Ubuntu16.04切换内核启动

1.该命令显示内核的启动顺序

zgw@zgw-ThinkPad:~$ grep menuentry /boot/grub/grub.cfg
if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
  menuentry_id_option=""
export menuentry_id_option
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-5bce3795-da96-4c6f-bed2-67d37185a77d' {
submenu 'Ubuntu 高级选项' $menuentry_id_option 'gnulinux-advanced-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu，Linux 4.8.0-26-lowlatency' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-lowlatency-advanced-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu, with Linux 4.8.0-26-lowlatency (upstart)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-lowlatency-init-upstart-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu, with Linux 4.8.0-26-lowlatency (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-lowlatency-recovery-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu，Linux 4.8.0-26-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-generic-advanced-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu, with Linux 4.8.0-26-generic (upstart)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-generic-init-upstart-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu, with Linux 4.8.0-26-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.4.0-45-generic-recovery-5bce3795-da96-4c6f-bed2-67d37185a77d' { menuentry 'Ubuntu，Linux 4.4.0-21-generic' -