On Thu, Jun 24, 2021 at 8:03 PM Hugo V.C. <[email protected]> wrote: > > 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?
Have you changed the implementation of poke_write? By the end of the tutorial there isn't a write error in the example shell output. I think if the kernel module returns a different length result than what was requested the shell interprets this as a write error. If you return the correct length that was requested then there would be no error. (This is a guess though) Kent. > Cheers, > _______________________________________________ > Devel mailing list -- [email protected] > To unsubscribe send an email to [email protected] _______________________________________________ Devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
