xxx_Init

Device Manager calls xxx_Init function to initialize your 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 installable device driver.

Return Value

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

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 can use this information to access data stored in the registry.

Some tasks this function might perform include:

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 Ctrl for the driver, and if such a key is present Device Manger calls xxx_IOControl. 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.