Organization (trees)

All files related to driver components are organized in 4 file trees:

• The 'dki' tree, populated by the ChorusOS operating system delivery and exporting the DKI set of APIs (header files onl).

• The 'ddi' tree, populated by the ChorusOS operating system delivery and exporting the DDI set of APIs (header files only).

• The 'drv' tree, populated by generic driver components and exporting the device-specific properties header files. Generic driver components are drivers which do not use the family specific DKI APIs, and therefore are portable across all families and platforms (header and 'c' files).

• The 'drv_f' tree, populated by processor family specific driver components and exporting device specific properties header files. Processor family-specific driver components are drivers which use one family specific DKI API, and therefore can run only on this processor family (header and 'c' files).

Note that both drv and drv_f trees are mainly populated by third party driver writers (although ChorusOS system deliveries contain drivers for the reference platform's devices).

The main functional components of the 'dki' tree are:

• <dki/dki.h> which defines the Common DKI API

• <dki/f_dki.h> which defines the processor family-specific DKI API

All other file trees are organized following the bus/device class provided APIs. In other words, there is a directory per class of bus and device, which contains the header file defining the API provided by this device class.

For drv and drv_f, in each bus/device class directory there is one directory per bus/device hardware controller for which a driver component is written.

Listed below are some path examples (header file paths are relative to the ChorusOS operating system delivery root directory):

    include/chorus/ddi/bus/bus.h              -> DDI's Common bus class API
    include/chorus/ddi/pci/pci.h               -> DDI's PCI bus class API
    include/chorus/ddi/uart/uart.h            -> DDI's UART device class API

    drv_f/src/pci/raven/ravenProp.h           -> family specific driver component
    drv_f/src/pci/raven/raven.h                      for the Motorola RAVEN PCI host
    drv_f/src/pci/raven/raven.c                       bridge
    drv_f/src/pci/raven/Imakefile

    drv/src/uart/ns16550/ns16550Prop.h    -> Generic driver component for
    drv/src/uart/ns16550/ns16550.h                NS16x50 compatible UART devices.
    drv/src/uart/ns16550/ns16550.c
    drv/src/uart/ns16550/Imakefile