add timer 'driver' and partially implemented file-backed block device
add SMP dependency
hardcode hz to 100
 remove unused variable
add back in starting init to init_main
 need ukern version for privileged operations
add apic_ops for nexus add s/f user functions to compat from glue (glue is for no-ops)
link in mountroot (for init) and pci (for later passthrough support)