The menu entry editor looks much like the main menu interface, but the
lines in the menu are individual commands in the selected entry instead
of entry names.
If an <ESC> is pressed in the editor, it aborts all the changes made
to the configuration entry and returns to the main menu interface.
When a particular line is selected, the editor places the user in a
special version of the GRUB command-line to edit that line. When the
user hits <RET>, GRUB replaces the line in question in the boot
entry with the changes (unless it was aborted via <ESC>,
in which case the changes are thrown away).
If you want to add a new line to the menu entry, press <o> if adding
a line after the current line or press <O> if before the current
line.
To delete a line, hit the key <d>. Although GRUB unfortunately
does not support undo, you can do almost the same thing by just
returning to the main menu.
Published under the terms of the GNU General Public License