Adaptation Quick Start

Adaptation +environment

The functionality of a particular hardware +technology is enabled when an interface to the standard for that technology +is defined.

The hardware is enabled when the following exist:

LDD – Logical +Device Driver
PDD – Physical +Device Driver

Kernel +extensions

Kernel extensions provide additional functionality +in the kernel and run with the same access rights and permissions +as the rest of the kernel.

Adaptation device drivers (LDD/PDD) +require low-level access to the device and implementing them as a +kernel extension gives them this access.

LDD

Each LDD has the following features:

the LDD is a +packaged DLL
provides user +side functionality
loaded into +the kernel
calls a function +that opens a DLogicalChannel
opens an RBusLogicalChannel
allows user +code to communicate with the hardware and send commands to control +the hardware
defines an abstract +class that must be implemented in the PDD

Mandatory – there must be one LDD for each hardware component.

PDD

PDDs have the following features:

the PDD is a +packaged DLL
provides access +to hardware
loaded into +the kernel
calls a function +that opens a physical channel
receives control +commands and other communications through its interface with the LDD
may be an extension +to an existing device driver

Mandatory – there must be one PDD for each hardware platform +for each hardware component.

Using +Kernel extensions

A Kernel Extension is additional functionality +that runs as part of the kernel.

For example, access to the +SD Card is provided through a kernel extension.

Adaptation ready architecture

Adaptation ready architecture +means the following have been created:

The LDD
The abstract +class that must be implemented in the PDD
The interface +to the user code
Any optional +kernel extension DLLs
Optional reference +implementation PDD

Adaptation options

There are broadly two types of hardware adaptation:

New hardware
Updated hardware

New hardware

The entire adaptation architecture, +as described above, must be defined. This includes:

Defining an +abstract class that the PDD creators are required to implement, creating +an LDD and so on.
The architecture +enables the new hardware.
The architecture +allows hardware manufacturers to create their own implementation (PDD).

New hardware adaptation will be supported with a reference +implementation, which will go a long way towards guiding the device +developer’s efforts.

Updated hardware

Updated +hardware which provides new or modified functionality requires a new +PDD to be created to either extend the functionality of the existing +PDD or to replace the existing PDD.

In most cases the new +functionality of the hardware will be enabled by extending the architecture +with a new extension PDD or be writing a new PDD that incorporates +all the existing and new functionality.

There are situations +where the entire adaptation architecture needs to be extended or redesigned, +such as when a hardware component is extended in a way that was not +expected. The Bluetooth baseband radio being extended to provide Bluetooth, +802.11, and FM radio from the same hardware component, for example, +will require a redesign of the adaptation architecture so the LDD +knows about 802.11 and FM as well as Bluetooth. Such a redesign should +ensure older Bluetooth PDDs will still work while extending the possible +PDDs that will work with the LDD to include Bluetooth, 802.11, FM +radio, and a combination of the above.

Where +to go next

Adaptation is described in more detail in these +documents:

What is +Adaptation?
What is +a Platform Service?
Adaptation +Process Guide