XWorld: some fixes

Should fix sound on most platforms... right now the main issue is the
mixer callback taking too long and causing the DMA to hang or crash on
some systems. Worked around for now with small chunk sizes, permanent
fix would involve moving mixing totally out of the callback. Also
rewrites input code with code taken from rockboy which was also used
in doom, which finally makes it possible to beat the first level!
Finally, cherry-picks a change from Gregory Montoir's `rawgl' to
always succeed on the code wheel verification.

Change-Id: I8df549c923c5075800c6625c36c8202e53de1d27

9 files changed, 248 insertions, 124 deletions

diff --git a/apps/plugins/xworld/SOURCES b/apps/plugins/xworld/SOURCES
index 98b5f14..eb331b1 100644
--- a/apps/plugins/xworld/SOURCES
+++ b/apps/plugins/xworld/SOURCES
@@ -1,7 +1,6 @@
 bank.c
 engine.c
 file.c
-intern.c
 mixer.c
 parts.c
 resource.c
diff --git a/apps/plugins/xworld/engine.c b/apps/plugins/xworld/engine.c
index 0d1c1bf..a0c0eb1 100644
--- a/apps/plugins/xworld/engine.c
+++ b/apps/plugins/xworld/engine.c
@@ -61,6 +61,9 @@ void engine_run(struct Engine* e) {
         engine_processInput(e);
 
         vm_hostFrame(&e->vm);
+
+        /* only yield() in the whole game :P */
+        rb->yield();
     }
 
 }
@@ -259,11 +262,11 @@ void engine_init(struct Engine* e) {
     player_init(&e->player);
 
     /* Init virtual machine, legacy way */
-    /* vm_initForPart(&e->vm, GAME_PART_FIRST); // This game part is the protection screen */
+    vm_initForPart(&e->vm, GAME_PART_FIRST); // This game part is the protection screen */
 
     /*  Try to cheat here. You can jump anywhere but the VM crashes afterward. */
     /*  Starting somewhere is probably not enough, the variables and calls return are probably missing. */
-    /* vm_initForPart(&e->vm, GAME_PART2);  Skip protection screen and go directly to intro */
+    /* vm_initForPart(&e->vm, GAME_PART2); /* Skip protection screen and go directly to intro */
     /* vm_initForPart(&e->vm, GAME_PART3);  CRASH */
     /* vm_initForPart(&e->vm, GAME_PART4);  Start directly in jail but then crash */
     /* vm->initForPart(&e->vm, GAME_PART5);   CRASH */
diff --git a/apps/plugins/xworld/intern.c b/apps/plugins/xworld/intern.c
deleted file mode 100644
index 0d58100..0000000
--- a/apps/plugins/xworld/intern.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2014 Franklin Wei, Benjamin Brown
- * Copyright (C) 2004 Gregory Montoir
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- * KIND, either express or implied.
- *
- ***************************************************************************/
-
-#include "intern.h"
-#include "awendian.h"
-
-uint8_t ICODE_ATTR scriptPtr_fetchByte(struct Ptr* p) {
-    return *p->pc++;
-}
-
-uint16_t ICODE_ATTR scriptPtr_fetchWord(struct Ptr* p) {
-    uint16_t i = READ_BE_UINT16(p->pc);
-    p->pc += 2;
-    return i;
-}
diff --git a/apps/plugins/xworld/intern.h b/apps/plugins/xworld/intern.h
index 3355f28..90b6408 100644
--- a/apps/plugins/xworld/intern.h
+++ b/apps/plugins/xworld/intern.h
@@ -34,11 +34,18 @@ struct Ptr {
     uint8_t* pc;
 };
 
-uint8_t scriptPtr_fetchByte(struct Ptr* p) ICODE_ATTR;
-uint16_t scriptPtr_fetchWord(struct Ptr* p) ICODE_ATTR;
-
 struct Point {
     int16_t x, y;
 };
 
+static inline uint8_t scriptPtr_fetchByte(struct Ptr* p) {
+    return *p->pc++;
+}
+
+static inline uint16_t scriptPtr_fetchWord(struct Ptr* p) {
+    uint16_t i = READ_BE_UINT16(p->pc);
+    p->pc += 2;
+    return i;
+}
+
 #endif
diff --git a/apps/plugins/xworld/mixer.c b/apps/plugins/xworld/mixer.c
index de7536c..6035045 100644
--- a/apps/plugins/xworld/mixer.c
+++ b/apps/plugins/xworld/mixer.c
@@ -24,7 +24,7 @@
 #include "serializer.h"
 #include "sys.h"
 
