Instructions for adding JavaFX support and hsdis (HotSpot disassembly) to the Oracle ARM JDK

Time needed to build the prerequisites to patch your JDK (on Raspberry Pi 3): 1 hour.
On a Raspberry Pi you should set the memory split to allocate 256MB to the GPU

Set memory split to 256MB GPU

sudo raspi-config
  -> 7 Advanced Options
  -> A3 Memory Split
  -> 256

Add pi user to the video and input groups

sudo usermod -a -G video pi
sudo usermod -a -G input pi
Save changes and reboot your Pi

Install required software packages (Raspbian)

Here is the list of installed packages on my Raspberry Pi needed for building hsdis, icedtea etc
Install this list of packages on your Pi using
sudo dpkg --set-selections < installed-software.log
sudo apt-get -u dselect-upgrade

Download Oracle JDK for ARM

Next download the latest ARM JDK from Oracle (Currently Java 8 update 121)
For the Raspberry Pi you will need the 32bit hard float download "Linux ARM 32 Hard Float ABI" filename jdk-8u121-linux-arm32-vfp-hflt.tar.gz
Unpack this compressed JDK
tar -xzf  jdk-8u121-linux-arm32-vfp-hflt.tar.gz
Set up JAVA_HOME environment variable to point to the JDK you just installed
export JAVA_HOME=/home/pi/jdk1.8.0_121

Patch your JDK

Choose a folder where you will download the required software
export JAVA_ARM=/home/pi/JAVA_ARM_DEV
mkdir $JAVA_ARM

OpenJFX Overlay

Download OpenJFX for ARM from my nightly build server
Unpack OpenJFX overlay into your JDK
unzip -d $JAVA_HOME

Build hsdis

Download and unpack GNU binutils (required to build hsdis)
tar -xzf binutils-2.28.tar.gz
Download icedtea 6 (needed to patch OpenJDK's hsdis files for ARM CPUs)
hg clone
Build icedtea (doesn't matter if the full build fails, we just need it to patch hsdis)
cd icedtea6/
./configure --with-jdk-home=$JAVA_HOME
Build hsdis (HotSpot disassembler)
cd openjdk/hotspot/src/share/tools/hsdis
make BINUTILS=$JAVA_ARM/binutils-2.28
Install the hsdis binary into your JDK
cp build/linux-arm/ $JAVA_HOME/jre/lib/arm/client/
cp build/linux-arm/ $JAVA_HOME/jre/lib/arm/server/

Download JITWatch

Download JITWatch from GitHub
git clone $JAVA_ARM/jitwatch
Build JITWatch
cd $JAVA_ARM/jitwatch
mvn clean compile

Run JITWatch

Launch JITWatch (using JavaFX switches to use the GTK platform so it runs windowed and not fullscreen)
./ -Dprism.order=sw -Dglass.platform=gtk
Get your first Java program compiled and analysed using the Sandbox feature.

Open the Sandbox

Click on the "Sandbox" button in the main window to open up JITWatch's sandbox environment for testing small code samples.

Open the Sandbox config

Click the "Configure Sandbox" button to customise the sandbox environment.

Enable server VM on ARM

You will probably want to configure the Sandbox to use the server VM to access the advanced HotSpot optimisations.
Add -server to Extra VM switches

Execute the example code

Click the "Run" button to compile and execute this example program with the JIT logging switches enabled.
JITWatch will then parse and analyse the resulting log file.

Examine the results

Inspect the source, bytecode, and assembly and look in the annotated bytecode for information about inlining, branch prediction, intrinsics and other optimisations made by HotSpot when it executed your program.
For more information about JITWatch visit