How to send boot files over uart

Question

I have a beaglebone black board. A host with 64 bit ubuntu14.04 I wanted to transfer uImage file over uart to beaglebone. So I stopped at u-boot and type

U-Boot# loadb
## Ready for binary (kermit) download to 0x80200000 at 115200 bps...

Now it is waiting for the file. What I have to do in order to send the uImage from pc to board.

Answer 1

After the loadb command prints "Ready for binary download", exit from the terminal(minicom, putty etc). Note down the serial device (eg: /dev/ttyUSB0). Install kermit or its variants (eg: gkermit and ckermit are available in Ubuntu).

Assuming that /dev/ttyUSB0 is your serial device, baudrate is 115200, and no flow control is used, provide the following parameters to kermit

$kermit
kermit> set port /dev/ttyUSB0
kermit> set speed 115200
kermit> set carrier-watch off
kermit> set flow-control none

Now issue the command send , to send the file over serial line:

  kermit> send filename

After the file transfer is successful, exit from kermit (use exit command), and re-open minicom. Now you can issue further commands.

NOTE : You can explicitly specify a load address to loadb. If not specified, U-boot takes load address from environment variables.

NOTE-2 : Some terminal programs have built-in facility to send files over serial line using protocols like xmodem or kermit.