Hi, just a simple question: why this tutorial: https://docs.sel4.systems/Tutorials/camkes-vm-linux.html shows this output: Welcome to Buildroot buildroot login: root Password: # grep poke /proc/devices # figure out the major number of our driver 244 poke # mknod /dev/poke c 244 0 # create the special file # echo > /dev/poke # write to the file [ 57.389643] hi -sh: write error: Bad address # the shell complains, but our module is being invoked! I'm not getting the shell complain error, just this: # grep poke /proc/devices 247 poke # mknod /dev/poke c 247 0 # echo > /dev/poke [ 138.946905] TOC TOC NEO... # FYI: my kernel is a custom compiled one but same version as the pre-compiled you provide: # uname -a Linux buildroot 4.9.189 #4 SMP Thu Jun 24 00:16:49 CEST 2021 aarch64 GNU/Linux Any hint? Cheers,