Size Device Extension

Is it necessary that the size of Device Extension of all the devices that a
driver create be the same?

My driver needs to support both pnp and legacy devices. So some
fields i maintain will be there only if the device is pnp and some only if
the device is legacy.

cheers
Sesha.
**************************************************************************
This email (including any attachments) is intended for the sole use of the
intended recipient/s and may contain material that is CONFIDENTIAL AND
PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying or
distribution or forwarding of any or all of the contents in this message is
STRICTLY PROHIBITED. If you are not the intended recipient, please contact
the sender by email and delete all copies; your cooperation in this regard
is appreciated.
**************************************************************************

No. This is why the size is a parameter to the Io Create call.

Jamey

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Seshagiri_Babu
Sent: Tuesday, July 02, 2002 5:44 AM
To: NT Developers Interest List
Subject: [ntdev] Size Device Extension

Is it necessary that the size of Device Extension of all the devices
that a
driver create be the same?

My driver needs to support both pnp and legacy devices. So some
fields i maintain will be there only if the device is pnp and some only
if
the device is legacy.

cheers
Sesha.
************************************************************************
**
This email (including any attachments) is intended for the sole use of
the
intended recipient/s and may contain material that is CONFIDENTIAL AND
PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying
or
distribution or forwarding of any or all of the contents in this message
is
STRICTLY PROHIBITED. If you are not the intended recipient, please
contact
the sender by email and delete all copies; your cooperation in this
regard
is appreciated.
************************************************************************
**


You are currently subscribed to ntdev as: xxxxx@storagecraft.com
To unsubscribe send a blank email to %%email.unsub%%

No. The extension size could be different to each separate call of
IoCreateDevice. For example a bus driver could have one extension for its
FDO and another extension for the PDOs it creates.


Nar Ganapathy
Windows Core OS group
This posting is provided “AS IS” with no warranties, and confers no rights.
“Seshagiri_Babu” wrote in message
news:xxxxx@ntdev…
>
> Is it necessary that the size of Device Extension of all the devices that
a
> driver create be the same?
>
> My driver needs to support both pnp and legacy devices. So some
> fields i maintain will be there only if the device is pnp and some only if
> the device is legacy.
>
> cheers
> Sesha.
>
> This email (including any attachments) is intended for the sole use of the
> intended recipient/s and may contain material that is CONFIDENTIAL AND
> PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying
or
> distribution or forwarding of any or all of the contents in this message
is
> STRICTLY PROHIBITED. If you are not the intended recipient, please contact
> the sender by email and delete all copies; your cooperation in this regard
> is appreciated.
>

>
>

> Is it necessary that the size of Device Extension of all the devices
that a

driver create be the same?

No for sure.

Max

Can the size be zero?

From: “Nar Ganapathy [MS]”
>Reply-To: “NT Developers Interest List”
>To: “NT Developers Interest List”
>Subject: [ntdev] Re: Size Device Extension
>Date: Tue, 2 Jul 2002 10:18:07 -0700
>
>No. The extension size could be different to each separate call of
>IoCreateDevice. For example a bus driver could have one extension for its
>FDO and another extension for the PDOs it creates.
>
>–
>Nar Ganapathy
>Windows Core OS group
>This posting is provided “AS IS” with no warranties, and confers no rights.
>“Seshagiri_Babu” wrote in message
>news:xxxxx@ntdev…
> >
> > Is it necessary that the size of Device Extension of all the devices
>that
>a
> > driver create be the same?
> >
> > My driver needs to support both pnp and legacy devices. So some
> > fields i maintain will be there only if the device is pnp and some only
>if
> > the device is legacy.
> >
> > cheers
> > Sesha.
> >
>
> > This email (including any attachments) is intended for the sole use of
>the
> > intended recipient/s and may contain material that is CONFIDENTIAL AND
> > PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying
>or
> > distribution or forwarding of any or all of the contents in this message
>is
> > STRICTLY PROHIBITED. If you are not the intended recipient, please
>contact
> > the sender by email and delete all copies; your cooperation in this
>regard
> > is appreciated.
> >
>

> >
> >
>
>
>
>—
>You are currently subscribed to ntdev as: xxxxx@hotmail.com
>To unsubscribe send a blank email to %%email.unsub%%

_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx

Well, if you think this is cool, save there a pointer to a 0 sized memory
allocation.

