TS-4800 System Configuration

From Technologic Systems Manuals

For development, it is recommended to work directly in Debian on the SD card. Debian provides many more packages and a much more familiar environment for users already versed in Debian. Through Debian it is possible to configure the network, use the 'apt-get' suite to manage packages, and perform other configuration tasks. Out of the box the Debian distribution does not have any default username/password set. The account "root" is set up with no password configured. It is possible to log in via the serial console without a password but many services such as ssh will require a password set or will not allow root login at all. It is advised to set a root password and create a user account when the unit is first booted.

Note: Setting up a password for root is only feasible on the uSD image.

It is also possible to cross compile applications. Using a Debian host system will allow for installing a cross compiler to build applications. The advantage of using a Debian host system comes from compiling against libraries. Debian cross platform support allows one to install the necessary development libraries on the host, building the application on the host, and simply installing the runtime libraries on the target device. The library versions will be the same and completely compatible with each other. See the respective Debian cross compiling section for more information.

1 Configuring the Network

From almost any Linux system you can use "ip" or the ifconfig/route commands to initially set up the network. To configure the network interface manually you can use the same set of commands in the initrd or Debian.

# Bring up the CPU network interface
ifconfig eth0 up

# Or if you're on a baseboard with a second ethernet port, you can use that as:
ifconfig eth1 up

# Set an ip address (assumes 255.255.255.0 subnet mask)
ifconfig eth0 192.168.0.50

# Set a specific subnet
ifconfig eth0 192.168.0.50 netmask 255.255.0.0

# Configure your route.  This is the server that provides your internet connection.
route add default gw 192.168.0.1

# Edit /etc/resolv.conf for your DNS server
echo "nameserver 192.168.0.1" > /etc/resolv.conf

Most commonly networks will offer DHCP which can be set up with one command:

Configure DHCP in Debian:

# To setup the default CPU ethernet port
dhclient eth0
# Or if you're on a baseboard with a second ethernet port, you can use that as:
dhclient eth1
# You can configure all ethernet ports for a dhcp response with
dhclient

Configure DHCP in the initrd:

udhcpc -i eth0
# Or if you're on a baseboard with a second ethernet port, you can use that as:
udhcpc -i eth1

To make your network settings take effect on startup in Debian, edit /etc/network/interfaces:

 # Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or 
 # /usr/share/doc/ifupdown/examples for more information.          
                                                                   
 # We always want the loopback interface.                          
 #
 auto lo
 iface lo inet loopback
 
 auto eth0
 iface eth0 inet static
   address 192.168.0.50
   netmask 255.255.255.0
   gateway 192.168.0.1                                             
 auto eth1
 iface eth1 inet dhcp
Note: During Debian's startup it will assign the interfaces eth0 and eth1 to the detected mac addresses in /etc/udev/rules.d/70-persistent-net.rules. If the system is imaged while this file exists it will assign the new interfaces as eth1 and eth2. This file is generated automatically on startup, and should be removed before your first software image is created. The initrd network configuration does not use this file.

In this example eth0 is a static configuration and eth1 receives its configuration from the DHCP server. For more information on network configuration in Debian see their documentation here.

To make your changes permanent in the initrd you will need to edit the linuxrc script. Use the same commands you would use to manually configure it and place them over the current ifconfig calls.

2 Installing New Software

Debian provides the apt-get system which lets you manage pre-built applications. Before you do this you need to update Debian's list of package versions and locations. This assumes you have a valid network connection to the internet.

Note: The NAND image is based on the emdebian project which is no longer maintained.

Debian Squeeze has been moved to archive so you will need to update /etc/apt/sources.list to contain only these two lines:

 deb http://archive.debian.org/debian squeeze main
 deb-src http://archive.debian.org/debian squeeze main
apt-get update

For example, lets say you wanted to install openjdk for Java support. You can use the apt-cache command to search the local cache of Debian's packages.

