One of the most important parts of any operating system is the boot loader. Learn more about Linux's boot loader, GRUB2, and how to customize it.
grub> set pager=1
grub> ls
(hd0) (hd0,msdos2) (hd0,msdos1)
grub> ls (hd0,1)/
lost+found/ bin/ boot/ cdrom/ dev/ etc/ home/ lib/ lib64/ media/ mnt/ opt/ proc/ root/ run/ sbin/ srv/ sys/ tmp/ usr/ var/ vmlinuz vmlinuz.old initrd.img initrd.img.old
grub> set root=(hd0,1)
grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
grub> initrd /boot/initrd.img-3.13.0-29-generic
grub> boot