Subject: Re: State of Java?

From: Edwin Foo <[email-masked]>
Date: Fri, 19 Jun 1998 13:01:20 -0400

Neil A. Carson wrote:

>John Lindley wrote:

>> >
>> > What tools currently exist for Java development under ARM Linux?
I've
>> > visited the Java-Linux site, which has JDK Linux ports for four
>> > platforms, but there's no mention of anything ARM related. A
JavaVM, JRE,
>> > etc. would prove useful! Or has anything come out from Corel yet,
who
>> > appear to be looking at Java support for ARMLinux?
>> >
>> ATM there is a freeware compiler called guavav. I haven't yet tried
>> compiling itbut AFAIK this is the only java compiler available for
Linux
>> outside the JDK. For compiling I've found thesource to a virtual
machine
>> for Linux but I can't remember the exact name.Thereis a link from
>> www.doc.ic.ac.uk.

>Kaffe runs on NetBSD on the ARM, so a Linux port should be trivial
>because all the changes were ARM- rather than OS-dependant from memory
>(apart from a couple of things which depend on the locations of
>registers within a jump buffer, yuck).

It wasn't quite so trivial. =) It took me about 2 weeks of solid work,
actually. But then, I'm not a Kaffe guru either -- someone on this
mailing list with better hacking skills than me can probably duplicate
the effort in far less time.

I was forwarded this by a colleague, so as I am not on the list please
include me explicitly in any replies/questions.

I have been working with Linux/ARM and the Kaffe JVM in the course of my
thesis research here, so among other things, we have a port of Kaffe to
Linux/ARM. Unfortunately, I'm not ready/allowed to release my patches
yet. But I can give a big hint to all would-be porters of Kaffe out
there.

I presume that you're trying to port to one of the Acorn machines (I'm
doing my work on a completely different StrongARM-based platform), but
the following should apply anyway. Use the interpreter, not the
translator/JIT, a SP_OFFSET value of 9 (this number is extremely
important in getting multithreading to work), and do _not_ use the
latest 0.10.1 distribution. You'll have to use a kaffe-snap.tar.gz
snapshot from the Kaffe CVS repository to take
advantage of some patches made after 0.10.1 was released. Look at the
Kaffe homepage (www.kaffe.org) for more information on where to find it.

-Edwin

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Edwin Foo        | MIT Computer Science - BS '98, MEng '99
[email-masked]     | Compaq Computer Corp. - Cambridge Research Lab
[email-masked] | Residential Computing Consultant (RCC) Developer

       "Love must be sincere; Hate what is evil; cling to what is good."
http://hesed.mit.edu/~efoo                       - Romans 12:9 <><
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---

From: Edwin Foo <[email-masked]>
Date: Mon, 22 Jun 1998 11:10:17 -0400

Neil Carson Wrote:
>ARM support is *certainly* in the latest Kaffe version. Try
>ftp.transvirtual.com. from memory, or see the port-arm32 announcement
>from the guy who ported it. I reckon it shouldn't take more than a few
>minutes to get a linux version up.

My previous post was made in reference to Godmar Back's port of Kaffe to
ARM/NetBSD. If you ftp the latest version -- kaffe-0.10.1.tar.gz from
ftp.transvirtual.com, you will find a configuration file and
thread-switch code for ARM/NetBSD. Note that you cannot use that file
though; see my previous post for details.

If you follow the hints I gave, it should not take that long. Maybe even
a few minutes like you claim. The hard part is finding out those little
gotchas in the first place, and that is what took me a couple of weeks.
If you have ported anything in the past you will know what I mean --
it's easier said than done to simply type "configure; make; make
install" and expect things to work when switching OSes, even when using
the same CPU.

-Edwin