DrvQueryDeviceIdParameter

LONG
    DrvQueryDeviceIdParameter(
        PREG_ACCESS RegAccess,
        UINT DeviceNumber,
        PTCHAR ValueName,
        PDWORD pValue);

The DrvQueryDeviceIdParameter function reads the value associated with the specified value name, under the specified driver’s \Parameters registry key.

Parameters

RegAccess

Pointer to a globally-defined structure of type REG_ACCESS.

DeviceNumber

Device number. Used as an index to the device subkeys under the \Parameters key. See the Comments section below.

ValueName

Pointer to a string representing the value name.

pValue

Pointer to a DWORD to receive the requested value.

Return Value

Returns ERROR_SUCCESS if the operation succeeds. Otherwise returns one of the error codes defined in winerror.h. See the Comments section below.

Comments

The structure pointed to by RegAccess must be a single, globally-defined REG_ACCESS structure that the driver uses with all calls to drvlib.lib functions requiring a RegAccess parameter.

The value name and value are read from the registry path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DriverName\Parameters\DeviceNumber, where Number represents the number supplied by the DeviceNumber parameter.

The function can only return a value that is stored as a REG_DWORD type.

The function calls RegQueryValueEx and returns its return value. (See the Win32 SDK.)

To store values under a driver’s \Parameters registry key, call DrvSetDeviceIdParameter.

Drivers must call DrvCreateServicesNode before calling DrvQueryDeviceIdParameter.

For additional information, see Installing and Configuring your Driver, Using drvlib.lib.