Can load without ROM in RGUI (HAVE_DYNAMIC).

Not sure how this will work on RARCH_CONSOLE, but it'll probably be
checked for in startup on core load somehow and either start in menu or args->no_rom.

dynamic.c

@@ -103,7 +103,23 @@ static bool environment_cb(unsigned cmd, void *data);
 #define DYNAMIC_EXT "so"
 #endif
 
-static dylib_t libretro_get_system_info_lib(const char *path, struct retro_system_info *info)
+static bool *load_no_rom_hook;
+static bool environ_cb_get_system_info(unsigned cmd, void *data)
+{
+   switch (cmd)
+   {
+      case RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME:
+         *load_no_rom_hook = *(const bool*)data;
+         break;
+
+      default:
+         return false;
+   }
+
+   return true;
+}
+
+static dylib_t libretro_get_system_info_lib(const char *path, struct retro_system_info *info, bool *load_no_rom)
 {
    dylib_t lib = dylib_load(path);
    if (!lib)
@@ -119,13 +135,30 @@ static dylib_t libretro_get_system_info_lib(const char *path, struct retro_syste
    }
 
    proc(info);
+
+   if (load_no_rom)
+   {
+      *load_no_rom = false;
+      void (*set_environ)(retro_environment_t) =
+         (void (*)(retro_environment_t))dylib_proc(lib, "retro_set_environment");
+
+      if (!set_environ)
+         return lib;
+
+      load_no_rom_hook = load_no_rom;
+
+      // load_no_rom gets set in this callback.
+      set_environ(environ_cb_get_system_info);
+   }
+
    return lib;
 }
 
-bool libretro_get_system_info(const char *path, struct retro_system_info *info)
+bool libretro_get_system_info(const char *path, struct retro_system_info *info,
+   bool *load_no_rom)
 {
    struct retro_system_info dummy_info = {0};
-   dylib_t lib = libretro_get_system_info_lib(path, &dummy_info);
+   dylib_t lib = libretro_get_system_info_lib(path, &dummy_info, load_no_rom);
    if (!lib)
       return false;
 
@@ -171,7 +204,7 @@ static bool find_first_libretro(char *path, size_t size,
       RARCH_LOG("Checking library: \"%s\".\n", list->elems[i].data);
 
       struct retro_system_info info = {0};
-      dylib_t lib = libretro_get_system_info_lib(list->elems[i].data, &info);
+      dylib_t lib = libretro_get_system_info_lib(list->elems[i].data, &info, NULL);
       if (!lib)
          continue;
 
@@ -374,6 +407,7 @@ void uninit_libretro_sym(void)
    g_extern.system.pix_fmt = RETRO_PIXEL_FORMAT_0RGB1555;
    g_extern.system.no_game = false;
    g_extern.system.shutdown = false;
+   g_extern.system.key_event = NULL;
 }
 
 #ifdef NEED_DYNAMIC

dynamic.h

@@ -48,7 +48,7 @@ function_t dylib_proc(dylib_t lib, const char *proc);
 #ifdef HAVE_DYNAMIC
 // Gets system info from an arbitrary lib.
 // The struct returned must be freed as strings are allocated dynamically.
-bool libretro_get_system_info(const char *path, struct retro_system_info *info);
+bool libretro_get_system_info(const char *path, struct retro_system_info *info, bool *load_no_rom);
 void libretro_free_system_info(struct retro_system_info *info);
 #endif
 

frontend/menu/history.c

@@ -63,7 +63,10 @@ void rom_history_push(rom_history_t *hist,
 {
    for (size_t i = 0; i < hist->size; i++)
    {
-      if (!strcmp(hist->entries[i].path, path) &&
+      bool equal_path = (!path && !hist->entries[i].path) ||
+         (path && hist->entries[i].path && !strcmp(path, hist->entries[i].path));
+
+      if (equal_path &&
             !strcmp(hist->entries[i].core_path, core_path) &&
             !strcmp(hist->entries[i].core_name, core_name))
       {
@@ -88,7 +91,7 @@ void rom_history_push(rom_history_t *hist,
    memmove(hist->entries + 1, hist->entries,
          (hist->cap - 1) * sizeof(struct rom_history_entry));
 
