Re: Java support on N900, the missing thing!!
 

They are Java SE Embedded - a slight, but important in licensing terms, difference.

I retract my previous post, after re-reading the FAQ it doesn't imply that a Java SE for ARM exists.

Re: Java support on N900, the missing thing!!
 

Plus, you simply don't just compile a JVM for a hardware platform (outside embedded systems)....you also compile for OS. You need an ARM/Maemo JVM.

Re: Java support on N900, the missing thing!!
 

Unless you get commercial gain I'd say we are rather beta testers.

If you get them from unofficial source here are the sha256 checksums

$ sha256sum ejre-1_6_0_10-ea-b39-linux-armv*
0d3df7ea125a1fb9dbf74cbe2412bcff67362604ed8736d976 9c2335e74528c6 ejre-1_6_0_10-ea-b39-linux-armv5-sflt-eabi-headless-eval-31_jul_2009.tar.gz
ddc017b48ea6a45599e25ea8b3a5af50ccbe60c64865e20970 88dc1242a11c0c ejre-1_6_0_10-ea-b39-linux-armv5-sflt-eabi-min-eval-31_jul_2009.tar.gz
f369777d24636c8805840fb8771dc7390d69a808d29d50104a b96c5e79a18d93 ejre-1_6_0_10-ea-b39-linux-armv6-sflt-eabi-headless-eval-30_jul_2009.tar.gz
b9e78e0c5d204d6ad2e50adfe89f0bfdf6e1bbb64492f53326 caf9df51ae4014 ejre-1_6_0_10-ea-b39-linux-armv6-vfp-eabi-headless-eval-30_jul_2009.tar.gz
5c707c8e38d1ceae039ad3910e5dc7663d28ec582a92bc8a3b 4f5915b096e5da ejre-1_6_0_10-ea-b39-linux-armv6-vfp-eabi-min-eval-30_jul_2009.tar.gz

As you can see the latest snapshot is from 20090730. And, there is no ARMv7 build.

There is no SUN Java SE 6 for Linux/ARM, but there is OpenJRE 6 for ARM(EL)

Re: Java support on N900, the missing thing!!
 

That won't help you on Maemo5....I presume this JVM runs naked on the processor.

Re: Java support on N900, the missing thing!!
 

Ouch, you're right.
I forgot that Cortex is a v7 family processor :(

@hogwash
openjre/jdk is just another JVM. no nudity :)

Re: Java support on N900, the missing thing!!
 

I understand this. My point was that it is no use for the stated desire of running java apps on Maemo5. If you want to build a new java OS on an ARM platform, you may be in luck, but this JVM (if I understand it) has no knowledge of Maemo interfaces/hildon/gtk/qt etc, so would be pretty useless.

Re: Java support on N900, the missing thing!!
 

why would the JVM need to know about hildon, gtk, qt? it's not about making java-applets run with the same interface as native maemo software, applets just use swing as they do in any other jvm on any other platform.

Re: Java support on N900, the missing thing!!
 

Opera Mini requires Java ME; not Java SE. When we refer to Java we usually refer to Java SE.

Opera Mini is optimized for specific devices (screen size, input methods, etc). I'm not entirely sure how this optimization works, but you cannot simply grab Opera Mini and run that on any device you get Java ME working on and get an optimized experience.

Have to admit I'm impressed with Opera Mini 5.0 beta btw.

I think SUN is aware of Nokia N900 because I see various blog posts by employers about that. JavaFX requires either Java ME or Java SE. An early access built of 1.2 is available for Windows Mobile only though.

[EDIT]phoneME was ported previously to 770 and N800 (Bora).

Project homepage: https://phoneme.dev.java.net
Linux/ARM port: https://phoneme.dev.java.net/downloads_previous.html
Nokia 770/N800 port: http://wiki.java.net/bin/view/Mobile...honeMEAdvanced[/EDIT]

What do you mean? That is always the case.

The JVM is static or dynamic compiled and utilizes the processor. Whether it runs on a Linux kernel and you have only Java SE programs running on the JVM (like with Jalimbo) or whether you run a full Linux server headless with Apache/Tomcat does not matter. The JVM runs on an OS with a kernel, and the Java applications run in the JVM.

The good news is that OpenJRE (OpenJDK 6 JRE) is almost completely compatible with SUN's Java SE 6. There are only a few proprietary parts of SUN Java SE 5 & 6. Effort is put in replacing these with open source variants.

All one has to do is recompile this and its dependancies in sbox. Which will take quite some time, and the built will not be optimized for Maemo 5 or ARMv7 (but Linux/ARMv5 and Linux/ARMv6 should work!). Once packed this binary may be distributed via extras-devel.

We could also use Jalimbo, its already ported to previous Java versions.

We'd also need a plugin for MicroB to be able to embed Java. These work with e.g. OpenJRE too.

In short, there are tons of methods to get a Java ME compatible VM or Java SE compatible VM working on Linux/ARM. Each requires effort though. Before I start effort on porting I rather first try SUN's proprietary packages to check performance and see if MicroEmu can be run from that.

Re: Java support on N900, the missing thing!!
 

The Java SE applications I use are either headless or Swing. Yes, doesn't look nice in desktop environment. Whatever. Both Qt (Qt Jambi) and GTK have bindings for Java, allowing you to give the application 'native feel'.

Re: Java support on N900, the missing thing!!
 

By "run naked on the processor" I mean that the JVM is the only software that runs on the processor - as is the case with embedded apps.

To actually see anything on your display, a whole truckload of library code needs to be implemented; take the simple case of Swing (which ain't that simple) - for a basic Swing window to visually appear on your N900, there needs to be bindings through to the hildon layer....ie. the JRE needs to be built - not only for the ARM platform - but also for the Maemo environment it will interact with. Not only that, but the limitations of the Maemo5 GUI will have a significant impact on how those bindings are implemented. Coding Java apps for Maemo5 will be a tad more awkward than for good ol' 'Doze or X ;)