-static int8_t ICODE_ATTR addclamp(int a, int b) {
+static int8_t addclamp(int a, int b) {
     int add = a + b;
     if (add < -128) {
         add = -128;
@@ -121,11 +121,11 @@ void mixer_stopAll(struct Mixer* mx) {
 /* Since there is no way to know when SDL will ask for a buffer fill, we need */
 /* to synchronize with a mutex so the channels remain stable during the execution */
 /* of this method. */
-static void ICODE_ATTR mixer_mix(struct Mixer* mx, int8_t *buf, int len) {
+static void mixer_mix(struct Mixer* mx, int8_t *buf, int len) {
     int8_t *pBuf;
 
-    struct MutexStack_t ms;
-    MutexStack(&ms, mx->sys, mx->_mutex);
+    /* disabled because this will be called in IRQ */
+    /*sys_lockMutex(mx->sys, mx->_mutex);*/
 
     /* Clear the buffer since nothing guarantees we are receiving clean memory. */
     rb->memset(buf, 0, len);
@@ -170,11 +170,10 @@ static void ICODE_ATTR mixer_mix(struct Mixer* mx, int8_t *buf, int len) {
 
     }
 
-    MutexStack_destroy(&ms);
+    /*sys_unlockMutex(mx->sys, mx->_mutex);*/
 }
 
-static void ICODE_ATTR mixer_mixCallback(void *param, uint8_t *buf, int len) {
-    debug(DBG_SND, "mixer_mixCallback");
+static void mixer_mixCallback(void *param, uint8_t *buf, int len) {
     mixer_mix((struct Mixer*)param, (int8_t *)buf, len);
 }
 
diff --git a/apps/plugins/xworld/resource.c b/apps/plugins/xworld/resource.c
index 2820dcb..4bd93f0 100644
--- a/apps/plugins/xworld/resource.c
+++ b/apps/plugins/xworld/resource.c
@@ -354,12 +354,14 @@ void res_allocMemBlock(struct Resource* res) {
         rb->audio_stop();
     /* steal the audio buffer */
     size_t sz;
-    /* memory usage is as follows:
-       [VM memory - 600K]
-       [Framebuffers - 128K]
-       [Temporary framebuffer - 192K]
-       [String table buffer]
-    */
+    /* memory usage is first statically allocated, then the remainder is used dynamically:
+     * static:
+     *  [VM memory - 600K]
+     *  [Framebuffers - 128K]
+     *  [Temporary framebuffer - 192K]
+     * dynamic:
+     *  [String table buffer]
+     */
     res->_memPtrStart = rb->plugin_get_audio_buffer(&sz);
     if(sz < MEM_BLOCK_SIZE + (4 * VID_PAGE_SIZE) + 320 * 200 * sizeof(fb_data))
     {
diff --git a/apps/plugins/xworld/sys.c b/apps/plugins/xworld/sys.c
index 03b032c..475f355 100644
--- a/apps/plugins/xworld/sys.c
+++ b/apps/plugins/xworld/sys.c
@@ -130,13 +130,32 @@ static bool sys_do_help(void)
     rb->lcd_set_background(LCD_BLACK);
 #endif
     rb->lcd_setfont(FONT_UI);
-    char* help_text[] = {"XWorld", "",
-                         "XWorld", "is", "an", "interpreter", "for", "Another", "World,", "a", "fantastic", "game", "by", "Eric", "Chahi."
-                        };
+    char *help_text[] = {
+        "XWorld", "",
+        "XWorld", "is", "a", "port", "of", "a", "bytecode", "interpreter", "for", "`Another", "World',", "a", "cinematic", "adventure", "game", "by", "Eric", "Chahi.",
+        "",
+        "",
+        "Level", "Codes:", "",
+        "Level", "1:", "LDKD", "",
+        "Level", "2:", "HTDC", "",
+        "Level", "3:", "CLLD", "",
+        "Level", "4:", "LBKG", "",
+        "Level", "5:", "XDDJ", "",
+        "Level", "6:", "FXLC", "",
+        "Level", "7:", "KRFK", "",
+        "Level", "8:", "KFLB", "",
+        "Level", "9:", "DDRX", "",
+        "Level", "10:", "BFLX", "",
+        "Level", "11:", "BRTD", "",
+        "Level", "12:", "TFBB", "",
+        "Level", "13:", "TXHF", "",
+        "Level", "14:", "CKJL", "",
+        "Level", "15:", "LFCK", "",
+    };
     struct style_text style[] = {
-        {0, TEXT_CENTER | TEXT_UNDERLINE},
-        LAST_STYLE_ITEM
+        { 0, TEXT_CENTER | TEXT_UNDERLINE },
     };
+
     return display_text(ARRAYLEN(help_text), help_text, style, NULL, true);
 }
 
