RE: [lwip-users] TCP checksumming

[Bill Auerbach]

> Bill Auerbach wrote:
> > One problem however: If I define LWIP_CHKSUM in my sys_arch.h,
> > inet_chksum.c doesn't know about it. I had to add #include
> > "sys_arch.h" to inet_chksum.c. In order to override LWIP_CHKSUM
> > without changing source code, shouldn't include sys_arch.h?
> >
> I don't think so: sys_arch.h is supposed to provide things needed for
> the sys layer (like threads, mboxes and semaphores). When compiling with
> NO_SYS=1, the whole stack should still be compilable without the whole
> sys_arch.h file. You will have to put the definition somewhere else.

OK.  I see.  This define (LWIP_CHKSUM) belongs in lwipopts.h not sys_arch.h
as per the comment.  The question becomes where to put the prototype for the
replacement function.  If it's in sys_arch.h to match sys_arch.c where the
function definition is, then lwipopts.h or inet_chksum.c need sys_arch.h
added to get the prototype pulled in.

Bill