-   hist->entries[0].path      = strdup(path);
+   hist->entries[0].path      = path ? strdup(path) : NULL;
    hist->entries[0].core_path = strdup(core_path);
    hist->entries[0].core_name = strdup(core_name);
    hist->size++;
@@ -102,10 +105,19 @@ static void rom_history_write_file(rom_history_t *hist)
 
    for (size_t i = 0; i < hist->size; i++)
    {
-      fprintf(file, "%s;%s;%s\n",
-            hist->entries[i].path,
-            hist->entries[i].core_path,
-            hist->entries[i].core_name);
+      if (hist->entries[i].path)
+      {
+         fprintf(file, "%s;%s;%s\n",
+               hist->entries[i].path,
+               hist->entries[i].core_path,
+               hist->entries[i].core_name);
+      }
+      else
+      {
+         fprintf(file, "%s;%s\n",
+               hist->entries[i].core_path,
+               hist->entries[i].core_name);
+      }
    }
 
    fclose(file);
@@ -152,16 +164,26 @@ static bool rom_history_read_file(rom_history_t *hist, const char *path)
       if (!list)
          break;
 
-      if (list->size != 3)
+      if (list->size < 2 || list->size > 3)
       {
          string_list_free(list);
          break;
       }
 
       struct rom_history_entry *entry = &hist->entries[hist->size];
-      entry->path = strdup(list->elems[0].data);
-      entry->core_path = strdup(list->elems[1].data);
-      entry->core_name = strdup(list->elems[2].data);
+
+      if (list->size == 3)
+      {
+         entry->path = strdup(list->elems[0].data);
+         entry->core_path = strdup(list->elems[1].data);
+         entry->core_name = strdup(list->elems[2].data);
+      }
+      else if (list->size == 2)
+      {
+         entry->core_path = strdup(list->elems[0].data);
+         entry->core_name = strdup(list->elems[1].data);
+      }
+
       string_list_free(list);
    }
 

frontend/menu/menu_common.c

@@ -365,9 +365,10 @@ void rgui_list_get_last(const rgui_list_t *list,
 
 void load_menu_game_prepare(void)
 {
-   if (*g_extern.fullpath)
+   if (*g_extern.fullpath || rgui->load_no_rom)
    {
-      if (g_extern.lifecycle_mode_state & (1ULL << MODE_INFO_DRAW))
+      if (*g_extern.fullpath &&
+            g_extern.lifecycle_mode_state & (1ULL << MODE_INFO_DRAW))
       {
          char tmp[PATH_MAX];
          char str[PATH_MAX];
@@ -378,7 +379,8 @@ void load_menu_game_prepare(void)
       }
 
       if (rgui->history)
-         rom_history_push(rgui->history, g_extern.fullpath,
+         rom_history_push(rgui->history,
+               *g_extern.fullpath ? g_extern.fullpath : NULL,
                g_settings.libretro, rgui->info.library_name);
    }
 
@@ -412,7 +414,17 @@ void load_menu_game_history(unsigned game_index)
          game_index, &path, &core_path, &core_name);
 
    strlcpy(g_settings.libretro, core_path, sizeof(g_settings.libretro));
-   strlcpy(g_extern.fullpath, path, sizeof(g_extern.fullpath));
+
+   if (path)
+   {
+      rgui->load_no_rom = false;
+      strlcpy(g_extern.fullpath, path, sizeof(g_extern.fullpath));
+   }
+   else
+   {
+      rgui->load_no_rom = true;
+      *g_extern.fullpath = '\0';
+   }
 
 #if !defined( HAVE_DYNAMIC) && defined(RARCH_CONSOLE)
    g_extern.lifecycle_mode_state &= ~(1ULL << MODE_GAME);
@@ -421,10 +433,9 @@ void load_menu_game_history(unsigned game_index)
    g_extern.lifecycle_mode_state |= (1ULL << MODE_EXITSPAWN_START_GAME);
 #elif defined(HAVE_DYNAMIC)
    libretro_free_system_info(&rgui->info);
-   libretro_get_system_info(g_settings.libretro, &rgui->info);
+   libretro_get_system_info(g_settings.libretro, &rgui->info, NULL);
    g_extern.lifecycle_mode_state |= (1ULL << MODE_LOAD_GAME);
 #endif
-
 }
 
