We’ve integrated Mender 3.5 on our Raspberry Pi 4 Yocto project.
We would like to make changes to u-boot’s configuration. Specifically, we want to disable certain input sources/devices such as serial/uart0, keyboard, etc.
I’m aware boot.scr and uEnv.txt are typically involved, but after adding mender and u-boot to a RPi4 Yocto build, what is the preferred method of doing this?
Hi @dpv,
I don’t think you can sufficiently affect u-boot to ignore the serial port and keyboard by boot scripts - effectively you need to do proper hardening. The first thing to look at would be the u-boot configuration, if I remember correctly it has a straightforward way to limit the serial terminal to a magic string/key for dropping into it. If you completely want to disable it, source code modifications might be required.
Greets,
Josef