@@ -149,9 +168,9 @@ static const struct opt_items scaling_settings[3] = {
 };
 
 static const struct opt_items rotation_settings[3] = {
-    { "Disabled"     , -1 },
-    { "Clockwise"    , -1 },
-    { "Anticlockwise", -1 }
+    { "Disabled"        , -1 },
+    { "Clockwise"       , -1 },
+    { "Counterclockwise", -1 }
 };
 
 static void do_video_settings(struct System* sys)
@@ -161,7 +180,7 @@ static void do_video_settings(struct System* sys)
                         "Scaling",
                         "Rotation",
                         "Show FPS",
-                        "Zoom on code",
+                        "Zoom on Code",
                         "Back");
     int sel = 0;
     while(1)
@@ -219,22 +238,14 @@ static void do_video_settings(struct System* sys)
     }
 }
 
-#define MAX_SOUNDBUF_SIZE 512
-const struct opt_items sound_bufsize_options[] = {
-    {"8 samples"  , 8},
-    {"16 samples" , 16},
-    {"32 samples" , 32},
-    {"64 samples" , 64},
-    {"128 samples", 128},
-    {"256 samples", 256},
-    {"512 samples", 512},
-};
+#define MAX_SOUNDBUF_SIZE 256
 
 static void do_sound_settings(struct System* sys)
 {
     MENUITEM_STRINGLIST(menu, "Sound Settings", NULL,
                         "Enabled",
                         "Buffer Level",
+                        "Volume",
                         "Back",
                        );
     int sel = 0;
@@ -246,10 +257,17 @@ static void do_sound_settings(struct System* sys)
             rb->set_bool("Enabled", &sys->settings.sound_enabled);
             break;
         case 1:
-            rb->set_option("Buffer Level", &sys->settings.sound_bufsize, INT,
-                           sound_bufsize_options, ARRAYLEN(sound_bufsize_options), NULL);
+            rb->set_int("Buffer Level", "samples", UNIT_INT, &sys->settings.sound_bufsize, NULL, 16, 16, MAX_SOUNDBUF_SIZE, NULL);
             break;
         case 2:
+        {
+            const struct settings_list* vol =
+                rb->find_setting(&rb->global_settings->volume, NULL);
+            rb->option_screen((struct settings_list*)vol, NULL, false, "Volume");
+            break;
+        }
+        case 3:
+        default:
             sys_save_settings(sys);
             return;
         }
@@ -259,11 +277,11 @@ static void do_sound_settings(struct System* sys)
 static void sys_reset_settings(struct System* sys)
 {
     sys->settings.negative_enabled = false;
-    sys->settings.rotation_option = 0;
-    sys->settings.scaling_quality = 1;
+    sys->settings.rotation_option = 0;   // off
+    sys->settings.scaling_quality = 1;   // fast
     sys->settings.sound_enabled = true;
-    sys->settings.sound_bufsize = 64;
-    sys->settings.showfps = true;
+    sys->settings.sound_bufsize = 32;
+    sys->settings.showfps = false;
     sys->settings.zoom = false;
     sys_rotate_keymap(sys);
 }
@@ -278,18 +296,32 @@ static int mainmenu_cb(int action, const struct menu_item_ex *this_item)
     return action;
 }
 
-static AudioCallback audio_callback;
+static AudioCallback audio_callback = NULL;
+static void get_more(const void** start, size_t* size);
 static void* audio_param;
 static struct System* audio_sys;
 
