Minoca-os/drivers/null/null.c

/*++

Copyright (c) 2012 Minoca Corp.

    This file is licensed under the terms of the GNU General Public License
    version 3. Alternative licensing terms are available. Contact
    info@minocacorp.com for details. See the LICENSE file at the root of this
    project for complete licensing information.

Module Name:

    null.c

Abstract:

    This module implements the NULL driver.

Author:

    Evan Green 25-Sep-2012

Environment:

    Kernel

--*/

//
// ------------------------------------------------------------------- Includes
//

#include <minoca/kernel/driver.h>

//
// ---------------------------------------------------------------- Definitions
//

//
// ------------------------------------------------------ Data Type Definitions
//

//
// ----------------------------------------------- Internal Function Prototypes
//

KSTATUS
NullAddDevice (
    PVOID Driver,
    PCSTR DeviceId,
    PCSTR ClassId,
    PCSTR CompatibleIds,
    PVOID DeviceToken
    );

VOID
NullDispatchStateChange (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    );

VOID
NullDispatchOpen (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    );

VOID
NullDispatchClose (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    );

VOID
NullDispatchIo (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    );

VOID
NullDispatchSystemControl (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    );

//
// -------------------------------------------------------------------- Globals
//

PDRIVER NullDriver = NULL;

//
// ------------------------------------------------------------------ Functions
//

__USED
KSTATUS
DriverEntry (
    PDRIVER Driver
    )

/*++

Routine Description:

    This routine is the entry point for the null driver. It registers its other
    dispatch functions, and performs driver-wide initialization.

Arguments:

    Driver - Supplies a pointer to the driver object.

Return Value:

    STATUS_SUCCESS on success.

    Failure code on error.

--*/

{

    DRIVER_FUNCTION_TABLE FunctionTable;
    KSTATUS Status;

    NullDriver = Driver;
    RtlZeroMemory(&FunctionTable, sizeof(DRIVER_FUNCTION_TABLE));
    FunctionTable.Version = DRIVER_FUNCTION_TABLE_VERSION;
    FunctionTable.AddDevice = NullAddDevice;
    FunctionTable.DispatchStateChange = NullDispatchStateChange;
    FunctionTable.DispatchOpen = NullDispatchOpen;
    FunctionTable.DispatchClose = NullDispatchClose;
    FunctionTable.DispatchIo = NullDispatchIo;
    FunctionTable.DispatchSystemControl = NullDispatchSystemControl;
    Status = IoRegisterDriverFunctions(Driver, &FunctionTable);
    return Status;
}

KSTATUS
NullAddDevice (
    PVOID Driver,
    PCSTR DeviceId,
    PCSTR ClassId,
    PCSTR CompatibleIds,
    PVOID DeviceToken
    )

/*++

Routine Description:

    This routine is called when a device is detected for which this driver
    acts as the function driver. The driver will attach itself to the stack.

Arguments:

    Driver - Supplies a pointer to the driver being called.

    DeviceId - Supplies a pointer to a string with the device ID.

    ClassId - Supplies a pointer to a string containing the device's class ID.

    CompatibleIds - Supplies a pointer to a string containing device IDs
        that would be compatible with this device.

    DeviceToken - Supplies an opaque token that the driver can use to identify
        the device in the system. This token should be used when attaching to
        the stack.

Return Value:

    STATUS_SUCCESS on success.

    Failure code if the driver was unsuccessful in attaching itself.

--*/

{

    KSTATUS Status;

    Status = IoAttachDriverToDevice(Driver, DeviceToken, NULL);
    return Status;
}

VOID
NullDispatchStateChange (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    )

/*++

Routine Description:

    This routine handles State Change IRPs.

Arguments:

    Irp - Supplies a pointer to the I/O request packet.

    DeviceContext - Supplies the context pointer supplied by the driver when it
        attached itself to the driver stack. Presumably this pointer contains
        driver-specific device context.

    IrpContext - Supplies the context pointer supplied by the driver when
        the IRP was created.

Return Value:

    None.

--*/

{

    ASSERT(Irp->MajorCode == IrpMajorStateChange);

    //
    // Do no processing on any IRPs. Let them flow.
    //

    return;
}

VOID
NullDispatchOpen (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    )

/*++

Routine Description:

    This routine handles Open IRPs.

Arguments:

    Irp - Supplies a pointer to the I/O request packet.

    DeviceContext - Supplies the context pointer supplied by the driver when it
        attached itself to the driver stack. Presumably this pointer contains
        driver-specific device context.

    IrpContext - Supplies the context pointer supplied by the driver when
        the IRP was created.

Return Value:

    None.

--*/

{

    return;
}

VOID
NullDispatchClose (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    )

/*++

Routine Description:

    This routine handles Close IRPs.

Arguments:

    Irp - Supplies a pointer to the I/O request packet.

    DeviceContext - Supplies the context pointer supplied by the driver when it
        attached itself to the driver stack. Presumably this pointer contains
        driver-specific device context.

    IrpContext - Supplies the context pointer supplied by the driver when
        the IRP was created.

Return Value:

    None.

--*/

{

    return;
}

VOID
NullDispatchIo (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    )

/*++

Routine Description:

    This routine handles I/O IRPs.

Arguments:

    Irp - Supplies a pointer to the I/O request packet.

    DeviceContext - Supplies the context pointer supplied by the driver when it
        attached itself to the driver stack. Presumably this pointer contains
        driver-specific device context.

    IrpContext - Supplies the context pointer supplied by the driver when
        the IRP was created.

Return Value:

    None.

--*/

{

    return;
}

VOID
NullDispatchSystemControl (
    PIRP Irp,
    PVOID DeviceContext,
    PVOID IrpContext
    )

/*++

Routine Description:

    This routine handles System Control IRPs.

Arguments:

    Irp - Supplies a pointer to the I/O request packet.

    DeviceContext - Supplies the context pointer supplied by the driver when it
        attached itself to the driver stack. Presumably this pointer contains
        driver-specific device context.

    IrpContext - Supplies the context pointer supplied by the driver when
        the IRP was created.

Return Value:

    None.

--*/

{

    ASSERT(Irp->MajorCode == IrpMajorSystemControl);

    //
    // Do no processing on any IRPs. Let them flow.
    //

    return;
}

//
// --------------------------------------------------------- Internal Functions
//