* vtoy_reserved[1]: vtoy_debug_level
* vtoy_reserved[2]: vtoy_chain_type 0:Linux 1:Windows
* vtoy_reserved[3]: vtoy_iso_format 0:iso9660 1:udf
+ * vtoy_reserved[4]: vtoy_windows_cd_prompt
*
*/
grub_uint8_t vtoy_reserved[32]; // Internal use by ventoy