Edit /etc/default/grub and change
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
for
GRUB_CMDLINE_LINUX_DEFAULT=""
and then
$ sudo update-grub2Edit /etc/default/grub and change
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
for
GRUB_CMDLINE_LINUX_DEFAULT=""
and then
$ sudo update-grub2