[lwip-users] New lwip user - large bss size

[David Aldrich]

Hi

I am a new user of lwip.  My target hardware is an embedded processor on an FPGA.  I have been given an "unofficial" port of lwip for this processor by a third party.  The port and a small http server application run successfully on a reference hardware design that has 1MB of data (i.e. not instruction) memory.  However, the port will not run on our target hardware that has only 128KB of data memory. 

Running the GNU size utility on our object file gives:

   text    data     bss     dec     hex filename
 103422    1888  558012  663322   a1f1a test.out

So you can see that the bss (uninitialised global data) size is >500KB, which is very large.  This is with a minimum application, so the data must be being mostly allocated for the port and lwip.

I would welcome any suggestions of how to find what is using this large amount of memory.  Is there a standard .h file in lwip that defines sizes of buffers etc?

What are typical data requirements of lwip?

Thanks for any help you can provide.

David