NdisReadConfiguration

This function returns the value of a named entry of the specified type from the registry, as long as it has the handle to an open registry key.

At a Glance

Header file:	Ndis.h
Windows CE versions:	2.0 and later

Syntax

VOID NdisReadConfiguration( OUT PNDIS_STATUS Status,
OUT PNDIS_CONFIGURATION_PARAMETER *ParameterValue,
IN NDIS_HANDLE ConfigurationHandle, IN PNDIS_STRING Keyword,
IN NDIS_PARAMETER_TYPE ParameterType );

Parameters

Status

Pointer to a caller-supplied variable in which this function returns the status of the call as one of the following:

NDIS_STATUS_SUCCESS: The buffer specified at ParameterValue contains the returned configuration information.
NDIS_STATUS_RESOURCES: NDIS could not allocate resources, usually enough memory, to return the requested information.
NDIS_STATUS_FAILURE: The requested information could not be found under the opened registry key designated by the ConfigurationHandle.

ParameterValue

Pointer to a caller-supplied variable in which a successful call to this function returns a pointer to an NDIS_CONFIGURATION_PARAMETER structure.

ConfigurationHandle

Handle returned by NdisOpenConfiguration to an NIC driver’s XXX\DriverName\Parameters registry key or by NdisOpenProtocolConfiguration to a protocol’s XXX\NICDriverInstance\Parameters\ProtocolName key in the protocol section of the registry.

Keyword

Pointer to a caller-supplied counted string, in the system-default character set, specifying the name of the entry under the open registry key for which to return the value.

This parameter can also point to one of the following predefined global keywords for all NDIS drivers:

Environment
ProcessorType

ParameterType

Specifies the type of the value entry as one of the following:

NdisParameterInteger: Specifies an integer in decimal notation.
NdisParameterHexInteger: Specifies an integer in hexadecimal notation.
NdisParameterString: Specifies a string of type NDIS_STRING.
NdisParameterMultiString: Specifies a multistring parameter of the Windows NT-defined REG_MULTI_SZ type.

Remarks

Every NDIS driver can set up configuration information in the registry for itself under the driver’s Parameters key, using an installation script. For example, a protocol driver might store its own name as an entry with a preformatted string value that can be passed in calls to the NdisRegisterProtocol function.

Each NIC driver also has associated value entries under the driver’s Parameters registry key. The value entries for any particular NIC driver can be device-dependent in nature. For example, an Ethernet NIC driver might have keywords such as InterruptNumber, SharedMemoryAddress, and MulticastListSize. The value associated with such an NDIS keyword can be either an integer ( ULONG-type ) or a string ( NDIS_STRING-type ). For example, the set of possible values for the InterruptNumber entry mentioned might be NdisParameterInteger values 2, 3, 4, or 5, or the equivalents in hexadecimal as NdisParameterHexInteger values.

This function buffers and copies the caller-supplied string at Keyword and releases the storage it allocates for this copy before it returns control to the caller. The memory it allocates for the NDIS_CONFIGURATION_PARAMETER structure is freed when the driver releases the ConfigurationHandle with the NdisCloseConfiguration function. The caller of this function is responsible for releasing the buffered string at Keyword.

A driver that calls this function runs at IRQL PASSIVE_LEVEL.