscreensstate IDATA_ATTR= false;
    static  gamestate_t  oldgamestate IDATA_ATTR= -1;
    boolean wipe;
    boolean viewactive = false, isborder = false;
@@ -254,7 +253,6 @@ void D_Display (void)
       HU_Drawer();
    }
 
-   inhelpscreensstate = inhelpscreens;
    isborderstate      = isborder;
    oldgamestate = wipegamestate = gamestate;
 
diff --git a/apps/plugins/doom/g_game.c b/apps/plugins/doom/g_game.c
index 8aab9fc3cf..e41c84c378 100644
--- a/apps/plugins/doom/g_game.c
+++ b/apps/plugins/doom/g_game.c
@@ -1549,7 +1549,7 @@ static const size_t num_version_headers = sizeof(version_headers) / sizeof(versi
 
 void G_DoLoadGame(void)
 {
-   int  length, i;
+   int  i;
    // CPhipps - do savegame filename stuff here
    char name[100+1];     // killough 3/22/98
    int savegame_compatibility = -1;
@@ -1558,7 +1558,7 @@ void G_DoLoadGame(void)
 
    gameaction = ga_nothing;
 
-   length = M_ReadFile(name, &savebuffer);
+   M_ReadFile(name, &savebuffer);
    save_p = savebuffer + SAVESTRINGSIZE;
 
    // CPhipps - read the description field, compare with supported ones
@@ -2565,7 +2565,6 @@ static const byte* G_ReadDemoHeader(const byte *demo_p)
    skill_t skill;
    int i, episode, map;
    int demover;
-   const byte *option_p = NULL;      /* killough 11/98 */
 
    basetic = gametic;  // killough 9/29/98
 
@@ -2674,10 +2673,6 @@ static const byte* G_ReadDemoHeader(const byte *demo_p)
       deathmatch = *demo_p++;
       consoleplayer = *demo_p++;
 
-      /* killough 11/98: save option pointer for below */
-      if (mbf_features)
-         option_p = demo_p;
-
       demo_p = G_ReadOptions(demo_p);  // killough 3/1/98: Read game options
 
       if (demover == 200)              // killough 6/3/98: partially fix v2.00 demos
diff --git a/apps/plugins/doom/hu_lib.c b/apps/plugins/doom/hu_lib.c
index df2fa883ec..eacb26b287 100644
--- a/apps/plugins/doom/hu_lib.c
+++ b/apps/plugins/doom/hu_lib.c
@@ -532,7 +532,7 @@ void HUlib_drawMBg
 //
 void HUlib_drawMText(hu_mtext_t* m)
 {
-   int i, idx, y;
+   int i, idx;
    hu_textline_t *l;
 
    if (!*m->on)
@@ -541,7 +541,7 @@ void HUlib_drawMText(hu_mtext_t* m)
    // draw everything
    if (hud_list_bgon)
       HUlib_drawMBg(m->x,m->y,m->w,m->h,m->bg);
-   y = m->y + HU_REFRESHSPACING;
+
    for (i=0 ; i<m->nl ; i++)
    {
       idx = m->cl - i;
diff --git a/apps/plugins/doom/i_sound.c b/apps/plugins/doom/i_sound.c
index 35cecd8abb..2d7b592818 100644
--- a/apps/plugins/doom/i_sound.c
+++ b/apps/plugins/doom/i_sound.c
@@ -534,26 +534,27 @@ static int musicdies=-1;
 void I_PlaySong(int handle, int looping)
 {
    // UNUSED.
-   handle = looping = 0;
+   (void)handle;
+   (void)looping;
    musicdies = gametic + TICRATE*30;
 }
 
 void I_PauseSong (int handle)
 {
    // UNUSED.
-   handle = 0;
+   (void)handle;
 }
 
 void I_ResumeSong (int handle)
 {
    // UNUSED.
-   handle = 0;
+   (void)handle;
 }
 
 void I_StopSong(int handle)
 {
    // UNUSED.
-   handle = 0;
+   (void)handle;
 
    looping = 0;
    musicdies = 0;
@@ -562,13 +563,13 @@ void I_StopSong(int handle)
 void I_UnRegisterSong(int handle)
 {
    // UNUSED.
-   handle = 0;
+   (void)handle;
 }
 
 int I_RegisterSong(const void *data)
 {
    // UNUSED.
-   data = NULL;
+   (void)data;
 
    return 1;
 }
@@ -577,7 +578,7 @@ int I_RegisterSong(const void *data)
 int I_QrySongPlaying(int handle)
 {
    // UNUSED.
-   handle = 0;
+   (void)handle;
    return looping || musicdies > gametic;
 }
 
diff --git a/apps/plugins/doom/m_menu.c b/apps/plugins/doom/m_menu.c
index b0b0f9fff8..aa82959aaf 100644
--- a/apps/plugins/doom/m_menu.c
+++ b/apps/plugins/doom/m_menu.c
@@ -522,7 +522,6 @@ menu_t  SaveDef =
 void M_ReadSaveStrings(void)
 {
    int             handle;
-   int             count;
    int             i;
    char    name[256];
 
