gen_kobject_list.py: device driver support

Device drivers need to be treated like other kernel objects, with
thread-level permissions and validation of struct device pointers passed
in from userspace when making API calls.

However it's not sufficient to identify an object as a driver, we need
to know what subsystem it belongs to (if any) so that userspace cannot,
for example, make Ethernet driver API calls using a UART driver object.

Upon encountering a variable representing a device struct, we look at
the value of its driver_api member. If that corresponds to an instance
of a driver API struct belonging to a known subsystem, the proper
K_OBJ_DRIVER_* enumeration type will be associated with this device in
the generated gperf table.

If there is no API struct or it doesn't correspond to a known subsystem,
the device is omitted from the table; it's presumably used internally
by the kernel or is a singleton with specific APIs for it that do not
take a struct device parameter.

The list of kobjects and subsystems in the script is simplified since
the enumeration type name is strongly derived from the name of the data
structure.

A device object is marked as initialized after its init function has
been run at boot.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
4 files changed