Java-Linux-Mobile Platform

Status Increasing number of small mobile Linux devices Java on mobile mobile and embedded devices Classpath & friends are 'grown up' but! Free java on Linux-embedded is rarely in use

Increasing number of small mobile Linux devices

Java on mobile mobile and embedded devices

Classpath & friends are 'grown up'

Free java on Linux-embedded is rarely in use

Java embedded? What is Java? J2ME CLDC J2ME CDC J2ME CDC + AGUI (JSR 209) J2SE Only certified platforms (JVMs+class libraries) are allowed to be named 'Java'. The alternative, free JVMs are not certified

What is Java?

J2ME CLDC

J2ME CDC

J2ME CDC + AGUI (JSR 209)

J2SE

Only certified platforms (JVMs+class libraries) are allowed to be named 'Java'.

The alternative, free JVMs are not certified

Java and Java-like Implementations Sun J2SE – (GPL and proprietary) Sun J2ME PhoneME (GPL) J2ME IBM J9 (proprietary) Gnu Classpath (GPL) with different JVMs cacaojvm (GPL) jamvm (GPL) kaffe (GPL) ... Aonix, Perc (proprietary) Aicas, JamaicaVM (proprietary) ... } Realtime capable

Sun J2SE – (GPL and proprietary)

Sun J2ME PhoneME (GPL)

J2ME IBM J9 (proprietary)

Gnu Classpath (GPL) with different JVMs

cacaojvm (GPL)

jamvm (GPL)

kaffe (GPL)

...

Aonix, Perc (proprietary)

Aicas, JamaicaVM (proprietary)

...

Realtime capable

As always - the GUI makes it! Except J2ME CLDC everything is ~ Java 1.3. Concise: The different GUI attempts. MIDP 2.0 (minimal) AWT (small amount of features) Swing (problems in performance) SWT (with GTK peer: many dependencies) SWT (with QT peer: proprietary) further possibilities Java-gnome escher (pure java X library) jsdl (java sdl bindings)

Except J2ME CLDC everything is ~ Java 1.3.

Concise: The different GUI attempts.

MIDP 2.0 (minimal)

AWT (small amount of features)

Swing (problems in performance)

SWT (with GTK peer: many dependencies)

SWT (with QT peer: proprietary)

further possibilities

Java-gnome

escher (pure java X library)

jsdl (java sdl bindings)

Pocket-Size Linux Distributions Familiar (OpenEmbedded, ipkg) Ångström (OpenEmbedded, ipkg) Maemo (Scratchbox, apt, dpkg) OpenMoko (OpenEmbedded, ipkg) Environments Opie (Framebuffer/QT embedded) GPE (Xserver/GTK) Maemo (Xserver/GTK + Hildon + Osso) OpenMoko (Xserver/GTK + libmokoui + libmokocore)

Distributions

Familiar (OpenEmbedded, ipkg)

Ångström (OpenEmbedded, ipkg)

Maemo (Scratchbox, apt, dpkg)

OpenMoko (OpenEmbedded, ipkg)

Environments

Opie (Framebuffer/QT embedded)

GPE (Xserver/GTK)

Maemo (Xserver/GTK + Hildon + Osso)

OpenMoko (Xserver/GTK + libmokoui + libmokocore)

Java @ Pocket-Size Linux mostly sporadic: e.g. jamvm and the old gnu classpath seldomly updated no concept for packaging and further integration GUI: mostly AWT (with gtk peer) OpenEmbedded: jamvm 1.4.2/classpath 0.90 Maemo: jamvm 1.4.2/classpath 0.91 (without 'hildonizing') sun PhoneME (as tar.gz, without gui) JaLiMo

mostly sporadic:

e.g. jamvm and the old gnu classpath

seldomly updated

no concept for packaging and further integration

GUI: mostly AWT (with gtk peer)

