JVM for i.MX21 (VCMX212) COG

[craighyatt]

I have the VCMX212 COG with the multimedia COG, etc. I loaded and
booted Linux and that works fine. Now I'd like to try running some
Java apps on the platform, so I need to find a JVM (Java Virtual
Machine) aka JRE (Java Runtime Environment) that executes on the
COG. I see from searching the newsgroup that (1) the COG ARM core
supports Jazelle for hardware acceleration. (2) Virtual Cogs hasn't
done any work (as of the last post I saw) towards getting a JVM
running.

I'd like to know if others have tried getting a JVM up and running
either native on the COG or on top of Linux. It would be nice if the
JVM were configured to make use of Jazelle, but I'd be happy with any
JVM at this point. Otherwise, I'll see what I can find and try it
out.

Thanks in advance,
Craig

P.S. Just to head off a "language wars" discussion... I don't really
prefer any particular development environment/language/IDE. I am just
interested in evaluating the use of Java on COGS.

[iain]

Hi,
This is an interesting topic.
Here's what I understand. PLEASE if anyone knows differently speak up!

Jazelle is a hardware inside the ARM core that lets it execute Java
Bytecode. It's specified by the "J" in the part number.
Since you can read all about the details by doing a websearch...let me
cut to the chase.

I don't think anyone uses it.

Conceptually at least, there is an insruction that says "execute this
java code". A friend of mine thought that the kernel might even be
aware of this, and you MIGHT just be able to execute a java program
fro the command line simply by calling it. I don't know much more
detail than this. I don't know if it's true. I suppose a very simple
java program could test this idea quickly.

My understanding is that Jazelle would be a great feature on a
resource constrained system, it's smaller and is much faster than
using a Java INTERPRETER. But generally most new designs really have
lots of memory(relatively speaking), and will use a JIT compiler
whichi compiles the Java to native executable code. ---am I wrong?

Certainly all the commercial Java vendors do this, and that is how
they claim optimized code, and faster execution.

Sun has/had a JVM called CVM, that is/was opensource, but I haven't
been able to find traces of sucess on an i.MX part yet. I am aware of
attempts to get it to compile for i.MX - that failed (could benefit
from more persistance). They recently changed the name as well, and it
seems to be well hidden. Anyone know where to find it now?

Regards,
Iain

[justanu]

I'm very interested in this too
I got in contact with ARM and asked them about any JVM on the market
on Linux, they said there might be something from a 3rd party, and
that might cost a fortune... no comment ... since RealView seems that
ARM does no longer support linux...
I'm very curious too if there is someone that got any Jazzelle
implementation
Thanks
Justin

On Jul 18, 10:06 am, craighyatt <craighy...@yahoo.com> wrote:

[Ex-Navy]

Sun has an open source project called PhoneME.

The version you need is MR3.

You might fight it useful to be able to build a JVM, called a CDLC and
a MIDP (mobile information device profile).

Since JVM has run on ARM for wireless hotspots this might be of
interest to you in your travels:

http://java.sun.com/javame/reference/docs/sjwc-2.1/pdf-html/html/build/linux-arm.html#50585621_pgfId-484160

> > interested in evaluating the use of Java on COGS.- Hide quoted text -
>
> - Show quoted text -

[Darren Olson]

Sun has an open source project called PhoneME (micro edition) started for the mobile phone market.

 

You might fight it useful to be able to build a JVM, called a CDLC and a MIDP (mobile information device profile).

 

Since JVM has run on ARM for wireless hotspots this might be of interest to you:

 

http://java.sun.com/javame/reference/docs/sjwc-2.1/pdf-html/html/build/linux-arm.html#50585621_pgfId-484160

 

Darren