Retrieve file over serial without kermit and lrzsz

Question

I have an embedded Linux on a custom board and I would like to send and receive file over its serial port.

The only way to communicate with this device is over serial and the device offers a console on this serial port.

This board doesn't have kermit neither busybox rx nor lrzsz.

- Sending file to remote

I was able to send file to the board following this thread.

Host side                              Remote side

cat file | base64 > file_b64
                                       cat > file_b64
minicom's ctrlA-S => send 'file_b64'
                                       cat file_b64 | base64 --decode > file

- Getting file from remote

Now I would like to retrieve a file from remote system.

Minicom has a tool for receiving files but as I only have the serial port's console using minicom to issue commands on remote side, I can't find how to do it.

I have tried using kermit on host side but it seems that I also needs to have kermit on the remote side.

---

EDIT:

I have also tried to reverse the sending method but with no success as i receive nothing from serial port on host side.

Host side                              Remote side

                                       cat file | base64 > file_b64
                                       (sleep 10; cat file_b64 > /dev/ttyS0) &
                                       minicom's ctrlA-X => exit minicom
cat /dev/ttyUSB0 > file_b64

Can't use minicom's receive tool cause it only support xmodem, ymodem, zmodem and kermit tranfers and not ascii.

---

Is there a way to retrieve files from remote without having to type commands into its console?

Solution 1

Finally found out that I was issuing the wrong command on receiver's side.

Receive command shall be : cat < /dev/ttyUSB0 > file_b64

Summary

To receive from remote :

          Host side                |             Remote side
                                   |
                                   |    #Encode to base64
                                   |    cat file | base64 > file_b64
                                   |
                                   |    #Send after timeout
                                   |    (sleep 10; cat file_b64 > /dev/ttyS0) &
                                   |
       #############################################################
       ### Exit minicom but keep configuration (ctrlA-Z, then Q) ###
       #############################################################
                                   |
#Receive file                      |
cat < /dev/ttyUSB0 > file_b64      |
                                   |
#Decode file                       |
cat file_b64 | base64 -di > file   |

Solution 2

Summarizing above posts i found something like this:

Sending.

Start receiving on target:

cat | base64 -d > filetotarget.bin

Exit minicom with Ctrl-A + Q and then run on host machine:

cat filetotarget.bin | base64 > /dev/ttyUSB0

Return to minicom and press Ctrl-D to finish receive process.

Receiving.

Start delayed send on target:

sleep 10 ; cat filefromtarget.bin | base64

Exit minicom with Ctrl-A + Q. Then start receiving on host:

cat < /dev/ttyUSB0 | base64 -di > filefromtarget.bin

Comments

[Ipor Sircer]

Why don't you use the slip module to build a tcp/ip connection? tldp.org/LDP/nag2/x-087-2-slip.operation.html

[Arkaik]

Didn't know this module, however slattach is not available on remote side