OpenEmbedded: jamvm 1.4.2/classpath 0.90

Maemo:

jamvm 1.4.2/classpath 0.91 (without 'hildonizing')

sun PhoneME (as tar.gz, without gui)

JaLiMo

Which problems exist? at the Java-Porting the Build Process is different, mostly dependencies for the GUI missing optimisation for the embedded area size & modularization startup-speed in development Embedded Java is different missing integration in the environments packaging + dependency management missing dependencies and bindings bad framework/toolchain support

at the Java-Porting

the Build Process is different, mostly

dependencies for the GUI

missing optimisation for the embedded area

size & modularization

startup-speed

in development

Embedded Java is different

missing integration in the environments

packaging + dependency management

missing dependencies and bindings

bad framework/toolchain support

JaLiMo JaLiMo is an initiative to build a complete free Java-Stack for mobile Linux devices. the integration and completion of existing projects has the focus. "Java-like environment for mobile Linux devices" Main tasks are the problems after porting the JVM!

JaLiMo is an initiative to build a complete free Java-Stack for mobile Linux devices.

the integration and completion of existing projects has the focus.

JaLiMo - Who? sponsored by the Tarent GmbH Sebastian Mancke Robert Schuster (Gnu Classpath) Fabian Köster Unterstützt durch Christian Thalinger (cacaojvm.org) Roman Kennke (Gnu Classpath, escher) Guillaume Legris (MIDPath) Andrew Cowie (java-gnome) ...

sponsored by the Tarent GmbH

Sebastian Mancke

Robert Schuster (Gnu Classpath)

Fabian Köster

Unterstützt durch

Christian Thalinger (cacaojvm.org)

Roman Kennke (Gnu Classpath, escher)

Guillaume Legris (MIDPath)

Andrew Cowie (java-gnome)

...

JaLiMo - What? Integration Integration GUI Runtime Build Plattform CACAO JVM JamVM GNU Classpath phoneME MIDPath Swing/escher java-gnome SWT maven packaging plugin OpenEmbedded integration mvn2deb libjalimo-core libopenmoko libmaemo maemo ...?... openmoko

Build Strategies - Cross Compiling Cross Toolchain (gcc, ld, .. for arm) Rootstrap setting: PATH, CC, LD, AR, PKG_CONFIG_PATH wrapper for: dpkg-architecture and pkg-config Advantages: the host tools (z.B. javac, javah, jar) are available. useage in combination with dpkg-buildpackage Problems: keeping Rootstrap up to date prone to errors by missing chroot

Cross Toolchain (gcc, ld, .. for arm)

Rootstrap

setting: PATH, CC, LD, AR, PKG_CONFIG_PATH

wrapper for: dpkg-architecture and pkg-config

Advantages:

the host tools (z.B. javac, javah, jar) are available.

useage in combination with dpkg-buildpackage

Problems:

keeping Rootstrap up to date

prone to errors by missing chroot

Build Strategies - Scratchbox an emulator based on Qemu integrated with Toolchain and Rootstrap Advantages: direct copy of the target system no more Cross Compiling Problems: no support of special Build Tools (z.B. javac, javah, ..) Java binaries (e.g. jamvm or cacao) are not working in scratchbox

an emulator based on Qemu

integrated with Toolchain and Rootstrap

Advantages:

direct copy of the target system

no more Cross Compiling

Problems:

no support of special Build Tools (z.B. javac, javah, ..)

Java binaries (e.g. jamvm or cacao) are not working in scratchbox

Build Strategies - maven2 established Java Build environment Advantages: Management of dependencies Standardized Build Process Plugin Architekture Disadvantages: highly Java centred bad support for JNI and Cross Compiling no packaging conzept

established Java Build environment

Advantages:

Management of dependencies

Standardized Build Process

Plugin Architekture

Disadvantages:

highly Java centred

bad support for JNI and Cross Compiling

no packaging conzept

maven packaging plugin Packaging IzPack installer (for desktop) .deb (for desktop and embedded) .ipkg (planned) generation of startscripts orientation towards debian guidelines conversion of the maven dependencies to debian dependencies A maven plugin, developed by the tarent (Robert Schuster) to pack projects – released under (GPL).

Packaging

IzPack installer (for desktop)

.deb (for desktop and embedded)

.ipkg (planned)

generation of startscripts

orientation towards debian guidelines

conversion of the maven dependencies to debian dependencies

A maven plugin, developed by the tarent (Robert Schuster) to pack projects – released under (GPL).

maven packaging plugin Java package for maemo in 5 minutes! .. writing of code and adaptation of pom.xml .. .. and the .deb archive is complete! mvn archetype:create -DarchetypeGroupId=org.jalimo.archetype -DarchetypeArtifactId=gtkapp -DarchetypeVersion=0.1.0-SNAPSHOT -DremoteRepositories=http://www.jalimo.org/maven -DgroupId=<your project group id> -DartifactId=<your artifact id> mvn -Dmaven.test.skip=true pkg:deb

Java package for maemo in 5 minutes!

.. writing of code and adaptation of pom.xml ..

.. and the .deb archive is complete!

maven with JNI code normal maven packaging project + makefile Process: mvn pkg:deb compiling of the Java classes generation of the header files with javah compiling of the C-code in scratchbox through /scratchbox/login <scriptfile> collection of the binaries generation of the .deb archives Many projects are composed of java and C code } } } Host Host Emulator example: java-gnome

normal maven packaging project + makefile

Process: mvn pkg:deb

compiling of the Java classes

generation of the header files with javah

compiling of the C-code in scratchbox through /scratchbox/login <scriptfile>

collection of the binaries

generation of the .deb archives

Many projects are composed of java and C code

Host

Host

Emulator

Java-gnome Java-gnome a project, that already exists for 9 years the 2 nd version has a quite high API-cover, but too many problems since the last 1,5 years: rewrite java-gnome4 clean Design lightweight small API-cover unfortunately just makes slow progress But: a good concept

Java-gnome a project, that already exists for 9 years

the 2 nd version has a quite high API-cover, but too many problems

since the last 1,5 years: rewrite java-gnome4

clean Design

lightweight

small API-cover

unfortunately just makes slow progress

But: a good concept

Java-gnome - concept Code Generation of the JNI layer Object definitions are built from the GTK header files. For each Gtk 'class' a C and Java file is generated that contains the whole JNI-code. Java scopes of this layer are restricted to 'package'. In a clean API layer the realization of the procedural code happens in a object-oriented API. The GTK's pseudo-class structure is properly mapped in Java. This way and the code generator are possibly suitable for other libraries: e. g. hildon or libopenmoko.

Code Generation of the JNI layer

Object definitions are built from the GTK header files.

For each Gtk 'class' a C and Java file is generated that contains the whole JNI-code.

Java scopes of this layer are restricted to 'package'.

In a clean API layer the realization of the procedural code happens in a object-oriented API.

The GTK's pseudo-class structure is properly mapped in Java.

This way and the code generator are possibly suitable for other libraries: e. g. hildon or libopenmoko.

Java-gnome Why Java-gnome high-performance, small Possibility of smooth integration support by Glade2 GUI Builder simple, lovely API

Why Java-gnome

high-performance, small

Possibility of smooth integration

support by Glade2 GUI Builder

simple, lovely API

Java-gnome - coverage very low in the upstream: Window, Widget, Button, Label, Hbox, VBox prototypical enhancements on two evenings: Entry TextView, TextBuffer ToggleButton CheckButton ComboBox MenuBar, Menu, MenuItem ScrolledWindow Frame Notebook HSeparator, VSeparator Image Obviously: good concept!

very low in the upstream:

Window, Widget, Button, Label, Hbox, VBox

prototypical enhancements on two evenings:

