Re: [lwip-users] lwip and altera ethernet driver

[Kieran Mansley]

On Thu, 2011-02-17 at 21:11 -0800, Lakshmi Ramesh wrote:
> I'm doing a project,trying to make altera's neek board to communicate with a
> PC.I could build and execute the  driver program successfully but when I
> tried to create a socket and receive/send data I encountered with several
> errors.It required to the changing of NO_SYS from 1 to 0 in lwipopts.h which
> lead to further errors like no reference to sys_sem_signal etc.This requires
> NO_SYS to be =1 to be defined in sys.h.
> can someone please help me with this....

If you're changing from NO_SYS=1 (a system without an operating system,
where this abstraction layer isn't needed) to NO_SYS=0 (a system with an
operating system where you will need the sys_* functionality) you've got
some work to do.  It's not sufficient to just change lwipopts.h; you'll
need to modify the port to work correctly in that very different
environment.  

sys_sem_signal is given a stub definition in sys.h if NO_SYS=1.  If
you've change NO_SYS to 0 then it declares the function, and it is up to
you to define it, normally in your sys_arch.c.  See for example the unix
port in contrib/ports/unix/sys_arch.c

Are you sure you want to change to NO_SYS=0?  I'm assuming you're
starting with a port of lwIP to the hardware and system you've got (for
example, where did you get your copy of lwIP from?) and that someone has
configured it like that on purpose.  

Kieran