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

[Paul Breneman]

I didn't know better, but last fall I also posted this topic in the Free 
Pascal section of the Lazarus forums.  Today and yesterday I left notes 
there about making small VMs with Debian Jessie RC2 *and* ReactOS:
http://forum.lazarus.freepascal.org/index.php/topic,26315.0.html


On 11/01/2014 06:17 AM, Paul Breneman wrote:
> 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.