009.04.91.27. The `00_header` script defines helper functions like `savedefault` and `load_video`.

{
    if[ -z "${boot_once}" ]
    then
        saved_entry="${chosen}"
        save_env saved_entry
    fi
}

The `savedefault` function updates the `saved_entry` env variable with the chosen choice unless it's a one-time boot setup ( `boot_once` ).


function load_video
{
    if[ x$feature_all_video_module = xy ];then
        insmod all_video
    else
        insmod efi_gop
        insmod efi_uga
        insmod vieo_bochs
    fi
}

`load-video` function loads video drivers dynamically. It loads generic module until and unless specified for custom module.