OpenJDK compilation (ARM native buildsystem installation)

[Xerxes Rånby]

When you have a working system running Fedora core 8 on a ARM platform 
with network support you can install all required packages to build 
Icedtea6 by running yum.

yum install vi mercurial cups-devel lesstif-devel libXp-devel 
libXtst-devel libXi-devel xalan-j2 xerces-j2 \
libXt-devel freetype-devel gcc gcc-c++ wget java-1.5.0-gcj-devel 
alsa-lib-devel firefox-devel glib2-devel gtk2-devel \
ant libXinerama-devel libjpeg-devel libpng-devel giflib-devel patch tar 
unzip make gzip rhino

When i did my last install yum complained that the eclipse-ecj package 
could not be found precompiled for armv5tel but there is a quick fix for 
that!
There is one available compiled by one of the Fedora core 8 maintainers 
for armv5tejl yet since the jazelle instructions is not used it can be 
installed on a armv5tel system!
rpm -i --ignorearch 
http://www.wantstofly.org/~buytenh/RPMS.built.crap/eclipse-ecj-3.3.0-30.fc8.armv5tejl.rpm

To improve your development experience i reccomend you to install a 
openssh server on your target!
gdb and ddd are usefull to have if you are going to do some debugging!

then you can simply ssh in to the target running ssh -X 
username at armdevtarget
and do remote graphical debugging with ddd by simply running ddd 
./executableToBeDebugged on the target!

With everything in place you can get the icedtea6 sources by running
hg clone http://icedtea.classpath.org/hg/icedtea6
cd icedtea6
autoconf
./configure --disable-docs
make

Some current issues with Icedtea6 on ARM:

If the compile complains about libffi headerfiles redeclared #ARM 
install libffi from sources. this have been fixed in libffi releases 
3.0.5 and above.
ftp://sources.redhat.com/pub/libffi/

It will build ok but then the built java will segfault when run.
Yesterday it wave been sorted out that the segfault was optimization 
related. With gcc compiler v 4.1.2 shipped with fc8  a pointer got 
mangled during execution when compiled with -O3 optimization on ARM target.
You can manually change the file 
openjdk-ecj/hotspot/build/linux/makefiles/gcc.make to change the 
optimization to -O0      (the file exists after make have downloaded the 
openjdk sources unpacked them and patched them)
Or better install a more recent gcc like 4.3.1 from source.
Im currently doing both and will see at the end of this day if all 
systems are go when running a -O0 compilation.

Several Java alternatives for ARM based on free software:

The description above compiles Icedtea6 with the default zero hotspot 
for ARM.

If you want to test some java code quickly on arm first try running your 
code using gcj ! Some swing applications do work and you can test JNI 
bindings and more. gcj can run java code both interperted and 
precompiled to native code. When gcj is installed you can run java 
classes by simply using the java "wrapper" command. Icedtea uses gcj för 
bootstrapping itself aswell!

Icedtea can be configured to use CACAO as VM instead of the default zero 
hotspot. Christian Thalinger have made this JIT VM compile and run with 
the icedtea classes on hos ARM machines. Ask him about anything Cacao 
related!

There is a new shark hotspot you could try as well with JIT support that 
can be enabled during configure of Icedtea6. This is all new cool and 
experimental.

Have a great day!
Xerxes


Xerxes Rånby skrev:
> Hi Aaron!
>
> Some quick notes how i installed a native arm build system to compile 
> icedtea6.
>
> I have set up a build environment using the Fedora core 8 ARM 
> distribution.
> http://fedoraproject.org/wiki/Architectures/ARM
>
> I have a AT91SAM9263 based arm-devkit (armv5tejl cpu). Yet when 
> running the build system on that one it is too slow since my devkit 
> have only about 98mb of ram.
> Instead I have set up my build system on a emulated arm platform by 
> using the qemu emulator.
> http://fedoraproject.org/wiki/Architectures/ARM/HowToQemu
>
> My installation went like this:
>
> First i downloaded a prebuild rootfilesystem for fc8:
> http://ftp.linux.org.uk/pub/linux/arm/fedora/rootfs/rootfs-f8.tar.bz2
> I uncompressed the rootfilesystem to a ext3 filesystem on a 
> usbmemorystick for my real hardware and on a loopbackmounted image 
> file for use in qemu.
>
> Then you have to compile your own linux kernel if you are going to run 
> it on your own hardware, there are prebuilt kernels from the fc8 
> homepage for emulated systems.
>
> for my real hardware i booted up my system by letting the hardware 
> load the kernel over a tftp server and boot the filesystem directly 
> from the usbflashdrive.
>
> on qemu it is just a matter of supplying the correct bootflags to the 
> qemu emulator to load the kernel and instruct it to use the image file 
> like a harddrive.
>
> i added some swapspace to both systems as well.
>
> ok.. now with everything in place fc8 can boot up!
>
> When you have fedora 8 running with networking up it is possible to 
> install all the devtools you need by using the yum command.
>
> i will continue in the next letter with some instructions what to 
> install using yum.
> comment if it is something you wish to have clarifyed.
>
> Have a great day!
> Xerxes
>