[[PageOutline]]

= Ubuntu on Newport =
This page provides details on running Ubuntu on a Gateworks Newport Board.

See also:
 * the Gateworks [wiki:newport#BoardSupportPackagesBSPSoftware] software page for other Linux options on Newport products.
 * [wiki:/ubuntu Gateworks Ubuntu Page for general notes]  


[=#prebuilt]
== Gateworks pre-built Ubuntu Disk Image ==
Gateworks provides a pre-built Ubuntu firmware images for the Newport Family:
 * [http://dev.gateworks.com/newport/kernel/linux-newport.tar.xz linux-newport.tar.xz] - Compressed TAR archive of pre-built Linux kernel
 * [http://dev.gateworks.com/newport/ubuntu/xenial/latest/xenial-newport.tar.xz xenial-newport.tar.xz] - Compressed TAR archive of Ubuntu 16.04 Xenial arm64 root filesystem (does not include kernel) ([http://dev.gateworks.com/newport/ubuntu/xenial/latest/xenial-newport.manifest package manifest])
 * [http://dev.gateworks.com/newport/images/xenial-newport.img.gz xenial-newport.img.gz] - Compressed Disk Image containing Firmware, Linux kernel, and Ubuntu 16.04 Xenial root filesystem. To update the firmware using this see [wiki:newport#serial-ethernet here]

Features:
- Ubuntu 16.04 aarch64 core (from debootstrap instructions)
- Gateworks Newport Linux kernel (Linux 4.14 based)
- eth0 dhcp with a 10 second timeout
- user root passwd root
- packages installed on top of core:
 * updated modemmanager/libqmi-utils/libmbim-utils (see [wiki:ubuntu#modem ubuntu/modem])
 * misc wireless: wpasupplicant iw 
 * misc utils: vim can-utils i2c-tools usbutils pciutils screen watchdog binutils
 * misc network: wget ethtool iperf iperf3 openssh-server iptables
 * linux firmware
 * mmc-utils from https://packages.debian.org/sid/utils/mmc-utils
 * Gateworks [hostapd-conf script https://raw.githubusercontent.com/Gateworks/meta-gateworks/master/recipes-support/hostapd-conf/hostapd-conf/hostapd-conf]
 * filesystems: e2fstools f2fs-tools btrfs-tools

To install the kernel and root filesystem on a removable block storage device see [#disk-images below].


[=#disk-images]
== Building a Bootable Disk Images ==
You will want to build your own Ubuntu disk image if you want control over any of the following:
 * contents of root filesystem (packages and configuration) (see [#debootstrap debootsrap below)
 * configuration of the Linux kernel (see [wiki:newport/bsp#kernel newport/bsp/kernel])

See [wiki:newport/boot#disk-images newpowrt/boot/disk-images] for detailed instructions.


[=#debootstrap]
== Root filesystem ==
A popular way to create an Ubuntu root filesystem is to use the {{{deboostrap}}} utility on a Debian or Ubuntu host. This tool provides a 2-stage install where the second stage is within a chroot environment using qemu.

Requirements:
- Linux Ubuntu or Debian System with network connection and sudo permissions

Important notes:
 * we set and use '''target''' and '''distro''' env variables in step 2 and use those env variables in the remaining steps to make this tutorial more version-agnostic. Please be aware of this and do not deviate from the steps unless or until you completely understand what you are doing.

Steps:
1. Install pre-requisites:
{{{
#!bash
sudo apt-get install qemu-user-static debootstrap binfmt-support
}}}

2. Perform first stage install of minimal filesystem for {{{arm64}}} architecture:
{{{
#!bash
target=rootfs
distro=xenial
sudo debootstrap --arch=arm64 --foreign $distro $target
# copy qemu-arm-static binary for the binfmt packages to find it and copy in resolv.conf from host
sudo cp /usr/bin/qemu-aarch64-static $target/usr/bin
}}}
 * See http://ports.ubuntu.com/ubuntu-ports/dists/ for a list of current Ubuntu releases: 16.10=yakkety (latest), 16.04=xenial (latest LTS), 15.04=vivid, 14.10=utopic (LTS), 14.04=trusty (LTS), 12.04=precise (LTS), 10.04=lucid (LTS).
 * this minimal rootfs can be considered about the same as an Ubuntu-core downloaded rootfs however it is still missing some core packages and configuration before it can be booted. These steps are taken care of in a 2nd stage install within a chroot shell
 * the chroot shell below will provide network support (inherited from the host)

3. we now have a minimal Ubuntu rootfs - chroot to it and perform the 2nd stage install:
{{{
#!bash
sudo chroot $target
# now we are in the chroot
distro=xenial
export LANG=C
# setup second stage
/debootstrap/debootstrap --second-stage
}}}
 * this is the most minimal rootfs we would recommend

