Re: [ECOS] lwIP questions

[Jani Monoses <jani at iv dot ro>]

> When I last took lwIP for a spin, I ended up with a couple of questions:
> 
> - I see that lwIP can not replace the openbsd/freebsd_net packages, and
> hence e.g. tftp is unavailable. Any chance of lwIP being made compatible
> with the rest of the eCos TCP/IP stuff?

Sure, step 0 has been done. Patches welcome :)
 
> - "Abundant choice makes for missery" (*). There are a *lot* of options
> in lwIP. What values should I use and how do I know that I got them
> right? 

Unlike with cereals you have default options and they do different things :)
The options are there because lwip was intended to work with a wide range of
hardware including hw with <10K of RAM and no OS.
For the typical ecos target I don't know what the right values would be so the
defaults given are probably not optimal for any target. But as people try lwip
out they can give feedback on such things and hopefully all those options can
get saner defaults.
The ones which clearly affect performace and memory consumption are PBUF
configs and TCP window configs. The others have an important role too but
they affect performance/memory unclearly and subtly :)
You can start with the some values which can fit in your targets memory then
after it works start tuning them either for footprint or performance.

Jani

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss