Setup TFTP Server for U-Boot

Our approach to setup a TFTP server is quite similar to other guides that you can find via Google.
Here we provide some instructions for reference:

Setup TFTP

Install TFTP packages:

$ sudo apt-get install openbsd-inetd tftpd tftp

Configuration

To enable the TFTP server, edit the file /etc/inetd.conf as the root user, and locate the line that looks like the following:

#tftp   dgram   udp     wait    root    /usr/sbin/tcpd  /usr/sbin/in.tftpd

Uncomment this line, and add the option and value -s /srv/tftp to the end of this line:

tftp   dgram   udp   wait   root   /usr/sbin/tcpd  /usr/sbin/in.tftpd -s /srv/tftp

Create and modify permissions on the TFTP root directory:

$ sudo mkdir /srv/tftp
$ sudo chown -R $(whoami) /srv/tftp

Restart the TFTP Service:

$ sudo /etc/init.d/xinetd restart

Setup For Target Device

To setup TFTP on your target device, you will need to:

  • Connect a LAN cable to your target device, and make sure your device is on same local network with your Host PC.
  • Connect a “Serial-To-USB Module” between the target device and Host PC and ensure you have done the correct setup.
  • Power-on your target device, and ensure the device has a Bootloader installed in it.

Stop U-Boot autoboot by hitting Enter or Space key at the moment you power on your target device:

U-Boot 2015.01-g1e20d03-dirty (Jan 01 2017 - 14:40:23)

DRAM: 2 GiB
Relocation Offset is: 76ed0000

...

[CANVAS]addr=0x3d800000 width=3840, height=2160
Hit Enter or space or Ctrl+C key to stop autoboot -- : 0
kvim#

Setup the ip address of the target client and TFTP host server:

kvim# setenv ipaddr 192.168.1.100
kvim# setenv serverip 192.168.1.168

Save the settings:

kvim# saveenv
Saving Environment to aml-storage...
mmc env offset: 0x7400000
Writing to MMC(1)... done
kvim#

Running saveenv will save the env values to the env partition on the eMMC. You can run defenv to restore the env to the default values.

Test Your TFTP Server

Make sure you have copied the testing file to the TFTF root path:

$ ls /srv/tftp/u-boot.bin
/srv/tftp/u-boot.bin
$

Load a file into the 0x1080000 address:

kvim# tftp 1080000 u-boot.bin
Speed: 100, full duplex
Using dwmac.c9410000 device
TFTP from server 192.168.1.168; our IP address is 192.168.1.100
Filename 'u-boot.bin'.
Load address: 0x1080000
Loading: #################################################################
#################################################################
###############################################
2.5 MiB/s
done
Bytes transferred = 901120 (dc000 hex)
kvim#

If everything goes well, the terminal print-out will look similar to what is shown above.

Troubleshooting

  • You might need to check the connection of your LAN cable if the terminal print-out looks like:

    kvim# tftp 1080000 u-boot.bin
    dwmac.c9410000 Waiting for PHY auto negotiation to complete......... TIMEOUT !
    dwmac.c9410000: No link.
    kvim#
  • You could have entered an incorrect server IP address if the print-out looks like:

    kvim#tftp 1080000 u-boot.bin
    Speed: 100, full duplex
    Using dwmac.c9410000 device
    TFTP from server 192.168.1.68; our IP address is 192.168.1.100
    Filename 'u-boot.bin'.
    Load address: 0x1080000
    Loading: T T T T T T T T T T
    Retry count exceeded; starting again
    Speed: 100, full duplex

In this instance, I had setup the server IP address to an incorrect one 192.168.1.68, it should be 192.168.1.168 instead.

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