Documentation made easier
grub-set-bootflag − set a bootflag in the GRUB environment block
’grub-set-bootflag <bootflag>’, where <bootflag> is one of:
boot_success menu_show_once
The full documentation for grub-set-bootflag is maintained as a Texinfo manual. If the info and grub-set-bootflag programs are properly installed at your site, the command
info grub-set-bootflag
should give you access to the complete manual.