VirtualBox Images for Xenomai 3.0 and Xenomai 2.4

Getting started with the image

At http://www.virtualbox.org/ you can download a free Virtual Box
Virtual Box lets you evaluate new or pre-release software contained in virtual machines, without any installation or configuration hassles. You can also share existing virtual machines with colleagues or friends. Just use VirtualBox to run any virtual machine.
VirtualBox is available for Linux, Macintosh, and Windows
Xenomai images
- Xenomai 3.0.8
  
  At http://www.cs.ru.nl/lab/downloads/xenomai3.0.8_debian9.8.0.7z you can download a VirtualBox image which contains a minimal debian 9.8.0 linux installation with the Xenomai 3.0.8 realtime system patches installed. Unzip the files and double click the .vbox file to run it.
  Note: after unpacking the image is 1.9GB in size, and to run it in VirtualBox you need another 1GB for the RAM memory file.
  Note: on first run it could say something is wrong with the network configuration, mainly because on the original host some netword device was named differently. To fix it just select edit network preferences, and the virtualbox gui will correct the network settings automatically, then you can close the preferencs again, and just start the image without problems.
  The description of the installation you can find at https://github.com/harcokuppens/xenomai3_rpi_gpio/blob/master/install/xenomai308_image_virtualbox.txt .
- Xenomai 3.0.2
  
  At http://www.cs.ru.nl/lab/downloads/xenomai-3.0.2_linux-4.1.18_debian-8.5.7z you can download a VirtualBox image which contains a minimal debian 8.5 linux installation with the Xenomai 3.0.2 realtime system patches installed. Unzip the files and double click the .vbox file to run it.
  Note: after unpacking the image is 1.15GB in size, and to run it in VirtualBox you need another 512MB for the RAM memory file.
  Important: on Macintosh computers you initially get some network interface error when trying to start the virtual machine causing the start to abort. The solution is very simple : just open the 'settings' dialog for this virtual machine once and immediately close it again, and the problem is solved. The reason for this error is probably that the .vbox file is created on Windows and on that platform probably there the network interface settings are a little bit different. By opening the 'setttings' panel once on the Macintosh computer Virtualbox will correct this automatically.
- Xenomai 2.4
  
  At http://www.cs.ru.nl/lab/downloads/virtualbox_xenomai_image.zip you can download a VirtualBox image which contains a minimal debian 4.0 linux installation with the Xenomai 2.4.3 realtime system patches installed. Unzip the files and double click the .vbox file to run it. Note: after unpacking the image is 800 MB in size, and to run it in VirtualBox you need another 256MB for the RAM memory file.
The host must have VT-x/AMD-v hardware virtualization enabled in BIOS otherwise the above images won't boot in virtualbox.
Note: it is convenient to unzip the file in your virtualbox machines directory and then in VirtualBox go to the menu "Machine->Add" and select the vbox file in your unzipped machine folder in the virtualbox machines directory. Convenient because all your virtual machines are stored at the same location.
you can log in with the following credentials:
```
      user:            root
      passwd:          <empty password>
      
```
The root user has an empty password which comes down to just pressing enter when asked for it.
The image has also network support using a 'host-only' adapter. This means that the virtual machines can talk to each other and the host as if they were connected through a physical ethernet switch. Note: the virtual machine cannot talk to the outside world. However this would be also possible when using a NAT adapter instead. However when using NAT the host cannot initiate a connection with the machine in VirtualBox, but we want to be able to ssh login from the host, or to mount the virtual machine's disk for easy editing with a host editor.
That's why a 'host only' adapter is used instead.
Update: In VirtualBox you can also add a second network adapter which does NAT, then you have both a "host-only" allowing you to communicate between guest-host and a "NAT" adapter which allows you to communicate with the outside world. We did add this second NAT adapter only in the newest images, and not in the 3.0.2 and 2.4 images.
Update: In VirtualBox you can replace the combination of NAT and host-only adapter with a single bridged adapter to get the same functionality: vm guest and host can communicate and the vm can communicate with the internet. However with a bridged adapter each vm gets an ip from the local network and is also reachable from the internet. However in general we don't need that the vm is reachable from the network, it is even unsafe because the software on a vm is often not patched with security updates. If a lot of people are going to use bridged virtual machines then there becomes a high demand on local ip adresses which are limited, causing other people not able to connect to the network anymore because we are out of local ip addresses. The bridged adapter should only be used if your virtual machine needs to be accessible from the outside network. For example when running a server on your virtual machine. So in general, and also for our xenomai vm, the combination NAT and host-only is preferred because the virtual machines are safely hidden from the outside world and do not require an ip address on the local network!
For more details see: https://www.virtualbox.org/manual/ch06.html#table-networking-modes
Important: On Macintosh computers you cannot use host-only network in the network settings of your virtual machine because this network is not yet setup. You can set it up by:
- in VirtualBox go to the "Preferences" dialog
- then go to "Network" → "Host-only Networks"
- click on the plus-icon after which "vboxnet0" appears, and then close the preferences dialog
- you now created a host-only network under the name "vboxnet0"
- now you can go to your virtual machine settings for your image and configure a network adapter which uses the host-only "vboxnet0" network

Remote access

to find out the ip address of the os running in VirtualBox type :
```
/sbin/ip address
```
```
or
```
```
/sbin/ifconfig
```
The ip address of the guest os starts with 192.168 which is an ip address for the host only network with which the host can easily access the guest os.
The nat network uses as prefix 10.0 which does not allow access to the guest from any outside host.
the next two services will be started :
1. ssh server : ssh root@<ip-address>
  With this server you can log in to a remote shell on the os running in VirtualBox. In this shell you can edit files with text editors like joe/nano/vim.
2. samba server :
  This server exports the root file system as networkshare for windows.
  On linux and macintosh computers you can access this share by going to the network location :
```
              smb://<ip-address>/root
              user: root
              passwd :<empty password>
          
```
  On windows you can access this share by typing the following in the explorer's address bar :
```
              \\<ip-address>\root
              user: root        
              passwd :<empty password>
          
```

Multiple consoles

you can use ctrl-alt-F1, ctrl-alt-F2, ..., ctrl-alt-F6 to switch between different consoles

Fix time and date using network

Fixing time and date automatically requires that your virtualbox machine has access to the outside network and to achieve that you have to configure NAT networking on your virtual machine. This can be done in a second adapter as mentioned above.
You can ask the time and date of the virtual machine with the following command :
```
  
            date 
      
```

When you pause the virtual machine it can happen that, when the machine is resumed much later, the date and time settings are totally wrong. Luckily there is a quick fix. You can synchronize the time easily with a server on the university with the following command :

          rdate -s time-srv.science.ru.nl
                     or 
          ntpdate ntp1.science.ru.nl

          note: for ntpdate to work you first have to do the following 
                  apt-get update
                  apt-get install ntpdate
                  tzconfig  # set timezone to Europe\Amsterdam  instead of America\NewYork