XXX_Init

This function is called by the Device Manager to initialize a device.

Syntax

DWORD XXX_Init( DWORD dwContext );

Parameters

dwContext

Specifies a pointer to a string containing the registry path to the active key for the stream interface driver.

Return Values

Returns a handle to the device context created. This handle is passed to the XXX_Open, XXX_PowerDown, XXX_PowerUp, and XXX_Deinit functions.

Remarks

The Device Manager calls this function as a result of a call to the RegisterDevice function. When the user starts using a device, such as when a PC Card is inserted, the Device Manager calls this function to initialize the device. This function is not called by applications.

The Device Manager specifies a pointer to a string containing the registry path to the active key of the specific PC Card device in the dwContext parameter. Usually, the string contains the registry path to a numbered subkey of the HKEY_LOCAL_MACHINE\Drivers\Active key. Your initialization function uses this information to access data stored in the registry.

This function might perform the following tasks:

• Initialize the installed device to a default state.
• Allocate resources used globally by the device driver.
• Register a status callback function with Card Services. When the status of the device changes, the operating system calls this status callback function. For example, the status of a PC Card changes when you insert it or remove it.
• Map system memory and I/O space to a PC Card device’s memory and I/O space.
• Request notification on specific callback events.
• For an interrupt-driven device, register an interrupt callback function. When the device generates an interrupt, the operating system calls this interrupt callback function.

After this function returns, the Device Manager checks the registry for a key named Ioctl for the driver, and if such a key is present the Device Manager calls XXX_IOControl, passing the value specified by Ioctl as the dwCode parameter. Your driver can use this function to finish initializing itself after it has been installed. For example, a driver might load additional modules that require the underlying driver to be installed before they can load.