I am running Ubuntu 11.04 on a Lenovo Ideapad S10-3t netbook. It runs well under normal operation when I boot normally (load X) and choose a Desktop environment (Unity or LXDE).

Recently I tried to add a boot menu option to boot straight in to a pure terminal (command line mode) without loading X. Grub2 gives the correct menu options but when I choose the command mode (pure terminal) option the screen splits (horizontally) in to two mirrored sections with vertical white lines across the screen (like a diffraction grating) and some unreadable text appears.

Although I can't read it I have a feeling that some error is being reported, at the very least I don't get a login prompt. I can however press Ctrl+Alt+F2 and do get a command prompt. However the screen problem persists. I can just manage to enter the 'sudo shutdown -r now' command to force the netbook to restart. I can still get in to a normal X-based desktop environment.

Here are links to two images of how the screen appears:

http://i.imgur.com/SYXR3.jpg
http://i.imgur.com/PDGKa.jpg

To help diagnose the problem let me describe how I attempted to boot directly in to a pure terminal (command mode). I followed instructions on http://ubuntuguide.net/add-a-grub2-e...lecommand-line and https://help.ubuntu.com/community/Gr...splay_Behavior and started by studying the /boot/grub/grub.cfg file:

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

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ "${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
}

function load_video {
  insmod vbe
  insmod vga
  insmod video_bochs
  insmod video_cirrus
}

insmod part_msdos
insmod ext2
set root='(/dev/sda,msdos2)'
search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(/dev/sda,msdos2)'
search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
set locale_dir=($root)/boot/grub/locale
set lang=en_US
insmod gettext
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=4
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
if background_color 44,0,30; then
  clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
if [ ${recordfail} != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 2.6.38-13-generic' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos2)'
	search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
	linux	/boot/vmlinuz-2.6.38-13-generic root=UUID=b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae ro   quiet splash vt.handoff=7
	initrd	/boot/initrd.img-2.6.38-13-generic
}
menuentry 'Ubuntu, with Linux 2.6.38-13-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos2)'
	search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
	echo	'Loading Linux 2.6.38-13-generic ...'
	linux	/boot/vmlinuz-2.6.38-13-generic root=UUID=b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae ro single 
	echo	'Loading initial ramdisk ...'
	initrd	/boot/initrd.img-2.6.38-13-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
### 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.

menuentry 'Ubuntu, with Linux 2.6.38-13-generic (command mode)' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos2)'
	search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
	linux	/boot/vmlinuz-2.6.38-13-generic root=UUID=b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae ro text vt.handoff=7
	initrd	/boot/initrd.img-2.6.38-13-generic
}
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
I copied the menuentry portion and edited as suggested by the first website and pasted the result in /etc/grub.d/40_custom :

Code:
#!/bin/sh
exec tail -n +3 $0
# 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.

menuentry 'Ubuntu, with Linux 2.6.38-13-generic (command mode)' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos2)'
	search --no-floppy --fs-uuid --set=root b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae
	linux	/boot/vmlinuz-2.6.38-13-generic root=UUID=b5e1f6d7-f1ac-4458-8df5-bb4eba8875ae ro text vt.handoff=7
	initrd	/boot/initrd.img-2.6.38-13-generic
}
The main change is in the second last line (starting with linux) where I replaced 'ro quiet splash vt.handoff=7' with 'ro text vt.handoff=7'. I ended by editing /etc/default/grub so that the menu was not hidden:

Code:
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=4
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"
I applied these changes using 'sudo update-grub' and after booting in to command mode the screen problems ensued.

Finally, the solutions I attempted included changing /etc/default/grub to specify a screen resolution, and various other attempts in the same vein in vain.

Any help will be greatly appreciated. My thanks in advance.