CMX255 Module Setup

Contents

• Configuring serial communications
• Installing the operating system
• Configuring the system
  • Setting the root password
  • Network configuration
  • Setting the hostname

Configuring serial communications

Connect the CMX255 module over serial port to a host computer and use a terminal emulation (e.g. minicom) to access it's ARMmon bootloader. Use the following configuration for your terminal emulation:

38400 Baud 
8 data bits, 1 stop bit, no parity (8N1)
no hardware flow control
no software flow control

Hit CTRL-C on start-up to access the bootloader if the cmx255 module is set to boot straight into an installed OS.

To have the module always stop at the ARMmon bootloader after startup, use this command

ARMmon > setboot setup

This bootloader command configures the module to boot straight into the installed operating system

ARMmon > setboot os

Installing the operating system

In order to use ethernet to install an operating system and kernel on the module, prepare it with the following commands. You will need a tftp server with the files available. The modules ip address ($IP_CMX) will need to on the same network:

ARMmon > setip eth1
ARMmon > setip ip $IP_CMX
ARMmon > setip mask 255.255.255.0
ARMmon > dhcp off
ARMmon > save

reboot in order for changes to become effective

In order to upload a kernel image over ethernet, place the image file (e.g. zimage-arm) in the public directory of the tftp server (e.g. /tftpboot) and type the following command into the bootloader:

ARMmon > download kernel tftp $FILENAME $IP_SERVER
ARMmon > flash kernel

Uploading a new operating system (file image) over ethernet works similar to the kernel image upload. Place the image (e.g. cmx255-ext3) in the public directory of the tftp server (e.g. /tftpboot) and type the following command into the bootloader:

ARMmon > nand write $FILENAME $IP_SERVER

Configuring the system

If the installation was successful you can now boot the system with

ARMmon > bootos

This will boot the module into the Edinburgh Robotics Linux distribution. From here you can log into the system as the "root" user. By default the root user has no password i.e. just hit return at the password prompt. The process of logging in should look something like this:

devbot login: root
Password:


BusyBox v1.1.1 (2006.12.10-17:51+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

[root@devbot /root]#

Once you're logged in, you are free to modify system settings as usual. Before distribution to students we recommend that you:

1. Set a unique root password (see Setting the root password)
2. Update the network configuration (see Network configuration)
3. Set a unique hostname (see Setting the hostname)

Setting the root password

Use the "passwd" program to update the root password. The program is easy to use, but for reference here is a sample interaction with it:

[root@devbot /root]# passwd root
Changing password for root
Enter the new password (minimum of 5, maximum of 8 characters)
Please use a combination of upper and lower case letters and numbers.
Enter new password:
Bad password: too short.

Warning: weak password (continuing).
Re-enter new password:
Password changed.
[root@devbot /root]#

Network configuration

Network configuration is stored in /etc/network/interfaces. Use the following command to invoke the text editor vi to review and update these settings:

[root@devbot /root]# vi /etc/network/interfaces

By default the file will look something like this:

# static setup
iface eth0 inet static
    address 192.168.0.1
    netmask 255.255.255.0
    broadcast 192.168.0.255
    gateway 192.168.0.254

You should adapt these settings to suit your network e.g.

# My place of work
iface eth0 inet static
    address 129.215.54.23
    netmask 255.255.255.0
    broadcast 129.215.54.255
    gateway 129.215.54.254

If you are uncertain what settings to use, consult your local network administrator. Note that you will have to reboot the module for these changes to take effect.

Alternatively, you may wish to use DHCP to configure your network settings. In this case edit the interfaces file to read instead

iface eth0 inet dhcp

If you require domain name resolution then create a file called /etc/resolv.conf and edit it to specify your DNS servers e.g.

nameserver 129.215.128.1
nameserver 129.215.168.33

Setting the hostname

The default hostname is devbot. This is configured in /etc/hostname. To change the hostname e.g. to "kendall" use the following command:

[root@devbot /root]# echo kendall > /etc/hostname

Again, the module must be rebooted for this change to take effect.

---