grub2更改默認啟動項

grub2 和 grub0.97 的啟動項目差別還是比較大的，最近Ubuntu自動更新，把默認啟動項目給更改了，導致很多驅動無法成功加載，需要改回去，這里記錄下修改過程：

通過sudo vim /boot/grub/grub.cfg打開grub2的默認配置文件

注意：

• grub2的一級和二級 menu 的索引都是從 0 開始的
• 假如第一個啟動項（索引為0）不包含子menu，可以通過修改配置set default="0"把默認啟動項設為第一個
• 如果一個啟動項包含子menu，可以通過set default="1> 3"的形式來設置默認啟動項，其中1是一級menu的索引，2是二級menu的索引

If you have a submenu in your grub.cfg you should use two digits like this:

grub-reboot '1>3'
The first is menu index, and the second is submenu index.

For example, to boot last entry from config like this:

grep menu /boot/grub/grub.cfg

menuentry 'Debian GNU/Linux' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option 'gnulinux-advanced-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 4.6.0-0.bpo.1-amd64' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.6.0-0.bpo.1-amd64-advanced-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 4.6.0-0.bpo.1-amd64 (sysvinit)' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.6.0-0.bpo.1-amd64-init-sysvinit-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 4.6.0-0.bpo.1-amd64 (recovery mode)' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.6.0-0.bpo.1-amd64-recovery-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 3.16.0-4-amd64' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.16.0-4-amd64-advanced-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 3.16.0-4-amd64 (sysvinit)' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.16.0-4-amd64-init-sysvinit-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
    menuentry 'Debian GNU/Linux, with Linux 3.16.0-4-amd64 (recovery mode)' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.16.0-4-amd64-recovery-1ffa16a9-fda2-43b5-91b9-c91a08ff190f' {
you should use:

grub-reboot '1>5'
and reboot.

參考鏈接

How to correctly set up the right GRUB 2 default menu entry?