1. Understanding Extension INFs and Component INFs
Luke Angelini
Sr. Program Manager

2. Device Installation Basics
Devices have multiple Device IDs which describe them
Driver Packages match the Device IDs for the devices the driver can support
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000002
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000003 …
INF
Hardware IDs:
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001&REV_rr
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
Compatible IDs:
PCI\VEN_vvvv&DEV_d001
PCI\CC_cccccc

3. Device Installation Basics
Driver Packages compete to be selected, through driver selection and ranking process
INF A
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001 …
Best match!
Hardware IDs:
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001&REV_rr
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
Compatible IDs:
PCI\VEN_vvvv&DEV_d001
PCI\CC_cccccc
INF B
PCI\VEN_vvvv&DEV_d001 …
Other match
No match!
INF C
PCI\VEN_vvvv&DEV_d002 …

4. Extension INFs
With extensions, multiple INFs can be installed on a single device
INF A
Class: Extension
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001 …
Extension INF Match
Hardware IDs:
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001&REV_rr
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
Compatible IDs:
PCI\VEN_vvvv&DEV_d001
PCI\CC_cccccc
INF B
Class: Media
PCI\VEN_vvvv&DEV_d001 …
Base INF Match

5. Extension INFs
Can be provided by a different company and updated independently from the base INF.
Looks the same as a base INF, but extends the base INF for customization or specialization.
Enhances the value of the device, but is not necessary for the base driver to work.
Must be a universal INF file.
A device can optionally have one or more extension INFs associated with it
Typical scenarios where you might use an extension INF include:
Modifying settings provided in a base INF, such as customizing the device friendly name or modifying a hardware configuration setting.
Creating one or more software components by specifying the INF AddComponent directive and providing a component INF file.

6. Component INFs
With components, additional device nodes are created. Fundamentally, the component INF is just another base INF.
INF A
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
AddComponent SWC\VEN_vvvv&DEV_d002 …
Hardware IDs:
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001&REV_rr
PCI\VEN_vvvv&DEV_d001&SUBSYS_s000001
Compatible IDs:
PCI\VEN_vvvv&DEV_d001
PCI\CC_cccccc
INF Match
AddComponent Creates
INF B
SWC\VEN_vvvv&DEV_d002 …
Component INF Match
Child Device
Hardware IDs:
PCI\VEN_vvvv&DEV_d002

7. Component INFs
To create component child devices, a parent extension INF specifies the AddComponent directive
Components can be updated independently just like any other device
Use as many different components as makes sense from a servicing perspective
AddSoftware directive can only be called from a component INF.
If your component INF specifies the AddSoftware directive, the component INF:
Must be a universal INF file.
Must specify the SoftwareComponent setup class.
You can specify the AddSoftware directive one or more times.
Does not require a function driver service.

8. 11/16/ :06 AM
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