Re: Kinetis TWR-K60N512-KIT questions

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Hi Drasko

Thanks for your encouraging words.

On 14.04.2011 17:04, Drasko DRASKOVIC wrote:
> On Thu, Apr 14, 2011 at 3:09 PM, Ilija Kocho <ilijak@xxxxxxxxxxx> wrote:
>> On 14.04.2011 13:11, Drasko DRASKOVIC wrote:
>>> Hi Ilija,
>>> for my curiosity, what is the footprint of this port ?
>>> If I am not mistaken,  K60 have only 128KB of on-chip SRAM. Can it fit ?
>> You are not mistaken regarding K60, only for eCos 128KiB RAM is not
>> "only", it's "a lot" - "puna kapa".
> Wow,
> this is great. I have been looking lately at these SoCs and I like
> eCos, but so fat I have been running it only on SoCs wit lot of
> external RAM. The images I was makeing have been ~1.5MB with my
> application.

How much of this is for eCos itself? How much is code and how much data?
I guess/speculate your experience is with general purpose OSses like Linux.
In eCos-like environments, unlike Linux, code is typically executed in
FLASH so you need RAM only for data (including stacks, etc).

> I am interested in haveing RedBoot, USB stack and TCP/IP stack. It
> would be impressive to me if this port can fit this all in K60 ! Can
> it ? What can it currently do ?

RedBoot is not an environment for running an application. You can use it
during development for loading code and debugging, but finally you burn
your (eCos) application image in FLASH.
Currently available K60 has 512 KiB FLASH + 128 KiB RAM, announced are 1
What it can do depends on your application requirements.
For example (Note: this may be extreme) on system with 32KiB RAM you can
have lwIP TCP/IP and run elementary HTTP server. Code would occupy less
than 64 KiB FLASH. Adding USB would add some memory but not much.

> Speaking of which, do what would be the crucial advantages for you of
> eCos ove Freescales MQX that comes with K60 ?

I can't speak for MQX technical merits as I haven't tried it. I can say
only what I like at eCos:

    - Excellent modular structure;
    - Source code configurabulity: again due to structure but also
    - Unix like I/O, POSIX compatibility - not every RTOS has it;
    - Well (could be better) documented (particularly kernel and system
    - Free as freedom. This is like roll-your-own, only you are not
alone. (Note: Freescale gives MQX free of charge but you are allowed to
use it only on their chips)
    - Community that helps and (very important for me) allows you to
participate (unlikely in proprietary SW world).

Speaking of Kinetis we have one apparent disadvantage regarding MQX -
we're lagging little-bit. This is the main reason why I decided for
early release of our port. Ethernet, SPI, USB are still on our ToDo
list, but what you have on Bugzilla has everything you need to start
     HAL - basic system initialization and system clock;
     HAL - diagnostic serial support - polled;
     Serial device driver - interrupt driven.

> Thanks for your help, for your answers and impressive work !

You are welcome.


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