> But the problems/disadvantages with Interniche: > > 6 They support scatter-gather DMA in hardware but their driver doesn't take > advantage of it. > Unless things have changed recently in Interniche land, this is also the main reason why Interniche uses much more RAM than lwIP. A full 1518 Byte buffer has to be allocated for every incoming packet, unless you want to do one extra copy and reallocation operation in the Ethernet driver.
Just this week I found bugs in Interniche IP fragmentation routines as well as in the handling of IP options. > The good parts: > 2. The scatter-gather DMA is nice if utilized. > Most processors with integrated 100Mbit MAC supports scatter-gather. Not really a noteworthy feature unless it supports some more advanced features such as automatic TCP/IP header length detection so that the scatter transfer can separate the TCP/IP or UDP/IP header from the payload, even when the headers may have varying lengths due to header options and vlan tags. If combined with a finely grained MMU, such a feature would allow true zero copy without the hazzle of having to handle pbuf chains in the application layer. /Timmy Brolin _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
