A.4.2.1 Calling ScsiPortInitialize

If its HBA can be connected on more than one type of I/O bus, a miniport driver needs to call ScsiPortInitialize for each bus type and must have a HwScsiFindAdapter routine for each bus type. Such a miniport driver must modify the AdapterInterfaceType and HwScsiFindAdapter members in the HW_INITIALIZATION_DATA after each call to ScsiPortInitialize, possibly modify the miniport-supplied context data for the new bus type, and call ScsiPortInitialize for each type of bus on which a supported HBA might be connected.

Before it calls the miniport’s HwScsiFindAdapter routine, ScsiPortInitialize does all of the following:

• Checks the validity of the HW_INITIALIZATION_DATA

• Collects and stores pertinent information in the device extension of a device object that it creates to represent the HBA

• Allocates memory for and initializes with zeros a device extension of the requested size in which the miniport driver can store driver-determined information about the HBA

• Allocates memory for a PORT_CONFIGURATION_INFORMATION-type buffer

• Fills in as much configuration information about an adapter on a particular I/O bus as it can from the registry

Then, ScsiPortInitialize calls the miniport driver’s HwScsiFindAdapter routine, described in Section A.4.3.

If the miniport’s DriverEntry routine sets a particular AdapterInterfaceType value in the HW_INITIALIZATION_DATA but there is no bus of that type in the machine, the port driver returns an OS-specific status value indicating that such an HBA does not exist in the current machine. It does not call the driver-supplied HwScsiFindAdapter routine for that bus type.

A miniport driver does not remain loaded if the machine has no I/O buses of the type(s) specified by the miniport’s DriverEntry routine.

Note that ScsiPortInitialize also is responsible for the following before it returns control to the miniport’s DriverEntry routine:

• Setting up all necessary system objects

• Getting configuration information from and setting configuration information in the registry

• Allocating system resources on behalf of the miniport driver, including memory for the miniport-specified DeviceExtensionSize, SpecificLuExtensionSize, and/or SrbExtensionSize in which the miniport driver can maintain HBA-specific state, per-logical-unit state, and/or per-request state, respectively

Each SCSI miniport driver defines the internal structure and contents of its device extension, logical unit extensions (if any), and SRB extensions (if any). A pointer to the HBA-specific device extension is an input argument to every system-defined miniport driver routine except DriverEntry. Many ScsiPortXxx routines require this pointer as an argument.

ScsiPortInitialize can be called only from a miniport driver’s DriverEntry routine. For more information about the HW_INITIALIZATION_DATA structure and ScsiPortInitialize, see the Kernel-Mode Driver Reference.