{f0e20f09-d97a-49a9-8046-bb6e22e6bb2e}

NTDEV
1

0: kd> dt 818f9520 _DEVPROPKEY
nt!_DEVPROPKEY
+0x000 fmtid : _GUID {f0e20f09-d97a-49a9-8046-bb6e22e6bb2e}
+0x010 pid : 1

What is this property?

TIA
Andrew

2

xxxxx@hotmail.com wrote:

0: kd> dt 818f9520 _DEVPROPKEY
nt!_DEVPROPKEY
+0x000 fmtid : _GUID {f0e20f09-d97a-49a9-8046-bb6e22e6bb2e}
+0x010 pid : 1

What is this property?

Where did this come from? It’s almost certainly random garbage. All
valid DEVPROPKEYs have a pid of 2 or greater.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

3

>It’s almost certainly random garbage

It is not

All valid DEVPROPKEYs have a pid of 2 or greater.

Not true, see for example

DEFINE_PCI_ROOT_BUS_DEVPKEY(DEVPKEY_PciRootBus_SecondaryInterface, 1)

4

I looked through the sources, this is an undocumented key that is not really used. Why do you care?

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@hotmail.com
Sent: Tuesday, March 11, 2008 4:14 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] {f0e20f09-d97a-49a9-8046-bb6e22e6bb2e}

It’s almost certainly random garbage

It is not

All valid DEVPROPKEYs have a pid of 2 or greater.

Not true, see for example

DEFINE_PCI_ROOT_BUS_DEVPKEY(DEVPKEY_PciRootBus_SecondaryInterface, 1)

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5

xxxxx@hotmail.com wrote:

> It’s almost certainly random garbage
>

It is not

Then where did it come from? The whole purpose of a GUID technique like
this is to allow drivers can define their own private property sets. If
this is coming on from some arbitrary third-party application, then it
is some private property set, and you should not respond.

> All valid DEVPROPKEYs have a pid of 2 or greater.
>

Not true, see for example

DEFINE_PCI_ROOT_BUS_DEVPKEY(DEVPKEY_PciRootBus_SecondaryInterface, 1)

It IS true. All that means is that someone at Microsoft didn’t follow
the rules. (Wouldn’t be the first time.) That is a bug that should
have been caught during code review. Quoting from devpropdef.h:

//
// All valid DEVPROPKEY definitions must use a PROPID that is equal to
or greater
// than DEVPROPID_FIRST_USABLE.
//
#define DEVPROPID_FIRST_USABLE 2

#endif // DEVPROPDEF_H

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

6

>It IS true. All that means is that someone at Microsoft didn’t follow

the rules.

Let MS folks decide what is the rules and what is an exception

I looked through the sources, this is an undocumented key that is not really
used.

Well, it looks like it is used by IopConnectMessageBasedInterrupt

Why do you care?

Debugging the HwMSInterruptRoutine