How to change the COM port number in WDM driver?

NTDEV
1

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

2

The msports class installer example demonstrates this. The real ports
class installer does indeed manually write the value to the registry and
then rebuilds the device stack (on OS’s after win2k).

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 7:32 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to change the COM port number in WDM driver?

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

3

When rebuilds the device stack, occur IRP?
How rebuilds the device stack in user mode application? use api?

“Doron Holan” wrote in message
news:xxxxx@ntdev…
The msports class installer example demonstrates this. The real ports
class installer does indeed manually write the value to the registry and
then rebuilds the device stack (on OS’s after win2k).

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 7:32 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to change the COM port number in WDM driver?

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

4

It uses SetupDi functions. The same functions that devcon would use if
you updated the stack using it. If the stack is rebuilt, you get a
query remove then remove and then AddDevice again.

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 8:16 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] How to change the COM port number in WDM driver?

When rebuilds the device stack, occur IRP?
How rebuilds the device stack in user mode application? use api?

“Doron Holan” wrote in message
news:xxxxx@ntdev…
The msports class installer example demonstrates this. The real ports
class installer does indeed manually write the value to the registry and
then rebuilds the device stack (on OS’s after win2k).

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 7:32 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to change the COM port number in WDM driver?

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

5

Changing the COMxxx name can all be done by changing the Dos Symbolic Link
and also the PortName and Friendlyname. I think that is about it.

Thanks
Mike Jones

“Doron Holan” wrote in message
news:xxxxx@ntdev…
It uses SetupDi functions. The same functions that devcon would use if
you updated the stack using it. If the stack is rebuilt, you get a
query remove then remove and then AddDevice again.

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 8:16 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] How to change the COM port number in WDM driver?

When rebuilds the device stack, occur IRP?
How rebuilds the device stack in user mode application? use api?

“Doron Holan” wrote in message
news:xxxxx@ntdev…
The msports class installer example demonstrates this. The real ports
class installer does indeed manually write the value to the registry and
then rebuilds the device stack (on OS’s after win2k).

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 7:32 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to change the COM port number in WDM driver?

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

6

There is a COM name arbiter that knows which com port numbers are in
use. You can certainly change the sym link name and friendly name
yourself, but then the com arbiter can hand out the same number to
another port b/c you didn’t go through it. Also, you need to change
the devnode’s “PortName” value, otherwise the driver will have no idea
about the change the next time it is loaded.

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Michael Jones
Sent: Monday, June 14, 2004 11:10 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] How to change the COM port number in WDM driver?

Changing the COMxxx name can all be done by changing the Dos Symbolic
Link
and also the PortName and Friendlyname. I think that is about it.

Thanks
Mike Jones

“Doron Holan” wrote in message
news:xxxxx@ntdev…
It uses SetupDi functions. The same functions that devcon would use if
you updated the stack using it. If the stack is rebuilt, you get a
query remove then remove and then AddDevice again.

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 8:16 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] How to change the COM port number in WDM driver?

When rebuilds the device stack, occur IRP?
How rebuilds the device stack in user mode application? use api?

“Doron Holan” wrote in message
news:xxxxx@ntdev…
The msports class installer example demonstrates this. The real ports
class installer does indeed manually write the value to the registry and
then rebuilds the device stack (on OS’s after win2k).

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Kim Seok June
Sent: Tuesday, June 08, 2004 7:32 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to change the COM port number in WDM driver?

Hello,

I’m writing a my serialui dll program. I’d like the feature to manually
assign the COM port number through the device manager.
When I change com1 to com 3, I see this request.

IRP_MJ_CREATE
IRP_MJ_CLEANUP
IRP_MJ_CLOSE

and Registry is changed.

I think that msports call function not direct change registry.
But I don’t know what this api.

How does this work internally in Windows 2000? How can I implement
this feature in my driver?

Thanks a lot,

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com