[En-Nut-Discussion] FW: AVR32 / ARM support

[Ulrich Prinz]

Hi Johan,

Am 09.10.2010 16:55, schrieb Johan van der Stoel:
> Dear repliers,
>
> Either through the forum or privately.
>
> I think it's good to summarize some things, but also to post some additional
> questions. Please comment if you have any additional suggestions!
>
> 1. CPU
> To me it looks like SAM7/9&  AVR32 are quite well supported, and Cortex M3
> is coming.

Cortex is coming definitely :) And I plan LPC2xxx as well as STM8. But 
there are some other CPUs that are interesting too. How about Nut/OS on 
the new Z80 derivatives like Z80Acclaim?
>
> 2. Nut/OS or Linux?
> Not many people have commented on this topic, but what I have heard and read
> I think:
> - minimum footprint for embedded Linux is 4 Mbyte. So when you decide to use
> embedded Linux, always an external flash memory device is needed.
Yes, that's right.

> - If you want to use IPv6 today, use Linux; the chance is low it will be
> available in Nut/OS within 1 year - or very limited. I would be very
> interested to hear some more opinions about this topic. I guess everybody
> will face this problem within a few years from now!

I don't agree! IPv6 is something our company is very interested in. But 
realtime tasking is not needed. As most operating systems that support 
the one, support the other too but also cost a lot of money, Nut/OS will 
get IPv6. The problem is, that no one seems to really start the task.
What I learned with projects in the internet is, that lot of people 
discuss how they really need this and that and how they think it could 
be done, but really going into actions is another thing.
But, if you start it and keep it going, some of them come back and 
really support you.
IPv6 is the same as the different wireless stacks or integrating a more 
or less different architecture: It looks to be very difficult and 
complicated and it is combined with 3200 pages of documentation you need 
to read.
But to be honest, if you start it you run into it and you get familiar 
with it and the how easy it can be. I had some respects too as I thought 
about integration of CortexM3. But then I got some ports from other guys 
of the list and I crawled the code. Now, it was based on old versions of 
Nut/OS and I just took the code to see how others did it before. But 
then I threw most of it away and did it different, hopefully better or 
more compliant with existing structures.

So, I cannot add CorteX, LPC, display drivers and so on alone. May be if 
I could write a driver for a physics flag, that stops time, I might 
be... But if one starts a project and keeps it going, we support and 
contribute.

I really see that IPv6 is needed and I know that Harald is of the same 
opinion. But if I had to write the stack alone it must wait until after 
CeBit next year.
>
> 3. Ethernet controller/switch
> I think the RTL8305 is a great device for our application. Nice to hear it
> is already supported!

Afaik only DM9000 is supported as external ethernet chip. But if you get 
me a demo board with an RTL8xxx on it, I will combine the work of 
writing the driver for STM32 internal EMAC and the RTL. I was looking 
for a discrete EMAC too, as STM only provides chips with large FLASH and 
external memory interface or with EMAC. I'd prefer a combination. On the 
other hand, our products will feature Ethernet as a plugin, so we could 
live with an external EMAC pretty fine.

It always helps to aks in the list, may be there is someone who forgot 
that he already wrote the driver and forgot to contribute it.

Hey, looked at your website. That's my favourite playground. The crown 
of my Cortex port will be Elektor Internet Radio running on the 
STM3210C-EVAL kit.

Best regards,
Ulrich