grub.cfg

#This is reference material for the post at http://aprivatebeach.com/blog/2010/05/upgrading-ubuntu-8-04-hardy-to-10-04-lucid/

In order to edit this file, one will have to hold down the Alt key and press the F2 key.  In the text box that appears, one will have to type gksu gedit /boot/grub/grub.cfg

If one wishes to use the command prompt instead, replace gksu with sudo

For those wishing to change the default Operating system to boot, one will have to change the set default.  For example, if the list of Operating systems at boot is:

Ubuntu

RedHat

Fedora

Centos

Windows

A set default=”4″ will set the cursor at Windows while a set default=”0″ will set the cursor at Ubuntu

By default, the set timeout=10.  One can change this to a smaller number such as 5 or a larger number such as 60.  The number tells GRUB in seconds how long to show the list of operating systems for before choosing the default.

If one wishes to change the menu item names, one just has to find menuentry and change the stuff between the ticks.  For example, menuentry ‘Ubuntu, with Linux 2.6.32-21-generic’

The line that one needs to edit is highlighted in bold below.

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
load_env
fi
set default=”4″
if [ ${prev_saved_entry} ]; then
set saved_entry=${prev_saved_entry}
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
if [ -z ${boot_once} ]; then
saved_entry=${chosen}
save_env saved_entry
fi
}

function recordfail {
set recordfail=1
if [ -n ${have_grubenv} ]; then if [ -z ${boot_once} ]; then save_env recordfail; fi; fi
}
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=640×480
insmod gfxterm
insmod vbe
if terminal_output gfxterm ; then true ; else
# For backward compatibility with versions of terminal.mod that don’t
# understand terminal_output
terminal gfxterm
fi
fi
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
set locale_dir=($root)/boot/grub/locale
set lang=en
insmod gettext
if [ ${recordfail} = 1 ]; then
set timeout=-1
else
set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry ‘Ubuntu, with Linux 2.6.32-21-generic’ –class ubuntu –class gnu-linux –class gnu –class os {
recordfail
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
linux    /boot/vmlinuz-2.6.32-21-generic root=UUID=90b37c66-049f-4a43-80fd-18b6261b269e ro   quiet splash
initrd    /boot/initrd.img-2.6.32-21-generic
}
menuentry ‘Ubuntu, with Linux 2.6.32-21-generic (recovery mode)’ –class ubuntu –class gnu-linux –class gnu –class os {
recordfail
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
echo    ‘Loading Linux 2.6.32-21-generic …’
linux    /boot/vmlinuz-2.6.32-21-generic root=UUID=90b37c66-049f-4a43-80fd-18b6261b269e ro single
echo    ‘Loading initial ramdisk …’
initrd    /boot/initrd.img-2.6.32-21-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry “Memory test (memtest86+)” {
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
linux16    /boot/memtest86+.bin
}
menuentry “Memory test (memtest86+, serial console 115200)” {
insmod ext2
set root='(hd0,6)’
search –no-floppy –fs-uuid –set 90b37c66-049f-4a43-80fd-18b6261b269e
linux16    /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry “Windows 7 (loader) (on /dev/sda1)” {
insmod ntfs
set root='(hd0,1)’
search –no-floppy –fs-uuid –set a6e2fad4e2faa7a7
chainloader +1
}
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the ‘exec tail’ line above.
### END /etc/grub.d/40_custom ###

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