Porting to i686-msdosdjgpp

[Thomas Stüfe]

On Mon, Nov 15, 2021 at 11:09 PM David Holmes <david.holmes at oracle.com>
wrote:

> On 16/11/2021 12:06 am, gnufan42 wrote:
> > David Holmes wrote:
> >> I'd say it is technically impossible to port OpenJDK to DOS as you do
> >> not have any of the necessary operating system support for threads,
> >> synchronization, virtual memory, ....
> >
> >       Well, these difficulties are all overcame by the DJGPP project.
> They use DPMI to let the code runs in 32-bit protected mode, they
> implemented a lot of POSIX functions, including pthread. Otherwise I won't
> be trying.
>
> I'd never heard of DJGPP but the pthread support still seems limited -
> hard to find an accurate current description of what is actually
> supported. So I would not say these difficulties are overcome :) This
> will be an exceedingly complex and challenging project.
>
> Cheers,
> David
>

I still think that the CVM (JavaME) may be better suited for the task. From
the time I worked with it I remember that it was targeted to low-memory
devices, its C code base was extremely portable, it was very configurable
(important for embedded) etc. We ran it with green threading (like Loom
today) and that worked. OpenJDK OTOH relies on native posix threads, and
there is no easy way around that.

I seemed to remember that Sun open-sourced JavaME in 2006. But I could not
find the project page.

https://en.wikipedia.org/wiki/Java_Platform,_Micro_Edition
https://en.wikipedia.org/wiki/PhoneME

PhoneME website seems defunct now. Does anyone know what happened with that
project?

Cheers, Thomas


>
> > Thanks,
> > Gnufan
> >
>
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