libretro: Pass the filename to the underlying emulation, since we can detect things based on what it contains.

src/libretro/StellaLIBRETRO.cxx

@@ -61,8 +61,6 @@ bool StellaLIBRETRO::create(bool logging)
 {
   system_ready = false;
 
-  FilesystemNode rom("rom");
-
   // build play system
   destroy();
 
@@ -115,6 +113,8 @@ bool StellaLIBRETRO::create(bool logging)
   settings.setValue(AudioSettings::SETTING_VOLUME, 100);
   settings.setValue(AudioSettings::SETTING_STEREO, audio_mode);
 
+  FilesystemNode rom(rom_path);
+
   if(myOSystem->createConsole(rom) != EmptyString)
     return false;
 
@@ -334,8 +334,10 @@ bool StellaLIBRETRO::getVideoResize()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void StellaLIBRETRO::setROM(const void* data, size_t size)
+void StellaLIBRETRO::setROM(const char* path, const void* data, size_t size)
 {
+  rom_path = path;
+
   memcpy(rom_image.get(), data, size);
 
   rom_size = static_cast<uInt32>(size);

src/libretro/StellaLIBRETRO.hxx

@@ -96,7 +96,7 @@ class StellaLIBRETRO
     Int16* getAudioBuffer() { return audio_buffer.get(); }
 
   public:
-    void   setROM(const void* data, size_t size);
+    void   setROM(const char* path, const void* data, size_t size);
 
     void   setConsoleFormat(uInt32 mode);
 
@@ -139,6 +139,7 @@ class StellaLIBRETRO
 
     unique_ptr<uInt8[]> rom_image;
     uInt32 rom_size;
+    string rom_path;
 
     ConsoleTiming console_timing;
     string console_format;

src/libretro/libretro.cxx

@@ -574,7 +574,7 @@ bool retro_load_game(const struct retro_game_info *info)
   }
 
 
-  stella.setROM(info->data, info->size);
+  stella.setROM(info->path, info->data, info->size);
 
   return reset_system();
 }