RE: [lwip-devel] again... Zero Copy Ethernet interface

[Grubb, Jared]

Are you only concerned about making sure the RX packets are located in a specific region, or do you need the TX packets to also be in that region?

It’s been a while, but I also required that RX packets were all fixed in a very specific spot of memory, and I was able to make it work. I can go back to the code and try to dig out how I did it if that’s what you’re looking for.

Jared

 

From: address@hidden [mailto:address@hidden On Behalf Of Piero 74
Sent: Tuesday, December 23, 2008 7:38 AM
To: lwip-devel
Subject: [lwip-devel] again... Zero Copy Ethernet interface

 

Hi all

 

I want to open again a thread for zero copy driver implementation

 

I think that it could be useful a more powerful implementation of pbufs, that could give to developer the possibility to build driver which can avoid a copy from friver to stack.

 

I have a microcontroller with an emac HW which uses DMA for ethernet packet managment. 

It works with a circular array of buffers with descriptors.

 

My ethernetif loop, checks if packet is present, copies it in a raw pbuf, and move DMA pointer.

 

I'd like to remove copy operation; i have to understand better how pbufs works, but i suppose that something have to change:

first, it could be necessary the possibility to allocate pbuf memory in particula memory region: my micro, for example, has emac dma which works on a fixed RAM region.

second, it could be necessary that stack informs lowlevel driver when a pbuf is free

 

Any idea? any implementation of this planned in the future?

 

and... out of thread...

what about of SOCKET2 (sockets build without netconn)? some news? is it planned in the future?

 

bye

Piero

 

" merry Christmas and happy new year!! :OD "