busybox-initramfs software package provides Standalone shell setup for initramfs, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install busybox-initramfs
busybox-initramfs is installed in your system.
Make ensure the busybox-initramfs package were installed using the commands given below,
$ sudo dpkg-query -l | grep busybox-initramfs *
You will get with busybox-initramfs package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Shells |
| Package | busybox-initramfs |
| Version | 1:1.22.0-15ubuntu1 |
| Description | Standalone shell setup for initramfs |
| Sub Section | Shells |