Difference between revisions of "Kermit"

Revision as of 23:02, 17 February 2011

Kermit is a serial line terminal emulator that allows you to take control of your board through the RS232 line. With it you can have access to the U-Boot/Linux console of your APF without needing to connect a keyboard/screen to the board. (For more informations on remote console)

Installation

On *Ubuntu / Debian

$ sudo apt-get install ckermit

Newer linux releases support only gkermit instead of ckermit. you can use in such case: sudo apt-get install gkermit.

Alternatively you can use your system's graphical package manager.

Last point: The command 'sudo' requises from your user to be register in the groupe 'sudo' or to be in the sudoers list on your PC.

On Fedora

# rpm -q ckermit

On OpenSUSE 11.3

# sudo zypper addrepo http://download.opensuse.org/repositories/openSUSE:/11.3:/Contrib/standard/ Contrib
# zypper install ckermit

Configuration

• Edit/Create .kermrc file in your $HOME/ directory (ex: /home/james/.kermrc) and fill it with:

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 /dev/ttyS0 (first serial port). Change this to the appropriate value if necessary. For example if you use an USB <-> Serial converter then serial port would surely be named like that: /dev/ttyUSB0 or /dev/ttyACM0
• If your 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

• Check that you have read/write rights on /dev/ttyS0 (ie your serial port): your user ID (here julien) should be part of the serial port access group (here dialout):

$ ls -al /dev/ttyS0
crw-rw---- 1 root dialout 4, 64 2009-05-15 14:56 /dev/ttyS0
$ id
uid=1000(julien) gid=1000(julien) groupes=4(adm),20(dialout),...

Usage

• To launch it:

 $ kermit -c

• If you get an error message such:

  /dev/ttyS0 
  ?SET SPEED has no effect without prior SET LINE 

then recheck that you have read/write rights on the serial port (Typically on Ubuntu: you are not member of "dialout" group). On OpenSUSE 11.3 you may need to be in "dialout" and 'uucp" groups and give the rights to write in /var/lock:

sudo chmod 777 /var/lock

• To switch from terminal mode to command mode:

CTRL + \ then c

• To switch from command mode to terminal mode:

C-Kermit>c then ENTER

• To quit:

Switch in command mode
C-Kermit>q then ENTER

Usefull tips

• Download a file via serial in U-Boot :

BIOS> loadb <Ctrl-\>c
kermit> send filename

Links

• http://www.columbia.edu/kermit/ckermit.html