I assume a bug in the Nucleo firmware (MAC driver? PHY driver?) or even the hardware.
I have implemented ping.c (from Lwip) on top of the board's Webserver example (from the recent Firmware package), so that it can ping a computer.
When the board issues a ping (echo request, ICMP type 😎 request to the computer, the ICMP checksum is 0x0000, although is was correctly calculated in the message buffer before, and put to DMA as such. I have tracked down the value until HAL_ETH.*** passes it to DMA.
I cannot track down further, so I assume that some lower instances do some calculations on their own. E.g., the IP packet checksum is calculated here as well - correctly.
Vice versa, when the board answers a ping request from the computer, the checksum is correct.
See a complete report attached.
Is there a quick solution?
Edits:
- I am using IPv4
- Just had a look in the Errata Sheet ES0334 Rev 6. This case is not covered, only a similar case concerning IPv6.
