LwIP Build Analyzer

[ESawa.1]

Hey there,

I have a question regarding the output of the build analyzer. When I set up freeRTOS + lwIP , like explained here:

• https://community.st.com/s/article/How-to-create-project-for-STM32H7-with-Ethernet-and-LwIP-stack-working

on my STM32H753 everything works as expected but the build analyzer shows that RAM D2 is almost full.

When I check the Memory Details, I see that there are only the assigned descriptors inside and the 6k for the RxBuffer. There is also 512B for an internal buffer I need.

But why is the build analyzer showing that the RAM D2 is almost full?

[ESawa.1]

Hey there,

sorry I forgot to add the part of the linker script. Please see the modifications in the linker script below:

   /* Modification start */
  .lwip_sec (NOLOAD) : {
    . = ABSOLUTE(0x30040000);
    *(.RxDecripSection) 
    
    . = ABSOLUTE(0x30040060);
    *(.TxDecripSection)
    
    . = ABSOLUTE(0x30040200);
    *(.RxArraySection) 
  } >RAM_D2
  /* Modification end */

[DWeb_2]

Your LwIP section begins right after the D2 RAM (is automatically placed there) . You can change the start of the section in the linker script to an absolute address. Keep in mind to include the LwIP heap.

[ESawa.1]

Dear DWeb_2,

thanks for your fast answer. This is great. Could you maybe share an example with me how to place the lwip_sec into an absoulte address and keeping the heap safe. My heap is set to "MEM_SIZE to 16360" as explained in the link above. The LWIP_RAM_HEAP_POINTER is set to 0x30044000. Do I have to take care also of the amount of TCP, UDP connections I allow? I have set MEMP_NUM_UDP_PCB to 3 and MEMP_NUM_TCP_PCB to 6.

[DWeb_2]

Try this snippet for the linker script:

.lwip_sec 0x30040000 (NOLOAD) :

I can't help you considering the LwIP config

[ESawa.1]

Dear DWeb_2,

okay got it. Thanks a lot for your support.