[lwip-users] Hardware Assisted Checksum

[EVS Hardware Dpt]

Hello,

I was wondering if anyone already tried to implement a hardware
assisted checksum routine.

In our project, data flows through a FPGA wich can easily compute a
checksum while transferring. So as soon as the data are in our cpu
ram, we can also have associated checksum. Conceptually, it should be
easy to compute a TCP checksum by adding TCP (header + pseudo header
)related data to already computed raw data.

The problem is how to pass to lower layer (in the case of data going
out cpu to lan medium) the computed value ? Something like
tcp_write(pcb, buf, size, copy_mode, RAW_DATA_CHECKSUM) would be
perfect.

Do you have any thoughs on this question ?

For informatin : Our plateform consists of a MPC8347 processor with
128 MB DDR memory running without OS (single threaded).

Thanks.

Frederic Lefranc - EVS Broadcast Equipment (www.evs.tv)