 /************************************** MAIN MENU ***************************************/
+/* called after game init */
 
 void sys_menu(struct System* sys)
 {
     sys_stopAudio(sys);
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    /* boost for load */
+    rb->cpu_boost(true);
+#endif
+
     rb->splash(0, "Loading...");
     sys->loaded = engine_loadGameState(sys->e, 0);
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(false);
+#endif
+
     rb->lcd_update();
+
     mainmenu_sysptr = sys;
     MENUITEM_STRINGLIST(menu, "XWorld Menu", mainmenu_cb,
                         "Resume Game",          /* 0  */
@@ -352,19 +384,21 @@ void sys_menu(struct System* sys)
             exit(PLUGIN_OK);
             break;
         default:
-            error("sys_menu: fall-through!");
+            break;
         }
     }
-    rb->lcd_clear_display();
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    /* boost for game */
+    rb->cpu_boost(true);
+#endif
+
     sys_startAudio(sys, audio_callback, audio_param);
 }
 
 void sys_init(struct System* sys, const char* title)
 {
     (void) title;
-#ifdef HAVE_ADJUSTABLE_CPU_FREQ
-    rb->cpu_boost(true);
-#endif
     backlight_ignore_timeout();
     rb_atexit(exit_handler);
     save_sys = sys;
@@ -599,6 +633,11 @@ void sys_copyRect(struct System* sys, uint16_t x, uint16_t y, uint16_t w, uint16
 static void do_pause_menu(struct System* sys)
 {
     sys_stopAudio(sys);
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(false);
+#endif
+
     int sel = 0;
     MENUITEM_STRINGLIST(menu, "XWorld Menu", NULL,
                         "Resume Game",         /* 0 */
@@ -663,52 +702,130 @@ static void do_pause_menu(struct System* sys)
             break;
         }
     }
-    rb->lcd_clear_display();
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(true);
+#endif
+
     sys_startAudio(sys, audio_callback, audio_param);
 }
 
 void sys_processEvents(struct System* sys)
 {
-    int btn = rb->button_get(false);
-    btn &= ~BUTTON_REDRAW;
+    int btn = rb->button_status();
+    rb->button_clear_queue();
+
+    static int oldbuttonstate = 0;
+
     debug(DBG_SYS, "button is 0x%08x", btn);
 
     /* exit early if we can */
-    if(btn == BUTTON_NONE)
+    if(btn == oldbuttonstate)
     {
         return;
     }
 
+    /* handle special keys first */
+    switch(btn)
+    {
+    case BTN_PAUSE:
+        do_pause_menu(sys);
+        sys->input.dirMask = 0;
+        sys->input.button = false;
+        /* exit early to avoid unwanted button presses being detected */
+        return;
+    default:
+        exit_on_usb(btn);
+        break;
+    }
+
     /* Ignore some buttons that cause errant input */
+
+    btn &= ~BUTTON_REDRAW;
+
 #if (CONFIG_KEYPAD == IPOD_4G_PAD) || \
     (CONFIG_KEYPAD == IPOD_3G_PAD) || \
     (CONFIG_KEYPAD == IPOD_1G2G_PAD)
     if(btn & 0x80000000)
         return;
 #endif
+
 #if (CONFIG_KEYPAD == SANSA_E200_PAD)
     if(btn == (BUTTON_SCROLL_FWD || BUTTON_SCROLL_BACK))
         return;
 #endif
+
 #if (CONFIG_KEYPAD == SANSA_FUZEPLUS_PAD)
     if(btn == (BUTTON_SELECT))
         return;
 #endif
 
