Re: The Linux Staging tree, what it is and is not.

[Robert Schwebel <r.schwebel@pengutronix.de>]

On Mon, Mar 23, 2009 at 10:03:23AM +0100, Daniel Krüger wrote:
>> what I understand from this thread is that the hardware is a standard
>> ethernet card.
>
> It may be a standard Ethernet controller. But it could also be a
> controller with a special hardware acceleration.

Industrial Ethernets or CANopen can also be implemented with hardware
solutions like a netX or an FPGA, which both would have shared memory to
the CPU plus a part of the stack in userspace; however, this is nothing
that should be abstracted with this driver infrastructure. It is an
issue for a more higher level interface, which is what we will provide
with the OSADL Fieldbus Framework:

+------------------------------------+
I            Application             I
+------------------------------------+

+------------------------------------+
I         Process Data Library       I
+------------------------------------+

+--------------------+ +-------------+
I   $FIELDBUS Stack  I I  Userspace  I
I                    I I    Driver   I
+--------------------+ +-------------+

+--------------------+ +-------------+
I AF_CAN / AF_PACKET I I     UIO     I
I     Socket         I I             I
+--------------------+ +-------------+ Userspace
                                        ___^___
+--------------------+ +-------------+     v
I    eth/can Card    I I UIO driver  I  Kernel
I with normal driver I I             I
+--------------------+ +-------------+

rsc
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