Re: [Caml-list] Ocaml on an embedded arm system (no linux)

[Dwight Schauer <dschauer@gmail.com>]

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No, the Flash/RAM sizes I mentioned are not a typo.

OCaPIC is a similar OCaml project for PIC microntrollers.
http://www.algo-prog.info/ocapic/web/index.php?id=OCAPIC:OCAPIC

The microcontrollers targetted by OCaPIC have the following characteristics:
  RAM memory: a few kB.
  Flash memory: a few tens of kB.
  Clock: a few MHz

The ARM microcontrollers I'm looking to target are much bigger than PIC
microcontrollers on all 3 of those counts are significantly larger.



On Fri, Sep 20, 2013 at 10:54 AM, Gerd Stolpmann <info@gerd-stolpmann.de>wrote:

> Am Freitag, den 20.09.2013, 09:13 -0500 schrieb Dwight Schauer:
>
> > The ARM processors I'm looking to target are:
> > STM32F407ZGT6 ARM Cortex-M4, 1MB Flash, 196KB RAM (Has floating point)
> > STM32F103RB ARM Cortex-M3, 128 KB Flash, 20K RAM (No floating point)
>
> I hope this isn't a typo. 196 KB RAM is way too low to even run a hello
> world program. The predecessor of ocaml, caml-light, needed 640K at
> minimum for running it on DOS, and that was 16 bit code. Ocaml is a lot
> larger, and generates less dense 32 bit code.
>
> For a very small app on bare metal, I think you need at least 4-8 MB of
> memory. For making you happy, calculate 64 MB. I cannot say much about
> the split flash mem vs. RAM - but you should take into account that the
> representation of values isn't optimized for compactness, and you also
> need extra RAM to give the garbage collector room.
>
> Maybe it is possible to lower the memory requirements by modifying the
> ocaml runtime (e.g. make the bytecode more compact at the cost of extra
> decoding steps, remove unneeded parts like the compactor, ...), but I
> doubt you'll be able to hit the mentioned limits.
>
> Gerd
>
>
> >
> >
> > On both I'd like to be able to run bytecode both out of Flash and RAM.
> > (Primarily flash, but RAM for debugging).
> >
> >
> > Speed is on overly important as long as I can control when the garbage
> > collection is run (could be done in C in the multitasker?).
> >
> >
> >
> > Dwight
> >
> >
>
> --
> ------------------------------------------------------------
> Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
> Creator of GODI and camlcity.org.
> Contact details:        http://www.camlcity.org/contact.html
> Company homepage:       http://www.gerd-stolpmann.de
> ------------------------------------------------------------
>

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