-    /* handle special keys first */
-    switch(btn)
+    /* copied from doom which was copied from rockboy... */
+    unsigned released = ~btn & oldbuttonstate;
+    unsigned pressed = btn & ~oldbuttonstate;
+    oldbuttonstate = btn;
+
+    if(released)
     {
-    case BTN_PAUSE:
-        do_pause_menu(sys);
-        sys->input.dirMask = 0;
-        sys->input.button = false;
-        /* exit early to avoid unwanted button presses being detected */
-        return;
-    default:
-        exit_on_usb(btn);
-        break;
+        if(released & BTN_FIRE)
+            sys->input.button = false;
+        if(released & sys->keymap.up)
+            sys->input.dirMask &= ~DIR_UP;
+        if(released & sys->keymap.down)
+            sys->input.dirMask &= ~DIR_DOWN;
+        if(released & sys->keymap.left)
+            sys->input.dirMask &= ~DIR_LEFT;
+        if(released & sys->keymap.right)
+            sys->input.dirMask &= ~DIR_RIGHT;
+#ifdef BTN_DOWN_LEFT
+        if(released & sys->keymap.downleft)
+            sys->input.dirMask &= ~(DIR_DOWN | DIR_LEFT);
+#endif
+#ifdef BTN_DOWN_RIGHT
+        if(released & sys->keymap.downright)
+            sys->input.dirMask &= ~(DIR_DOWN | DIR_RIGHT);
+#endif
+#ifdef BTN_UP_LEFT
+        if(released & sys->keymap.upleft)
+            sys->input.dirMask &= ~(DIR_UP | DIR_LEFT);
+#endif
+#ifdef BTN_UP_RIGHT
+        if(released & sys->keymap.upright)
+            sys->input.dirMask &= ~(DIR_UP | DIR_RIGHT);
+#endif
     }
 
+    if(pressed)
+    {
+        if(pressed & BTN_FIRE)
+            sys->input.button = true;
+        if(pressed & sys->keymap.up)
+            sys->input.dirMask |= DIR_UP;
+        if(pressed & sys->keymap.down)
+            sys->input.dirMask |= DIR_DOWN;
+        if(pressed & sys->keymap.left)
+            sys->input.dirMask |= DIR_LEFT;
+        if(pressed & sys->keymap.right)
+            sys->input.dirMask |= DIR_RIGHT;
+#ifdef BTN_DOWN_LEFT
+        if(pressed & sys->keymap.downleft)
+            sys->input.dirMask |= (DIR_DOWN | DIR_LEFT);
+#endif
+#ifdef BTN_DOWN_RIGHT
+        if(pressed & sys->keymap.downright)
+            sys->input.dirMask |= (DIR_DOWN | DIR_RIGHT);
+#endif
+#ifdef BTN_UP_LEFT
+        if(pressed & sys->keymap.upleft)
+            sys->input.dirMask |= (DIR_UP | DIR_LEFT);
+#endif
+#ifdef BTN_UP_RIGHT
+        if(pressed & sys->keymap.upright)
+            sys->input.dirMask |= (DIR_UP | DIR_RIGHT);
+#endif
+    }
+
+#if 0
     /* handle releases */
     if(btn & BUTTON_REL)
     {
@@ -774,6 +891,7 @@ void sys_processEvents(struct System* sys)
     }
     debug(DBG_SYS, "dirMask is 0x%02x", sys->input.dirMask);
     debug(DBG_SYS, "button is %s", sys->input.button == true ? "true" : "false");
+#endif
 }
 
 void sys_sleep(struct System* sys, uint32_t duration)
@@ -789,26 +907,28 @@ uint32_t sys_getTimeStamp(struct System* sys)
     return (uint32_t) (*rb->current_tick * (1000/HZ));
 }
 
-static int16_t rb_soundbuf [MAX_SOUNDBUF_SIZE] IBSS_ATTR;
-static int8_t temp_soundbuf[MAX_SOUNDBUF_SIZE] IBSS_ATTR;
-static void ICODE_ATTR get_more(const void** start, size_t* size)
+/* game provides us mono samples, we need stereo */
+static int16_t rb_soundbuf[MAX_SOUNDBUF_SIZE * 2];
+static int8_t temp_soundbuf[MAX_SOUNDBUF_SIZE];
+
+static void get_more(const void** start, size_t* size)
 {
-    if(audio_sys->settings.sound_enabled)
+    if(audio_sys->settings.sound_enabled && audio_callback)
     {
         audio_callback(audio_param, temp_soundbuf, audio_sys->settings.sound_bufsize);
-        /* convert xworld format (signed 8-bit) to rockbox format (signed 16-bit) */
+
+        /* convert xworld format (signed 8-bit) to rockbox format (stereo signed 16-bit) */
         for(int i = 0; i < audio_sys->settings.sound_bufsize; ++i)
         {
-            rb_soundbuf[i] = temp_soundbuf[i] * 0x100;
+            rb_soundbuf[2*i] = rb_soundbuf[2*i+1] = temp_soundbuf[i] * 256;
         }
-        *start = rb_soundbuf;
-        *size = audio_sys->settings.sound_bufsize;
     }
     else
     {
-        *start = NULL;
-        *size = 0;
+        rb->memset(rb_soundbuf, 0, audio_sys->settings.sound_bufsize * 2 * sizeof(int16_t));
     }
+    *start = rb_soundbuf;
+    *size = audio_sys->settings.sound_bufsize * 2 * sizeof(int16_t);
 }
 
