Re: [ECOS] redboot tftp lag issue

[Jonathan Larmour <jifl at eCosCentric dot com>]

On 26/06/12 11:39, lryylryylryy wrote:
> Hi,
> 
> I'm using redboot to launch ecos application,but I found that loading file
> via tftp lags randomly. I traced in, and found the root cause is that UDP
> checksum error.

I assume you mean when receiving packets, rather than when sending ACKs.

> My platform is STM32 with DM9000. The ecos package version is original
> V3.0. I adapted the bus timing, DM9000 works fine.
> 
> Who encounter the same problem?

I haven't noticed any problem with TFTP in RedBoot before in general. Assuming
the host resends and you receive it correctly, I'd suggest editing
redboot/v3_0/src/net/udp.c:__udp_handler, and saving the erroneous packet, and
then in tftp_client.c, when acking a packet, check its block number, and if it
matches one saved in udp_handler, then save the correct form of the packet.
Comparing the two saved packets will give you an idea where the corruption is
occurring - at the beginning, end or just randomly anywhere. That may give you
a better idea of where to look for a problem.

Alternatively to avoid the hassle of dealing with TFTP, you could instead look
at using the 'ping' command. Set it to a higher rate using -r (I think the
units are milliseconds) and a large -n, and then use ping to see how reliable
things are there.

Personally I suspect some sort of hardware noise issues in the lines
connecting the STM32 with the DM9000.

Jifl
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