 <user>@<hostname>:~# apt-cache search openjdk                                                                                  
 icedtea-6-jre-cacao - Alternative JVM for OpenJDK, using Cacao                                                           
 icedtea6-plugin - web browser plugin based on OpenJDK and IcedTea to execute Java applets                                 
 openjdk-6-dbg - Java runtime based on OpenJDK (debugging symbols)                                                        
 openjdk-6-demo - Java runtime based on OpenJDK (demos and examples)                                                      
 openjdk-6-doc - OpenJDK Development Kit (JDK) documentation                                                              
 openjdk-6-jdk - OpenJDK Development Kit (JDK)                                                                            
 openjdk-6-jre-headless - OpenJDK Java runtime, using Hotspot Zero (headless)                                             
 openjdk-6-jre-lib - OpenJDK Java runtime (architecture independent libraries)                                            
 openjdk-6-jre-zero - Alternative JVM for OpenJDK, using Zero/Shark                                                       
 openjdk-6-jre - OpenJDK Java runtime, using Hotspot Zero                                                                 
 openjdk-6-source - OpenJDK Development Kit (JDK) source files                                                            
 openoffice.org - office productivity suite                                                                               
 freemind - Java Program for creating and viewing Mindmaps                                                                
 default-jdk-doc - Standard Java or Java compatible Development Kit (documentation)                                       
 default-jdk - Standard Java or Java compatible Development Kit                                                           
 default-jre-headless - Standard Java or Java compatible Runtime (headless)                                               
 default-jre - Standard Java or Java compatible Runtime                                                                   

In this case you will likely want openjdk-6-jre to provide a runtime environment, and possibly openjdk-6-jdk to provide a development environment. You can often find the names of packages from Debian's wiki or from just searching on google as well.

Once you have the package name you can use apt-get to install the package and any dependencies. This assumes you have a network connection to the internet.

apt-get install openjdk-6-jre
# You can also chain packages to be installed
apt-get install openjdk-6-jre nano vim mplayer

For more information on using apt-get refer to Debian's documentation here.

3 Setting up SSH

On our boards we include the Debian package for openssh-server, but we remove the automatically generated keys for security reasons. To regenerate these keys:

dpkg-reconfigure openssh-server

Make sure your board is configured properly on the network, and set a password for your remote user. SSH will not allow remote connections without a password or a shared key.

Note: Setting up a password for root is only feasible on the uSD image.
passwd root

You should now be able to connect from a remote Linux or OSX system using "ssh" or from Windows using a client such as putty.

Note: If your intended application does not have a DNS source on the target network, it can save login time to add "UseDNS no" in /etc/ssh/sshd_config.

4 Starting Automatically

From Debian the most straightforward way to add your application to startup is to create a startup script. This is an example simple startup script that will toggle the red led on during startup, and off during shutdown. In this case I'll name the file customstartup, but you can replace this with your application name as well.

Edit the file /etc/init.d/customstartup to contain this:

 #! /bin/sh
 # /etc/init.d/customstartup
 
 case "$1" in
   start)
     /sbin/ts4700ctl --redledon
     ## If you are launching a daemon or other long running processes
     ## this should be started with
     # nohup /usr/local/bin/yourdaemon &
     ;;
   stop)
     /sbin/ts4700ctl --redledoff
     ;;
   *)
     echo "Usage: customstartup start|stop" >&2
     exit 3
     ;;
 esac
 
 exit 0
Note: The $PATH variable is not set up by default in init scripts so this will either need to be done manually or the full path to your application must be included.

To make this run during startup and shutdown:

update-rc.d customstartup defaults

To manually start and stop the script:

/etc/init.d/customstartup start
/etc/init.d/customstartup stop

To make your application startup from the initrd you only need to add this from the linuxrc script. Usually the best place to add in your application is right after /mnt/root/ is mounted so the Debian libraries and applications are available.

5 Creating a Custom Startup Splash

Our splash screens are generated by writing the raw pixel format directly to the screen. For our touchscreens this is RGB565. To generate this first create a PNG of your logo. You can use ffmpeg either on the board installed from the apt repositories, or from another desktop system. When designing your splash screen keep in mind that it will compress much better in this format when there are solid colors. Our default splash has our logo in the center with a solid black background at 800x480 which is about 3kb. If the file is too large you may have to reformat the disk to expand the size of the initrd.

# Replace image.png with your filename
ffmpeg -vcodec png -i image.png -vcodec rawvideo -f rawvideo -pix_fmt rgb565 splash-800x480

gzip splash-800x480

In the initrd you will find a splash-<resolution>.gz which is loaded automatically on startup. The actual resolution of the PNG should match the size of your display as well. The resolution is varied based on which display you are using:

Baseboard Resolution
TS-TPC-8390 800x480
TS-TPC-8400 640x480
TS-TPC-8900 800x600