Kernel Ring Hardware System User
Cosmos.Kernel Cosmos.Hardware Cosmos.Sys  
Cosmos.Kernel.Plugs   Cosmos.Filesystem  

For more info see http://www.gocosmos.org/Milestones/Future/Rings.aspx

Comos.Kernel.Debug - This needs to be called from user code and system, but is in Kernel. Make it a special ring?