GRUB2 manually booting Ubuntu

Test machine os for Ubuntu 14.04.1 LTS x86_64

The disk partitioning situation is:

Filesystem 1k-blocks used Available use% mounted on
/DEV/SDA1 19736236 3676896 15033756 20%/
None 4 0 4 0%/sys/fs/cgroup
Udev 369132 4 369128 1%/dev
TMPFS 75984 840 75144 2%/run
None 5120 0 5120 0%/run/lock
None 379908 0 379908 0%/run/shm
None 102400 0 102400 0%/run/user

On the GRUB2 command line (enter C in the boot interface), for example, the following:

Set root= (HD0,MSDOS1)

The hd0 is the disk where the root folder resides, and the IDE hard drive starts with HD and the SCSI drive starts with SD. The floppy disk is opened with FD . Naming is not as big as Linux. is from 0.

Press the TAB key to view after entering HD. MSDOS1 is the partition where the root folder resides, and you can view it by pressing the TAB key after entering Msdos.

linux/boot/vmlinuz* ro root=/dev/sda1

The * number is the kernel version number, enter/boot/vmlinuz and press TAB to be able to make their own active completion. SDA1 is the partition where the root folder resides.

If the boot folder is separate partition as LINUX/VM ... If boot is not a separate partition, enter LINUX/BOOT/VM ...

Initrd/initrd.img

Boot

Finally successfully entered the landing screen.

GRUB2 manually booting Ubuntu