tools for:
* bus manager:
  - make sure SPLIT_TIMEOUT registers are consistent
  - initialize BUS_TIME
  - set PRIORITY_BUDGET
    (higher priority for SBP-x devices, or configurable?)
  - optimize gap counts by PHY pinging
    (also take over table-based optimization from the kernel)
  - disable cycle master when not needed
  - IEEE1212-2001 7.5.4.2 with a cute penguin