Questions about SrbExtension in SCSI miniport dirver

Hi:

The size of SrbExtension is defined in DriverEntry and it is allocated for each SRB sent to SCSI miniport driver.

Is there any limitation to the size of SrbExtension?

WDK docs says that the data in SRbExtension can be accessed directly by HBA. Does it mean that the memory allocated for SrbExtension is physically continuous?

Yes. SrbExtensions are allocated out of a slab of common buffer if your device is a bus-master, so in that case they’re physically contiguous and accessible by your controller. Scsiport allocates a limited number of them as a result.

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
Sent: Saturday, September 25, 2010 12:48 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Questions about SrbExtension in SCSI miniport dirver

Hi:

The size of SrbExtension is defined in DriverEntry and it is allocated for each SRB sent to SCSI miniport driver.

Is there any limitation to the size of SrbExtension?

WDK docs says that the data in SRbExtension can be accessed directly by HBA. Does it mean that the memory allocated for SrbExtension is physically continuous?


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