running:
java -Djavafx.platform=monocle -Djava.ext.dirs=build/armv6hf-sdk/rt/lib/ext com.sun.glass.ui.monocle.linux.GetEvent
works as expected.

Running any applications against a oppen-jfx build throws exceptions
(java -Djava.ext.dirs=build/armv6hf-sdk/rt/lib/ext ...) NoClassDefFoundError:

Prism pipeline init order: es2 sw
Using platform text rasterizer
Using native-based Pisces rasterizer
Using dirty region optimizations
Using system sized mask for primitives
Not forcing power of 2 sizes for textures
Using hardware CLAMP_TO_ZERO mode
Opting in for HiDPI pixel scaling
Prism pipeline name = com.sun.prism.es2.ES2Pipeline
Loading ES2 native library ... prism_es2_eglfb
succeeded.
GLFactory using com.sun.prism.es2.EGLFBGLFactory
(X) Got class = class com.sun.prism.es2.ES2Pipeline
Initialized prism pipeline: com.sun.prism.es2.ES2Pipeline
Maximum supported texture size: 2048
Non power of two texture support = true
Graphics Vendor: Broadcom
       Renderer: VideoCore IV HW
        Version: OpenGL ES 2.0
 vsync: true vpipe: true
Exception in Application start method
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: Could not initialize class javafx.scene.CssStyleHelper
at javafx.scene.Node.impl_processCSS(Node.java:8898)
at javafx.scene.Parent.impl_processCSS(Parent.java:1240)
at javafx.scene.Node.processCSS(Node.java:8753)
at javafx.scene.Scene.doCSSPass(Scene.java:508)
at javafx.scene.Scene.access$3700(Scene.java:140)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2352)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:322)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:320)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:320)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:349)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:481)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:462)
at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:329)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: Could not initialize class javafx.scene.CssStyleHelper
at javafx.scene.Node.impl_processCSS(Node.java:8898)
at javafx.scene.Parent.impl_processCSS(Parent.java:1240)
at javafx.scene.Node.processCSS(Node.java:8753)
at javafx.scene.Scene.doCSSPass(Scene.java:508)
at javafx.scene.Scene.access$3700(Scene.java:140)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2352)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:322)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:320)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:320)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:349)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:481)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:462)
at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:329)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: Could not initialize class javafx.scene.CssStyleHelper
at javafx.scene.Node.impl_processCSS(Node.java:8898)
at javafx.scene.Parent.impl_processCSS(Parent.java:1240)
at javafx.scene.Node.processCSS(Node.java:8753)
at javafx.scene.Scene.doCSSPass(Scene.java:508)
at javafx.scene.Scene.access$3700(Scene.java:140)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2352)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:322)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:320)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:320)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:349)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:481)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:462)
at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:329)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: Could not initialize class javafx.scene.CssStyleHelper
at javafx.scene.Node.impl_processCSS(Node.java:8898)
at javafx.scene.Parent.impl_processCSS(Parent.java:1240)
at javafx.scene.Node.processCSS(Node.java:8753)
at javafx.scene.Scene.doCSSPass(Scene.java:508)
at javafx.scene.Scene.access$3700(Scene.java:140)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2352)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:322)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:320)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:320)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:349)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:481)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:462)
at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:329)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:367)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:305)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:894)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:56)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:158)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.ExceptionInInitializerError
at javafx.scene.Node.impl_processCSS(Node.java:8898)
at javafx.scene.Parent.impl_processCSS(Parent.java:1240)
at javafx.scene.Node.processCSS(Node.java:8753)
at javafx.scene.Scene.doCSSPass(Scene.java:508)
at javafx.scene.Scene.preferredSize(Scene.java:1544)
at javafx.scene.Scene.impl_preferredSize(Scene.java:1621)
at javafx.stage.Window$9.invalidated(Window.java:750)
at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:109)
at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:143)
at javafx.stage.Window.setShowing(Window.java:826)
at javafx.stage.Window.show(Window.java:841)
at javafx.stage.Stage.show(Stage.java:252)
at helloworld.HelloWorld.start(HelloWorld.java:42)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
... 1 more
Caused by: java.lang.NullPointerException
at com.sun.javafx.font.PrismFontLoader.loadFont(PrismFontLoader.java:192)
at javafx.scene.text.Font.<init>(Font.java:319)
at javafx.scene.text.Font.getDefault(Font.java:86)
at javafx.scene.CssStyleHelper.<clinit>(CssStyleHelper.java:1500)
... 22 more
Exception in thread "JavaFX Application Thread" java.nio.BufferOverflowException
at java.nio.DirectByteBuffer.put(DirectByteBuffer.java:363)
at java.nio.DirectByteBuffer.put(DirectByteBuffer.java:342)
at com.sun.glass.ui.monocle.Framebuffer.clearBufferContents(Framebuffer.java:77)
at com.sun.glass.ui.monocle.linux.FBDevScreen.shutdown(FBDevScreen.java:150)
at com.sun.glass.ui.monocle.NativePlatform.shutdown(NativePlatform.java:48)
at com.sun.glass.ui.monocle.MonocleApplication.finishTerminating(MonocleApplication.java:354)
at com.sun.glass.ui.Application.terminate(Application.java:390)
at com.sun.javafx.tk.quantum.QuantumToolkit.exit(QuantumToolkit.java:690)
at com.sun.javafx.application.PlatformImpl$10.run(PlatformImpl.java:465)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)

