Flashing a Robot

Flashing a Robot

To install Arch Linux (our OS of choice) on to a robot perform the following instructions. Make sure you know the robot number for this NUC before beginning.

1. Download the latest Arch Linux LiveUSB image and burn it on to a USB thumb drive using the following instructions

   • Find the USB drive in your system. This will vary from one system to another and choosing the wrong drive will cause irreversible data loss.
     • Use sudo fdisk -l, or the Disks GUI program to find your USB drive. It will probably be /dev/sdX, where X is a letter of the alphabet.
   • Burn the Arch Linux ISO you just downloaded to the USB drive (in this example we are using /dev/sdb)

   • Copy
     sudo dd bs=4M if=~/Downloads/archlinux-2019.11.01-x86_64.iso of=/dev/sdb status=progress oflag=sync

2. If you are using a brand new NUC, Boot into the BIOS on the NUC

   • Turn the NUC on and hold down the F2 button
   • Intel Visual BIOS should appear
   • Navigate to "Advanced" menu
   • Navigate to "Power" then set "After Power Failure" to "Power On"

     

   • Navigate to "Boot" and then "Boot Configuration"
     • Ensure "Boot USB Devices First" is enabled in "UEFI Boot"
     • Ensure "USB" is enabled in "Boot Devices"

       

   • Navigate to "Secure Boot" and disable "Secure Boot"

     

   • Press F10 to save settings and exit and ensure you USB drive is plugged in

3. If you are not using a brand new NUC, ensure your USB drive is plugged in and turn the NUC on

4. Once the system has booted into the LiveUSB environment on the robot, ensure the robot has an active network connection

   • 

   • Run ip addr and look for a inet line that has a valid IP address on it. If you can't see one you don't have a network connection. Alternatively, run ping -c 3 google.com and look for a response time.

     

     

   • If you have no connection and need to set up the WiFi interface, see below.

5. Download the installation script https://git.io/JeWaF and make sure the script is executable

   • Copy
     curl -L https://git.io/JeWaF -o ./arch_install.sh
     chmod +x ./arch_install.sh

   • The installation script is located in the NUbots repository at doc/ArchInstall/arch_install.sh

6. Execute the script and follow the instructions

   • Copy
     ./arch_install.sh

7. The installation script will end by downloading a secondary script and providing you with a command that you must run

   Copy
   ROBOT_NUMBER=<N> arch-chroot /mnt ./arch-chroot_install.sh

   Substitute <N> with the number of the robot that you are building. This will influence the IP address of the robot as well as the robots' hostname.

   The secondary script assumes that the network interfaces are named eth0 for ethernet and wlp58s0 for WiFi. If you know this is not the case then execute the script as follows

   Copy
   ROBOT_NUMBER=<N> \
   ETHERNET_INTERFACE=IF_NAME \
   WIFI_INTERFACE=IF_NAME \
   arch-chroot /mnt ./arch-chroot_install.sh

8. Once that script has finished, run the following command.

   Copy
   /mnt/arch-post_install.sh

   This command will end by rebooting the robot. When this happens be sure to remove the USB installation drive from robot so that you may boot into the new system.

   The other two scripts can be found at doc/ArchInstall/arch-chroot_install.sh and doc/ArchInstall/arch-post_install.sh

9. Finally, we need to run the SystemConfigurator.

   • Make sure you have built the system_configuration role and run

     Copy
     ./b install n<N>

     Where <N> is again replaced with the robot number.

   • Now ssh into the robot and run

     Copy
     ./system_configuration

Testing the new robot

Once installation is complete and you have booted into your shiny new OS, you should perform a couple of simple tests to ensure everything is operational.

First, login to system

Now check for a network connection, the same as we did before. If ip addr indicates that there is no connection then it is likely that the secondary installation script made the wrong guess about the name of the network interfaces. Inspect the output from ip link and make note of the ethernet and wifi interface names.

If there is no connection, then the following files need to be modified (using either sudo nano or sudo vim)

• /etc/systemd/network/20-eth0.network
• /etc/systemd/network/30-wlan0.network
• /etc/systemd/network/99-eth0.network
• /etc/systemd/network/99-wlan0.network
• /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

These 5 files need to be both renamed (replacing eth0 or wlp58s0 with the new interface name) and the contents of the files need to be edited, specifically the line that says Name=eth0 or Name=wlp58s0.

Next, correct the wpa_supplicant service by running

Copy
sudo systemctl disable wpa_supplicant@wlan0
sudo systemctl enable wpa_supplicant@new_interface

Be sure to replace new_interface with the name of the WiFi interface.

Once these files have been fixed, reboot by typing sudo systemctl reboot and then login again. Hopefully, ip addr indicates that there is an active network connection (on bond0) and ping -c 3 google.com also indicates an active connection.

Manually setting up a WiFi connection on the robot

To set up the WiFi interface you first need to know the name of the interface. To find this, run

Copy
ip link

and look for an interface starting with wl. On our robots it is usually wlan0.

The rest of these instructions assume a network using WPA2 (like the network used in the NUbots lab).

1. Make sure the wpa_supplicant configuration directory exists

   • Copy
     mkdir -p /etc/wpa_supplicant

2. Setup the network configuration

   • Copy
     wpa_passphrase <Network SSID> <Network Passphrase> > /etc/wpa_supplicant/wpa_supplicant-<WiFi Interface>.conf

   • Be sure to replace <Network SSID> with the SSID of the wireless network to connect to (either epsilon-x or epsilon-z in the lab), <Network Passphrase> with the password for the network (ask someone for the lab password if you don't know it), and <WiFi Interface> with the name of the interface found earlier.

3. Now start all of the necessary services

   • Copy
     systemctl start dhcpcd.service
     systemctl start wpa_supplicant.service
     systemctl start wpa_supplicant@<Wifi Interface>.service

   • Be sure to replace <WiFi Interface> with the name of the interface found earlier.
   • Wait a handful of seconds and run ip addr to check that the WiFi interface has an IP address