@@ -540,7 +539,7 @@ void M_ReadSaveStrings(void)
          LoadMenu[i].status = 0;
          continue;
       }
-      count = read (handle, &savegamestrings[i], SAVESTRINGSIZE);
+      read (handle, &savegamestrings[i], SAVESTRINGSIZE);
       close (handle);
       LoadMenu[i].status = 1;
    }
@@ -1027,8 +1026,7 @@ void M_Options(int choice)
 //
 void M_ChangeMessages(int choice)
 {
-   // warning: unused parameter `int choice'
-   choice = 0;
+   (void)choice;
    showMessages = 1 - showMessages;
 
    if (!showMessages)
@@ -1059,7 +1057,7 @@ void M_EndGameResponse(int ch)
 
 void M_EndGame(int choice)
 {
-   choice = 0;
+   (void)choice;
    if (!usergame)
    {
       S_StartSound(NULL,sfx_oof);
@@ -1083,19 +1081,19 @@ void M_EndGame(int choice)
 //
 void M_ReadThis(int choice)
 {
-   choice = 0;
+   (void)choice;
    M_SetupNextMenu(&ReadDef1);
 }
 
 void M_ReadThis2(int choice)
 {
-   choice = 0;
+   (void)choice;
    M_SetupNextMenu(&ReadDef2);
 }
 
 void M_FinishReadThis(int choice)
 {
-   choice = 0;
+   (void)choice;
    M_SetupNextMenu(&MainDef);
 }
 
diff --git a/apps/plugins/doom/p_doors.c b/apps/plugins/doom/p_doors.c
index 0b6d777e17..750b3474bd 100644
--- a/apps/plugins/doom/p_doors.c
+++ b/apps/plugins/doom/p_doors.c
@@ -434,7 +434,6 @@ int EV_VerticalDoor
   mobj_t* thing )
 {
    player_t* player;
-   int   secnum;
    sector_t* sec;
    vldoor_t* door;
 
@@ -492,7 +491,6 @@ int EV_VerticalDoor
 
    // get the sector on the second side of activating linedef
    sec = sides[line->sidenum[1]].sector;
-   secnum = sec-sectors;
 
    /* if door already has a thinker, use it
     * cph 2001/04/05 -
diff --git a/apps/plugins/doom/p_spec.c b/apps/plugins/doom/p_spec.c
index f2757f8399..8ad77a732d 100644
--- a/apps/plugins/doom/p_spec.c
+++ b/apps/plugins/doom/p_spec.c
@@ -2394,11 +2394,6 @@ void P_SpawnSpecials (void)
 {
    sector_t*   sector;
    int         i;
-   int         episode;
-
-   episode = 1;
-   if (W_CheckNumForName("texture2") >= 0)
-      episode = 2;
 
    // See if -timer needs to be used.
    levelTimer = false;
diff --git a/apps/plugins/doom/v_video.c b/apps/plugins/doom/v_video.c
index 76993ea5ee..8c475614ff 100644
--- a/apps/plugins/doom/v_video.c
+++ b/apps/plugins/doom/v_video.c
@@ -525,12 +525,9 @@ void V_DrawMemPatch(int x, int y, int scrn, const patch_t *patch,
       int   DXI = (320<<16)          / SCREENWIDTH;
       int   DY  = (SCREENHEIGHT<<16) / 200;
       register int DYI = (200<<16)   / SCREENHEIGHT;
-      int   DY2, DYI2;
 
       stretchx = ( x * DX ) >> 16;
       stretchy = ( y * DY ) >> 16;
-      DY2  = DY / 2;
-      DYI2 = DYI* 2;
 
       if (!scrn)
          V_MarkRect ( stretchx, stretchy, (SHORT( patch->width ) * DX ) >> 16,
diff --git a/apps/plugins/doom/wi_stuff.c b/apps/plugins/doom/wi_stuff.c
index 5aec366026..7c7831d084 100644
--- a/apps/plugins/doom/wi_stuff.c
+++ b/apps/plugins/doom/wi_stuff.c
@@ -1176,11 +1176,8 @@ void WI_drawDeathmatchStats(void)
    int   y;
    int   w;
 
-   int   lh; // line height
    int   halfface = V_NamePatchWidth(facebackp)/2;
 
-   lh = WI_SPACINGY;
-
    WI_slamBackground();
 
