JAVA on i.MX
Sun Microsystems has pre-built versions of Java Virtual Machine for ARM Processors. It's possible to download them at: http://java.sun.com/javase/downloads/embedded.jsp
All pre-built software mentioned on site above are distributed as evaluation software. For more information about use and license, please contact Sun Microsystems
i.MX31 PDK will be used as an example to describe installation, compilation and execution procedures. It can be easily done for other i.MX platforms
Installing Sun Java on i.MX
For i.MX31, i.MX35, download the following version:
| Usage | Headful | Binary Version |
| Non-Graphical Applications | ARMv6 Linux - Headless (Early Access) | EABI, glibc 2.5, Hard Float (VFP), Little Endian |
| Graphical Applications | ARMv6 Linux - Headful (Early Access) | EABI, glibc 2.5, Hard Float (VFP), Little Endian |
For i.MX21, i.MX25, i.MX27, download the following version:
| Usage | Headful | Binary Version |
| Non-Graphical Applications | ARMv5 Linux - Headless (Early Access) | EABI, glibc 2.5, Soft Float, Little Endian |
| Graphical Applications | ARMv5 Linux - Headful (Early Access) | EABI, glibc 2.5, Soft Float, Little Endian |
On following example, a graphical application will be compiled, the headful version will be used.
This example uses X11 as graphical server. On LTIB, select X11 and also the package libXtst and libXi.
Extract the downloaded package (in this case "ejre-1_6_0_10-ea-b39-linux-armv6-vfp-eabi-min-eval-30_jul_2009.tar.gz")
tar xzvf ejre-1_6_0_10-ea-b39-linux-armv6-vfp-eabi-min-eval-30_jul_2009.tar.gz
Create a new folder on <LTIB Directory>/rootfs/ called ejre1.6.0_10
cd rootfs sudo mkdir ejre1.6.0_10
Copy all files and folders located inside the extracted package to <LTIB Directory>/rootfs/ejre1.6.0_10/
cd rootfs/ejre1.6.0_10 cp -a ../../ejre1.6.0_10/* .
Include the bin folder to the PATH:
export PATH=$PATH:/ejre1.6.0_10/bin/
In this example the X11 will be used as graphical server. Add the display environment variable:
export DISPLAY=:0
Running a simple program
Compiling and testing on Host PC
Let's first compile and test a simple program on Host Machine (PC).
Create a file called Example1.java and add the following code:
import java.awt.*;
public class Example1 extends java.applet.Applet
{
public void init()
{
add(new Button("One"));
add(new Button("Two"));
}
public Dimension preferredSize()
{
return new Dimension(480, 640);
}
public static void main(String [] args)
{
Frame f = new Frame("Example 1");
Example1 ex = new Example1();
ex.init();
f.add("Center", ex);
f.pack();
f.show();
}
}
On terminal, compile the source code using ecj:
$ ecj Example1.java
ecj Java Compiler is needed to compile this example. To install ecj on Debian based OS, install the packages: sudo apt-get install ecj ecj-gcj libecj-java libecj-java-gcj
Now it's possible to test the compiled program. Just type on host:
$ java Example1
The following window will be shown:
Running on i.MX
Copy the file Example1.class to <LTIB Directory>/rootfs/home
cp Example1.class rootfs/home
On i.MX Linux, start Xfbdev in background:
$ Xfbdev &
Run Example1:
$ java Example1
The following screen will be shown on LCD:
