Porting JVM to MINX

Applications Programming
1

Hi,
As you may see from the title, for some reason I need to make running .class files on Minix possible (a compiler is not necessary). So could somebody point me in any direction, suggest some literature or give some advice? Generally, how would you do it?
Also how big is this project? I guess I should port openJDK and make some kind of interpreter. But I never did something similar. (I'm CS student on second year)

I have also read Tanenbaum's "operating systems design and implementation". It gave me a lot of insight of minix internals.

Thanks in advance

2

Go to the oracle site and see if there is java for your architecture. It won't do any good to write java code without a Java Virtual Machine. This is actually the system-specific piece you need. It may be part of a JDK for your box. I do not know.

If it exists, then everything is a simple install.

The only word of caution is that some releases of the jvm have had issues in UNIX.
Check out via reviews what you are getting before you install it.

3

there is java for my architecture its x86.. I found jamVM, does anybody have any tips for porting it to unix?

4

JamVM is probably the best option for your task assuming you are prepared to port/write some assembly code.
Another issue is JamVM relies on Posix threads but Minix doesn't implement them. You might have a look to JAmiga (A port of JamVM to Amiga) which managed to overcome that issue.

5

thank you for JAmiga hope it will help, but isn't Minix a POSIX standard os?

EDIT: could I strip JamVM of any threads? I don't need java threads, lets say ill use just single threaded apps. Could JVM be just one process without taking care of threads inside? Its a college project if I manage to execute one System.out it would be miracle :slight_smile: . No really is it possible to strip the jvm threads?

6

It might be but POSIX Threads is an optional feature.

Not really. Java is inherently multi-threaded, even if your application is not.

7

Thanks again, sorry for bothering you but do you think that is possible to port openJDK to minix?

8

If you can't port jamvm, I sincerely doubt you'd be able to port something megatons bigger and more complicated. Did you look up what jamvm was?

9

I would have replied not reasonably several years ago. I have no recent experience with Minix but it might be doable now although don't expect something trivial like "./configure;make;make install" to work and the lack of posix thread support might also be an issue here.

Another issue is the build process uses "ant" which itself needs java, kind of chicken and egg problem.

Looks like someone already attempted that port by the way:
porting OpenJDK to a different OS not having java

OTOH, I agree with Corona688 reply, according to its web site, JamVM should be much easier to port.