Handle grub menu after reboot - Handle grub2 to boot from hard disk (opposed to installation) - Handle passphrase for encrypted disks - Handle booting of snapshot or XEN, acconding to BOOT_TO_SNAPSHOT or XEN - Enable plymouth debug if product if GRUB_KERNEL_OPTION_APPEND is set, or product is sle, aarch64 and PLYMOUTH_DEBUG is set


Due to pre-installation setup, qemu boot order is always booting from CD-ROM.