How to allocate a physical contiguous memory of 64K?

NTDEV
1

All,

Is there a way for the driver in Win2K to allocate a physical
contiguous memory block of more than 4K, preferably around 64K or
more, for the hardware sitting on the PCI bus to send/receive the
data in/out of the main memory?

best regards,
Peter

2

AllocateCommonBuffer

-p

-----Original Message-----
From: Peter Teng [mailto:xxxxx@yahoo.com]
Sent: Friday, February 07, 2003 10:34 AM
To: NT Developers Interest List

All,

Is there a way for the driver in Win2K to allocate a physical
contiguous memory block of more than 4K, preferably around 64K or more,
for the hardware sitting on the PCI bus to send/receive the data in/out
of the main memory?

best regards,
Peter

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

3

MmAllocateContiguousMemory

Peter Teng schrieb:

All,

Is there a way for the driver in Win2K to allocate a physical
contiguous memory block of more than 4K, preferably around 64K or
more, for the hardware sitting on the PCI bus to send/receive the
data in/out of the main memory?

best regards,
Peter

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

4

MmAllocateContiguousMemory shouldn’t be used to get memory you plan to
share with a device since the information about what physical memory
ranges are addressable by the controller is only available to the DMA
APIs (like AllocateCommonBuffer).

MmAllocateContiguousMemory will work in most circumstances, but there’s
no way for your driver to determine on any particular machine whether
it’s sure to work. The DMA API will provide memory that’s sure to work.

This has been discussed many times on this alias.

-p

-----Original Message-----
From: Burkhardt Braun [mailto:xxxxx@nolatch.com]
Sent: Friday, February 07, 2003 2:21 PM
To: NT Developers Interest List

MmAllocateContiguousMemory

Peter Teng schrieb:

All,

Is there a way for the driver in Win2K to allocate a physical
contiguous memory block of more than 4K, preferably around 64K or
more, for the hardware sitting on the PCI bus to send/receive the data

in/out of the main memory?

best regards,
Peter

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

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

5

->AllocateCommonBuffer is a way.
You can also use HalAllocateCommonBuffer which is an inline function
around AllocateCommonBuffer.

Max

----- Original Message -----
From: “Peter Teng”
To: “NT Developers Interest List”
Sent: Friday, February 07, 2003 9:33 PM
Subject: [ntdev] How to allocate a physical contiguous memory of 64K?

> All,
>
> Is there a way for the driver in Win2K to allocate a physical
> contiguous memory block of more than 4K, preferably around 64K or
> more, for the hardware sitting on the PCI bus to send/receive the
> data in/out of the main memory?
>
> best regards,
> Peter
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>