调用IoStartPacket为什么会出现Page Fault错误？

在分派例程中调用IoStartPacket时为什么会出现Page Fault错误？开始我在做IO空间读写时从来没出现过这种情况，后来硬件采用设备内存，因此我把设备内存空间映射到核心虚拟地址空间，再做读写操作时问题就来了,怎么回事这是？（NTDDK）

That means you were touching the paged memory at raised IRQL, probably in your startIo routine.
If you're using memory-map device, make sure you translate the hardware address and map the address to non-paged pool correctly.

If you are using NT 4,
call HalTranslateBusAddress and MmMapIoSpace(..INMEMORY).

If it's a native WDM driver, when receiving the
IRP_MN_START_DEVICE in your DispatchPnp routine, use the translated resource descriptor to map the memory.

Good luck

It's really a 低级失误.It should be "if(MemIo==NULL) then".
However,I have uncarefully written "if(MemIo=NULL) then"!
But still thank u for ur advice.