    // draw animated background
diff --git a/apps/plugins/imageviewer/imageviewer.c b/apps/plugins/imageviewer/imageviewer.c
index 0635a877d4..6750c6c912 100644
--- a/apps/plugins/imageviewer/imageviewer.c
+++ b/apps/plugins/imageviewer/imageviewer.c
@@ -345,7 +345,9 @@ static int show_menu(void) /* return 1 to quit */
 static int ask_and_get_audio_buffer(const char *filename)
 {
     int button;
+#if defined(IMGVIEW_ZOOM_PRE)
     int lastbutton = BUTTON_NONE;
+#endif
     rb->lcd_setfont(FONT_SYSFIXED);
     rb->lcd_clear_display();
     rb->lcd_puts(0, 0, rb->strrchr(filename,'/')+1);
@@ -414,9 +416,10 @@ static int ask_and_get_audio_buffer(const char *filename)
                         == SYS_USB_CONNECTED)
                     return PLUGIN_USB_CONNECTED;
         }
-
+#if defined(IMGVIEW_ZOOM_PRE)
         if (button != BUTTON_NONE)
             lastbutton = button;
+#endif
     }
 }
 #endif /* USE_PLUG_BUF */
@@ -548,7 +551,9 @@ static void pan_view_down(struct image_info *info)
 static int scroll_bmp(struct image_info *info)
 {
     int button;
+#if defined(IMGVIEW_ZOOM_PRE) || defined(IMGVIEW_MENU_PRE)
     int lastbutton = BUTTON_NONE;
+#endif
 
     while (true)
     {
@@ -669,9 +674,10 @@ static int scroll_bmp(struct image_info *info)
             break;
 
         } /* switch */
-
+#if defined(IMGVIEW_ZOOM_PRE) || defined(IMGVIEW_MENU_PRE)
         if (button != BUTTON_NONE)
             lastbutton = button;
+#endif
     } /* while (true) */
 }
 
diff --git a/apps/plugins/midi/midiutil.c b/apps/plugins/midi/midiutil.c
index e10c593dc1..f960b72654 100644
--- a/apps/plugins/midi/midiutil.c
+++ b/apps/plugins/midi/midiutil.c
@@ -136,11 +136,10 @@ int midi_debug(const char *fmt, ...)
 {
     static int p_xtpt = 0;
     char p_buf[50];
-    bool ok;
     va_list ap;
 
     va_start(ap, fmt);
-    ok = rb->vsnprintf(p_buf,sizeof(p_buf), fmt, ap);
+    rb->vsnprintf(p_buf,sizeof(p_buf), fmt, ap);
     va_end(ap);
 
     int i=0;
diff --git a/apps/plugins/minesweeper.c b/apps/plugins/minesweeper.c
index adecc00502..5b5b422e08 100644
--- a/apps/plugins/minesweeper.c
+++ b/apps/plugins/minesweeper.c
@@ -692,7 +692,9 @@ enum minesweeper_status minesweeper( void )
 {
     int i, j;
     int button;
+#if defined(HAVE_TOUCHSCREEN) || defined(MINESWP_TOGGLE_PRE)
     int lastbutton = BUTTON_NONE;
+#endif
 
     /* the cursor coordinates */
     int x=0, y=0;
@@ -898,8 +900,10 @@ enum minesweeper_status minesweeper( void )
                     return MINESWEEPER_USB;
                 break;
         }
+#if defined(HAVE_TOUCHSCREEN) || defined(MINESWP_TOGGLE_PRE)
         if( button != BUTTON_NONE )
             lastbutton = button;
+#endif
     }
 
 }
diff --git a/apps/plugins/mpegplayer/mpegplayer.c b/apps/plugins/mpegplayer/mpegplayer.c
index 22136d8393..2a84307857 100644
--- a/apps/plugins/mpegplayer/mpegplayer.c
+++ b/apps/plugins/mpegplayer/mpegplayer.c
@@ -607,7 +607,7 @@ static void draw_oriented_mono_bitmap_part(const unsigned char *src,
 {
     const unsigned char *src_end;
     fb_data *dst, *dst_end;
-    unsigned fg_pattern, bg_pattern;
+    unsigned fg_pattern;
 
     if (x + width > SCREEN_WIDTH)
         width = SCREEN_WIDTH - x; /* Clip right */
@@ -623,8 +623,8 @@ static void draw_oriented_mono_bitmap_part(const unsigned char *src,
     if (height <= 0)
         return; /* nothing left to do */
 