4. (optional) add additional apt package repos:
{{{
#!bash
cat <<EOT > /etc/apt/sources.list
deb http://ports.ubuntu.com/ubuntu-ports $distro main restricted universe multiverse
deb http://ports.ubuntu.com/ubuntu-ports $distro-updates main restricted universe multiverse
deb http://ports.ubuntu.com/ubuntu-ports $distro-security main restricted universe multiverse
EOT
}}}
 * you may want to customize the above list, depending on your needs. See [#packages below] for more detail on Ubuntu package feeds

5. (optional) update package database and setup locales (do not skip this step if you are needing to install any packages for the steps below or otherwise)
{{{
#!bash
apt-get update
apt-get -f install # fixup missing package dependencies
apt-get install locales dialog
dpkg-reconfigure locales
}}}

6. set hostname:
{{{
#!bash
echo ${distro}-$(uname -m) > /etc/hostname
}}}

7. set a root passwd so you can login
{{{
#!bash
passwd
}}}
 - or consider adding a user via {{{adduser}}}:
{{{
#!bash
adduser myuser
usermod -a -G tty myuser # add to tty group for tty access
usermod -a -G dialout myuser # add to dialout group for UART access
usermod -a -G sudo myuser # add to sudo group for root access
}}}

8. (optional) configure networking:
 - wired ethernet with DHCP on eth0
{{{
#!bash
cat <<EOF >> /etc/network/interfaces
allow-hotplug eth0
auto eth0
iface eth0 inet dhcp

EOF
}}}
 - or static IP:
{{{
#!bash
cat <<EOF >> /etc/network/interfaces
allow-hotplug eth0
auto eth0
iface eth0 inet static
address 192.168.1.1
netmask 255.255.255.0
gateway 192.168.1.254

EOF
}}}
 - or wireless (requires ~3MB of additional packages):
{{{
#!bash
apt-get install wpasupplicant iw
cat << EOF >> /etc/network/interfaces
# Wireless interface
auto wlan0
iface wlan0 inet dhcp
        wireless_mode managed
        wireless_essid any
        wpa-driver nl80211
        wpa-conf /etc/wpa_supplicant.conf

EOF
wpa_passphrase <myssid> <mypass> >> /etc/wpa_supplicant.conf
}}}

9. (optional) install some useful packages
{{{
#!bash
apt-get install openssh-server # ssh server for remote access
apt-get install can-utils i2c-tools usbutils pciutils # cmdline tools for various hardware support
}}}
 * Note that by default root ssh access is disabled for security. See [#ssh below] for info on enabling it

10. exit the chroot shell and remove files we no longer need
{{{
#!bash
exit
sudo rm $target/usr/bin/qemu-arm-static
}}}

At this point you have a directory containing a root filesystem (without kernel) and likely want to install it onto removable storage or the on-board FLASH of a target board. Some intermediate formats that are useful to keep around would be a tarball, perhaps an ext4 filesystem image, or a compressed disk image suitable for flashing in the U-Boot bootloader.

To create a tarball which is the most flexible storage format and can be used for a variety of future installation uses:
{{{#!bash
sudo tar --numeric-owner -cvJf xenial-newport.tar.xz -C rootfs/ .
}}}
 * the '--numeric-owner' is required to store user/group as a number instead of a name
 * the '-C rootfs/' is required to eliminate the rootfs directory prefix
 * the sudo is needed to be able to read the root owned files

To create a 'Compressed Disk Image' using this tarball see [#disk-images above] and to install this onto a board's embedded FLASH see [wiki:newport#serial-ethernet here].


=== ext4 filesystem ===
If desired you can create an ext4 filesystem from the directory or tarball. This requires you choose a size for the filesystem. This size can be increased at runtime using {{{resize2fs}}} as long as the partition table has room for it to grow. The advantage of using an as small as possible size is that the time necessary to flash it onto storage is reduced to a minimum (when flashing you have to write the entire ext4 fs but when formatting or resizing it only has to write periodic markers to FLASH).

For a given size (see SIZEMB variable below) you can create a rootfs with:
{{{#!bash
SIZEMB=1536 # 1.5GB - expandable later with resize2fs
OUT=xenial-newport.ext4
# create a file of specific size
truncate -s ${SIZEMB}M ${OUT}
# format it as an ext4 filesystem
mkfs.ext4 -q -F -L rootfs ${OUT}
# mount it to a temporary mount point
tmp_mnt=$(mktemp -d -p/tmp)
mount ${OUT} ${tmp_mnt}
# copy files to it
cp -rup rootfs/* ${tmp_mnt}
# and/or extract files from a tarball
tar -C ${tmp_mnt} -xf linux-newport.tar.xz
# unmount temporary mount point
umount ${tmp_mnt}
sync
# compress it
gzip -k -f ${OUT}
}}}