boot.loader.grub.timeoutStyle
NixOS option
menu shows the menu. countdown uses a text-mode countdown. hidden hides GRUB entirely. When using a theme, the default value (menu) is appropriate for the graphical countdown. When attempting to do flicker-free boot, hidden should be used. See the GRUB documentation section about timeout_style. If this option is set to ‘countdown’ or ‘hidden’ […] and ESC or F4 are pressed, or SHIFT is held down during that time, it will display the menu and wait for input. From: Simple configuration handling page, under GRUB_TIMEOUT_STYLE.
type: one of "menu", "countdown", "hidden"Default
declared in: nixos/modules/system/boot/loader/grub/grub.nixView source on NixOS/nixpkgs →"menu"