porting openJDK to MINIX

[Andrew Haley]

On 12/14/2012 01:19 PM, John Smith wrote:

> I need to port openJDK to MINIX (and also write some bytecode
> interpreter if not the whole JVM, it only needs to run .class files
> compiler is not needed). Given that I'm CS student on second year, I
> would be very thankful if somebody can point me in right direction,
> suggest some literature or give me some insight for solving this
> problem. Also, if its possible for somebody to roughly estimate how
> much time is needed for this project, it would help me to get a
> better picture.

I think there is a porting guide, but I've never seen it.

With regard to the CPU:

If you're prepared to use the Zero port, which is written in C++, it's
just a matter of recompilation.  Zero on the current HotSpot is
broken, but you can use an earlier version.

If you're prepared to use the C++ interpreter with some assembler
help, that's a bigger job.  You'll need to write an assembler (HotSpot
use its own) and code to link Java and native code.

If you want to write the whole bytecode interpreter in assembler
that's a much bigger job: I'd estimate 6 months to one year -- if you
know what you're doing.

With regard to the OS:

I don't know how long it would take to port the OS layer.  There are
already ports to Solaris and Linux, so you have a good starting point.
It's the really low-level interfaces that will give you trouble,
though.

Andrew.