[fpc-devel] Small virtual machine to cross compile FPC

[Paul Breneman]

On 11/01/2014 03:13 AM, Hans-Peter Diettrich wrote:
> Paul Breneman schrieb:
>
>>> I think 100Mb is a bit small.
>>> You'll need cross-binutils, X, cross-dev libs and whatnot.
>>>
>>> 650Mb would be feasable, I guess.
>>
>> Thanks for that info, but couldn't most of that be download into the
>> VM *after* it is running?  Seems to me I'd like the *smallest* VM and
>> then have a way to load things into that standard PC.  But maybe I'm
>> thinking wrongly?  If so please help me get it right.
>
> I don't understand why the VM *size* should matter - unless it's >30GB
> for current Windows versions. My goal would be a *simple* OS, easy to
> configure and manage, and then install into it whatever is required. Why
> download and configure all the required tools whenever the VM is run?
> This may take half an day, to get the VM up for cross-development, and
> the downloads end up on the virtual disk as well.
>
> For cross-development I'd install a network of dedicated target VMs, one
> of which can host the project files, and then build the project in every
> target VM. This would allow for parallel builds, and every created
> executable can be tested immediately on its platform - also in parallel
> for comparison of the GUI and operation. With a single development VM
> you would need another VM or emulator to perform the final checks, for
> every single target platform.
>
>> I've looked at (or tried) laz4android and fpcup.  Seems that such an
>> approach would work much better on a "standard" PC?
>
> Virtual machines work well on the same hardware (CPU), but for other
> targets (ARM instead of x86) an emulator is required. Wikipedia says
> that a LiveCD and AndroVM with Android for x86 is available, where it
> might be possible to develop Android applications somewhat "natively" on
> an x86 machine. But finally an emulator or physical device is required,
> where the cross-compiled programs can run on their target CPU, using the
> according libraries (RTL, VCL... for ARM).
>
> Please don't ask me about Adroid, my experience is limited to
> FPC/Lazarus development on various Windows and Linux VMs, and I never
> tried to cross-compile myself. Why cross-compile when I cannot check the
> results?
>
> DoDi

Thanks DoDi for all of your feedback.

You are correct that the size of the VM doesn't matter much.  I was 
thinking of leaving out things that change often but maybe that is 
really only the source code.

Building FPC is complex and mobile seems even more complex.  So an easy 
and simple way to see things work might be a valuable first step even 
though the developer should move over to a better development 
environment ASAP.