 bool load_menu_game(void)
@@ -440,6 +451,7 @@ bool load_menu_game(void)
    args.state_path    = *g_extern.savestate_dir ? g_extern.savestate_dir : NULL;
    args.rom_path      = *g_extern.fullpath ? g_extern.fullpath : NULL;
    args.libretro_path = g_settings.libretro;
+   args.no_rom        = rgui->load_no_rom;
 
    if (rarch_main_init_wrap(&args) == 0)
    {
@@ -480,7 +492,7 @@ void menu_init(void)
    else if (*g_settings.libretro)
    {
       fill_pathname_basedir(rgui->libretro_dir, g_settings.libretro, sizeof(rgui->libretro_dir));
-      libretro_get_system_info(g_settings.libretro, &rgui->info);
+      libretro_get_system_info(g_settings.libretro, &rgui->info, NULL);
    }
 #else
    retro_get_system_info(&rgui->info);

frontend/menu/menu_common.h

@@ -232,6 +232,7 @@ typedef struct
    char libretro_dir[PATH_MAX];
 #endif
    struct retro_system_info info;
+   bool load_no_rom;
 
 #ifdef HAVE_OSKUTIL
    unsigned osk_param;

frontend/menu/rgui.c

@@ -1927,12 +1927,18 @@ static void history_parse(rgui_handle_t *rgui)
       rom_history_get_index(rgui->history, i,
             &path, &core_path, &core_name);
 
-      char path_short[PATH_MAX];
-      fill_pathname(path_short, path_basename(path), "", sizeof(path_short));
-
       char fill_buf[PATH_MAX];
-      snprintf(fill_buf, sizeof(fill_buf), "%s (%s)",
-            path_short, core_name);
+
+      if (path)
+      {
+         char path_short[PATH_MAX];
+         fill_pathname(path_short, path_basename(path), "", sizeof(path_short));
+
+         snprintf(fill_buf, sizeof(fill_buf), "%s (%s)",
+               path_short, core_name);
+      }
+      else
+         strlcpy(fill_buf, core_name, sizeof(fill_buf));
 
       rgui_list_push(rgui->selection_buf, fill_buf, RGUI_FILE_PLAIN, 0);
    }
@@ -2178,7 +2184,18 @@ int rgui_iterate(rgui_handle_t *rgui)
 #if defined(HAVE_DYNAMIC)
                fill_pathname_join(g_settings.libretro, dir, path, sizeof(g_settings.libretro));
                libretro_free_system_info(&rgui->info);
-               libretro_get_system_info(g_settings.libretro, &rgui->info);
+               libretro_get_system_info(g_settings.libretro, &rgui->info,
+                     &rgui->load_no_rom);
+
+               // No ROM needed for this core, load game immediately.
+               if (rgui->load_no_rom)
+               {
+                  g_extern.lifecycle_mode_state |= (1ULL << MODE_LOAD_GAME);
+                  *g_extern.fullpath = '\0';
+                  rgui->msg_force = true;
+                  ret = -1;
+               }
+
                // Core selection on non-console just updates directory listing.
                // Will take affect on new ROM load.
 #elif defined(GEKKO)

general.h

@@ -611,6 +611,7 @@ struct rarch_main_wrap
    const char *config_path;
    const char *libretro_path;
    bool verbose;
+   bool no_rom;
 };
 
 enum

retroarch.c

@@ -3131,15 +3131,18 @@ int rarch_main_init_wrap(const struct rarch_main_wrap *args)
 
    argv[argc++] = strdup("retroarch");
 
-   if (args->rom_path)
+   if (!args->no_rom)
    {
-      RARCH_LOG("Using ROM: %s.\n", args->rom_path);
-      argv[argc++] = strdup(args->rom_path);
-   }
-   else
-   {
-      RARCH_LOG("No ROM, starting dummy core.\n");
-      argv[argc++] = strdup("--menu");
+      if (args->rom_path)
+      {
+         RARCH_LOG("Using ROM: %s.\n", args->rom_path);
+         argv[argc++] = strdup(args->rom_path);
+      }
+      else
+      {
+         RARCH_LOG("No ROM, starting dummy core.\n");
+         argv[argc++] = strdup("--menu");
+      }
    }
 
    if (args->sram_path)