Re: [lwip-devel] Porting with not threads!

[Walter ZAMBOTTI]

Erik

Thanks for the response.

I have found :

lwip.fandom.com

http://www.nongnu.org/lwip/2_0_x.

https://git.savannah.nongnu.org/cgit/lwip.git/tree

these resources before! Thanks!

The OS I have is Microware OS9, 16 bit which was pre-thread support.  So 
no semaphores or mailboxes.

It has context (task) switching interrupt driven devices drivers, but no 
threads.  So I would like to have OS support which requires NO_SYS = 0 
and at the same time no thread support which requires NO_SYS = 1.

With No_SYS = 1 I would effectively be running the complete stack in 
user land and nothing in the kernel.

The more I read I'm getting the impression it's one or the other.

Without knowing the internal requirements of lwip it's hard to determine 
what compromises I can make in lwip to make some hybrid with OS hooks 
but without threads.

Looking at the NO_SYS sample code it utilizes a busy poll loop which is 
antisocial for a real time kernel.

Anyhow I will keep educating myself.  Taking a look through the core 
code there is no use of threads.  All thread use occurs in the api and 
one instance in slipif.

So I get the impression I should be able to ignore threads as long as I 
don't build/use tcpip and netconn but just use the raw call back api.

Regards

Walter

On 11/3/21 5:58 am, Erik Ekman wrote:
> I think you are looking for the NO_SYS variable, which controls if an
> operating system is used or not.
>
> Maybe this is slightly more up to date:
> https://lwip.fandom.com/wiki/LwIP_with_or_without_an_operating_system
> There is also 
> https://git.savannah.nongnu.org/cgit/lwip.git/tree/doc/NO_SYS_SampleCode.c
> and the unix port in contrib/ which is pretty minimal.
>
> /Erik
>
> On Wed, 3 Mar 2021 at 08:09, Walter ZAMBOTTI <zambotti@iinet.net.au> wrote:
> > I might be using an out of date porting guide referenced here :
> >
> > https://lwip.fandom.com/wiki/Porting_for_an_OS_1.4.0
> >
> > Is there is a more up to date porting guide?
> >
> > Anyway it states for threads:
> >
> > Threads
> >
> > Threads are not required for lwIP, although lwIP is written to use them 
> > efficiently. The following function will be used to instantiate a thread for 
> > lwIP:
> >
> > sys_thread_t sys_thread_new(char *name, void (* thread)(void *arg), void *arg, 
> > int stacksize, int prio): name is the thread name. thread(arg) is the call made 
> > as the thread's entry point. stacksize is the recommanded stack size for this 
> > thread. prio is the priority that lwIP asks for. Stack size(s) and 
> > priority(ies) have to be are defined in lwipopts.h, and so are completely 
> > customizable for your system
> >
> > However there is no mention as what is meant to be configured in order to 
> > either use threads or not to use threads.
> >
> > I assume there is a define that needs to be changed somewhere!
> >
> > Walter
> >
> > _______________________________________________
> > lwip-devel mailing list
> > lwip-devel@nongnu.org
> > https://lists.nongnu.org/mailman/listinfo/lwip-devel