1. Add default_file option in theme plugin

2. Add F5 Tools --> Theme Select menu to swith between themes

GRUB2/MOD_SRC/grub-2.04/grub-core/normal/menu.c

@@ -402,6 +402,7 @@ int g_menu_update_mode = 0;
 int g_ventoy_tip_label_enable = 0;
 const char * g_ventoy_tip_msg1 = NULL;
 const char * g_ventoy_tip_msg2 = NULL;
+char g_ventoy_theme_path[256] = {0};
 static const char *g_ventoy_cur_img_path = NULL;
 static void menu_set_chosen_tip(grub_menu_t menu, int entry)
 {
@@ -410,9 +411,15 @@ static void menu_set_chosen_tip(grub_menu_t menu, int entry)
     menu_tip *tip;
     grub_menu_entry_t e = grub_menu_get_entry (menu, entry);
 
+    if (g_ventoy_theme_path[0])
+    {
+        grub_env_set("theme", g_ventoy_theme_path);        
+    }
+
     g_ventoy_tip_msg1 = g_ventoy_tip_msg2 = NULL;
     if (e && e->id && grub_strncmp(e->id, "VID_", 4) == 0) 
     {
+        g_ventoy_theme_path[0] = 0;
         img = (img_info *)(void *)grub_strtoul(e->id + 4, NULL, 16);
         if (img)
         {
@@ -423,6 +430,7 @@ static void menu_set_chosen_tip(grub_menu_t menu, int entry)
     }
     else if (e && e->id && grub_strncmp(e->id, "DIR_", 4) == 0)
     {
+        g_ventoy_theme_path[0] = 0;
         for (i = 0; i < e->argc; i++)
         {
             if (e->args[i] && grub_strncmp(e->args[i], "_VTIP_", 6) == 0)

GRUB2/MOD_SRC/grub-2.04/grub-core/ventoy/ventoy_cmd.c

@@ -5268,6 +5268,8 @@ static cmd_para ventoy_cmds[] =
     { "vt_sel_wimboot", ventoy_cmd_sel_wimboot, 0, NULL, "", "", NULL },
     { "vt_set_wim_load_prompt", ventoy_cmd_set_wim_prompt, 0, NULL, "", "", NULL },
     { "vt_set_theme", ventoy_cmd_set_theme, 0, NULL, "", "", NULL },
+    { "vt_set_theme_path", ventoy_cmd_set_theme_path, 0, NULL, "", "", NULL },
+    { "vt_select_theme_cfg", ventoy_cmd_select_theme_cfg, 0, NULL, "", "", NULL },
 
     { "vt_get_efi_vdisk_offset", ventoy_cmd_get_efivdisk_offset, 0, NULL, "", "", NULL },
     { "vt_search_replace_initrd", ventoy_cmd_search_replace_initrd, 0, NULL, "", "", NULL },

GRUB2/MOD_SRC/grub-2.04/grub-core/ventoy/ventoy_def.h

@@ -1077,6 +1077,8 @@ int ventoy_get_block_list(grub_file_t file, ventoy_img_chunk_list *chunklist, gr
 int ventoy_check_block_list(grub_file_t file, ventoy_img_chunk_list *chunklist, grub_disk_addr_t start);
 void ventoy_plugin_dump_persistence(void);
 grub_err_t ventoy_cmd_set_theme(grub_extcmd_context_t ctxt, int argc, char **args);
+grub_err_t ventoy_cmd_set_theme_path(grub_extcmd_context_t ctxt, int argc, char **args);
+grub_err_t ventoy_cmd_select_theme_cfg(grub_extcmd_context_t ctxt, int argc, char **args);
 grub_err_t ventoy_cmd_plugin_check_json(grub_extcmd_context_t ctxt, int argc, char **args);
 grub_err_t ventoy_cmd_check_password(grub_extcmd_context_t ctxt, int argc, char **args);
 grub_err_t ventoy_cmd_linux_get_main_initrd_index(grub_extcmd_context_t ctxt, int argc, char **args);

GRUB2/MOD_SRC/grub-2.04/grub-core/ventoy/ventoy_plugin.c

@@ -57,6 +57,7 @@ static auto_memdisk *g_auto_memdisk_head = NULL;
 static image_list *g_image_list_head = NULL;
 static conf_replace *g_conf_replace_head = NULL;
 
