Add RETRO_ENVIRONMENT_SET_LIBRETRO_PATH to libretro API. Also gives us opportunity

to write internal code - other libretro implementations can now just implement
this environ callback and have other external frontends of their own be able to swap
in/out libretro cores from outside

dynamic.c

@@ -93,8 +93,6 @@ unsigned (*pretro_get_region)(void);
 void *(*pretro_get_memory_data)(unsigned);
 size_t (*pretro_get_memory_size)(unsigned);
 
-static bool environment_cb(unsigned cmd, void *data);
-
 #ifdef HAVE_DYNAMIC
 #if defined(__APPLE__)
 #define DYNAMIC_EXT "dylib"
@@ -397,7 +395,7 @@ void init_libretro_sym(bool dummy)
 
    load_symbols(dummy);
 
-   pretro_set_environment(environment_cb);
+   pretro_set_environment(rarch_environment_cb);
 }
 
 void uninit_libretro_sym(void)
@@ -471,7 +469,7 @@ void dylib_close(dylib_t lib)
 }
 #endif
 
-static bool environment_cb(unsigned cmd, void *data)
+bool rarch_environment_cb(unsigned cmd, void *data)
 {
    switch (cmd)
    {
@@ -757,7 +755,12 @@ static bool environment_cb(unsigned cmd, void *data)
          g_extern.system.frame_time = *info;
          break;
       }
-
+      case RETRO_ENVIRONMENT_SET_LIBRETRO_PATH:
+      {
+         struct retro_variable *var = (struct retro_variable*)data;
+         strlcpy(g_settings.libretro, var->value, sizeof(g_settings.libretro));
+         break;
+      }
       default:
          RARCH_LOG("Environ UNSUPPORTED (#%u).\n", cmd);
          return false;

dynamic.h

@@ -101,6 +101,8 @@ extern unsigned (*pretro_get_region)(void);
 extern void *(*pretro_get_memory_data)(unsigned);
 extern size_t (*pretro_get_memory_size)(unsigned);
 
+extern bool rarch_environment_cb(unsigned cmd, void *data);
+
 #ifdef __cplusplus
 }
 #endif

frontend/frontend.c

@@ -63,8 +63,11 @@ static bool libretro_install_core(const char *path_prefix,
       return false;
    }
 
-   strlcpy(g_settings.libretro, new_path,
-         sizeof(g_settings.libretro));
+   struct retro_variable var;
+   var.key = "core_path";
+   var.value = new_path;
+
+   rarch_environment_cb(RETRO_ENVIRONMENT_SET_LIBRETRO_PATH, &var);
 
    return true;
 }

frontend/menu/menu_common.c

@@ -438,13 +438,15 @@ void load_menu_game_prepare(void)
 void load_menu_game_history(unsigned game_index)
 {
    const char *path = NULL;
-   const char *core_path = NULL;
    const char *core_name = NULL;
+   struct retro_variable var;
+
+   var.key = "core_path";
 
    rom_history_get_index(rgui->history,
-         game_index, &path, &core_path, &core_name);
+         game_index, &path, &var.value, &core_name);
 
-   strlcpy(g_settings.libretro, core_path, sizeof(g_settings.libretro));
+   rarch_environment_cb(RETRO_ENVIRONMENT_SET_LIBRETRO_PATH, &var);
 
    if (path)
    {

frontend/menu/rgui.c

@@ -2654,7 +2654,13 @@ int rgui_iterate(rgui_handle_t *rgui)
                // Core selection on non-console just updates directory listing.
                // Will take affect on new ROM load.
 #elif defined(GEKKO) && defined(HW_RVL)
-               strlcpy(g_settings.libretro, path, sizeof(g_settings.libretro)); // Is this supposed to be here?
+               struct retro_variable var;
+
+               var.key = "core_path";
+               var.value = path;
+
+               rarch_environment_cb(RETRO_ENVIRONMENT_SET_LIBRETRO_PATH, &var);
+
                fill_pathname_join(g_extern.fullpath, default_paths.core_dir,
                      SALAMANDER_FILE, sizeof(g_extern.fullpath));
                g_extern.lifecycle_mode_state &= ~(1ULL << MODE_GAME);

frontend/menu/rmenu.c

@@ -460,7 +460,6 @@ static int select_file(void *data, uint64_t input)
    char extensions[128];
    char comment[128];
    char path[PATH_MAX];
-   bool ret = true;
    bool pop_menu_stack = false;
    font_params_t font_parms = {0};
 
@@ -495,7 +494,7 @@ static int select_file(void *data, uint64_t input)
    if (input & (1ULL << DEVICE_NAV_B))
    {
       if (filebrowser_iterate(rgui->browser, FILEBROWSER_ACTION_PATH_ISDIR))
-         ret = filebrowser_iterate(rgui->browser, FILEBROWSER_ACTION_OK);
+         filebrowser_iterate(rgui->browser, FILEBROWSER_ACTION_OK);
       else
       {
          strlcpy(path, rgui->browser->current_dir.path, sizeof(path));
@@ -560,9 +559,16 @@ static int select_file(void *data, uint64_t input)
                         true, menu_texture->width, menu_texture->height, 1.0f);
                break;
             case LIBRETRO_CHOICE:
-               strlcpy(g_settings.libretro, path, sizeof(g_settings.libretro));
-               g_extern.lifecycle_mode_state |= (1ULL << MODE_EXITSPAWN);
-               return -1;
+               {
+                  struct retro_variable var;
+
+                  var.key = "core_path";
+                  var.value = path;
+
+                  rarch_environment_cb(RETRO_ENVIRONMENT_SET_LIBRETRO_PATH, &var);
+                  g_extern.lifecycle_mode_state |= (1ULL << MODE_EXITSPAWN);
+                  return -1;
+               }
          }
 
          pop_menu_stack = true;

libretro.h

@@ -509,7 +509,9 @@ enum retro_mod
                                            // Lets the core know how much time has passed since last invocation of retro_run().
                                            // The frontend can tamper with the timing to fake fast-forward, slow-motion, frame stepping, etc.
                                            // In this case the delta time will use the reference value in frame_time_callback..
-                                          
+#define RETRO_ENVIRONMENT_SET_LIBRETRO_PATH 22
+                                           // const char ** --
+                                           // Sets the absolute path for the libretro core pointed to.
 
 // Notifies libretro that audio data should be written.
 typedef void (*retro_audio_callback_t)(void);