I have tried to stop at U-Boot to change the environment variables for the 7" resistive touch display.
This did not go as planned:
- I connected a USB RS232ttl3V3 cable
to the pins 28,27,21 on the Iris
board. - I can see the U-Boot output in Putty
and other serial terminal programs
but I can not stop U-Boot. - I am also not able to login after
boot, as mentioned in other
questions. - I have tried to disable flow control
in putty, but this did not help. - I can send characters if I short TX
and RX of the serial cable.
My workaround:
- May temporary solution was to install
EmbeddedLinux via the
Toradex-Easy-Installer, started via
the recovery mode. This process with
shorting the recovery pins on the
colibri board is very tedious and
requires a micro USB cable from the
Iris board to a PC with the recovery
tool. - However, after installing
EmbeddedLinux, I used a keyboard
connected to the USB of the Iris
board to change the environment
variables via the fw_setenv command
in Linux. This fixed the issue with
the incorrect screen resolution and
touch not working. - After that I installed the Boot2Qt
image again. The u-boot environment
variables were not deleted and the
resistive touch screen worked fine in
the Qt Demo image.
However, The Toradex-Easy-Installer only has the Boot2Qt 5.15.0 image and not the 5.15.1 image that I would like to use.
In order for me to install the newer boot2qt image, I want to follow the described steps: https://doc.qt.io/QtForDeviceCreation/qtee-preparing-hardware-colibri-imx6.html
These steps describe to stop in U-Boot, which I can not.
Also, it might be useful to stop in U-Boot in the future, which I can not do at the moment.
Also it is a very tedious process to go into recovery mode two times and to install two images, just to change an environment variable in U-Boot.
Please help. How can I stop in U-Boot?