| 3/8*$1'3/$<'(9,&( |
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75(( | The Plug and Play Manager maintains a device tree, viewable through Device | |
Manager, which keeps track of the active devices in the system and information | ||
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| about those devices. The Plug and Play Manager updates the device tree as |
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| devices are added and removed or as resources are reallocated. The device tree is |
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| hierarchical, with devices on a bus represented as children of the bus adapter or |
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| controller. The registry is the central repository for static hardware information. Plug |
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| and Play system components and drivers build, maintain, and access new and |
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| existing subtrees in the registry . |
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| During enumeration, data for each device is stored under a new |
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| HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum key in the registry |
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| (this is the enum tree). Plug and Play makes decisions about which device drivers |
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| are loaded based on the results of enumeration. Thus, there is an important |
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| connection between the enum tree and the services list in |
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| HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services. |
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| Figure 2 shows a Plug and Play device tree for a hypothetical ACPI system |
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| configuration. In practice, a device tree would consist of many additional devices, |
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| but Figure 2 shows only the devices needed in this discussion. |
Windows 2000 White Paper | 10 |