----- Original Message -----
From: “Ta H.”
To: “NT Developers Interest List”
Sent: Saturday, July 06, 2002 10:21 PM
Subject: [ntdev] Re: Size Device Extension

> Can the size be zero?
>
>
> >From: “Nar Ganapathy [MS]”
> >Reply-To: “NT Developers Interest List”
> >To: “NT Developers Interest List”
> >Subject: [ntdev] Re: Size Device Extension
> >Date: Tue, 2 Jul 2002 10:18:07 -0700
> >
> >No. The extension size could be different to each separate call of
> >IoCreateDevice. For example a bus driver could have one extension for its
> >FDO and another extension for the PDOs it creates.
> >
> >–
> >Nar Ganapathy
> >Windows Core OS group
> >This posting is provided “AS IS” with no warranties, and confers no
rights.
> >“Seshagiri_Babu” wrote in message
> >news:xxxxx@ntdev…
> > >
> > > Is it necessary that the size of Device Extension of all the devices
> >that
> >a
> > > driver create be the same?
> > >
> > > My driver needs to support both pnp and legacy devices. So some
> > > fields i maintain will be there only if the device is pnp and some
only
> >if
> > > the device is legacy.
> > >
> > > cheers
> > > Sesha.
> > >
>
>
> > > This email (including any attachments) is intended for the sole use of
> >the
> > > intended recipient/s and may contain material that is CONFIDENTIAL AND
> > > PRIVATE COMPANY INFORMATION. Any review or reliance by others or
copying
> >or
> > > distribution or forwarding of any or all of the contents in this
message
> >is
> > > STRICTLY PROHIBITED. If you are not the intended recipient, please
> >contact
> > > the sender by email and delete all copies; your cooperation in this
> >regard
> > > is appreciated.
> > >
>
>

> > >
> > >
> >
> >
> >
> >—
> >You are currently subscribed to ntdev as: xxxxx@hotmail.com
> >To unsubscribe send a blank email to %%email.unsub%%
>
>
>
>
> _________________________________________________________________
> MSN Photos is the easiest way to share and print your photos:
> http://photos.msn.com/support/worldwide.aspx
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

yes, but the I/O system may still put a pointer in the DeviceExtension
field. Since the device extension is allocated at the tail end of the
device object structure the I/O system used to just stick the pointer to
the byte after the object in there no matter what.

but sicne you know you don’t have a device extension there’s no reason
to access it anyway is there? :slight_smile:

-p

-----Original Message-----
From: Ta H. [mailto:xxxxx@hotmail.com]
Sent: Saturday, July 06, 2002 12:22 PM
To: NT Developers Interest List
Subject: [ntdev] Re: Size Device Extension

Can the size be zero?

From: “Nar Ganapathy [MS]”
>Reply-To: “NT Developers Interest List”
>To: “NT Developers Interest List”
>Subject: [ntdev] Re: Size Device Extension
>Date: Tue, 2 Jul 2002 10:18:07 -0700
>
>No. The extension size could be different to each separate call of
>IoCreateDevice. For example a bus driver could have one extension for
>its FDO and another extension for the PDOs it creates.
>
>–
>Nar Ganapathy
>Windows Core OS group
>This posting is provided “AS IS” with no warranties, and confers no
>rights. “Seshagiri_Babu” wrote in message
>news:xxxxx@ntdev…
> >
> > Is it necessary that the size of Device Extension of all the devices
>that
>a
> > driver create be the same?
> >
> > My driver needs to support both pnp and legacy devices. So some
> > fields i maintain will be there only if the device is pnp and some
> > only
>if
> > the device is legacy.
> >
> > cheers
> > Sesha.
> >
> ********************************************************************
>

> > This email (including any attachments) is intended for the sole use
> > of
>the
> > intended recipient/s and may contain material that is CONFIDENTIAL
> > AND PRIVATE COMPANY INFORMATION. Any review or reliance by others or

> > copying
>or
> > distribution or forwarding of any or all of the contents in this
> > message
>is
> > STRICTLY PROHIBITED. If you are not the intended recipient, please
>contact
> > the sender by email and delete all copies; your cooperation in this
>regard
> > is appreciated.
> >
> ********************************************************************
>

> >
> >
>
>
>
>—
>You are currently subscribed to ntdev as: xxxxx@hotmail.com
>To unsubscribe send a blank email to %%email.unsub%%

_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx


You are currently subscribed to ntdev as: xxxxx@microsoft.com To
unsubscribe send a blank email to %%email.unsub%%