-    fg_pattern = rb->lcd_get_foreground();
-    bg_pattern = rb->lcd_get_background();
+    fg_pattern =     rb->lcd_get_foreground();
+    /*bg_pattern =*/ rb->lcd_get_background();
 
     src += stride * (src_y >> 3) + src_x; /* move starting point */
     src_y  &= 7;
@@ -719,7 +719,7 @@ static void draw_oriented_alpha_bitmap_part(const unsigned char *src,
                                             int width, int height)
 {
     fb_data *dst, *dst_start;
-    unsigned fg_pattern, bg_pattern;
+    unsigned fg_pattern;
 
     if (x + width > SCREEN_WIDTH)
         width = SCREEN_WIDTH - x; /* Clip right */
@@ -738,8 +738,8 @@ static void draw_oriented_alpha_bitmap_part(const unsigned char *src,
     /* initialize blending */
     BLEND_INIT;
 
-    fg_pattern = rb->lcd_get_foreground();
-    bg_pattern = rb->lcd_get_background();
+    fg_pattern =    rb->lcd_get_foreground();
+    /*bg_pattern=*/ rb->lcd_get_background();
 
     dst_start = rb->lcd_framebuffer + (LCD_WIDTH - y - 1) + x*LCD_WIDTH;
     int col, row = height;
diff --git a/apps/plugins/reversi/reversi-gui.c b/apps/plugins/reversi/reversi-gui.c
index 6f5d53da58..184b5ad7f0 100644
--- a/apps/plugins/reversi/reversi-gui.c
+++ b/apps/plugins/reversi/reversi-gui.c
@@ -610,7 +610,10 @@ enum plugin_status plugin_start(const void *parameter) {
 #ifdef HAVE_TOUCHSCREEN
     int button_x, button_y;
 #endif
+#if defined(REVERSI_BUTTON_MENU_LONGPRESS) || \
+    defined(REVERSI_BUTTON_MAKE_MOVE_SHORTPRESS)
     int lastbutton = BUTTON_NONE;
+#endif
     int row, col;
     int w_cnt, b_cnt;
     
@@ -787,10 +790,12 @@ enum plugin_status plugin_start(const void *parameter) {
             /* Quit if USB has been connected */
             return PLUGIN_USB_CONNECTED;
         }
-
+#if defined(REVERSI_BUTTON_MENU_LONGPRESS) || \
+    defined(REVERSI_BUTTON_MAKE_MOVE_SHORTPRESS)
         if (button != BUTTON_NONE) {
             lastbutton = button;
         }
+#endif
     }
 
     return PLUGIN_OK;
diff --git a/apps/plugins/sokoban.c b/apps/plugins/sokoban.c
index 29bdbbbba5..157f53ca92 100644
--- a/apps/plugins/sokoban.c
+++ b/apps/plugins/sokoban.c
@@ -1527,7 +1527,10 @@ static int sokoban_menu(void)
 static bool sokoban_loop(void)
 {
     bool moved;
-    int i = 0, button = 0, lastbutton = 0;
+    int i = 0, button = 0;
+#if defined(SOKOBAN_UNDO_PRE)
+    int lastbutton = 0;
+#endif
     int w, h;
     char *loc;
 
@@ -1629,8 +1632,9 @@ static bool sokoban_loop(void)
                     return PLUGIN_USB_CONNECTED;
                 break;
         }
-
+#if defined(SOKOBAN_UNDO_PRE)
         lastbutton = button;
+#endif
 
         if (moved) {
             rb->lcd_clear_display();
diff --git a/apps/plugins/sudoku/sudoku.c b/apps/plugins/sudoku/sudoku.c
index 81c00803f8..f0bff4d2a4 100644
--- a/apps/plugins/sudoku/sudoku.c
+++ b/apps/plugins/sudoku/sudoku.c
@@ -1029,7 +1029,9 @@ enum plugin_status plugin_start(const void* parameter)
 {
     bool exit;
     int button;
+#if defined(SUDOKU_BUTTON_TOGGLE_PRE) || defined(SUDOKU_BUTTON_MENU_PRE)
     int lastbutton = BUTTON_NONE;
+#endif
     int res;
     int rc = PLUGIN_OK;
     long ticks;
@@ -1289,8 +1291,10 @@ enum plugin_status plugin_start(const void* parameter)
                 }
                 break;
         }
+#if defined(SUDOKU_BUTTON_TOGGLE_PRE) || defined(SUDOKU_BUTTON_MENU_PRE)
         if (button != BUTTON_NONE)
             lastbutton = button;
+#endif
 
         display_board(&state);
     }
diff --git a/firmware/common/dircache.c b/firmware/common/dircache.c
index 45726a3237..c3360adee6 100644
--- a/firmware/common/dircache.c
+++ b/firmware/common/dircache.c
@@ -781,7 +781,7 @@ void* dircache_steal_buffer(long *size)
 void dircache_init(void)
 {
     int i;
-    int thread_id;
+    int thread_id __attribute__((unused));
     
     dircache_initialized = false;
     dircache_initializing = false;