[fpc-pascal] Embedded ARM system unit

[Florian Klaempfl]

Marco van de Voort wrote:

>>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.

Maybe we should think about a generic embedded rtl which is configurable what's
included.

> 
> 
>>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.

Enabling fpu exceptions.