On 4 February 2012 14:47, Paulo Pinto <pjmlp@progtools.org> wrote:

So are you writting your own crt0 startup code?

Absolutely. Most microcontroller based systems will have a custom written init routine.

Are you also creating the code that takes care to validate if there
are atexit() handlers in need to be called after main?

main will never exit on a typical microcontroller implementation.

Are you writing the code that takes care to handle program arguments
and passing them to main() or whatever is your program entry point?

Unlikely. Embedded systems/microcontrollers typically just begin executing when they receive power.

You probably won't even have main, you just declare a 'void start()' function and make sure to place it at the boot address.

Because if you aren't, then you are using C runtime library no matter what.

I've never linked a c runtime to a microcontroller app.

All that said, some of the faster arduino systems are reasonably capable, and have little linux kernels. They might work fine with an adapted druntime, as long as the exe doesn't bloat, and it doesn't allocate like a hog.

But D should at least be capable of producing a raw exe without any libs either way. It's just a compiler, there's no technical reason why it shouldn't, except a few language features that depend on intrinsic library calls which you would have to avoid.

On 03.02.2012 20:32, Manu wrote:

On 3 February 2012 16:45, Paulo Pinto <pjmlp@progtools.org
<mailto:pjmlp@progtools.org>> wrote:

The only language without runtime is pure assembly.

And C.. there's no requirement to link the CRT in a C app. In fact, in
many of my projects, I don't.
I frequently find that the ONLY function I use from the CRT is
sprintf... which I really should write(/copy) my own version of, so I
can never link a CRT again :P

All high level languages require a runtime library, even C, despite
what many people think.

Wrong, the C _language_ depends on NOTHING in the CRT. I prefer to avoid

linking it wherever possible. Strangely enough, I find the 'standard' C
library to be one of the least standard libraries out there, and avoid
it for that reason.

Now in this case what would be nice would be the possibility to
generate code that runs on top of the arduino without any
real OS. This is a common use case in embedded systems and here the
runtime has even an higher value as it takes the
role of an OS.

All that's required is a toolchain that's capable of producing an exe
without the requirement to link any compulsory library.

--
Paulo
"Manu" <turkeyman@gmail.com <mailto:turkeyman@gmail.com>> wrote in

message news:mailman.312.1328277504.25230.digitalmars-d@puremagic.com...
On 3 February 2012 15:37, Alex_Dovhal <alex_dovhal@yahoo.com
<mailto:alex_dovhal@yahoo.com>> wrote:

__
>Andrea Fontana" <advmail@katamail.com

<mailto:advmail@katamail.com>> wrote:
>In this case can we hope for a d frontend?
That depends if it's MCU or MPU. If it will be MCU(like
ARM7TDMI), which means Harvard Architecture (where Program code
and RAM are physically different). Also internal RAM of a few KB
and no Linux.
If it'll be MCU then it can have Linux OS, so theoretically it
can have GDC ported.

Eh? Why would GDC depend on linux at all? If you disable the GC (and
dependent language functionality), and manage to do something about
the horrible exe bloat, there's no reason it shouldn't be able to
target anything...
The obvious advantage over C is the syntax features. Clearly D as a
*language* shouldn't DEPEND on the druntime, other than some
language features that imply GC, like dynamic arrays/etc.
Is the toolchain not capable of producing a working exe without
linking any library? Surely you can write a totally raw app with no
libs at all? (assuming you avoid language features that make
implicit druntime calls)