Problem while flashing the image 2.5 Beta 3 in colibri t20

I am trying to flash the image 2.5 Beta 3 in colibri t20 board as given in http://developer.toradex.com/knowledge-base/flashing-linux-on-tegra-modules#Colibri_T20. I went up to the step “Download U-Boot directly into RAM using the -d aka debug parameter of the update.sh script” using below command

$ sudo ./update.sh -d -r 256 -v V1_2

After that step , i saw a screen displaying like this
alt text

then i have to “run setupdate” but for that where do i type that command?
Because my keyboard connected to colibri board is not working, since it is in recovery mode.
Also i could not able to type that command via minicom as i connected a null modem serial cable in X13 of iris board.

FYI: I am using colibri t20 board of 256MB ram , v 1.2

You’ll need to use the serial console to enter the update commands. As you’ve noticed, a keyboard connected to the board will not work in the U-boot bootloader. If you fail to see anything on the serial console, ensure that you have the serial port wired correctly as indicated by the serial header pinout in the Iris carrier board datasheet. Also check that minicom is configured for 8n1 @ 115200 baud.

It appears that you may also need to rewrite the config block. You can do so using the U-boot command cfgblock create which is described in the “Flashing from Scratch” section.

I am using a similar set up as mentioned in http://developer.toradex.com/knowledge-base/iris-carrier-board-peripherals#RS232_port_on_X13 for serial communication. I connected that null modem cable to my laptop via a serial to USB converter. Also minicom is configured for 8n1 @ 115200 baud.

When i type the command in minicom, i see garbage values are displaying in the screen of colibri t20 board like below. Some times i see these kind of garbage values even when i not opened my USB port via minicom i.e when i just connected USB cable to my laptop

146-img-20160318-132023.jpg

Should i use any level converter in between?
Should i try with different baud rate?

What exact carrier board are we talking about? Most of our carrier boards feature built-in level shifters and/or even USB-to-serial chips. Only for Viola one would have to use separate level shifters or a 3.3 volt capable USB-to-serial adapter.

@marcel: I am using Iris v 1.1 carrier board

Problem solved by using a straight cable instead of null modem cable. Thanks all.