To display the GRUB menu, comment GRUB_HIDDEN_TIMEOUT=0 and GRUB_HIDDEN_TIMEOUT_QUIET=true as shown in the image above
The meaning of the above parameters is explained as follows:
The GRUB menu item is enabled by default. The specific GRUB items can be found in /boot/grub/grub.cfg
This configuration will affect the menu display. If this option is set, the menu is hidden for this time and the boot screen is displayed. The menu will be hidden unless you add a # sign at the beginning of the line. (# GRUB_HIDDEN_TIMEOUT = 0). The first time GRUB 2 is executed, it will look for other operating systems. If no other operating system is detected, the menu is configured to be hidden. If other operating systems are recognized, the menu will display. If an integer is greater than 0, the system will pause according to the number of seconds configured, but no menu will be displayed. 0, the menu will not be displayed and there will be no delay. Users can hold down the Shift key at startup to force the menu to appear. During startup, the SHIFT key status is checked. If the keystroke status is not recognized, there is a short delay to allow the user to display the menu by pressing the Esc key.
True does not display a countdown. The screen will be blank. False The time configured in GRUB_HIDDEN_TIMEOUT. There will be a countdown timer on the blank screen.
This command will comply with the GRUB_HIDDEN_TIMEOUT configuration unless GRUB_HIDDEN_TIMEOUT is commented out (#). If GRUB_HIDDEN_TIMEOUT is enabled,GRUB_TIMEOUT will only be executed once when the menu is displayed. Configuring this value to -1 will cause the menu to remain displayed until the user selects it. The GRUB 2 menu is hidden by default unless other operating systems are detected by the system. If there is no other operating system, this line will be commented out unless the user modifies it. To display the menu on startup each time, uncomment this line and use a value of 1 or greater.
This command is used to set the default startup mode of the system, which can be set as character interface or graphical interface with parameters including quite, splash, text
(1) the meaning of quiet: kernel startup to simplify the prompt message (the prompt message when starting the system, adding this command will simplify the prompt message)
(2) The meaning of splash: the character output process of init is replaced by a graphical progress bar at startup
(3) text meaning: set the system after the character interface, from the character interface to enter the graphical interface can use startx