[lwip-users] LwIP and memory section relocation

[MÅrîØ Raƒƒin]

Dear All,
    I am using LwIP with FreeRTOS on STM32F7 MCU and I am experimentig 
an odd behaviour.

These MCU have two contiguous memory areas: a section close coupled to 
the core (DTCM) and a normal RAM section.
When I use the standard linker script the bss section and the LwIP 
buffers ( "memp_memory_PBUF_POOL_base" (21K) ,"ram_heap" (9K) and other 
buffers as memp_memory_PBUF_base 3K and some other with lower size) fall 
into the DTCM memory and aberything is fine.

When I change the linker script and the bss section is allocated in the 
normal RAM, the LwIP stack works badly, sometimes the device is not 
reachable from network, sometimes (with other board e.g. Nucleo-F767ZI) 
the ping loses more than half of the packets.

I don't think the LwIP needs the DTCM to work. I can't figure out the 
reason of this behaviour, some idea would be very appreciated.

Thank you.

Mario
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