[fpc-pascal] Embedded ARM system unit

[Marco van de Voort]

> I am in the first stage of creating a system unit for 
> Embedded ARM. Things are working but I get a lot of 
> Warnings and Hints (See some of them below).
> Should I be worried about this?

I see no troubling ones. THe first few mean that generic might not be 64-bit
clean, but are probably false. (since generic.inc is used for the 64-bit ports too),
the others are simply unused Unix symbols. This is normal, because these includefiles
are also used in a few other places (like baseunix), where they _are_ used.

> In the "fpc_InitializeUnits" procedure I have excluded the call 
> to the "fpc_cpuinit" procedure, my system cannot start if it is 
> included in the start up code. I cannot figure out the meaning 
> of this procedure. Dos anyone know what it is meant to do.

> (*****************
> procedure fpc_cpuinit;
> begin
>   asm
>     rfs r0
>     and r0,r0,#0xffe0ffff
>     orr r0,r0,#0x00020000
>     wfs r0
>   end;
> end;

Probably modifications to the processor's exceptions registers. IOW, enable certain exceptions so
that they can be trapped to Delphi language exceptions.