[riot-devel] HotSpot JVM on RIOT-OS?

Marc Sissom MSissom at krypton-solutions.com
Tue Aug 11 23:19:06 CEST 2015

Hi Zac,

Have you looked at the sam3x8e datasheet? Right on the front page it says it has 512KB of flash (AKA ROM or nonvolatile program and data storage). The chip has 96KB of RAM. Looking into task manager on Windows 7 I see a javaw.exe that is occupying 133MB of RAM and my JRE takes up 153MB of disk. Admittedly this is not a perfect comparison, but surely these numbers mean something to you.

RIOT is meant for *small* systems. Not SMALL or S M A L L but small systems. Some of these systems are so small that they can't do "Hello World" because the "printf" code takes up too much space.

> Thoughts? Criticisms? Hate mail?

In other words, you're nuts!


Given that, here's a true Java bytecode chip that I worked with a few years back:


Here's an FPGA core:


And an ARM product:


In other words, you are not the first to think of this, and in some cases it's not a bad idea. On the other hand, I think you can safely forget Akka on RIOT.

You also mentioned Python; have a look here:



Marc Sissom
Krypton Solutions

-----Original Message-----
From: devel [mailto:devel-bounces at riot-os.org] On Behalf Of Zac Harvey
Sent: Tuesday, August 11, 2015 3:23 PM
To: RIOT OS kernel developers
Subject: Re: [riot-devel] HotSpot JVM on RIOT-OS?

Thanks Kaspar and Joakim,

I'm not trying to be difficult here (I promise!) I'm just trying to see the forest through the trees.

When you say that "The OpenJDK would probably require many megabytes of both ROM and RAM, this means it will not run on the sam3x8e...", why? Is it because it would require "many megabytes", or because it requires ROM, which I'm guessing isn't supported by RIOT-OS?

And yes, I will definitely dive into Darjeeling/LLVM, but am trying to see if I can't brute force an easier solution first. :-)

Thanks again!

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