Network Driver Registry Settings (Compact 2013)

  • Article

3/26/2014

Windows Embedded Compact 2013 implementation of the Network Driver Interface Specification (NDIS) includes registry keys that you can use to configure the behavior of network drivers.

You can force a network miniport driver on an x86 platform to use cached shared memory buffers for increased performance by using the registry values located in the following key.

HKEY_LOCAL_MACHINE\Drivers\BuiltIn\<Your Driver>

Name

Type

Description

Default value

CachedSharedMem

REG_DWORD

Boolean value that indicates whether NdisMAllocateSharedMemory allocates cached shared memory for this network driver, regardless of the value passed to the Cached parameter.

  • 1 = When this network driver calls NdisMAllocateSharedMemory, the returned shared memory is always cached.
  • 0 = When this network driver calls NdisMAllocateSharedMemory, the returned shared memory is cached only if the Cached parameter is set to TRUE.

1

Remarks

The CachedSharedMem registry setting is ignored on non-x86 platforms (such as ARM platforms). For information about configuring device driver registry settings, see Add and Build a Device Driver. You do not have to recompile network driver source code to use this setting.

Use the CachedSharedMem registry setting as a temporary method to enable shared memory caching without modifying driver code, or as a way to force caching on a network driver where you do not have access to the driver source code. If possible, we recommend that your network driver call NdisMAllocateSharedMemory with Cached always set to TRUE rather than use the CachedSharedMem registry setting to force caching. You can set the CachedSharedMem registry setting to measure the amount of performance improvement that cached shared memory provides in the network driver before you modify network driver code to call NdisMAllocateSharedMemory with the Cached parameter set to TRUE. For more information about how to use cached shared memory to improve networking performance, see Enable Caching to Improve NDIS 6.0 DMA Performance.

Examples

The following registry code example configures the RTL8139 network miniport driver to use cached shared memory.

[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\PCI\Template\RTL8139]
"CachedSharedMem"=dword:1

See Also

Other Resources

Network Drivers