Driver/Kernel Interface (DKI)

The DKI interface defines all services provided by the microkernel to driver components. Following the layered interface model, all services implemented by the DKI are called by the drivers, and take place in the microkernel.

Common DKI services are services common to all platforms and processors, usable by all drivers, no matter what layer in the hierarchical model they inhabit. These services are globally designed by the DKI class name.

Common DKI services cover:

• Synchronization through the DKI thread

• Device tree

• Driver registry

• Device registry

• General purpose memory allocation

• Timeout

• Precise busy wait

• Special-purpose physical memory allocation

• System event management

• Global interrupts masking

• Specific I/O services

Processor family specific DKI services are defined and available only for a given processor family and should be used only by the lowest-level drivers. Lowest-level drivers are those for buses and devices which are directly connected to the processor local bus. Note that these drivers typically use only the DKI services (no available layer of DDI). These services are globally designed by the FDKI class name (for Family DKI).

Processor family specific DKI (FDKI) services cover:

• Processor interrupts management

• Processor caches management

• Processor specific I/O services

• Physical to virtual memory mapping

All DKI services are implemented as part of the embedded system library (libebd.s.a). Most of them are implemented as microkernel system calls. Note that the dki(9) man page gives an entry point to a detailed description of all DKI APIs.