Entry

TextView, TextBuffer

ToggleButton

CheckButton

ComboBox

MenuBar, Menu, MenuItem

ScrolledWindow

Frame

Notebook

HSeparator, VSeparator

Image

libmaemo Enhancements of the java-gnome components with bindings to the Hildon framework. Necessary steps: Wrapper for HildonWindow and HildonProgram (already existing) Enhanced Widgets of the Hildon Frameworks Bindings for Status Bar Plugins Wrapper for the libosso communication between applications maybe possible with the existing project java-dbus

Enhancements of the java-gnome components with bindings to the Hildon framework. Necessary steps:

Wrapper for HildonWindow and HildonProgram (already existing)

Enhanced Widgets of the Hildon Frameworks

Bindings for Status Bar Plugins

Wrapper for the libosso

communication between applications

maybe possible with the existing project java-dbus

MIDPath MIDPath is a MIDP2 implementation based on MIDP code of Sun's PhoneME. On the opposite to PhoneME, MIDPath runs on Java SE as well as Java ME CLDC. By that it can be used out of the box with Kaffe, Cacao, JamVM or other JVMs. Guillaume Legris has written a GTK Backend for JaLiMo, that we were able to fit to the Maemo Input Framework.

MIDPath is a MIDP2 implementation based on MIDP

code of Sun's PhoneME.

On the opposite to PhoneME, MIDPath runs on Java SE as well as Java ME CLDC.

By that it can be used out of the box with Kaffe, Cacao, JamVM or other JVMs.

Guillaume Legris has written a GTK Backend for JaLiMo, that we were able to fit to the Maemo Input Framework.

MIDPath - architekture By different Backends, the MIDPath is quite portable. For the use on small devices, there is an alternative using the Cacao CLDC Version. MIDPATH Java ME CLDC AWT SWT JavaSound SDL X11 ALSA Cacao JamVM Kaffe Cacao CLDC GNU Classpath JVMs Standard Libraries Backends Core GTK

By different Backends, the MIDPath is quite portable.

For the use on small devices, there is an alternative using the Cacao CLDC Version.

MIDPath - Status Status: quite stable APIs: JSR-118 + FileConnection (JSR-75) Missing: SSL, UDP, tone playing OGG/MP3 support Soon: Audio streaming support Midlet managment for Maemo Future: adding further Java ME JSRs

Status:

quite stable

APIs: JSR-118 + FileConnection (JSR-75)

Missing: SSL, UDP, tone playing

OGG/MP3 support

Soon:

Audio streaming support

Midlet managment for Maemo

Future:

adding further Java ME JSRs

Swing/Escher Swing/AWT Support of GNU Classpath in maemo would require a higher gtk version. Alternative Pure Java X library: Escher Classpath has different peers for AWT and Swing Swing/Escher runs on maemo, but is still in progress: problems with the handlig of windows repainting soft keyboard input look and feel customizing

Swing/AWT Support of GNU Classpath in maemo would require a higher gtk version.

Alternative

Pure Java X library: Escher

Classpath has different peers for AWT and Swing

Swing/Escher runs on maemo, but is still in progress:

problems with the handlig of windows

repainting

soft keyboard input

look and feel customizing

Swing/Escher – Difficulty of Maemo Input Soft Keyboard doesn't activate any X Key-Events text oriented undocumented Xmessages, that are realized over the Hildon/GTK Input Framework in GTK. TODO: Generation of XMessages on Softkeyboard (raise/lower) Receiving of Messages, conversion in AWT Key Events

Soft Keyboard doesn't activate any X Key-Events

text oriented

undocumented Xmessages, that are realized over the Hildon/GTK Input Framework in GTK.

