PowerPC build ???

[Mark Wielaard]

On Wed, 2010-11-24 at 20:39 -0600, kevin diggs wrote:
> This question is a little ... weird ... but ...
> 
> Is the thought of trying to build your sdk with gcj ... heresy (sp?).
> If not please give me ... your thought as to whether it has any chance
> of working. I would think that if it is for compiles and the like ...
> it might work ...

Not weird at all! This is exactly what the IcedTea project set out to
do. Make OpenJDK bootstrap using only free tools. Since GCJ is the main
free java implementation already available on GNU/Linux that is what it
has used. http://icedtea.classpath.org/

> Also, what is in this binary plug? Am I completely wasting my time
> since I don't have this? Any chance of getting a powerpc binary plug
> (or access to the source so one can be built)?

And this is one other goal of IcedTea, make sure there are no "binary
plugs" necessary by providing free software replacements.

There are multiple ways towards getting a powerpc port. One is using the
Zero interpreter, which has (almost) zero architecture specific
(assembly) code. Another is using Shark, which uses LLVM to generate
code. Both of these extend the Hotspot runtime.
http://icedtea.classpath.org/wiki/ZeroSharkFaq

Another way is replacing the Hotspot runtime with one of the free ones
already ported to other architectures (but using the rest of the tools
and core libraries), like can be done with Cacao.
http://c1.complang.tuwien.ac.at/cacaowiki/OpenJDK

Both are fully integrated into the IcedTea build process, so in theory
it is just a "hg clone http://icedtea.classpath.org/hg/icedtea6 && cd
icedtea6 && ./configure && make" away. (In practice you probably have to
give some configure options like --with-additional-vms=cacao,shark.
See ./configure --help for more.)

Where possible these extensions are also pushed into OpenJDK proper.