lwip tftp not working on imx8mm

[Jerome Forissier]

Hi Tim,

On 5/23/25 20:31, Tim Harvey wrote:
> Hi Jerome,
> 
> I've enabled LWIP on imx8mm_venice to see how it's doing and while
> dhcp/dns/ping/wget appear to work great, tftp is broken.
> 
> Enabling LWIP_DEBUG shows the following:
> ip4_input: packet accepted on interface et
> IP packet dropped since it was fragmented (0x2000) (while IP_REASSEMBLY == 0).

Hmmmmm IP_REASSEMBLY should probably default to 1.
> 
> I tried enabling IP_REASSEMBLY in lwip but that seems to change the issue to:
> ip4_input: packet accepted on interface et
> ip4_input:
> IP header:
> +-------------------------------+
> | 4 | 5 |  0xc0 |       108     | (v, hl, tos, len)
> +-------------------------------+
> |    10568      |000|       0   | (id, flags, offset)
> +-------------------------------+
> |   64  |    1  |    0xe25b     | (ttl, proto, chksum)
> +-------------------------------+
> |  172  |   24  |    0  |    2  | (src)
> +-------------------------------+
> |  172  |   24  |   21  |  251  | (dest)
> +-------------------------------+
> ip4_input: p->len 108 p->tot_len 108
> Unsupported transport protocol 1
> 
> Any ideas what the issue is here?

Not really :-/ Does the transfer work with a smaller block size?
(CONFIG_TFTP_BLOCKSIZE, default 1468, try 500 for instance). You could
also enable CONFIG_LWIP_DEBUG_RXTX in order to get a full hex dump of
the messages going into/out of the lwIP stack.

Regards,
-- 
Jerome

> 
> Best Regards,
> 
> Tim