Re: [lwip-devel] Porting question.

[address@hidden]

Am 15.02.2021 um 08:29 schrieb Walter ZAMBOTTI:
> The 1.4 porting guide states under sys_arch.c

Which porting guide are you talking about? 1.4.x is *really* old now and
not recommended to use!

>
> The sys_arch provides semaphores and mailboxes to lwIP. For the full
> lwIP functionality, multiple threads support can be implemented in the
> sys_arch, but this is not required for the basic lwIP functionality.
>
> It is not clear what controls/determines this "basic ... functionality".

That's not really clear to me as well. Which porting guide do you mean?

>
> If |SYS_LIGHTWEIGHT_PROT is set (to 1) are Semaphores and/or mailboxs
> still required?|

There's an OS mode (required if you use any sequential API like sockets,
netconn, etc) or a "raw main-loop" mode (where you can only use a
callback style API and need to take care of not using lwIP in main loop
and interrupt level at the same time).

In OS mode, you need at least semaphores, mailboxes and 1 thread
(providing a mutex implementation is also required but binary semaphores
can be used if you don't have mutexes).

When implementing generic examples, you might need to implement the full
"sys_thread_new()" functionality as well.

Regards,
Simon