====== Grub2 Config Recipes ======

===== Force grub to show menu =====

  - comment out **GRUB_HIDDEN_***
  - run **update-grub**
<file grub /etc/defaults/grub>
...
#GRUB_HIDDEN_TIMEOUT=0
#GRUB_HIDDEN_TIMEOUT_QUIET=true
...
</file>

===== Add a custom entry to boot menu =====
  - Add entry to /etc/grub.d/40_custom
  - run update-grub

===== Add Default Kernel options =====
  - update **GRUB_CMDLINE_LINUX_DEFAULT=** in **/etc/defaults/grub**
  - run update-grub