:The purpose of this installer is to guide you through creating a bootable
Enea NFV Access installation on a physical media (e.g. USB stick or HDD).

Prerequisites:
    - A GRUB .efi binary
    - A drive of 16GB or larger
    - For USB booting you will need:
        - A development based rootfs (e.g. enea-nfv-access-dev-inteld1521.tar.gz)
    - For booting from an SSD or HDD you will need:
        - Any rootfs that needs to be installed on the board
          (e.g. enea-nfv-access.tar.gz)

A bootable media is created after the installer runs the following steps:
    1. Create two partitions on a designated drive (e.g. /dev/sda):
       - a 512MB partition for GRUB
       - the rest of the drive is reserved for the rootfs.
    2. Configure GRUB on one partition (usually the first one).
    3. Copy a root filesystem on the other partition.

Note: Running step 3 will implicitly copy the installer on that root filesystem
in /usr/bin/install_nfvaccess.sh
----------------------------------------------------------------------------------------
To get a list of what commands are built in the installer, launch it with root
rights and press ENTER, once the "nfv_installer>" console is displayed:
    help              - a guide on how to use the installer
    list-params       - lists parameters
    list-steps        - lists the available steps and the parameters that they depend on
    set               - sets a parameter (e.g. "set drive=/dev/sda")
    clear             - clears a parameter (e.g. "clear drive")
    list-partitions   - lists current drives and partitions
    dry               - describes the steps to be executed and checks if the files exist
    run               - executes the steps
    q or quit         - exits the script

Run 'list-steps' to understand the built-in steps that the installer
can execute and what parameters they depend on in order to be executed.

Running 'list-steps' will print the following:
    1. Format drive - Uses the drive set for the "drive" parameter to create a
    512MB partition for GRUB and another partition for the rootfs. The rootfs
    partition will be as large as the physical media minus 512MB.
        Depends on the following parameter(s):
            drive=
    2. GRUB install - Installs the binary pointed by "grub_binary" on the drive
    set in "grub_destination". A grub.cfg file will be created that will be
    configured to boot off of "rootfs_destination".
        Depends on the following parameters:
            grub_destination=
            grub_binary=
            rootfs_destination=
    3. Root filesystem install - Copies the files found in "rootfs_targz" to
    the drive set in "rootfs_destination".
        Depends on the following parameters:
            rootfs_targz=
            rootfs_destination=

A parameter can be set through the "set" command or cleared through "clear".
As some parameters are common for multiple steps, like rootfs_destination
is for the GRUB and rootfs installation steps, you can get a list of all the
parameters, by running "list-params".

The following parameters can be configured:
    grub_destination=[drive]    - specifies the drive where GRUB will be
                                  installed
    grub_binary=[file]          - points to the GRUB executable to be installed
                                  where grub_destination is set
    rootfs_destination=[drive]  - specifies where the rootfs will be deployed
    rootfs_targz=[.tar.gz file] - what file to unpack to where
                                  rootfs_destination is set
    drive=[/dev/sdaX]            - what drive to partition

Before running the actual partitioning and copying, a dry run can be executed
without affecting the actual layout of the physical media, by running the
"dry" command.

Example of partitioning a drive:
    set drive=/dev/sda
    run

Example of partitioning a drive, installing GRUB and a root filesystem:
    set drive=/dev/sda
    set grub_destination=/dev/sda1
    set grub_binary=/home/user/grub-binary.efi
    set rootfs_destination=/dev/sda2
    set rootfs_targz=/home/user/rootfs.tar.gz
    run

Example of deploying ONLY a root filesystem:
    set rootfs_destination=/dev/sda2
    set rootfs_targz=/home/user/rootfs.tar.gz
    runs

Troubleshooting:
    - GRUB is throwing "error: no such partition" or "error: disk not found":
    The default GRUB config is set to use 'hd0' as the primary drive for
    booting.
    Due to this, the errors described above have two possible causes:
        - The drive where NFV Access was installed is not identified as 'hd0'
        by the BIOS
        - The BIOS has assigned the 'hd0' label to a different drive (e.g. USB
        stick) than the one where NFV Access was installed.
    Solution:
        1. In the GRUB selection screen press 'c' to enter the command line.
        2. Run 'ls' to list all the available partitions.
        3. For each available partition run 'ls PARTITION' in order to identify
        where NFV Access was installed.
        4. After identifying the partition, press ESC to return to the GRUB
        selection screen and press 'e' to edit the boot command.
        5. Set the boot partition to the one identified in step 3
        6. Press F10 to boot