ARM Cortex-M Microcontroller startup files

[Martin Nowak via Digitalmars-d]

On 04/30/2015 01:30 PM, Mike wrote:
> While this may seem simple to achieve, I think it will raise a few
> questions that will need answering.
> 
> * Can ModuleInfo be leveraged, without introducing overhead, to call
> module constructors and static constructors?  They might be useful for
> hardware initialization.

Currently D sorts modules by initialization order,which requires every
moduleinfo to contain an array of imported modules. Quite a lot of RAM
for a nice to have feature, so we should drop it or at least provide a
-fno-moduleinfo switch.

> * Is dynamic memory allocation a requirement of D, or a library feature?

Definitely a library feature, though many language features, like array
appending, won't work without it (delegate closures won't even work
without a GC).

> * Does D need the C runtime, or can it init on its own?

It shouldn't need a C runtime.

> * Should the C standard library bindings be part of the runtime, or
> exist as an external Deimos library?  Either way they can still be used
> by the runtime, I'm just suggesting that they should be encapsulated.

It doesn't cost you anything to include the bindings in a release, they
could be maintained in a separate project if that helps.

> * What will be done about TypeInfo for now?  It's causing me some
> serious code-bloat problems.  See
> http://forum.dlang.org/post/quemhwpgijwmqtpxukiv@forum.dlang.org

Implement a -fno-rtti switch for GDC.

> * Is data and bss initialization part of  the runtime, or delegated to
> toolchain, silicon, and BSP vendors?

We should provide appropriate linker scripts and do the initialization.