修改grub分辨率

方法:
1.在 /etc/modprobe.d/blacklist-framebuffer.conf 里注释掉"blacklist vesafb"并添加一行 "blacklist vga16fb"
2.在 /etc/initramfs-tools/modules里添加 fbcon 和 vesafb
   在终端运行 sudo update-initramfs -u -k `uname -r`
3.执行 sudo gedit /boot/grub/grub.cfg
找到linux启动项，在kernel行之前加入 set gfxpayload=1024x768x16（ 此处不能改）
我的配置文件内容如下：
#
# 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="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 ${boot_once} ]; then save_env recordfail; fi; fi
}
insmod ext2
set root='(hd0,9)'
search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  insmod gfxterm
  insmod vbe
  if terminal_output gfxterm ; then true ; else
    # For backward compatibility with versions of terminal.mod that don't
    # understand terminal_output
    terminal gfxterm
  fi
fi
insmod ext2
set root='(hd0,9)'
search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
set locale_dir=($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 2.6.32-24-generic' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod ext2
    set root='(hd0,9)'
    search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
        set gfxpayload=1024x768x16
    linux    /boot/vmlinuz-2.6.32-24-generic root=UUID=bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8 ro  splash  quiet splash
    initrd    /boot/initrd.img-2.6.32-24-generic
}
menuentry 'Ubuntu, with Linux 2.6.32-24-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod ext2
    set root='(hd0,9)'
    search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
    echo    'Loading Linux 2.6.32-24-generic ...'
    linux    /boot/vmlinuz-2.6.32-24-generic root=UUID=bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8 ro single  splash
    echo    'Loading initial ramdisk ...'
    initrd    /boot/initrd.img-2.6.32-24-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
    insmod ext2
    set root='(hd0,9)'
    search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
    linux16    /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
    insmod ext2
    set root='(hd0,9)'
    search --no-floppy --fs-uuid --set bc0a0ec5-2618-4ff8-8582-d8f6d1a543c8
    linux16    /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Microsoft Windows XP Professional (on /dev/sda1)" {
    insmod fat
    set root='(hd0,1)'
    search --no-floppy --fs-uuid --set f87a-2a85
    drivemap -s (hd0) ${root}
    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 ###

保存文件退出重启就有效果了。