+static int g_theme_id = 0;
 static int g_theme_num = 0;
 static theme_list *g_theme_head = NULL;
 static int g_theme_random = vtoy_theme_random_boot_second;
@@ -281,6 +282,7 @@ static int ventoy_plugin_theme_check(VTOY_JSON *json, const char *isodisk)
 static int ventoy_plugin_theme_entry(VTOY_JSON *json, const char *isodisk)
 {
     const char *value;
+    char val[64];
     char filepath[256];
     VTOY_JSON *node = NULL;
     theme_list *tail = NULL;
@@ -366,6 +368,18 @@ static int ventoy_plugin_theme_entry(VTOY_JSON *json, const char *isodisk)
             }
         }
     }
+
+    grub_snprintf(val, sizeof(val), "%d", g_theme_num);
+    grub_env_set("VTOY_THEME_COUNT", val);
+    grub_env_export("VTOY_THEME_COUNT");
+    if (g_theme_num > 0)
+    {
+        vtoy_json_get_int(json->pstChild, "default_file", &g_theme_id);
+        if (g_theme_id > g_theme_num || g_theme_id < 0)
+        {
+            g_theme_id = 0;
+        }
+    }
     
     value = vtoy_json_get_string_ex(json->pstChild, "gfxmode");
     if (value)
@@ -3277,6 +3291,65 @@ end:
     return 0;
 }
 
+grub_err_t ventoy_cmd_select_theme_cfg(grub_extcmd_context_t ctxt, int argc, char **args)
+{
+    int pos = 0;
+    int bufsize = 0;
+    char *name = NULL;
+    char *buf = NULL;
+    theme_list *node = NULL;
+
+    (void)argc;
+    (void)args;
+    (void)ctxt;
+
+    if (g_theme_single_file[0])
+    {
+        return 0;
+    }
+
+    if (g_theme_num < 2)
+    {
+        return 0;
+    }
+
+    bufsize = (g_theme_num + 1) * 1024;
+    buf = grub_malloc(bufsize);
+    if (!buf)
+    {
+        return 0;
+    }
+    
+    for (node = g_theme_head; node; node = node->next)
+    {
+        name = grub_strstr(node->theme.path, ")/");
+        if (name)
+        {
+            name++;
+        }
+        else
+        {
+            name = node->theme.path;
+        }
+    
+        pos += grub_snprintf(buf + pos, bufsize - pos, 
+            "menuentry \"%s\" --class=debug_theme_item --class=debug_theme_select --class=F5tool {\n"
+                "vt_set_theme_path \"%s\"\n"
+            "}\n",
+            name, node->theme.path);
+    }
+
+    pos += grub_snprintf(buf + pos, bufsize - pos, 
+            "menuentry 'Return to previous menu [Esc]' --class=vtoyret VTOY_RET {\n"
+                "echo 'Return ...'\n"
+            "}\n");
+
+    grub_script_execute_sourcecode(buf);
+    grub_free(buf);
+    
+    return 0;
+}
+
 grub_err_t ventoy_cmd_set_theme(grub_extcmd_context_t ctxt, int argc, char **args)
 {
     grub_uint32_t i = 0;
@@ -3301,6 +3374,17 @@ grub_err_t ventoy_cmd_set_theme(grub_extcmd_context_t ctxt, int argc, char **arg
     {
         goto end;
     }
+    
+    if (g_theme_id > 0 && g_theme_id <= g_theme_num)
+    {
+        for (i = 0; i < (grub_uint32_t)(g_theme_id - 1) && node; i++)
+        {
+            node = node->next;
+        }
+
+        grub_env_set("theme", node->theme.path);
+        goto end;
+    }
 
     grub_memset(&datetime, 0, sizeof(datetime));
     grub_get_datetime(&datetime);
@@ -3332,7 +3416,25 @@ grub_err_t ventoy_cmd_set_theme(grub_extcmd_context_t ctxt, int argc, char **arg
     grub_env_set("theme", node->theme.path);
 
 end:
+
     VENTOY_CMD_RETURN(GRUB_ERR_NONE);
 }
 
+extern char g_ventoy_theme_path[256];
+grub_err_t ventoy_cmd_set_theme_path(grub_extcmd_context_t ctxt, int argc, char **args)
+{
+    (void)argc;
+    (void)ctxt;
+
+    if (argc == 0)
+    {
+        g_ventoy_theme_path[0] = 0;
+    }
+    else
+    {
+        grub_snprintf(g_ventoy_theme_path, sizeof(g_ventoy_theme_path), "%s", args[0]);
+    }
+
+    VENTOY_CMD_RETURN(GRUB_ERR_NONE);
+}
 

INSTALL/grub/debug.cfg

@@ -38,6 +38,12 @@ submenu "Screen Display Mode" --class=debug_screen_mode --class=F5tool {
     }
 }
 
+if [ $VTOY_THEME_COUNT -gt 1 ]; then
+    submenu "Theme Select" --class=debug_theme_select --class=F5tool {
+        vt_select_theme_cfg
+    }
+fi
+
 if [ "$grub_platform" != "pc" ]; then
     submenu 'Ventoy UEFI Utilities' --class=debug_util --class=F5tool {
         menuentry 'Show EFI Drivers' --class=debug_util_efidrv --class=debug_util --class=F5tool {