Re: Point a beginner in the right direction? Cheap bare-board to run with a RTOS for running ADA

[Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP>]

On 2013-07-08, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
> On Mon, 8 Jul 2013 17:23:06 +0000 (UTC), Simon Clubley wrote:
>>>> There's nothing to stop a end user programmer writing their own BSP; this
>>>> appears to be a common capability for RTOS environments. I've written 2-3
>>>> BSPs for RTEMS over the years.
>>>
>>> Fine. Why don't you bundle it with GNAT and GPS and resell the package to
>>> those crowds of hobbyist longing for it?
>> 
>> With those specific products, what you would be selling would be support
>> and that's something which needs to be supplied by a existing vendor
>> using their existing infrastructure.
>
> No. You would sell your tool chain and re-sell the hardware.
>

Dmitry, the whole reason behind this discussion is the desire to get Ada
running on existing hardware available from a variety of sources.

BTW, not even, say, RedHat sells hardware; they don't even really
sell RHEL itself but sell support for it. If you want RHEL for free,
you can get it in the form of Centos or Scientific Linux.

I mention RHEL because the products I mentioned are available with
similar license conditions to those packages found in RHEL.

>> Besides, that's only viable when you can use RTEMS instead of running on
>> the bare metal.
>
> You said customers need no OS. Why do you expect anybody would do something
> you consider not viable?
>

You have completely misunderstood. RTEMS comes into this because of it's
existing support for Ada and the ability of RTEMS to run on a number of
platforms.

If you can run RTEMS on your chosen platform (including writing a BSP if
required) then great, you can have Ada. But there are many platforms on
which RTEMS will either not run or for which it's not appropriate for the
job at hand. In that case, you are coding for bare metal and then face the
Ada availability issues which we are discussing.

>> Even when you use RTEMS, the end user still has to supply
>> a BSP if their board is not already supported.
>
> You said it would be simple. You want customers writing a BSP for YOUR
> board?
>

Huh? Where did I say anything about creating a specific board and selling
that ?

What is needed is to create a Ada compiler which will run in bare metal
mode on a number of specific architectures (ARM and MIPS would be my
personal initial preferences). People can then use the compiler to write
code which runs on their specific board of interest.

This is exactly what happens in the C world when writing bare metal code.
I use the same physical GCC cross compiler for ARM C projects and it
produces code which can run on all the ARM boards I have used. What you
need to then add in are the libraries (and linker scripts) which support
the hardware on each specific board.

The board or MCU specific hardware support is a separate problem from the
bare metal compiler which will generate code for the architecture as a
whole.

In the Ada world, we still need a finished equivalent of the first part;
the cross compiler which generates code for running on the architecture in
bare metal mode.

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
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