Re: [Caml-list] OCaml embedded

[Kenneth Adam Miller <kennethadammiller@gmail.com>]

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Oh yeah, you need a OCaml tool chain targeted to arm... whoops. Sorry about
that, I missed that part.

On Fri, Jun 26, 2015 at 1:40 AM, Kenneth Adam Miller <
kennethadammiller@gmail.com> wrote:

> It's easy to compile images that can be run in qemu with buildroot. I
> don't know much about yocto, but you can use the crosstool-ng toolkit to
> compile a tool chain for cross compiling. You can have multiple tool
> chains, and have unique images for each of your respective targets,
> possibly just running your ocaml code locally and recompiling it for arm
> when you want to put it on the device :)
>
> On Thu, Jun 25, 2015 at 11:04 PM, Berke Durak <berke.durak@gmail.com>
> wrote:
>
>> On Tue, Jun 23, 2015 at 6:32 AM, Markus Weißmann
>> <markus.weissmann@in.tum.de> wrote:
>> >
>> > I can offer experience in the following cases:
>> > 1) If your system is powerful enough (e.g. rasperry pi), you can just
>> install the ocaml toolchain on your system and develop there on your target
>> system.
>>
>> Seconded.  We did almost that for one of our projects and it works
>> pretty well.  The difference is that we didn't use QEmu, but two of
>> our custom Q7 board (based on a Zynq ARM Cortex A9 with 512 MB RAM,
>> see http://xiphos.com/products/q7-processor/ ).
>>
>> We use Yocto to generate two versions of a Linux system: the target
>> system, and a much larger version that contains developer tools (C
>> compiler, m4, etc.)  The development system runs from microSD cards,
>> and takes the better part of a gigabyte, while the target system has
>> to run from < 64 megs of flash.  The required run-time dependencies of
>> the target system have to be manually configured in the Yocto recipes.
>>
>> We then manually install opam on the developer board, and use it to
>> compile our OCaml code. The generated native ARM executables are then
>> packaged into .ipks and transferred to the target Q7 board (connected
>> to actual hardware:
>> http://www.ghgsat.com/wp-content/uploads/2015/03/Payload-Selfie.jpg )
>> The packaging is done using a simple shell script that invokes ar and
>> tar.
>>
>> We did try using QEmu but it's significantly slower, however it may
>> come into play as automating the build process (using a virtual
>> machine or dedicated hardware) is on our to do list, and build time
>> isn't as important when it's a nightly automated build.
>>
>> Initially we looked into using a cross-compiler but we decided that
>> being able to use Opam largely outweighs any possible benefit we could
>> get from cross-compiling.  And cross-compiling is often a source of
>> headaches, even when compiling plain old C.  We would have to write a
>> lot of Yocto recipes to get it running.  Note that Yocto is written in
>> a progarmming language called Python and requires recipes to be
>> expressed mostly the same language.
>>
>> To conclude, as powerful ARM systems are very cheap and plentiful
>> these days, and since the convenience of Opam is immense, I'm not sure
>> there is much incentive in using a cross-compiler.  BTW, is there a
>> maintained ARM cross-compiler?
>> --
>> Berke Durak
>>
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>>
>
>

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