 void sys_startAudio(struct System* sys, AudioCallback callback, void *param)
@@ -817,6 +937,7 @@ void sys_startAudio(struct System* sys, AudioCallback callback, void *param)
     audio_callback = callback;
     audio_param = param;
     audio_sys = sys;
+
     rb->pcm_play_data(get_more, NULL, NULL, 0);
 }
 
@@ -872,13 +993,18 @@ void *sys_createMutex(struct System* sys)
 {
     if(!sys)
         error("sys is NULL!");
+
+    debug(DBG_SYS, "allocating mutex");
+
+    /* this bitfield works as follows: bit set = free, unset = in use */
     for(int i = 0; i < MAX_MUTEXES; ++i)
     {
+        /* check that the corresponding bit is 1 (free) */
         if(sys->mutex_bitfield & (1 << i))
         {
-            rb->mutex_init(&sys->mutex_memory[i]);
-            sys->mutex_bitfield |= (1 << i);
-            return &sys->mutex_memory[i];
+            rb->mutex_init(sys->mutex_memory + i);
+            sys->mutex_bitfield &= ~(1 << i);
+            return sys->mutex_memory + i;
         }
     }
     warning("Out of mutexes!");
@@ -888,20 +1014,18 @@ void *sys_createMutex(struct System* sys)
 void sys_destroyMutex(struct System* sys, void *mutex)
 {
     int mutex_number = ((char*)mutex - (char*)sys->mutex_memory) / sizeof(struct mutex); /* pointer arithmetic! check for bugs! */
-    sys->mutex_bitfield &= ~(1 << mutex_number);
+    sys->mutex_bitfield |= 1 << mutex_number;
 }
 
 void sys_lockMutex(struct System* sys, void *mutex)
 {
     (void) sys;
-    debug(DBG_SYS, "calling mutex_lock");
     rb->mutex_lock((struct mutex*) mutex);
 }
 
 void sys_unlockMutex(struct System* sys, void *mutex)
 {
     (void) sys;
-    debug(DBG_SYS, "calling mutex_unlock");
     rb->mutex_unlock((struct mutex*) mutex);
 }
 
@@ -937,4 +1061,5 @@ void MutexStack(struct MutexStack_t* s, struct System *stub, void *mutex)
 void MutexStack_destroy(struct MutexStack_t* s)
 {
     sys_unlockMutex(s->sys, s->_mutex);
+
 }
diff --git a/apps/plugins/xworld/video_data.c b/apps/plugins/xworld/video_data.c
index e658c17..afed9e0 100644
--- a/apps/plugins/xworld/video_data.c
+++ b/apps/plugins/xworld/video_data.c
@@ -126,9 +126,10 @@ uint8_t video_font[FONT_SIZE] = {
     0x00, 0xA0, 0x10, 0x80, 0x10, 0x80, 0x50, 0x00, /* DEL */
 };
 
+/* default bogus strings */
 struct StrEntry video_stringsTableEng[MAX_STRING_TABLE_SIZE] = {
     { 0x001, "B A N A N A  2000" },
-    { 0x002, "Copyright  } 2014 Banana Corporation \nGPLv2\n\nBUNIX Revision 3.14" },
+    { 0x002, "Copyright  } 2016 Franklin Wei\nGPLv2\n\nBUNIX Revision 3.14" },
     { 0x003, "1" },
     { 0x004, "3" },
     { 0x005, "." },
diff --git a/apps/plugins/xworld/vm.c b/apps/plugins/xworld/vm.c
index de632d7..10c3957 100644
--- a/apps/plugins/xworld/vm.c
+++ b/apps/plugins/xworld/vm.c
@@ -52,7 +52,13 @@ void vm_init(struct VirtualMachine* m) {
 
