15.1.47 timeout

If this variable is set, it specifies the time in seconds to wait for keyboard input before booting the default menu entry. A timeout of ‘0’ means to boot the default entry immediately without displaying the menu; a timeout of ‘-1’ (or unset) means to wait indefinitely.

If ‘timeout_style’ (see timeout_style) is set to ‘countdown’ or ‘hidden’, the timeout is instead counted before the menu is displayed.

This variable is often set by ‘GRUB_TIMEOUT’ (see Simple configuration).