Use persistent data buffer API extension (plus fallback for frontends

that don't support it)

libretro/libretro.c

@@ -249,6 +249,10 @@ static retro_input_state_t		input_cb = NULL;
 static retro_audio_sample_batch_t			audio_batch_cb = NULL;
 static retro_environment_t		environ_cb = NULL;
 
+static uint8 *rom_buf              = NULL;
+static const uint8 *rom_data       = NULL;
+static size_t rom_size             = 0;
+
 static unsigned frameskip_type = 0;
 static unsigned frameskip_threshold = 0;
 static uint16_t frameskip_counter = 0;
@@ -1408,9 +1412,10 @@ static void init_descriptors(void)
 	environ_cb(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, desc);
 }
 
-bool retro_load_game(const struct retro_game_info *game)
+bool retro_load_game(const struct retro_game_info *info)
 {
 	int loaded;
+   const struct retro_game_info_ext *info_ext = NULL;
 	struct retro_memory_map map;
 
 	init_descriptors();
@@ -1419,8 +1424,41 @@ bool retro_load_game(const struct retro_game_info *game)
 	map.descriptors = memorydesc + MAX_MAPS - memorydesc_c;
 	map.num_descriptors = memorydesc_c;
 
+   /* Snes9x 2010 requires a persistent ROM data buffer */
+   rom_buf  = NULL;
+   rom_data = NULL;
+   rom_size = 0;
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_GAME_INFO_EXT, &info_ext) &&
+       info_ext->persistent_data)
+   {
+      rom_data = (const uint8*)info_ext->data;
+      rom_size = info_ext->size;
+   }
+
+   /* If frontend does not support persistent
+    * content data, must create a copy */
+   if (!rom_data)
+   {
+      if (!info)
+         return false;
+
+      rom_size = info->size;
+      rom_buf  = (uint8*)malloc(rom_size);
+
+      if (!rom_buf)
+      {
+         if (log_cb)
+            log_cb(RETRO_LOG_INFO, "[Snes9x 2010]: Failed to allocate ROM buffer!\n");
+         return false;
+      }
+
+      memcpy(rom_buf, (const uint8*)info->data, rom_size);
+      rom_data = (const uint8*)rom_buf;
+   }
+
 	/* Hack. S9x cannot do stuff from RAM. <_< */
-	memstream_set_buffer((uint8_t*)game->data, (uint64_t)game->size);
+	memstream_set_buffer((uint8_t*)rom_data, (uint64_t)rom_size);
 
 	loaded = LoadROM("");
 	if (!loaded)
@@ -1454,7 +1492,15 @@ bool retro_load_game_special(unsigned game_type, const struct retro_game_info *i
 	return false;
 }
 
-void retro_unload_game (void) { }
+void retro_unload_game (void)
+{
+   if (rom_buf)
+      free(rom_buf);
+
+   rom_buf               = NULL;
+   rom_data              = NULL;
+   rom_size              = 0;
+}
 
 unsigned retro_get_region (void)
 {