Communicate with your board from a Linux Host (Basics)

RS232 configuration

We suggest you to use Kermit as Terminal emulator for RS232 connection. Minicom was sadly reported to have problems when communicating with U-Boot (ZModem data transfer). If you just need a simple serial console and not to transfer data then GTKTerm is the perfect choice ! (package gtkterm in Ubuntu)

Kermit installation

• On *Ubuntu / Debian:

# apt-get install ckermit

or use Synaptic graphical package manager.

• On Fedora:

# rpm -q ckermit

Kermit configuration

• Edit/Create .kermrc file in your $HOME directory and put in it:

set line /dev/ttyS0
set speed 115200
set carrier-watch off
set handshake none
set flow-control none
robust
set file type bin
set file name lit
set rec pack 1000
set send pack 1000
set window 5
set transmit linefeed on

• In this example, we assume that your serial port is ttyS0 (first serial port). Change this to correct value if necessary.
• If you use an USB <-> Serial converter then serial port would surely be named like that: ttyUSB0
  • If USB <-> Serial converter doesn't seem to work, run the dmesg command. You should read this thread if you see some disconnection data like this :

[ 2445.568000] usb 1-1.4: new full speed USB device using uhci_hcd and address 22
...
[ 2446.964000] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[ 2446.964000] ftdi_sio 1-1.4:1.0: device disconnected

• If you get an error message such:

$ kermit -c
 /dev/ttyS0 
 ?SET SPEED has no effect without prior SET LINE 

check that you have read/write rights on /dev/ttyS0 (ie your serial port)

Kermit usage

• To launch it:

$ kermit -c

• To switch from terminal mode to command mode:

CTRL + \ then c

• To switch from command mode to terminal mode:

C-Kermit>c then ENTER

TFTP server

In order to send your image files (U-Boot, Linux, RootFS or Firmware) with higher speed to your Armadeus board, you can use the Ethernet link and a TFTP server. Once the server started, the files located in the server shared directory (/tftpboot by default) will be accessible from the U-Boot TFTP client.

TFTP server installation

• On *Ubuntu / Debian:

# sudo apt-get install tftpd xinetd

or use Synaptic

• On Fedora:

# rpm -q tftpd xinetd

• Then create the directory that will contain all the files that the server will export (you have to be root to do that):

# mkdir /tftpboot
# chmod 777 /tftpboot

Server configuration

• Edit or create the configuration file /etc/xinetd.d/tftp and modify/add it the following lines:

# default: off
# description: The tftp server serves files using the trivial file transfer
#       protocol.  The tftp protocol is often used to boot diskless
#       workstations, download configuration files to network-aware printers,
#       and to start the installation process for some operating systems.
service tftp
{
       socket_type             = dgram
       protocol                = udp
       wait                    = yes
       user                    = root
       server                  = /usr/sbin/in.tftpd
       server_args             = -s /tftpboot
#       disable                 = yes
}

• Restart xinetd service:

# killall -HUP xinetd

• Put some files in /tftpboot

Links

• Kermit Homepage
• GTKTerm Homepage