TODO:

Generation of XMessages on Softkeyboard (raise/lower)

Receiving of Messages, conversion in AWT Key Events

lib-JaLiMo the JaLiMo project ist still getting off the ground completeness of a 1.0 is planned for the end of 2008 so far: focus on the basis platform the main focus is on applikation framework Creation of mobile applications for the realization of end-to-end business processes.

the JaLiMo project ist still getting off the ground

completeness of a 1.0 is planned for the end of 2008

so far: focus on the basis platform

the main focus is on applikation framework

lib-JaLiMo concepts Messaging Asynchrone messaging as the application's basis connection of different sources with connectors, e.g. SOAP/HTTP, XMPP, RMI, dbus application MessageBroker

Messaging

Asynchrone messaging as the application's basis

connection of different sources with connectors, e.g. SOAP/HTTP, XMPP, RMI, dbus

lib-JaLiMo concepts Data-Binding Bindung of data and view through messages to each other declarative connection, without two-way referencing of the specific objects offers stronger decoupling than MVC-paradigm Action Framework consequent use of the Command Pattern in GUI applications All actions are definded as Action and can be used in different cases.

Data-Binding

Bindung of data and view through messages to each other

declarative connection, without two-way referencing of the specific objects

offers stronger decoupling than MVC-paradigm

Action Framework

consequent use of the Command Pattern in GUI applications

All actions are definded as Action and can be used in different cases.

lib-JaLiMo Konzepte GUI Templating Creation of parts of the GUI by using description languages, e.g. HTML embedded in Swing Glade für Java-Gnome JSP oder Velocity für Web Combination of GUI and application with actions and bindings Aim: easier re-use of applications in different contexts rapid prototyping division of designing and development

GUI Templating

Creation of parts of the GUI by using description languages, e.g.

HTML embedded in Swing

Glade für Java-Gnome

JSP oder Velocity für Web

Combination of GUI and application with actions and bindings

Aim:

easier re-use of applications in different contexts

rapid prototyping

division of designing and development

JaLiMo - Robots Why? To clarify how easy open standard components are for comlpex architectures. autonomous Java controller Java-gnome GUI Asynchronous communication over XMPP effort of the development ~ 1 week

Why? To clarify how easy open standard components are for comlpex architectures.

autonomous Java controller

Java-gnome GUI

Asynchronous communication over XMPP

effort of the development

~ 1 week

Jazelle DBX (Direct Bytecode eXecution) The N770 and the N800 have the proprietary Jazelle enhancement in their processor. DBX is an additional instruction modus of the arm processor. after a so called branch to java, the bytecode can be executed local. 123 bytecodes are supported, directly. A software interrupt is activated for the rest. Unfortunately Arm holds back the specification!!! Is it possible to use it, anyway?

The N770 and the N800 have the proprietary Jazelle enhancement in their processor.

DBX is an additional instruction modus of the arm processor.

after a so called branch to java, the bytecode can be executed local.

123 bytecodes are supported, directly. A software interrupt is activated for the rest.

Unfortunately Arm holds back the specification!!!

Jazelle DBX (Direct Bytecode eXecution) To change to the DBX-Modus seems to be no problem Debugging with gdb shows, that the program always crashes after the last correct bytecode. All the earlier ones seem to be proceeded. After one of the untreated bytecodes, the program counter is 0x11000. This seems to be the state after an interrupt. Open questions: Who has an interupt handler to look like? How may parameters beeing passed and returned?

To change to the DBX-Modus seems to be no problem

Debugging with gdb shows, that the program always crashes after the last correct bytecode. All the earlier ones seem to be proceeded.

After one of the untreated bytecodes, the program counter is 0x11000. This seems to be the state after an interrupt.

Open questions:

Who has an interupt handler to look like?

How may parameters beeing passed and returned?

JaLiMo Resources www.jalimo.org Soon in addition: www.elvolvis.org Gforge infrastructure open svn Mailinglists better management of individual projects in other respects: [email_address]

www.jalimo.org

Soon in addition: www.elvolvis.org

Gforge infrastructure

open svn

Mailinglists

better management of individual projects

in other respects: [email_address]