2.) running touchyfxy.jar (https://bitbucket.org/shemnon/touchyfxy) a BufferOverflowException is thrown:
Prism pipeline init order: es2 sw
Using platform text rasterizer
Using native-based Pisces rasterizer
Using dirty region optimizations
Using system sized mask for primitives
Not forcing power of 2 sizes for textures
Using hardware CLAMP_TO_ZERO mode
Opting in for HiDPI pixel scaling
Prism pipeline name = com.sun.prism.es2.ES2Pipeline
Loading ES2 native library ... prism_es2_eglfb
succeeded.
GLFactory using com.sun.prism.es2.EGLFBGLFactory
(X) Got class = class com.sun.prism.es2.ES2Pipeline
Initialized prism pipeline: com.sun.prism.es2.ES2Pipeline
Maximum supported texture size: 2048
Non power of two texture support = true
Graphics Vendor: Broadcom
       Renderer: VideoCore IV HW
        Version: OpenGL ES 2.0
 vsync: true vpipe: true
Exception in Application start method
Exception in thread "JavaFX Application Thread" java.nio.BufferOverflowException
at java.nio.DirectByteBuffer.put(DirectByteBuffer.java:363)
at java.nio.DirectByteBuffer.put(DirectByteBuffer.java:342)
at com.sun.glass.ui.monocle.Framebuffer.clearBufferContents(Framebuffer.java:77)
at com.sun.glass.ui.monocle.linux.FBDevScreen.shutdown(FBDevScreen.java:150)
at com.sun.glass.ui.monocle.NativePlatform.shutdown(NativePlatform.java:48)
at com.sun.glass.ui.monocle.MonocleApplication.finishTerminating(MonocleApplication.java:354)
at com.sun.glass.ui.Application.terminate(Application.java:390)
at com.sun.javafx.tk.quantum.QuantumToolkit.exit(QuantumToolkit.java:690)
at com.sun.javafx.application.PlatformImpl$10.run(PlatformImpl.java:465)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
at java.lang.Thread.run(Thread.java:744)
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:367)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:305)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:894)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:56)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:158)
at java.lang.Thread.run(Thread.java:744)
Caused by: javafx.fxml.LoadException:
file:/home/pi/open-jfx/touchyfxy-0.0.jar!/touchyfxy/touchyfxy.fxml:46

at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2593)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2571)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2433)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2401)
at touchyfxy.Main.start(Main.java:48)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:80)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:47)
... 1 more
Caused by: java.lang.NullPointerException
at com.sun.javafx.font.PrismFontLoader.loadFont(PrismFontLoader.java:192)
at javafx.scene.text.Font.<init>(Font.java:319)
at com.sun.javafx.fxml.builder.JavaFXFontBuilder.build(JavaFXFontBuilder.java:75)
at com.sun.javafx.fxml.builder.JavaFXFontBuilder.build(JavaFXFontBuilder.java:42)
at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:757)
at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2815)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2524)
... 12 more