     rb->memset(m->vmVariables, 0, sizeof(m->vmVariables));
     m->vmVariables[0x54] = 0x81;
-    m->vmVariables[VM_VARIABLE_RANDOM_SEED] = *rb->current_tick;
+    m->vmVariables[VM_VARIABLE_RANDOM_SEED] = *rb->current_tick % 0x10000;
+
+    /* rawgl has these, but they don't seem to do anything */
+    //m->vmVariables[0xBC] = 0x10;
+    //m->vmVariables[0xC6] = 0x80;
+    //m->vmVariables[0xF2] = 4000;
+    //m->vmVariables[0xDC] = 33;
 
     m->_fastMode = false;
     m->player->_markVar = &m->vmVariables[VM_VARIABLE_MUS_MARK];
@@ -81,7 +87,7 @@ void vm_op_add(struct VirtualMachine* m) {
 
 void vm_op_addConst(struct VirtualMachine* m) {
     if (m->res->currentPartId == 0x3E86 && m->_scriptPtr.pc == m->res->segBytecode + 0x6D48) {
-        warning("vm_op_addConst() hack for non-stop looping gun sound bug");
+        //warning("vm_op_addConst() hack for non-stop looping gun sound bug");
         // the script 0x27 slot 0x17 doesn't stop the gun sound from looping, I
         // don't really know why ; for now, let's play the 'stopping sound' like
         // the other scripts do
@@ -152,10 +158,9 @@ void vm_op_jnz(struct VirtualMachine* m) {
 #define BYPASS_PROTECTION
 void vm_op_condJmp(struct VirtualMachine* m) {
 
-    //printf("Jump : %X \n",m->_scriptPtr.pc-m->res->segBytecode);
+    //debug(DBG_VM, "Jump : %X \n",m->_scriptPtr.pc-m->res->segBytecode);
 //FCS Whoever wrote this is patching the bytecode on the fly. This is ballzy !!
-#ifdef BYPASS_PROTECTION
-
+#if 0
     if (m->res->currentPartId == GAME_PART_FIRST && m->_scriptPtr.pc == m->res->segBytecode + 0xCB9) {
 
         // (0x0CB8) condJmp(0x80, VAR(41), VAR(30), 0xCD3)
@@ -168,6 +173,8 @@ void vm_op_condJmp(struct VirtualMachine* m) {
         debug(DBG_VM, "vm_op_condJmp() bypassing protection");
         debug(DBG_VM, "bytecode has been patched");
 
+        //warning("bypassing protection");
+
         //vm_bypassProtection(m);
     }
 
@@ -175,7 +182,8 @@ void vm_op_condJmp(struct VirtualMachine* m) {
 #endif
 
     uint8_t opcode = scriptPtr_fetchByte(&m->_scriptPtr);
-    int16_t b = m->vmVariables[scriptPtr_fetchByte(&m->_scriptPtr)];
+    uint8_t var = scriptPtr_fetchByte(&m->_scriptPtr);
+    int16_t b = m->vmVariables[var];
     uint8_t c = scriptPtr_fetchByte(&m->_scriptPtr);
     int16_t a;
 
@@ -193,6 +201,22 @@ void vm_op_condJmp(struct VirtualMachine* m) {
     switch (opcode & 7) {
     case 0:     // jz
         expr = (b == a);
+
+#ifdef BYPASS_PROTECTION
+        /* always succeed in code wheel verification */
+        if (m->res->currentPartId == GAME_PART_FIRST && var == 0x29 && (opcode & 0x80) != 0) {
+
+            m->vmVariables[0x29] = m->vmVariables[0x1E];
+            m->vmVariables[0x2A] = m->vmVariables[0x1F];
+            m->vmVariables[0x2B] = m->vmVariables[0x20];
+            m->vmVariables[0x2C] = m->vmVariables[0x21];
+            // counters
+            m->vmVariables[0x32] = 6;
+            m->vmVariables[0x64] = 20;
+            expr = true;
+            //warning("Script::op_condJmp() bypassing protection");
+        }
+#endif
         break;
     case 1: // jnz
         expr = (b != a);
@@ -605,8 +629,6 @@ void vm_executeThread(struct VirtualMachine* m) {
         {
             (vm_opcodeTable[opcode])(m);
         }
-
-        rb->yield();
     }
 }