add message to set block size of controller

Link: https://github.com/GeneAssembly/biosal/issues/216
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
add kernel director

Link: https://github.com/GeneAssembly/biosal/issues/217
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>