Creating a Machinekit Debian Image

Alexander Rössler edited this page Mar 23, 2015 · 4 revisions

step 1: Download BBB Debian image

Download latest image from http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#Debian_Releases and check the md5 sum

wget <url>
md5sum <name of image>.img.xz

step 2: flash image file to SD card

WARNING: Be careful when typing these commands

Use dmesg to check for the name of the SD card partition then flash the image file. Flashing to the wrong device can result in data loss.

Reconnect your SD card reader with the SD card inserted and type the following:

dmesg | tail

You should see something mentioning /dev/sdX or /dev/mmcblkX. This is the name of your SD card device.

Extract the image file

unxz <name of image>.img.xz

Flash the image

sudo dd bs=4096k if=<name of image>.img of=/dev/<device> oflag=direct

NOTE: if you use the SD card image you may want to resize it to use the whole SD card. You can use GParted for this purpose.

Alternative with progress bar

For the following commands you need the tool pv installed. On Debian or Ubuntu this can be done with sudo apt-get install pv

For 2GB images:

xz -dc <name of image>.img.xz | pv -s 1800000000 | sudo dd bs=4096k iflag=fullblock of=/dev/<device> oflag=direct

For 4GB images:

xz -dc <name of image>.img.xz | pv -s 3880000000 | sudo dd bs=4096k iflag=fullblock of=/dev/<device> oflag=direct

step 3: insert SD card and boot

Insert the SD card into your BBB and wait for the device to boot. The lights will be indication what your device is doing.

  • No lights means something went wrong (or your device is not powered).
  • Randomly blinking lights mean your device is doing something (good sign).
  • Running lights mean the SD card content is being flashed to eMMC.
  • Four flashing lights mean that you tried flashing a 4GB image to a BBB older than RevC.

If you want to connect to your BBB over Ethernet make sure you connect it to a DHCP server before booting.

NOTE: If the image is not booting you may need to flash a new bootloader using the console eMMC-flasher images. (usually happens with older RevB boards)

step 4: connect to the BBB using SSH

Use you favorite terminal application to connect to the BBB:

    ssh root@beaglebone.local

NOTE: On Windows or Mac you may need to enter the IP address of the BBB instead of the hostname beaglebone.local. If you are connected over USB this is 192.168.7.2

step 5: add a new user

To make Machinekit work properly we need a new user:

adduser machinekit
usermod -aG  sudo,xenomai,kmem machinekit

Remove the sudo password by adding a new entry to sudoers.d:

sudo su -c 'echo -e "# No sudo password for machinekit user\nmachinekit ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/90-machinekit'

Now change the root user password to improve security:

passwd

step 6: change the hostname

You may want to change the hostname of the image. Change beaglebone in the following two files with the name you want using the nano editor.

nano /etc/hostname
nano /etc/hosts

Reboot to apply the changes.

reboot

step 7: logout and login as new user

ssh machinekit@beaglebone.local

step 7: install Machinekit

Now we need to install the Machinekit packages. Follow the BeagleBone steps at Machinekit Debian Packages. Make sure to install the correct Linux kernel image:

sudo apt-get install linux-image-xenomai.beaglebone-omap

step 8: deactivate all unneeded capes

We should check all the capes that are loaded by default (can change between images) and deactivate all that are not necessary. You can check the loaded capes with:

cat /sys/devices/bone_capemgr.*/slots

To deactive loading of specific cape at boot you need to edit the ´uEnv.txt´:

sudo nano /boot/uEnv.txt

For many Machinekit configurations you will need to disable the HDMI cape. This can be done by uncommenting the following command:

cape_disable=capemgr.disable_partno=BB-BONELT-HDMI

step 9: change SSH banner message

The default banner message on the BBB image is located at ´/etc/issue.net´ you can edit by running:

sudo nano /etc/issue.net

step 10: disable SSH DNS reverse checking

The SSH DNS reverse checking feature makes the SSH login slower. As we use the BBB in an internal network only we can deactivate the reverse checking and speed things up.

    sudo su -c 'echo -e "UseDNS no" >> /etc/ssh/sshd_config'

step 11: WiFi

If you want to use you BBB in combination with a WiFi network please follow these steps.

Infrastructure: wicd-curses

wicd-curses is ncurses based graphical terminal user interface to connect to (wireless) networks. You can install it by running following commands:

   sudo apt-get update
   sudo apt-get install wicd-curses

To configure your wireless network run wicd-curses and follow the on screen instructions.

Access-Point: Install AP-Hotspot

To make it possible to connect the BBB using the a AP Wifi network we have to install the AP-Hotspot script:

mkdir bin
cd bin
git clone https://github.com/strahlex/AP-Hotspot.git
cd AP-Hotspot/
sudo apt-get update
sudo apt-get install libnotify-bin iw dnsmasq
sudo make install

I can recommend the WiPi USB dongle from element14 or any other USB wifi adapter with the same chipset. NOTE: For some reason the EDIMAX EW-7811UN Wireless USB Adapter dongle works only with a Nexus 7 as client

step 12: Additional modifications

We may need a folder in the home directory of the machinekit user for gcode files:

mkdir ~/nc_files

It is possible to rename the FAT32 partition that is mounted when the BBB is connected to a computer using USB. This may be done with any suitable application.

Starting the a Machinekit configuration at boot is also possible Starting-a-Machinekit-configuration-at-boot