The variable PWBDrvPowerCaps contains the device power capabilities of the driver in a POWER_CAPABILITIES structure.ĭX_MASK(D0) | DX_MASK(D2) | DX_MASK(D3) | DX_MASK(D4),įor information on the meaning of each parameter please refer MSDN. *pdwBytesTransferred = sizeof(PWBDrvPowerCaps)
Memcpy(pOutBuf, &PWBDrvPowerCaps, sizeof(PWBDrvPowerCaps)) This IOCTL should return the device capabilities.
If the call returns false, the driver wont be registered otherwise it will be. When power manager receives a request to register a device driver under a particular device class, it first passes IOCTL_POWER_CAPABILITIES to the driver. ** - This IOCTL is mandatory for the entire thing to work The driver needs to implement the following IOCTLs for interacting with power manager: Note : We should atleast implement IOCTL_POWER_CAPABILITIES in a driver to make it power managed The details I will explain in the next section. Now power manager will start issuing the IOCTLs to the driver and query the capabilities of the driver. When device manager loads the driver, it will associate the device to the class. "IClass"="" we are making it as generic device over here I will make this power button driver as a generic device Associating a device to a power manager class is really easy, just by adding a registry entry to the device driver entry, as follows. Each class is identified by a certain GUID(defined in pm.h). In addition to handheld computers and cable TV boxes, Windows CE is also offered as the operating system for the Auto PC, Microsoft's concept of controlling applications (such as selecting radio channels) while driving, using interactive speech technology.Now as the documentation for power manager, each power managed device needs to be classified under a certain category i.e Generic power-manageable devices, Power-manageable block devices and Power-manageable NDIS miniports. Microsoft argues that Windows desktop system users will find that products with Windows CE provide a familiar user interface. Microsoft emphasizes that the system was "built from scratch" while taking advantage of Windows architectural concepts and interfaces. Like the full-scale Windows systems, Windows CE is a 32-bit multitasking, multithreading operating system. It competes with EPOC and also with similar operating systems from 3Com (for its PalmPilot) and other companies. Although Microsoft does not explain the "CE," it is reported to have originally stood for "Consumer Electronics." Windows CE is used in several brands of handheld computers and as part of cable TV set-top boxes built for TCI. Windows CE is based on the Microsoft Windows operating system but is designed for including or embedding in mobile and other space-constrained devices.
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