DaCapo benchmarks

This page describes how to get the Oracle-Sun JRE version 7 working on a disk image for use with ARM gem5. This will allow you to use the DaCapo benchmarks, which are on the Ubuntu image for gem5 ARM in the /benchmarks/dacapo directory.

Installing Oracle-Sun Java on an Ubuntu image for ARM gem5

Download the standard edition(SE) of Java 7; the SE version is the free version of Java available from Oracle. Make sure to get the headless version of the JRE for ARMv6/7 from here. You may need to register with Oracle before being allowed to download. Once you have this, untar it.

• Create a mount point and mount the Ubuntu image:

sudo mkdir /mnt/ubuntu-gem5
sudo mount -o loop,offset=32256 arm-ubuntu-natty-headless-java.img /mnt/ubuntu-gem5

//setup the Java install directory and copy the Java directory over to your image
cd /mnt/ubuntu-gem5/usr/lib
sudo mkdir jvm
cd ./jvm
sudo cp -a /path_to_jre/jre_dir .
sudo ln -s ./jre_dir java-7-sun

• Install Java:

cd /mnt/ubuntu-gem5
sudo mount -o bind /proc ./proc
sudo mount -o bind /dev ./dev
sudo mount -o bind /sys ./sys
sudo chroot .
exec ./bin/bash

//now install Java
cd /usr/lib/jvm
update-alternatives --install /usr/bin/java java /usr/lib/jvm/java-7-sun/bin/java 1
update-alternatives --install /usr/bin/keytool keytool /usr/lib/jvm/java-7-sun/bin/keytool 1

//setup .jinfo file
echo "name=java-7-sun" > .java-7-sun.jinfo
echo "alias=java-7-sun" >> .java-7-sun.jinfo
echo "priority=1" >> .java-7-sun.jinfo
echo "section=non-free" >> .java-7-sun.jinfo
echo "jre java /usr/lib/jvm/java-7-sun/bin/java" >> .java-7-sun.jinfo
echo "jre keytool /usr/lib/jvm/java-7-sun/bin/keytool" >> .java-7-sun.jinfo

//update java alternatives
update-java-alternatives -s java-7-sun

Once you have unmounted the image, you should be able to run Java with this disk image. Boot this image on gem5 and from the terminal type java -version to verify the Java version on your image. E.g., the version tested on gem5 is:

root@gem5sim:~# java -version
java version "1.7.0_04-ea"
Java(TM) SE Runtime Environment for Embedded (build 1.7.0_04-ea-b20, headless)
Java HotSpot(TM) Embedded Client VM (build 23.0-b21, mixed mode)